libbpf: ensure F_DUPFD_CLOEXEC is defined #88
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This definition seems to be missing from some older toolchains.
Note that the fcntl.h in libbpf_internal.h is not a kernel header
but rather a toolchain libc header.
Fixes:
libbpf_internal.h:521:18: error: 'F_DUPFD_CLOEXEC' undeclared (first use in this function); did you mean 'FD_CLOEXEC'?
fd = fcntl(fd, F_DUPFD_CLOEXEC, 3);
^~~~~~~~~~~~~~~
FD_CLOEXEC
Signed-off-by: James Hilliard <[email protected]>
kernel-patches-bot
pushed a commit
that referenced
this pull request
Mar 17, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number. Therefore, this patch tries to
convert the offsets.
The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.
FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.
Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.
For example, for the following bpftrace command:
bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'
Without this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: mov x25, sp
1c: mov x26, #0x0 // #0
20: bti j
24: sub sp, sp, #0x90
28: add x19, x0, #0x0
2c: mov x0, #0x0 // #0
30: mov x10, #0xffffffffffffff78 // #-136
34: str x0, [x25, x10]
38: mov x10, #0xffffffffffffff80 // #-128
3c: str x0, [x25, x10]
40: mov x10, #0xffffffffffffff88 // #-120
44: str x0, [x25, x10]
48: mov x10, #0xffffffffffffff90 // #-112
4c: str x0, [x25, x10]
50: mov x10, #0xffffffffffffff98 // #-104
54: str x0, [x25, x10]
58: mov x10, #0xffffffffffffffa0 // #-96
5c: str x0, [x25, x10]
60: mov x10, #0xffffffffffffffa8 // #-88
64: str x0, [x25, x10]
68: mov x10, #0xffffffffffffffb0 // #-80
6c: str x0, [x25, x10]
70: mov x10, #0xffffffffffffffb8 // #-72
74: str x0, [x25, x10]
78: mov x10, #0xffffffffffffffc0 // #-64
7c: str x0, [x25, x10]
80: mov x10, #0xffffffffffffffc8 // #-56
84: str x0, [x25, x10]
88: mov x10, #0xffffffffffffffd0 // #-48
8c: str x0, [x25, x10]
90: mov x10, #0xffffffffffffffd8 // #-40
94: str x0, [x25, x10]
98: mov x10, #0xffffffffffffffe0 // #-32
9c: str x0, [x25, x10]
a0: mov x10, #0xffffffffffffffe8 // #-24
a4: str x0, [x25, x10]
a8: mov x10, #0xfffffffffffffff0 // #-16
ac: str x0, [x25, x10]
b0: mov x10, #0xfffffffffffffff8 // #-8
b4: str x0, [x25, x10]
b8: mov x10, #0x8 // #8
bc: ldr x2, [x19, x10]
[...]
With this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: stp x27, x28, [sp, #-16]!
1c: mov x25, sp
20: sub x27, x25, #0x88
24: mov x26, #0x0 // #0
28: bti j
2c: sub sp, sp, #0x90
30: add x19, x0, #0x0
34: mov x0, #0x0 // #0
38: str x0, [x27]
3c: str x0, [x27, #8]
40: str x0, [x27, #16]
44: str x0, [x27, #24]
48: str x0, [x27, #32]
4c: str x0, [x27, #40]
50: str x0, [x27, #48]
54: str x0, [x27, #56]
58: str x0, [x27, #64]
5c: str x0, [x27, #72]
60: str x0, [x27, #80]
64: str x0, [x27, #88]
68: str x0, [x27, #96]
6c: str x0, [x27, #104]
70: str x0, [x27, #112]
74: str x0, [x27, #120]
78: str x0, [x27, #128]
7c: ldr x2, [x19, #8]
[...]
Signed-off-by: Xu Kuohai <[email protected]>
kernel-patches-bot
pushed a commit
that referenced
this pull request
Mar 17, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number. Therefore, this patch tries to
convert the offsets.
The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.
FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.
Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.
For example, for the following bpftrace command:
bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'
Without this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: mov x25, sp
1c: mov x26, #0x0 // #0
20: bti j
24: sub sp, sp, #0x90
28: add x19, x0, #0x0
2c: mov x0, #0x0 // #0
30: mov x10, #0xffffffffffffff78 // #-136
34: str x0, [x25, x10]
38: mov x10, #0xffffffffffffff80 // #-128
3c: str x0, [x25, x10]
40: mov x10, #0xffffffffffffff88 // #-120
44: str x0, [x25, x10]
48: mov x10, #0xffffffffffffff90 // #-112
4c: str x0, [x25, x10]
50: mov x10, #0xffffffffffffff98 // #-104
54: str x0, [x25, x10]
58: mov x10, #0xffffffffffffffa0 // #-96
5c: str x0, [x25, x10]
60: mov x10, #0xffffffffffffffa8 // #-88
64: str x0, [x25, x10]
68: mov x10, #0xffffffffffffffb0 // #-80
6c: str x0, [x25, x10]
70: mov x10, #0xffffffffffffffb8 // #-72
74: str x0, [x25, x10]
78: mov x10, #0xffffffffffffffc0 // #-64
7c: str x0, [x25, x10]
80: mov x10, #0xffffffffffffffc8 // #-56
84: str x0, [x25, x10]
88: mov x10, #0xffffffffffffffd0 // #-48
8c: str x0, [x25, x10]
90: mov x10, #0xffffffffffffffd8 // #-40
94: str x0, [x25, x10]
98: mov x10, #0xffffffffffffffe0 // #-32
9c: str x0, [x25, x10]
a0: mov x10, #0xffffffffffffffe8 // #-24
a4: str x0, [x25, x10]
a8: mov x10, #0xfffffffffffffff0 // #-16
ac: str x0, [x25, x10]
b0: mov x10, #0xfffffffffffffff8 // #-8
b4: str x0, [x25, x10]
b8: mov x10, #0x8 // #8
bc: ldr x2, [x19, x10]
[...]
With this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: stp x27, x28, [sp, #-16]!
1c: mov x25, sp
20: sub x27, x25, #0x88
24: mov x26, #0x0 // #0
28: bti j
2c: sub sp, sp, #0x90
30: add x19, x0, #0x0
34: mov x0, #0x0 // #0
38: str x0, [x27]
3c: str x0, [x27, #8]
40: str x0, [x27, #16]
44: str x0, [x27, #24]
48: str x0, [x27, #32]
4c: str x0, [x27, #40]
50: str x0, [x27, #48]
54: str x0, [x27, #56]
58: str x0, [x27, #64]
5c: str x0, [x27, #72]
60: str x0, [x27, #80]
64: str x0, [x27, #88]
68: str x0, [x27, #96]
6c: str x0, [x27, #104]
70: str x0, [x27, #112]
74: str x0, [x27, #120]
78: str x0, [x27, #128]
7c: ldr x2, [x19, #8]
[...]
Signed-off-by: Xu Kuohai <[email protected]>
kernel-patches-bot
pushed a commit
that referenced
this pull request
Mar 18, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number. Therefore, this patch tries to
convert the offsets.
The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.
FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.
Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.
For example, for the following bpftrace command:
bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'
Without this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: mov x25, sp
1c: mov x26, #0x0 // #0
20: bti j
24: sub sp, sp, #0x90
28: add x19, x0, #0x0
2c: mov x0, #0x0 // #0
30: mov x10, #0xffffffffffffff78 // #-136
34: str x0, [x25, x10]
38: mov x10, #0xffffffffffffff80 // #-128
3c: str x0, [x25, x10]
40: mov x10, #0xffffffffffffff88 // #-120
44: str x0, [x25, x10]
48: mov x10, #0xffffffffffffff90 // #-112
4c: str x0, [x25, x10]
50: mov x10, #0xffffffffffffff98 // #-104
54: str x0, [x25, x10]
58: mov x10, #0xffffffffffffffa0 // #-96
5c: str x0, [x25, x10]
60: mov x10, #0xffffffffffffffa8 // #-88
64: str x0, [x25, x10]
68: mov x10, #0xffffffffffffffb0 // #-80
6c: str x0, [x25, x10]
70: mov x10, #0xffffffffffffffb8 // #-72
74: str x0, [x25, x10]
78: mov x10, #0xffffffffffffffc0 // #-64
7c: str x0, [x25, x10]
80: mov x10, #0xffffffffffffffc8 // #-56
84: str x0, [x25, x10]
88: mov x10, #0xffffffffffffffd0 // #-48
8c: str x0, [x25, x10]
90: mov x10, #0xffffffffffffffd8 // #-40
94: str x0, [x25, x10]
98: mov x10, #0xffffffffffffffe0 // #-32
9c: str x0, [x25, x10]
a0: mov x10, #0xffffffffffffffe8 // #-24
a4: str x0, [x25, x10]
a8: mov x10, #0xfffffffffffffff0 // #-16
ac: str x0, [x25, x10]
b0: mov x10, #0xfffffffffffffff8 // #-8
b4: str x0, [x25, x10]
b8: mov x10, #0x8 // #8
bc: ldr x2, [x19, x10]
[...]
With this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: stp x27, x28, [sp, #-16]!
1c: mov x25, sp
20: sub x27, x25, #0x88
24: mov x26, #0x0 // #0
28: bti j
2c: sub sp, sp, #0x90
30: add x19, x0, #0x0
34: mov x0, #0x0 // #0
38: str x0, [x27]
3c: str x0, [x27, #8]
40: str x0, [x27, #16]
44: str x0, [x27, #24]
48: str x0, [x27, #32]
4c: str x0, [x27, #40]
50: str x0, [x27, #48]
54: str x0, [x27, #56]
58: str x0, [x27, #64]
5c: str x0, [x27, #72]
60: str x0, [x27, #80]
64: str x0, [x27, #88]
68: str x0, [x27, #96]
6c: str x0, [x27, #104]
70: str x0, [x27, #112]
74: str x0, [x27, #120]
78: str x0, [x27, #128]
7c: ldr x2, [x19, #8]
[...]
Signed-off-by: Xu Kuohai <[email protected]>
kernel-patches-bot
pushed a commit
that referenced
this pull request
Mar 18, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number. Therefore, this patch tries to
convert the offsets.
The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.
FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.
Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.
For example, for the following bpftrace command:
bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'
Without this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: mov x25, sp
1c: mov x26, #0x0 // #0
20: bti j
24: sub sp, sp, #0x90
28: add x19, x0, #0x0
2c: mov x0, #0x0 // #0
30: mov x10, #0xffffffffffffff78 // #-136
34: str x0, [x25, x10]
38: mov x10, #0xffffffffffffff80 // #-128
3c: str x0, [x25, x10]
40: mov x10, #0xffffffffffffff88 // #-120
44: str x0, [x25, x10]
48: mov x10, #0xffffffffffffff90 // #-112
4c: str x0, [x25, x10]
50: mov x10, #0xffffffffffffff98 // #-104
54: str x0, [x25, x10]
58: mov x10, #0xffffffffffffffa0 // #-96
5c: str x0, [x25, x10]
60: mov x10, #0xffffffffffffffa8 // #-88
64: str x0, [x25, x10]
68: mov x10, #0xffffffffffffffb0 // #-80
6c: str x0, [x25, x10]
70: mov x10, #0xffffffffffffffb8 // #-72
74: str x0, [x25, x10]
78: mov x10, #0xffffffffffffffc0 // #-64
7c: str x0, [x25, x10]
80: mov x10, #0xffffffffffffffc8 // #-56
84: str x0, [x25, x10]
88: mov x10, #0xffffffffffffffd0 // #-48
8c: str x0, [x25, x10]
90: mov x10, #0xffffffffffffffd8 // #-40
94: str x0, [x25, x10]
98: mov x10, #0xffffffffffffffe0 // #-32
9c: str x0, [x25, x10]
a0: mov x10, #0xffffffffffffffe8 // #-24
a4: str x0, [x25, x10]
a8: mov x10, #0xfffffffffffffff0 // #-16
ac: str x0, [x25, x10]
b0: mov x10, #0xfffffffffffffff8 // #-8
b4: str x0, [x25, x10]
b8: mov x10, #0x8 // #8
bc: ldr x2, [x19, x10]
[...]
With this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: stp x27, x28, [sp, #-16]!
1c: mov x25, sp
20: sub x27, x25, #0x88
24: mov x26, #0x0 // #0
28: bti j
2c: sub sp, sp, #0x90
30: add x19, x0, #0x0
34: mov x0, #0x0 // #0
38: str x0, [x27]
3c: str x0, [x27, #8]
40: str x0, [x27, #16]
44: str x0, [x27, #24]
48: str x0, [x27, #32]
4c: str x0, [x27, #40]
50: str x0, [x27, #48]
54: str x0, [x27, #56]
58: str x0, [x27, #64]
5c: str x0, [x27, #72]
60: str x0, [x27, #80]
64: str x0, [x27, #88]
68: str x0, [x27, #96]
6c: str x0, [x27, #104]
70: str x0, [x27, #112]
74: str x0, [x27, #120]
78: str x0, [x27, #128]
7c: ldr x2, [x19, #8]
[...]
Signed-off-by: Xu Kuohai <[email protected]>
kernel-patches-bot
pushed a commit
that referenced
this pull request
Mar 18, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number. Therefore, this patch tries to
convert the offsets.
The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.
FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.
Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.
For example, for the following bpftrace command:
bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'
Without this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: mov x25, sp
1c: mov x26, #0x0 // #0
20: bti j
24: sub sp, sp, #0x90
28: add x19, x0, #0x0
2c: mov x0, #0x0 // #0
30: mov x10, #0xffffffffffffff78 // #-136
34: str x0, [x25, x10]
38: mov x10, #0xffffffffffffff80 // #-128
3c: str x0, [x25, x10]
40: mov x10, #0xffffffffffffff88 // #-120
44: str x0, [x25, x10]
48: mov x10, #0xffffffffffffff90 // #-112
4c: str x0, [x25, x10]
50: mov x10, #0xffffffffffffff98 // #-104
54: str x0, [x25, x10]
58: mov x10, #0xffffffffffffffa0 // #-96
5c: str x0, [x25, x10]
60: mov x10, #0xffffffffffffffa8 // #-88
64: str x0, [x25, x10]
68: mov x10, #0xffffffffffffffb0 // #-80
6c: str x0, [x25, x10]
70: mov x10, #0xffffffffffffffb8 // #-72
74: str x0, [x25, x10]
78: mov x10, #0xffffffffffffffc0 // #-64
7c: str x0, [x25, x10]
80: mov x10, #0xffffffffffffffc8 // #-56
84: str x0, [x25, x10]
88: mov x10, #0xffffffffffffffd0 // #-48
8c: str x0, [x25, x10]
90: mov x10, #0xffffffffffffffd8 // #-40
94: str x0, [x25, x10]
98: mov x10, #0xffffffffffffffe0 // #-32
9c: str x0, [x25, x10]
a0: mov x10, #0xffffffffffffffe8 // #-24
a4: str x0, [x25, x10]
a8: mov x10, #0xfffffffffffffff0 // #-16
ac: str x0, [x25, x10]
b0: mov x10, #0xfffffffffffffff8 // #-8
b4: str x0, [x25, x10]
b8: mov x10, #0x8 // #8
bc: ldr x2, [x19, x10]
[...]
With this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: stp x27, x28, [sp, #-16]!
1c: mov x25, sp
20: sub x27, x25, #0x88
24: mov x26, #0x0 // #0
28: bti j
2c: sub sp, sp, #0x90
30: add x19, x0, #0x0
34: mov x0, #0x0 // #0
38: str x0, [x27]
3c: str x0, [x27, #8]
40: str x0, [x27, #16]
44: str x0, [x27, #24]
48: str x0, [x27, #32]
4c: str x0, [x27, #40]
50: str x0, [x27, #48]
54: str x0, [x27, #56]
58: str x0, [x27, #64]
5c: str x0, [x27, #72]
60: str x0, [x27, #80]
64: str x0, [x27, #88]
68: str x0, [x27, #96]
6c: str x0, [x27, #104]
70: str x0, [x27, #112]
74: str x0, [x27, #120]
78: str x0, [x27, #128]
7c: ldr x2, [x19, #8]
[...]
Signed-off-by: Xu Kuohai <[email protected]>
kernel-patches-bot
pushed a commit
that referenced
this pull request
Mar 18, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number. Therefore, this patch tries to
convert the offsets.
The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.
FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.
Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.
For example, for the following bpftrace command:
bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'
Without this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: mov x25, sp
1c: mov x26, #0x0 // #0
20: bti j
24: sub sp, sp, #0x90
28: add x19, x0, #0x0
2c: mov x0, #0x0 // #0
30: mov x10, #0xffffffffffffff78 // #-136
34: str x0, [x25, x10]
38: mov x10, #0xffffffffffffff80 // #-128
3c: str x0, [x25, x10]
40: mov x10, #0xffffffffffffff88 // #-120
44: str x0, [x25, x10]
48: mov x10, #0xffffffffffffff90 // #-112
4c: str x0, [x25, x10]
50: mov x10, #0xffffffffffffff98 // #-104
54: str x0, [x25, x10]
58: mov x10, #0xffffffffffffffa0 // #-96
5c: str x0, [x25, x10]
60: mov x10, #0xffffffffffffffa8 // #-88
64: str x0, [x25, x10]
68: mov x10, #0xffffffffffffffb0 // #-80
6c: str x0, [x25, x10]
70: mov x10, #0xffffffffffffffb8 // #-72
74: str x0, [x25, x10]
78: mov x10, #0xffffffffffffffc0 // #-64
7c: str x0, [x25, x10]
80: mov x10, #0xffffffffffffffc8 // #-56
84: str x0, [x25, x10]
88: mov x10, #0xffffffffffffffd0 // #-48
8c: str x0, [x25, x10]
90: mov x10, #0xffffffffffffffd8 // #-40
94: str x0, [x25, x10]
98: mov x10, #0xffffffffffffffe0 // #-32
9c: str x0, [x25, x10]
a0: mov x10, #0xffffffffffffffe8 // #-24
a4: str x0, [x25, x10]
a8: mov x10, #0xfffffffffffffff0 // #-16
ac: str x0, [x25, x10]
b0: mov x10, #0xfffffffffffffff8 // #-8
b4: str x0, [x25, x10]
b8: mov x10, #0x8 // #8
bc: ldr x2, [x19, x10]
[...]
With this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: stp x27, x28, [sp, #-16]!
1c: mov x25, sp
20: sub x27, x25, #0x88
24: mov x26, #0x0 // #0
28: bti j
2c: sub sp, sp, #0x90
30: add x19, x0, #0x0
34: mov x0, #0x0 // #0
38: str x0, [x27]
3c: str x0, [x27, #8]
40: str x0, [x27, #16]
44: str x0, [x27, #24]
48: str x0, [x27, #32]
4c: str x0, [x27, #40]
50: str x0, [x27, #48]
54: str x0, [x27, #56]
58: str x0, [x27, #64]
5c: str x0, [x27, #72]
60: str x0, [x27, #80]
64: str x0, [x27, #88]
68: str x0, [x27, #96]
6c: str x0, [x27, #104]
70: str x0, [x27, #112]
74: str x0, [x27, #120]
78: str x0, [x27, #128]
7c: ldr x2, [x19, #8]
[...]
Signed-off-by: Xu Kuohai <[email protected]>
kernel-patches-bot
pushed a commit
that referenced
this pull request
Mar 18, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number. Therefore, this patch tries to
convert the offsets.
The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.
FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.
Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.
For example, for the following bpftrace command:
bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'
Without this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: mov x25, sp
1c: mov x26, #0x0 // #0
20: bti j
24: sub sp, sp, #0x90
28: add x19, x0, #0x0
2c: mov x0, #0x0 // #0
30: mov x10, #0xffffffffffffff78 // #-136
34: str x0, [x25, x10]
38: mov x10, #0xffffffffffffff80 // #-128
3c: str x0, [x25, x10]
40: mov x10, #0xffffffffffffff88 // #-120
44: str x0, [x25, x10]
48: mov x10, #0xffffffffffffff90 // #-112
4c: str x0, [x25, x10]
50: mov x10, #0xffffffffffffff98 // #-104
54: str x0, [x25, x10]
58: mov x10, #0xffffffffffffffa0 // #-96
5c: str x0, [x25, x10]
60: mov x10, #0xffffffffffffffa8 // #-88
64: str x0, [x25, x10]
68: mov x10, #0xffffffffffffffb0 // #-80
6c: str x0, [x25, x10]
70: mov x10, #0xffffffffffffffb8 // #-72
74: str x0, [x25, x10]
78: mov x10, #0xffffffffffffffc0 // #-64
7c: str x0, [x25, x10]
80: mov x10, #0xffffffffffffffc8 // #-56
84: str x0, [x25, x10]
88: mov x10, #0xffffffffffffffd0 // #-48
8c: str x0, [x25, x10]
90: mov x10, #0xffffffffffffffd8 // #-40
94: str x0, [x25, x10]
98: mov x10, #0xffffffffffffffe0 // #-32
9c: str x0, [x25, x10]
a0: mov x10, #0xffffffffffffffe8 // #-24
a4: str x0, [x25, x10]
a8: mov x10, #0xfffffffffffffff0 // #-16
ac: str x0, [x25, x10]
b0: mov x10, #0xfffffffffffffff8 // #-8
b4: str x0, [x25, x10]
b8: mov x10, #0x8 // #8
bc: ldr x2, [x19, x10]
[...]
With this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: stp x27, x28, [sp, #-16]!
1c: mov x25, sp
20: sub x27, x25, #0x88
24: mov x26, #0x0 // #0
28: bti j
2c: sub sp, sp, #0x90
30: add x19, x0, #0x0
34: mov x0, #0x0 // #0
38: str x0, [x27]
3c: str x0, [x27, #8]
40: str x0, [x27, #16]
44: str x0, [x27, #24]
48: str x0, [x27, #32]
4c: str x0, [x27, #40]
50: str x0, [x27, #48]
54: str x0, [x27, #56]
58: str x0, [x27, #64]
5c: str x0, [x27, #72]
60: str x0, [x27, #80]
64: str x0, [x27, #88]
68: str x0, [x27, #96]
6c: str x0, [x27, #104]
70: str x0, [x27, #112]
74: str x0, [x27, #120]
78: str x0, [x27, #128]
7c: ldr x2, [x19, #8]
[...]
Signed-off-by: Xu Kuohai <[email protected]>
kernel-patches-bot
pushed a commit
that referenced
this pull request
Mar 18, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number. Therefore, this patch tries to
convert the offsets.
The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.
FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.
Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.
For example, for the following bpftrace command:
bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'
Without this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: mov x25, sp
1c: mov x26, #0x0 // #0
20: bti j
24: sub sp, sp, #0x90
28: add x19, x0, #0x0
2c: mov x0, #0x0 // #0
30: mov x10, #0xffffffffffffff78 // #-136
34: str x0, [x25, x10]
38: mov x10, #0xffffffffffffff80 // #-128
3c: str x0, [x25, x10]
40: mov x10, #0xffffffffffffff88 // #-120
44: str x0, [x25, x10]
48: mov x10, #0xffffffffffffff90 // #-112
4c: str x0, [x25, x10]
50: mov x10, #0xffffffffffffff98 // #-104
54: str x0, [x25, x10]
58: mov x10, #0xffffffffffffffa0 // #-96
5c: str x0, [x25, x10]
60: mov x10, #0xffffffffffffffa8 // #-88
64: str x0, [x25, x10]
68: mov x10, #0xffffffffffffffb0 // #-80
6c: str x0, [x25, x10]
70: mov x10, #0xffffffffffffffb8 // #-72
74: str x0, [x25, x10]
78: mov x10, #0xffffffffffffffc0 // #-64
7c: str x0, [x25, x10]
80: mov x10, #0xffffffffffffffc8 // #-56
84: str x0, [x25, x10]
88: mov x10, #0xffffffffffffffd0 // #-48
8c: str x0, [x25, x10]
90: mov x10, #0xffffffffffffffd8 // #-40
94: str x0, [x25, x10]
98: mov x10, #0xffffffffffffffe0 // #-32
9c: str x0, [x25, x10]
a0: mov x10, #0xffffffffffffffe8 // #-24
a4: str x0, [x25, x10]
a8: mov x10, #0xfffffffffffffff0 // #-16
ac: str x0, [x25, x10]
b0: mov x10, #0xfffffffffffffff8 // #-8
b4: str x0, [x25, x10]
b8: mov x10, #0x8 // #8
bc: ldr x2, [x19, x10]
[...]
With this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: stp x27, x28, [sp, #-16]!
1c: mov x25, sp
20: sub x27, x25, #0x88
24: mov x26, #0x0 // #0
28: bti j
2c: sub sp, sp, #0x90
30: add x19, x0, #0x0
34: mov x0, #0x0 // #0
38: str x0, [x27]
3c: str x0, [x27, #8]
40: str x0, [x27, #16]
44: str x0, [x27, #24]
48: str x0, [x27, #32]
4c: str x0, [x27, #40]
50: str x0, [x27, #48]
54: str x0, [x27, #56]
58: str x0, [x27, #64]
5c: str x0, [x27, #72]
60: str x0, [x27, #80]
64: str x0, [x27, #88]
68: str x0, [x27, #96]
6c: str x0, [x27, #104]
70: str x0, [x27, #112]
74: str x0, [x27, #120]
78: str x0, [x27, #128]
7c: ldr x2, [x19, #8]
[...]
Signed-off-by: Xu Kuohai <[email protected]>
kernel-patches-bot
pushed a commit
that referenced
this pull request
Mar 18, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number. Therefore, this patch tries to
convert the offsets.
The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.
FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.
Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.
For example, for the following bpftrace command:
bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'
Without this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: mov x25, sp
1c: mov x26, #0x0 // #0
20: bti j
24: sub sp, sp, #0x90
28: add x19, x0, #0x0
2c: mov x0, #0x0 // #0
30: mov x10, #0xffffffffffffff78 // #-136
34: str x0, [x25, x10]
38: mov x10, #0xffffffffffffff80 // #-128
3c: str x0, [x25, x10]
40: mov x10, #0xffffffffffffff88 // #-120
44: str x0, [x25, x10]
48: mov x10, #0xffffffffffffff90 // #-112
4c: str x0, [x25, x10]
50: mov x10, #0xffffffffffffff98 // #-104
54: str x0, [x25, x10]
58: mov x10, #0xffffffffffffffa0 // #-96
5c: str x0, [x25, x10]
60: mov x10, #0xffffffffffffffa8 // #-88
64: str x0, [x25, x10]
68: mov x10, #0xffffffffffffffb0 // #-80
6c: str x0, [x25, x10]
70: mov x10, #0xffffffffffffffb8 // #-72
74: str x0, [x25, x10]
78: mov x10, #0xffffffffffffffc0 // #-64
7c: str x0, [x25, x10]
80: mov x10, #0xffffffffffffffc8 // #-56
84: str x0, [x25, x10]
88: mov x10, #0xffffffffffffffd0 // #-48
8c: str x0, [x25, x10]
90: mov x10, #0xffffffffffffffd8 // #-40
94: str x0, [x25, x10]
98: mov x10, #0xffffffffffffffe0 // #-32
9c: str x0, [x25, x10]
a0: mov x10, #0xffffffffffffffe8 // #-24
a4: str x0, [x25, x10]
a8: mov x10, #0xfffffffffffffff0 // #-16
ac: str x0, [x25, x10]
b0: mov x10, #0xfffffffffffffff8 // #-8
b4: str x0, [x25, x10]
b8: mov x10, #0x8 // #8
bc: ldr x2, [x19, x10]
[...]
With this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: stp x27, x28, [sp, #-16]!
1c: mov x25, sp
20: sub x27, x25, #0x88
24: mov x26, #0x0 // #0
28: bti j
2c: sub sp, sp, #0x90
30: add x19, x0, #0x0
34: mov x0, #0x0 // #0
38: str x0, [x27]
3c: str x0, [x27, #8]
40: str x0, [x27, #16]
44: str x0, [x27, #24]
48: str x0, [x27, #32]
4c: str x0, [x27, #40]
50: str x0, [x27, #48]
54: str x0, [x27, #56]
58: str x0, [x27, #64]
5c: str x0, [x27, #72]
60: str x0, [x27, #80]
64: str x0, [x27, #88]
68: str x0, [x27, #96]
6c: str x0, [x27, #104]
70: str x0, [x27, #112]
74: str x0, [x27, #120]
78: str x0, [x27, #128]
7c: ldr x2, [x19, #8]
[...]
Signed-off-by: Xu Kuohai <[email protected]>
kernel-patches-bot
pushed a commit
that referenced
this pull request
Mar 19, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number. Therefore, this patch tries to
convert the offsets.
The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.
FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.
Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.
For example, for the following bpftrace command:
bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'
Without this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: mov x25, sp
1c: mov x26, #0x0 // #0
20: bti j
24: sub sp, sp, #0x90
28: add x19, x0, #0x0
2c: mov x0, #0x0 // #0
30: mov x10, #0xffffffffffffff78 // #-136
34: str x0, [x25, x10]
38: mov x10, #0xffffffffffffff80 // #-128
3c: str x0, [x25, x10]
40: mov x10, #0xffffffffffffff88 // #-120
44: str x0, [x25, x10]
48: mov x10, #0xffffffffffffff90 // #-112
4c: str x0, [x25, x10]
50: mov x10, #0xffffffffffffff98 // #-104
54: str x0, [x25, x10]
58: mov x10, #0xffffffffffffffa0 // #-96
5c: str x0, [x25, x10]
60: mov x10, #0xffffffffffffffa8 // #-88
64: str x0, [x25, x10]
68: mov x10, #0xffffffffffffffb0 // #-80
6c: str x0, [x25, x10]
70: mov x10, #0xffffffffffffffb8 // #-72
74: str x0, [x25, x10]
78: mov x10, #0xffffffffffffffc0 // #-64
7c: str x0, [x25, x10]
80: mov x10, #0xffffffffffffffc8 // #-56
84: str x0, [x25, x10]
88: mov x10, #0xffffffffffffffd0 // #-48
8c: str x0, [x25, x10]
90: mov x10, #0xffffffffffffffd8 // #-40
94: str x0, [x25, x10]
98: mov x10, #0xffffffffffffffe0 // #-32
9c: str x0, [x25, x10]
a0: mov x10, #0xffffffffffffffe8 // #-24
a4: str x0, [x25, x10]
a8: mov x10, #0xfffffffffffffff0 // #-16
ac: str x0, [x25, x10]
b0: mov x10, #0xfffffffffffffff8 // #-8
b4: str x0, [x25, x10]
b8: mov x10, #0x8 // #8
bc: ldr x2, [x19, x10]
[...]
With this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: stp x27, x28, [sp, #-16]!
1c: mov x25, sp
20: sub x27, x25, #0x88
24: mov x26, #0x0 // #0
28: bti j
2c: sub sp, sp, #0x90
30: add x19, x0, #0x0
34: mov x0, #0x0 // #0
38: str x0, [x27]
3c: str x0, [x27, #8]
40: str x0, [x27, #16]
44: str x0, [x27, #24]
48: str x0, [x27, #32]
4c: str x0, [x27, #40]
50: str x0, [x27, #48]
54: str x0, [x27, #56]
58: str x0, [x27, #64]
5c: str x0, [x27, #72]
60: str x0, [x27, #80]
64: str x0, [x27, #88]
68: str x0, [x27, #96]
6c: str x0, [x27, #104]
70: str x0, [x27, #112]
74: str x0, [x27, #120]
78: str x0, [x27, #128]
7c: ldr x2, [x19, #8]
[...]
Signed-off-by: Xu Kuohai <[email protected]>
kernel-patches-bot
pushed a commit
that referenced
this pull request
Mar 21, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number. Therefore, this patch tries to
convert the offsets.
The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.
FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.
Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.
For example, for the following bpftrace command:
bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'
Without this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: mov x25, sp
1c: mov x26, #0x0 // #0
20: bti j
24: sub sp, sp, #0x90
28: add x19, x0, #0x0
2c: mov x0, #0x0 // #0
30: mov x10, #0xffffffffffffff78 // #-136
34: str x0, [x25, x10]
38: mov x10, #0xffffffffffffff80 // #-128
3c: str x0, [x25, x10]
40: mov x10, #0xffffffffffffff88 // #-120
44: str x0, [x25, x10]
48: mov x10, #0xffffffffffffff90 // #-112
4c: str x0, [x25, x10]
50: mov x10, #0xffffffffffffff98 // #-104
54: str x0, [x25, x10]
58: mov x10, #0xffffffffffffffa0 // #-96
5c: str x0, [x25, x10]
60: mov x10, #0xffffffffffffffa8 // #-88
64: str x0, [x25, x10]
68: mov x10, #0xffffffffffffffb0 // #-80
6c: str x0, [x25, x10]
70: mov x10, #0xffffffffffffffb8 // #-72
74: str x0, [x25, x10]
78: mov x10, #0xffffffffffffffc0 // #-64
7c: str x0, [x25, x10]
80: mov x10, #0xffffffffffffffc8 // #-56
84: str x0, [x25, x10]
88: mov x10, #0xffffffffffffffd0 // #-48
8c: str x0, [x25, x10]
90: mov x10, #0xffffffffffffffd8 // #-40
94: str x0, [x25, x10]
98: mov x10, #0xffffffffffffffe0 // #-32
9c: str x0, [x25, x10]
a0: mov x10, #0xffffffffffffffe8 // #-24
a4: str x0, [x25, x10]
a8: mov x10, #0xfffffffffffffff0 // #-16
ac: str x0, [x25, x10]
b0: mov x10, #0xfffffffffffffff8 // #-8
b4: str x0, [x25, x10]
b8: mov x10, #0x8 // #8
bc: ldr x2, [x19, x10]
[...]
With this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: stp x27, x28, [sp, #-16]!
1c: mov x25, sp
20: sub x27, x25, #0x88
24: mov x26, #0x0 // #0
28: bti j
2c: sub sp, sp, #0x90
30: add x19, x0, #0x0
34: mov x0, #0x0 // #0
38: str x0, [x27]
3c: str x0, [x27, #8]
40: str x0, [x27, #16]
44: str x0, [x27, #24]
48: str x0, [x27, #32]
4c: str x0, [x27, #40]
50: str x0, [x27, #48]
54: str x0, [x27, #56]
58: str x0, [x27, #64]
5c: str x0, [x27, #72]
60: str x0, [x27, #80]
64: str x0, [x27, #88]
68: str x0, [x27, #96]
6c: str x0, [x27, #104]
70: str x0, [x27, #112]
74: str x0, [x27, #120]
78: str x0, [x27, #128]
7c: ldr x2, [x19, #8]
[...]
Signed-off-by: Xu Kuohai <[email protected]>
kernel-patches-bot
pushed a commit
that referenced
this pull request
Mar 21, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number. Therefore, this patch tries to
convert the offsets.
The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.
FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.
Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.
For example, for the following bpftrace command:
bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'
Without this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: mov x25, sp
1c: mov x26, #0x0 // #0
20: bti j
24: sub sp, sp, #0x90
28: add x19, x0, #0x0
2c: mov x0, #0x0 // #0
30: mov x10, #0xffffffffffffff78 // #-136
34: str x0, [x25, x10]
38: mov x10, #0xffffffffffffff80 // #-128
3c: str x0, [x25, x10]
40: mov x10, #0xffffffffffffff88 // #-120
44: str x0, [x25, x10]
48: mov x10, #0xffffffffffffff90 // #-112
4c: str x0, [x25, x10]
50: mov x10, #0xffffffffffffff98 // #-104
54: str x0, [x25, x10]
58: mov x10, #0xffffffffffffffa0 // #-96
5c: str x0, [x25, x10]
60: mov x10, #0xffffffffffffffa8 // #-88
64: str x0, [x25, x10]
68: mov x10, #0xffffffffffffffb0 // #-80
6c: str x0, [x25, x10]
70: mov x10, #0xffffffffffffffb8 // #-72
74: str x0, [x25, x10]
78: mov x10, #0xffffffffffffffc0 // #-64
7c: str x0, [x25, x10]
80: mov x10, #0xffffffffffffffc8 // #-56
84: str x0, [x25, x10]
88: mov x10, #0xffffffffffffffd0 // #-48
8c: str x0, [x25, x10]
90: mov x10, #0xffffffffffffffd8 // #-40
94: str x0, [x25, x10]
98: mov x10, #0xffffffffffffffe0 // #-32
9c: str x0, [x25, x10]
a0: mov x10, #0xffffffffffffffe8 // #-24
a4: str x0, [x25, x10]
a8: mov x10, #0xfffffffffffffff0 // #-16
ac: str x0, [x25, x10]
b0: mov x10, #0xfffffffffffffff8 // #-8
b4: str x0, [x25, x10]
b8: mov x10, #0x8 // #8
bc: ldr x2, [x19, x10]
[...]
With this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: stp x27, x28, [sp, #-16]!
1c: mov x25, sp
20: sub x27, x25, #0x88
24: mov x26, #0x0 // #0
28: bti j
2c: sub sp, sp, #0x90
30: add x19, x0, #0x0
34: mov x0, #0x0 // #0
38: str x0, [x27]
3c: str x0, [x27, #8]
40: str x0, [x27, #16]
44: str x0, [x27, #24]
48: str x0, [x27, #32]
4c: str x0, [x27, #40]
50: str x0, [x27, #48]
54: str x0, [x27, #56]
58: str x0, [x27, #64]
5c: str x0, [x27, #72]
60: str x0, [x27, #80]
64: str x0, [x27, #88]
68: str x0, [x27, #96]
6c: str x0, [x27, #104]
70: str x0, [x27, #112]
74: str x0, [x27, #120]
78: str x0, [x27, #128]
7c: ldr x2, [x19, #8]
[...]
Signed-off-by: Xu Kuohai <[email protected]>
kernel-patches-bot
pushed a commit
that referenced
this pull request
Mar 21, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number. Therefore, this patch tries to
convert the offsets.
The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.
FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.
Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.
For example, for the following bpftrace command:
bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'
Without this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: mov x25, sp
1c: mov x26, #0x0 // #0
20: bti j
24: sub sp, sp, #0x90
28: add x19, x0, #0x0
2c: mov x0, #0x0 // #0
30: mov x10, #0xffffffffffffff78 // #-136
34: str x0, [x25, x10]
38: mov x10, #0xffffffffffffff80 // #-128
3c: str x0, [x25, x10]
40: mov x10, #0xffffffffffffff88 // #-120
44: str x0, [x25, x10]
48: mov x10, #0xffffffffffffff90 // #-112
4c: str x0, [x25, x10]
50: mov x10, #0xffffffffffffff98 // #-104
54: str x0, [x25, x10]
58: mov x10, #0xffffffffffffffa0 // #-96
5c: str x0, [x25, x10]
60: mov x10, #0xffffffffffffffa8 // #-88
64: str x0, [x25, x10]
68: mov x10, #0xffffffffffffffb0 // #-80
6c: str x0, [x25, x10]
70: mov x10, #0xffffffffffffffb8 // #-72
74: str x0, [x25, x10]
78: mov x10, #0xffffffffffffffc0 // #-64
7c: str x0, [x25, x10]
80: mov x10, #0xffffffffffffffc8 // #-56
84: str x0, [x25, x10]
88: mov x10, #0xffffffffffffffd0 // #-48
8c: str x0, [x25, x10]
90: mov x10, #0xffffffffffffffd8 // #-40
94: str x0, [x25, x10]
98: mov x10, #0xffffffffffffffe0 // #-32
9c: str x0, [x25, x10]
a0: mov x10, #0xffffffffffffffe8 // #-24
a4: str x0, [x25, x10]
a8: mov x10, #0xfffffffffffffff0 // #-16
ac: str x0, [x25, x10]
b0: mov x10, #0xfffffffffffffff8 // #-8
b4: str x0, [x25, x10]
b8: mov x10, #0x8 // #8
bc: ldr x2, [x19, x10]
[...]
With this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: stp x27, x28, [sp, #-16]!
1c: mov x25, sp
20: sub x27, x25, #0x88
24: mov x26, #0x0 // #0
28: bti j
2c: sub sp, sp, #0x90
30: add x19, x0, #0x0
34: mov x0, #0x0 // #0
38: str x0, [x27]
3c: str x0, [x27, #8]
40: str x0, [x27, #16]
44: str x0, [x27, #24]
48: str x0, [x27, #32]
4c: str x0, [x27, #40]
50: str x0, [x27, #48]
54: str x0, [x27, #56]
58: str x0, [x27, #64]
5c: str x0, [x27, #72]
60: str x0, [x27, #80]
64: str x0, [x27, #88]
68: str x0, [x27, #96]
6c: str x0, [x27, #104]
70: str x0, [x27, #112]
74: str x0, [x27, #120]
78: str x0, [x27, #128]
7c: ldr x2, [x19, #8]
[...]
Signed-off-by: Xu Kuohai <[email protected]>
kernel-patches-bot
pushed a commit
that referenced
this pull request
Mar 21, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number. Therefore, this patch tries to
convert the offsets.
The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.
FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.
Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.
For example, for the following bpftrace command:
bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'
Without this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: mov x25, sp
1c: mov x26, #0x0 // #0
20: bti j
24: sub sp, sp, #0x90
28: add x19, x0, #0x0
2c: mov x0, #0x0 // #0
30: mov x10, #0xffffffffffffff78 // #-136
34: str x0, [x25, x10]
38: mov x10, #0xffffffffffffff80 // #-128
3c: str x0, [x25, x10]
40: mov x10, #0xffffffffffffff88 // #-120
44: str x0, [x25, x10]
48: mov x10, #0xffffffffffffff90 // #-112
4c: str x0, [x25, x10]
50: mov x10, #0xffffffffffffff98 // #-104
54: str x0, [x25, x10]
58: mov x10, #0xffffffffffffffa0 // #-96
5c: str x0, [x25, x10]
60: mov x10, #0xffffffffffffffa8 // #-88
64: str x0, [x25, x10]
68: mov x10, #0xffffffffffffffb0 // #-80
6c: str x0, [x25, x10]
70: mov x10, #0xffffffffffffffb8 // #-72
74: str x0, [x25, x10]
78: mov x10, #0xffffffffffffffc0 // #-64
7c: str x0, [x25, x10]
80: mov x10, #0xffffffffffffffc8 // #-56
84: str x0, [x25, x10]
88: mov x10, #0xffffffffffffffd0 // #-48
8c: str x0, [x25, x10]
90: mov x10, #0xffffffffffffffd8 // #-40
94: str x0, [x25, x10]
98: mov x10, #0xffffffffffffffe0 // #-32
9c: str x0, [x25, x10]
a0: mov x10, #0xffffffffffffffe8 // #-24
a4: str x0, [x25, x10]
a8: mov x10, #0xfffffffffffffff0 // #-16
ac: str x0, [x25, x10]
b0: mov x10, #0xfffffffffffffff8 // #-8
b4: str x0, [x25, x10]
b8: mov x10, #0x8 // #8
bc: ldr x2, [x19, x10]
[...]
With this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: stp x27, x28, [sp, #-16]!
1c: mov x25, sp
20: sub x27, x25, #0x88
24: mov x26, #0x0 // #0
28: bti j
2c: sub sp, sp, #0x90
30: add x19, x0, #0x0
34: mov x0, #0x0 // #0
38: str x0, [x27]
3c: str x0, [x27, #8]
40: str x0, [x27, #16]
44: str x0, [x27, #24]
48: str x0, [x27, #32]
4c: str x0, [x27, #40]
50: str x0, [x27, #48]
54: str x0, [x27, #56]
58: str x0, [x27, #64]
5c: str x0, [x27, #72]
60: str x0, [x27, #80]
64: str x0, [x27, #88]
68: str x0, [x27, #96]
6c: str x0, [x27, #104]
70: str x0, [x27, #112]
74: str x0, [x27, #120]
78: str x0, [x27, #128]
7c: ldr x2, [x19, #8]
[...]
Signed-off-by: Xu Kuohai <[email protected]>
kernel-patches-bot
pushed a commit
that referenced
this pull request
Mar 21, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number. Therefore, this patch tries to
convert the offsets.
The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.
FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.
Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.
For example, for the following bpftrace command:
bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'
Without this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: mov x25, sp
1c: mov x26, #0x0 // #0
20: bti j
24: sub sp, sp, #0x90
28: add x19, x0, #0x0
2c: mov x0, #0x0 // #0
30: mov x10, #0xffffffffffffff78 // #-136
34: str x0, [x25, x10]
38: mov x10, #0xffffffffffffff80 // #-128
3c: str x0, [x25, x10]
40: mov x10, #0xffffffffffffff88 // #-120
44: str x0, [x25, x10]
48: mov x10, #0xffffffffffffff90 // #-112
4c: str x0, [x25, x10]
50: mov x10, #0xffffffffffffff98 // #-104
54: str x0, [x25, x10]
58: mov x10, #0xffffffffffffffa0 // #-96
5c: str x0, [x25, x10]
60: mov x10, #0xffffffffffffffa8 // #-88
64: str x0, [x25, x10]
68: mov x10, #0xffffffffffffffb0 // #-80
6c: str x0, [x25, x10]
70: mov x10, #0xffffffffffffffb8 // #-72
74: str x0, [x25, x10]
78: mov x10, #0xffffffffffffffc0 // #-64
7c: str x0, [x25, x10]
80: mov x10, #0xffffffffffffffc8 // #-56
84: str x0, [x25, x10]
88: mov x10, #0xffffffffffffffd0 // #-48
8c: str x0, [x25, x10]
90: mov x10, #0xffffffffffffffd8 // #-40
94: str x0, [x25, x10]
98: mov x10, #0xffffffffffffffe0 // #-32
9c: str x0, [x25, x10]
a0: mov x10, #0xffffffffffffffe8 // #-24
a4: str x0, [x25, x10]
a8: mov x10, #0xfffffffffffffff0 // #-16
ac: str x0, [x25, x10]
b0: mov x10, #0xfffffffffffffff8 // #-8
b4: str x0, [x25, x10]
b8: mov x10, #0x8 // #8
bc: ldr x2, [x19, x10]
[...]
With this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: stp x27, x28, [sp, #-16]!
1c: mov x25, sp
20: sub x27, x25, #0x88
24: mov x26, #0x0 // #0
28: bti j
2c: sub sp, sp, #0x90
30: add x19, x0, #0x0
34: mov x0, #0x0 // #0
38: str x0, [x27]
3c: str x0, [x27, #8]
40: str x0, [x27, #16]
44: str x0, [x27, #24]
48: str x0, [x27, #32]
4c: str x0, [x27, #40]
50: str x0, [x27, #48]
54: str x0, [x27, #56]
58: str x0, [x27, #64]
5c: str x0, [x27, #72]
60: str x0, [x27, #80]
64: str x0, [x27, #88]
68: str x0, [x27, #96]
6c: str x0, [x27, #104]
70: str x0, [x27, #112]
74: str x0, [x27, #120]
78: str x0, [x27, #128]
7c: ldr x2, [x19, #8]
[...]
Signed-off-by: Xu Kuohai <[email protected]>
kernel-patches-bot
pushed a commit
that referenced
this pull request
Mar 21, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number. Therefore, this patch tries to
convert the offsets.
The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.
FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.
Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.
For example, for the following bpftrace command:
bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'
Without this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: mov x25, sp
1c: mov x26, #0x0 // #0
20: bti j
24: sub sp, sp, #0x90
28: add x19, x0, #0x0
2c: mov x0, #0x0 // #0
30: mov x10, #0xffffffffffffff78 // #-136
34: str x0, [x25, x10]
38: mov x10, #0xffffffffffffff80 // #-128
3c: str x0, [x25, x10]
40: mov x10, #0xffffffffffffff88 // #-120
44: str x0, [x25, x10]
48: mov x10, #0xffffffffffffff90 // #-112
4c: str x0, [x25, x10]
50: mov x10, #0xffffffffffffff98 // #-104
54: str x0, [x25, x10]
58: mov x10, #0xffffffffffffffa0 // #-96
5c: str x0, [x25, x10]
60: mov x10, #0xffffffffffffffa8 // #-88
64: str x0, [x25, x10]
68: mov x10, #0xffffffffffffffb0 // #-80
6c: str x0, [x25, x10]
70: mov x10, #0xffffffffffffffb8 // #-72
74: str x0, [x25, x10]
78: mov x10, #0xffffffffffffffc0 // #-64
7c: str x0, [x25, x10]
80: mov x10, #0xffffffffffffffc8 // #-56
84: str x0, [x25, x10]
88: mov x10, #0xffffffffffffffd0 // #-48
8c: str x0, [x25, x10]
90: mov x10, #0xffffffffffffffd8 // #-40
94: str x0, [x25, x10]
98: mov x10, #0xffffffffffffffe0 // #-32
9c: str x0, [x25, x10]
a0: mov x10, #0xffffffffffffffe8 // #-24
a4: str x0, [x25, x10]
a8: mov x10, #0xfffffffffffffff0 // #-16
ac: str x0, [x25, x10]
b0: mov x10, #0xfffffffffffffff8 // #-8
b4: str x0, [x25, x10]
b8: mov x10, #0x8 // #8
bc: ldr x2, [x19, x10]
[...]
With this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: stp x27, x28, [sp, #-16]!
1c: mov x25, sp
20: sub x27, x25, #0x88
24: mov x26, #0x0 // #0
28: bti j
2c: sub sp, sp, #0x90
30: add x19, x0, #0x0
34: mov x0, #0x0 // #0
38: str x0, [x27]
3c: str x0, [x27, #8]
40: str x0, [x27, #16]
44: str x0, [x27, #24]
48: str x0, [x27, #32]
4c: str x0, [x27, #40]
50: str x0, [x27, #48]
54: str x0, [x27, #56]
58: str x0, [x27, #64]
5c: str x0, [x27, #72]
60: str x0, [x27, #80]
64: str x0, [x27, #88]
68: str x0, [x27, #96]
6c: str x0, [x27, #104]
70: str x0, [x27, #112]
74: str x0, [x27, #120]
78: str x0, [x27, #128]
7c: ldr x2, [x19, #8]
[...]
Signed-off-by: Xu Kuohai <[email protected]>
kernel-patches-bot
pushed a commit
that referenced
this pull request
Mar 21, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number. Therefore, this patch tries to
convert the offsets.
The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.
FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.
Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.
For example, for the following bpftrace command:
bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'
Without this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: mov x25, sp
1c: mov x26, #0x0 // #0
20: bti j
24: sub sp, sp, #0x90
28: add x19, x0, #0x0
2c: mov x0, #0x0 // #0
30: mov x10, #0xffffffffffffff78 // #-136
34: str x0, [x25, x10]
38: mov x10, #0xffffffffffffff80 // #-128
3c: str x0, [x25, x10]
40: mov x10, #0xffffffffffffff88 // #-120
44: str x0, [x25, x10]
48: mov x10, #0xffffffffffffff90 // #-112
4c: str x0, [x25, x10]
50: mov x10, #0xffffffffffffff98 // #-104
54: str x0, [x25, x10]
58: mov x10, #0xffffffffffffffa0 // #-96
5c: str x0, [x25, x10]
60: mov x10, #0xffffffffffffffa8 // #-88
64: str x0, [x25, x10]
68: mov x10, #0xffffffffffffffb0 // #-80
6c: str x0, [x25, x10]
70: mov x10, #0xffffffffffffffb8 // #-72
74: str x0, [x25, x10]
78: mov x10, #0xffffffffffffffc0 // #-64
7c: str x0, [x25, x10]
80: mov x10, #0xffffffffffffffc8 // #-56
84: str x0, [x25, x10]
88: mov x10, #0xffffffffffffffd0 // #-48
8c: str x0, [x25, x10]
90: mov x10, #0xffffffffffffffd8 // #-40
94: str x0, [x25, x10]
98: mov x10, #0xffffffffffffffe0 // #-32
9c: str x0, [x25, x10]
a0: mov x10, #0xffffffffffffffe8 // #-24
a4: str x0, [x25, x10]
a8: mov x10, #0xfffffffffffffff0 // #-16
ac: str x0, [x25, x10]
b0: mov x10, #0xfffffffffffffff8 // #-8
b4: str x0, [x25, x10]
b8: mov x10, #0x8 // #8
bc: ldr x2, [x19, x10]
[...]
With this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: stp x27, x28, [sp, #-16]!
1c: mov x25, sp
20: sub x27, x25, #0x88
24: mov x26, #0x0 // #0
28: bti j
2c: sub sp, sp, #0x90
30: add x19, x0, #0x0
34: mov x0, #0x0 // #0
38: str x0, [x27]
3c: str x0, [x27, #8]
40: str x0, [x27, #16]
44: str x0, [x27, #24]
48: str x0, [x27, #32]
4c: str x0, [x27, #40]
50: str x0, [x27, #48]
54: str x0, [x27, #56]
58: str x0, [x27, #64]
5c: str x0, [x27, #72]
60: str x0, [x27, #80]
64: str x0, [x27, #88]
68: str x0, [x27, #96]
6c: str x0, [x27, #104]
70: str x0, [x27, #112]
74: str x0, [x27, #120]
78: str x0, [x27, #128]
7c: ldr x2, [x19, #8]
[...]
Signed-off-by: Xu Kuohai <[email protected]>
kernel-patches-bot
pushed a commit
that referenced
this pull request
Mar 21, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number. Therefore, this patch tries to
convert the offsets.
The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.
FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.
Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.
For example, for the following bpftrace command:
bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'
Without this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: mov x25, sp
1c: mov x26, #0x0 // #0
20: bti j
24: sub sp, sp, #0x90
28: add x19, x0, #0x0
2c: mov x0, #0x0 // #0
30: mov x10, #0xffffffffffffff78 // #-136
34: str x0, [x25, x10]
38: mov x10, #0xffffffffffffff80 // #-128
3c: str x0, [x25, x10]
40: mov x10, #0xffffffffffffff88 // #-120
44: str x0, [x25, x10]
48: mov x10, #0xffffffffffffff90 // #-112
4c: str x0, [x25, x10]
50: mov x10, #0xffffffffffffff98 // #-104
54: str x0, [x25, x10]
58: mov x10, #0xffffffffffffffa0 // #-96
5c: str x0, [x25, x10]
60: mov x10, #0xffffffffffffffa8 // #-88
64: str x0, [x25, x10]
68: mov x10, #0xffffffffffffffb0 // #-80
6c: str x0, [x25, x10]
70: mov x10, #0xffffffffffffffb8 // #-72
74: str x0, [x25, x10]
78: mov x10, #0xffffffffffffffc0 // #-64
7c: str x0, [x25, x10]
80: mov x10, #0xffffffffffffffc8 // #-56
84: str x0, [x25, x10]
88: mov x10, #0xffffffffffffffd0 // #-48
8c: str x0, [x25, x10]
90: mov x10, #0xffffffffffffffd8 // #-40
94: str x0, [x25, x10]
98: mov x10, #0xffffffffffffffe0 // #-32
9c: str x0, [x25, x10]
a0: mov x10, #0xffffffffffffffe8 // #-24
a4: str x0, [x25, x10]
a8: mov x10, #0xfffffffffffffff0 // #-16
ac: str x0, [x25, x10]
b0: mov x10, #0xfffffffffffffff8 // #-8
b4: str x0, [x25, x10]
b8: mov x10, #0x8 // #8
bc: ldr x2, [x19, x10]
[...]
With this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: stp x27, x28, [sp, #-16]!
1c: mov x25, sp
20: sub x27, x25, #0x88
24: mov x26, #0x0 // #0
28: bti j
2c: sub sp, sp, #0x90
30: add x19, x0, #0x0
34: mov x0, #0x0 // #0
38: str x0, [x27]
3c: str x0, [x27, #8]
40: str x0, [x27, #16]
44: str x0, [x27, #24]
48: str x0, [x27, #32]
4c: str x0, [x27, #40]
50: str x0, [x27, #48]
54: str x0, [x27, #56]
58: str x0, [x27, #64]
5c: str x0, [x27, #72]
60: str x0, [x27, #80]
64: str x0, [x27, #88]
68: str x0, [x27, #96]
6c: str x0, [x27, #104]
70: str x0, [x27, #112]
74: str x0, [x27, #120]
78: str x0, [x27, #128]
7c: ldr x2, [x19, #8]
[...]
Signed-off-by: Xu Kuohai <[email protected]>
kernel-patches-bot
pushed a commit
that referenced
this pull request
Mar 21, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number. Therefore, this patch tries to
convert the offsets.
The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.
FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.
Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.
For example, for the following bpftrace command:
bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'
Without this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: mov x25, sp
1c: mov x26, #0x0 // #0
20: bti j
24: sub sp, sp, #0x90
28: add x19, x0, #0x0
2c: mov x0, #0x0 // #0
30: mov x10, #0xffffffffffffff78 // #-136
34: str x0, [x25, x10]
38: mov x10, #0xffffffffffffff80 // #-128
3c: str x0, [x25, x10]
40: mov x10, #0xffffffffffffff88 // #-120
44: str x0, [x25, x10]
48: mov x10, #0xffffffffffffff90 // #-112
4c: str x0, [x25, x10]
50: mov x10, #0xffffffffffffff98 // #-104
54: str x0, [x25, x10]
58: mov x10, #0xffffffffffffffa0 // #-96
5c: str x0, [x25, x10]
60: mov x10, #0xffffffffffffffa8 // #-88
64: str x0, [x25, x10]
68: mov x10, #0xffffffffffffffb0 // #-80
6c: str x0, [x25, x10]
70: mov x10, #0xffffffffffffffb8 // #-72
74: str x0, [x25, x10]
78: mov x10, #0xffffffffffffffc0 // #-64
7c: str x0, [x25, x10]
80: mov x10, #0xffffffffffffffc8 // #-56
84: str x0, [x25, x10]
88: mov x10, #0xffffffffffffffd0 // #-48
8c: str x0, [x25, x10]
90: mov x10, #0xffffffffffffffd8 // #-40
94: str x0, [x25, x10]
98: mov x10, #0xffffffffffffffe0 // #-32
9c: str x0, [x25, x10]
a0: mov x10, #0xffffffffffffffe8 // #-24
a4: str x0, [x25, x10]
a8: mov x10, #0xfffffffffffffff0 // #-16
ac: str x0, [x25, x10]
b0: mov x10, #0xfffffffffffffff8 // #-8
b4: str x0, [x25, x10]
b8: mov x10, #0x8 // #8
bc: ldr x2, [x19, x10]
[...]
With this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: stp x27, x28, [sp, #-16]!
1c: mov x25, sp
20: sub x27, x25, #0x88
24: mov x26, #0x0 // #0
28: bti j
2c: sub sp, sp, #0x90
30: add x19, x0, #0x0
34: mov x0, #0x0 // #0
38: str x0, [x27]
3c: str x0, [x27, #8]
40: str x0, [x27, #16]
44: str x0, [x27, #24]
48: str x0, [x27, #32]
4c: str x0, [x27, #40]
50: str x0, [x27, #48]
54: str x0, [x27, #56]
58: str x0, [x27, #64]
5c: str x0, [x27, #72]
60: str x0, [x27, #80]
64: str x0, [x27, #88]
68: str x0, [x27, #96]
6c: str x0, [x27, #104]
70: str x0, [x27, #112]
74: str x0, [x27, #120]
78: str x0, [x27, #128]
7c: ldr x2, [x19, #8]
[...]
Signed-off-by: Xu Kuohai <[email protected]>
kernel-patches-bot
pushed a commit
that referenced
this pull request
Mar 21, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number. Therefore, this patch tries to
convert the offsets.
The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.
FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.
Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.
For example, for the following bpftrace command:
bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'
Without this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: mov x25, sp
1c: mov x26, #0x0 // #0
20: bti j
24: sub sp, sp, #0x90
28: add x19, x0, #0x0
2c: mov x0, #0x0 // #0
30: mov x10, #0xffffffffffffff78 // #-136
34: str x0, [x25, x10]
38: mov x10, #0xffffffffffffff80 // #-128
3c: str x0, [x25, x10]
40: mov x10, #0xffffffffffffff88 // #-120
44: str x0, [x25, x10]
48: mov x10, #0xffffffffffffff90 // #-112
4c: str x0, [x25, x10]
50: mov x10, #0xffffffffffffff98 // #-104
54: str x0, [x25, x10]
58: mov x10, #0xffffffffffffffa0 // #-96
5c: str x0, [x25, x10]
60: mov x10, #0xffffffffffffffa8 // #-88
64: str x0, [x25, x10]
68: mov x10, #0xffffffffffffffb0 // #-80
6c: str x0, [x25, x10]
70: mov x10, #0xffffffffffffffb8 // #-72
74: str x0, [x25, x10]
78: mov x10, #0xffffffffffffffc0 // #-64
7c: str x0, [x25, x10]
80: mov x10, #0xffffffffffffffc8 // #-56
84: str x0, [x25, x10]
88: mov x10, #0xffffffffffffffd0 // #-48
8c: str x0, [x25, x10]
90: mov x10, #0xffffffffffffffd8 // #-40
94: str x0, [x25, x10]
98: mov x10, #0xffffffffffffffe0 // #-32
9c: str x0, [x25, x10]
a0: mov x10, #0xffffffffffffffe8 // #-24
a4: str x0, [x25, x10]
a8: mov x10, #0xfffffffffffffff0 // #-16
ac: str x0, [x25, x10]
b0: mov x10, #0xfffffffffffffff8 // #-8
b4: str x0, [x25, x10]
b8: mov x10, #0x8 // #8
bc: ldr x2, [x19, x10]
[...]
With this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: stp x27, x28, [sp, #-16]!
1c: mov x25, sp
20: sub x27, x25, #0x88
24: mov x26, #0x0 // #0
28: bti j
2c: sub sp, sp, #0x90
30: add x19, x0, #0x0
34: mov x0, #0x0 // #0
38: str x0, [x27]
3c: str x0, [x27, #8]
40: str x0, [x27, #16]
44: str x0, [x27, #24]
48: str x0, [x27, #32]
4c: str x0, [x27, #40]
50: str x0, [x27, #48]
54: str x0, [x27, #56]
58: str x0, [x27, #64]
5c: str x0, [x27, #72]
60: str x0, [x27, #80]
64: str x0, [x27, #88]
68: str x0, [x27, #96]
6c: str x0, [x27, #104]
70: str x0, [x27, #112]
74: str x0, [x27, #120]
78: str x0, [x27, #128]
7c: ldr x2, [x19, #8]
[...]
Signed-off-by: Xu Kuohai <[email protected]>
kernel-patches-bot
pushed a commit
that referenced
this pull request
Mar 22, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number. Therefore, this patch tries to
convert the offsets.
The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.
FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.
Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.
For example, for the following bpftrace command:
bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'
Without this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: mov x25, sp
1c: mov x26, #0x0 // #0
20: bti j
24: sub sp, sp, #0x90
28: add x19, x0, #0x0
2c: mov x0, #0x0 // #0
30: mov x10, #0xffffffffffffff78 // #-136
34: str x0, [x25, x10]
38: mov x10, #0xffffffffffffff80 // #-128
3c: str x0, [x25, x10]
40: mov x10, #0xffffffffffffff88 // #-120
44: str x0, [x25, x10]
48: mov x10, #0xffffffffffffff90 // #-112
4c: str x0, [x25, x10]
50: mov x10, #0xffffffffffffff98 // #-104
54: str x0, [x25, x10]
58: mov x10, #0xffffffffffffffa0 // #-96
5c: str x0, [x25, x10]
60: mov x10, #0xffffffffffffffa8 // #-88
64: str x0, [x25, x10]
68: mov x10, #0xffffffffffffffb0 // #-80
6c: str x0, [x25, x10]
70: mov x10, #0xffffffffffffffb8 // #-72
74: str x0, [x25, x10]
78: mov x10, #0xffffffffffffffc0 // #-64
7c: str x0, [x25, x10]
80: mov x10, #0xffffffffffffffc8 // #-56
84: str x0, [x25, x10]
88: mov x10, #0xffffffffffffffd0 // #-48
8c: str x0, [x25, x10]
90: mov x10, #0xffffffffffffffd8 // #-40
94: str x0, [x25, x10]
98: mov x10, #0xffffffffffffffe0 // #-32
9c: str x0, [x25, x10]
a0: mov x10, #0xffffffffffffffe8 // #-24
a4: str x0, [x25, x10]
a8: mov x10, #0xfffffffffffffff0 // #-16
ac: str x0, [x25, x10]
b0: mov x10, #0xfffffffffffffff8 // #-8
b4: str x0, [x25, x10]
b8: mov x10, #0x8 // #8
bc: ldr x2, [x19, x10]
[...]
With this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: stp x27, x28, [sp, #-16]!
1c: mov x25, sp
20: sub x27, x25, #0x88
24: mov x26, #0x0 // #0
28: bti j
2c: sub sp, sp, #0x90
30: add x19, x0, #0x0
34: mov x0, #0x0 // #0
38: str x0, [x27]
3c: str x0, [x27, #8]
40: str x0, [x27, #16]
44: str x0, [x27, #24]
48: str x0, [x27, #32]
4c: str x0, [x27, #40]
50: str x0, [x27, #48]
54: str x0, [x27, #56]
58: str x0, [x27, #64]
5c: str x0, [x27, #72]
60: str x0, [x27, #80]
64: str x0, [x27, #88]
68: str x0, [x27, #96]
6c: str x0, [x27, #104]
70: str x0, [x27, #112]
74: str x0, [x27, #120]
78: str x0, [x27, #128]
7c: ldr x2, [x19, #8]
[...]
Signed-off-by: Xu Kuohai <[email protected]>
kernel-patches-bot
pushed a commit
that referenced
this pull request
Mar 22, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number. Therefore, this patch tries to
convert the offsets.
The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.
FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.
Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.
For example, for the following bpftrace command:
bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'
Without this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: mov x25, sp
1c: mov x26, #0x0 // #0
20: bti j
24: sub sp, sp, #0x90
28: add x19, x0, #0x0
2c: mov x0, #0x0 // #0
30: mov x10, #0xffffffffffffff78 // #-136
34: str x0, [x25, x10]
38: mov x10, #0xffffffffffffff80 // #-128
3c: str x0, [x25, x10]
40: mov x10, #0xffffffffffffff88 // #-120
44: str x0, [x25, x10]
48: mov x10, #0xffffffffffffff90 // #-112
4c: str x0, [x25, x10]
50: mov x10, #0xffffffffffffff98 // #-104
54: str x0, [x25, x10]
58: mov x10, #0xffffffffffffffa0 // #-96
5c: str x0, [x25, x10]
60: mov x10, #0xffffffffffffffa8 // #-88
64: str x0, [x25, x10]
68: mov x10, #0xffffffffffffffb0 // #-80
6c: str x0, [x25, x10]
70: mov x10, #0xffffffffffffffb8 // #-72
74: str x0, [x25, x10]
78: mov x10, #0xffffffffffffffc0 // #-64
7c: str x0, [x25, x10]
80: mov x10, #0xffffffffffffffc8 // #-56
84: str x0, [x25, x10]
88: mov x10, #0xffffffffffffffd0 // #-48
8c: str x0, [x25, x10]
90: mov x10, #0xffffffffffffffd8 // #-40
94: str x0, [x25, x10]
98: mov x10, #0xffffffffffffffe0 // #-32
9c: str x0, [x25, x10]
a0: mov x10, #0xffffffffffffffe8 // #-24
a4: str x0, [x25, x10]
a8: mov x10, #0xfffffffffffffff0 // #-16
ac: str x0, [x25, x10]
b0: mov x10, #0xfffffffffffffff8 // #-8
b4: str x0, [x25, x10]
b8: mov x10, #0x8 // #8
bc: ldr x2, [x19, x10]
[...]
With this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: stp x27, x28, [sp, #-16]!
1c: mov x25, sp
20: sub x27, x25, #0x88
24: mov x26, #0x0 // #0
28: bti j
2c: sub sp, sp, #0x90
30: add x19, x0, #0x0
34: mov x0, #0x0 // #0
38: str x0, [x27]
3c: str x0, [x27, #8]
40: str x0, [x27, #16]
44: str x0, [x27, #24]
48: str x0, [x27, #32]
4c: str x0, [x27, #40]
50: str x0, [x27, #48]
54: str x0, [x27, #56]
58: str x0, [x27, #64]
5c: str x0, [x27, #72]
60: str x0, [x27, #80]
64: str x0, [x27, #88]
68: str x0, [x27, #96]
6c: str x0, [x27, #104]
70: str x0, [x27, #112]
74: str x0, [x27, #120]
78: str x0, [x27, #128]
7c: ldr x2, [x19, #8]
[...]
Signed-off-by: Xu Kuohai <[email protected]>
kernel-patches-bot
pushed a commit
that referenced
this pull request
Mar 22, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number. Therefore, this patch tries to
convert the offsets.
The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.
FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.
Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.
For example, for the following bpftrace command:
bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'
Without this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: mov x25, sp
1c: mov x26, #0x0 // #0
20: bti j
24: sub sp, sp, #0x90
28: add x19, x0, #0x0
2c: mov x0, #0x0 // #0
30: mov x10, #0xffffffffffffff78 // #-136
34: str x0, [x25, x10]
38: mov x10, #0xffffffffffffff80 // #-128
3c: str x0, [x25, x10]
40: mov x10, #0xffffffffffffff88 // #-120
44: str x0, [x25, x10]
48: mov x10, #0xffffffffffffff90 // #-112
4c: str x0, [x25, x10]
50: mov x10, #0xffffffffffffff98 // #-104
54: str x0, [x25, x10]
58: mov x10, #0xffffffffffffffa0 // #-96
5c: str x0, [x25, x10]
60: mov x10, #0xffffffffffffffa8 // #-88
64: str x0, [x25, x10]
68: mov x10, #0xffffffffffffffb0 // #-80
6c: str x0, [x25, x10]
70: mov x10, #0xffffffffffffffb8 // #-72
74: str x0, [x25, x10]
78: mov x10, #0xffffffffffffffc0 // #-64
7c: str x0, [x25, x10]
80: mov x10, #0xffffffffffffffc8 // #-56
84: str x0, [x25, x10]
88: mov x10, #0xffffffffffffffd0 // #-48
8c: str x0, [x25, x10]
90: mov x10, #0xffffffffffffffd8 // #-40
94: str x0, [x25, x10]
98: mov x10, #0xffffffffffffffe0 // #-32
9c: str x0, [x25, x10]
a0: mov x10, #0xffffffffffffffe8 // #-24
a4: str x0, [x25, x10]
a8: mov x10, #0xfffffffffffffff0 // #-16
ac: str x0, [x25, x10]
b0: mov x10, #0xfffffffffffffff8 // #-8
b4: str x0, [x25, x10]
b8: mov x10, #0x8 // #8
bc: ldr x2, [x19, x10]
[...]
With this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: stp x27, x28, [sp, #-16]!
1c: mov x25, sp
20: sub x27, x25, #0x88
24: mov x26, #0x0 // #0
28: bti j
2c: sub sp, sp, #0x90
30: add x19, x0, #0x0
34: mov x0, #0x0 // #0
38: str x0, [x27]
3c: str x0, [x27, #8]
40: str x0, [x27, #16]
44: str x0, [x27, #24]
48: str x0, [x27, #32]
4c: str x0, [x27, #40]
50: str x0, [x27, #48]
54: str x0, [x27, #56]
58: str x0, [x27, #64]
5c: str x0, [x27, #72]
60: str x0, [x27, #80]
64: str x0, [x27, #88]
68: str x0, [x27, #96]
6c: str x0, [x27, #104]
70: str x0, [x27, #112]
74: str x0, [x27, #120]
78: str x0, [x27, #128]
7c: ldr x2, [x19, #8]
[...]
Signed-off-by: Xu Kuohai <[email protected]>
kernel-patches-bot
pushed a commit
that referenced
this pull request
Mar 23, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number. Therefore, this patch tries to
convert the offsets.
The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.
FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.
Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.
For example, for the following bpftrace command:
bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'
Without this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: mov x25, sp
1c: mov x26, #0x0 // #0
20: bti j
24: sub sp, sp, #0x90
28: add x19, x0, #0x0
2c: mov x0, #0x0 // #0
30: mov x10, #0xffffffffffffff78 // #-136
34: str x0, [x25, x10]
38: mov x10, #0xffffffffffffff80 // #-128
3c: str x0, [x25, x10]
40: mov x10, #0xffffffffffffff88 // #-120
44: str x0, [x25, x10]
48: mov x10, #0xffffffffffffff90 // #-112
4c: str x0, [x25, x10]
50: mov x10, #0xffffffffffffff98 // #-104
54: str x0, [x25, x10]
58: mov x10, #0xffffffffffffffa0 // #-96
5c: str x0, [x25, x10]
60: mov x10, #0xffffffffffffffa8 // #-88
64: str x0, [x25, x10]
68: mov x10, #0xffffffffffffffb0 // #-80
6c: str x0, [x25, x10]
70: mov x10, #0xffffffffffffffb8 // #-72
74: str x0, [x25, x10]
78: mov x10, #0xffffffffffffffc0 // #-64
7c: str x0, [x25, x10]
80: mov x10, #0xffffffffffffffc8 // #-56
84: str x0, [x25, x10]
88: mov x10, #0xffffffffffffffd0 // #-48
8c: str x0, [x25, x10]
90: mov x10, #0xffffffffffffffd8 // #-40
94: str x0, [x25, x10]
98: mov x10, #0xffffffffffffffe0 // #-32
9c: str x0, [x25, x10]
a0: mov x10, #0xffffffffffffffe8 // #-24
a4: str x0, [x25, x10]
a8: mov x10, #0xfffffffffffffff0 // #-16
ac: str x0, [x25, x10]
b0: mov x10, #0xfffffffffffffff8 // #-8
b4: str x0, [x25, x10]
b8: mov x10, #0x8 // #8
bc: ldr x2, [x19, x10]
[...]
With this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: stp x27, x28, [sp, #-16]!
1c: mov x25, sp
20: sub x27, x25, #0x88
24: mov x26, #0x0 // #0
28: bti j
2c: sub sp, sp, #0x90
30: add x19, x0, #0x0
34: mov x0, #0x0 // #0
38: str x0, [x27]
3c: str x0, [x27, #8]
40: str x0, [x27, #16]
44: str x0, [x27, #24]
48: str x0, [x27, #32]
4c: str x0, [x27, #40]
50: str x0, [x27, #48]
54: str x0, [x27, #56]
58: str x0, [x27, #64]
5c: str x0, [x27, #72]
60: str x0, [x27, #80]
64: str x0, [x27, #88]
68: str x0, [x27, #96]
6c: str x0, [x27, #104]
70: str x0, [x27, #112]
74: str x0, [x27, #120]
78: str x0, [x27, #128]
7c: ldr x2, [x19, #8]
[...]
Signed-off-by: Xu Kuohai <[email protected]>
kernel-patches-bot
pushed a commit
that referenced
this pull request
Mar 23, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number. Therefore, this patch tries to
convert the offsets.
The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.
FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.
Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.
For example, for the following bpftrace command:
bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'
Without this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: mov x25, sp
1c: mov x26, #0x0 // #0
20: bti j
24: sub sp, sp, #0x90
28: add x19, x0, #0x0
2c: mov x0, #0x0 // #0
30: mov x10, #0xffffffffffffff78 // #-136
34: str x0, [x25, x10]
38: mov x10, #0xffffffffffffff80 // #-128
3c: str x0, [x25, x10]
40: mov x10, #0xffffffffffffff88 // #-120
44: str x0, [x25, x10]
48: mov x10, #0xffffffffffffff90 // #-112
4c: str x0, [x25, x10]
50: mov x10, #0xffffffffffffff98 // #-104
54: str x0, [x25, x10]
58: mov x10, #0xffffffffffffffa0 // #-96
5c: str x0, [x25, x10]
60: mov x10, #0xffffffffffffffa8 // #-88
64: str x0, [x25, x10]
68: mov x10, #0xffffffffffffffb0 // #-80
6c: str x0, [x25, x10]
70: mov x10, #0xffffffffffffffb8 // #-72
74: str x0, [x25, x10]
78: mov x10, #0xffffffffffffffc0 // #-64
7c: str x0, [x25, x10]
80: mov x10, #0xffffffffffffffc8 // #-56
84: str x0, [x25, x10]
88: mov x10, #0xffffffffffffffd0 // #-48
8c: str x0, [x25, x10]
90: mov x10, #0xffffffffffffffd8 // #-40
94: str x0, [x25, x10]
98: mov x10, #0xffffffffffffffe0 // #-32
9c: str x0, [x25, x10]
a0: mov x10, #0xffffffffffffffe8 // #-24
a4: str x0, [x25, x10]
a8: mov x10, #0xfffffffffffffff0 // #-16
ac: str x0, [x25, x10]
b0: mov x10, #0xfffffffffffffff8 // #-8
b4: str x0, [x25, x10]
b8: mov x10, #0x8 // #8
bc: ldr x2, [x19, x10]
[...]
With this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: stp x27, x28, [sp, #-16]!
1c: mov x25, sp
20: sub x27, x25, #0x88
24: mov x26, #0x0 // #0
28: bti j
2c: sub sp, sp, #0x90
30: add x19, x0, #0x0
34: mov x0, #0x0 // #0
38: str x0, [x27]
3c: str x0, [x27, #8]
40: str x0, [x27, #16]
44: str x0, [x27, #24]
48: str x0, [x27, #32]
4c: str x0, [x27, #40]
50: str x0, [x27, #48]
54: str x0, [x27, #56]
58: str x0, [x27, #64]
5c: str x0, [x27, #72]
60: str x0, [x27, #80]
64: str x0, [x27, #88]
68: str x0, [x27, #96]
6c: str x0, [x27, #104]
70: str x0, [x27, #112]
74: str x0, [x27, #120]
78: str x0, [x27, #128]
7c: ldr x2, [x19, #8]
[...]
Signed-off-by: Xu Kuohai <[email protected]>
kernel-patches-bot
pushed a commit
that referenced
this pull request
Mar 24, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number. Therefore, this patch tries to
convert the offsets.
The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.
FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.
Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.
For example, for the following bpftrace command:
bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'
Without this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: mov x25, sp
1c: mov x26, #0x0 // #0
20: bti j
24: sub sp, sp, #0x90
28: add x19, x0, #0x0
2c: mov x0, #0x0 // #0
30: mov x10, #0xffffffffffffff78 // #-136
34: str x0, [x25, x10]
38: mov x10, #0xffffffffffffff80 // #-128
3c: str x0, [x25, x10]
40: mov x10, #0xffffffffffffff88 // #-120
44: str x0, [x25, x10]
48: mov x10, #0xffffffffffffff90 // #-112
4c: str x0, [x25, x10]
50: mov x10, #0xffffffffffffff98 // #-104
54: str x0, [x25, x10]
58: mov x10, #0xffffffffffffffa0 // #-96
5c: str x0, [x25, x10]
60: mov x10, #0xffffffffffffffa8 // #-88
64: str x0, [x25, x10]
68: mov x10, #0xffffffffffffffb0 // #-80
6c: str x0, [x25, x10]
70: mov x10, #0xffffffffffffffb8 // #-72
74: str x0, [x25, x10]
78: mov x10, #0xffffffffffffffc0 // #-64
7c: str x0, [x25, x10]
80: mov x10, #0xffffffffffffffc8 // #-56
84: str x0, [x25, x10]
88: mov x10, #0xffffffffffffffd0 // #-48
8c: str x0, [x25, x10]
90: mov x10, #0xffffffffffffffd8 // #-40
94: str x0, [x25, x10]
98: mov x10, #0xffffffffffffffe0 // #-32
9c: str x0, [x25, x10]
a0: mov x10, #0xffffffffffffffe8 // #-24
a4: str x0, [x25, x10]
a8: mov x10, #0xfffffffffffffff0 // #-16
ac: str x0, [x25, x10]
b0: mov x10, #0xfffffffffffffff8 // #-8
b4: str x0, [x25, x10]
b8: mov x10, #0x8 // #8
bc: ldr x2, [x19, x10]
[...]
With this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: stp x27, x28, [sp, #-16]!
1c: mov x25, sp
20: sub x27, x25, #0x88
24: mov x26, #0x0 // #0
28: bti j
2c: sub sp, sp, #0x90
30: add x19, x0, #0x0
34: mov x0, #0x0 // #0
38: str x0, [x27]
3c: str x0, [x27, #8]
40: str x0, [x27, #16]
44: str x0, [x27, #24]
48: str x0, [x27, #32]
4c: str x0, [x27, #40]
50: str x0, [x27, #48]
54: str x0, [x27, #56]
58: str x0, [x27, #64]
5c: str x0, [x27, #72]
60: str x0, [x27, #80]
64: str x0, [x27, #88]
68: str x0, [x27, #96]
6c: str x0, [x27, #104]
70: str x0, [x27, #112]
74: str x0, [x27, #120]
78: str x0, [x27, #128]
7c: ldr x2, [x19, #8]
[...]
Signed-off-by: Xu Kuohai <[email protected]>
kernel-patches-bot
pushed a commit
that referenced
this pull request
Mar 29, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number. Therefore, this patch tries to
convert the offsets.
The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.
FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.
Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.
For example, for the following bpftrace command:
bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'
Without this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: mov x25, sp
1c: mov x26, #0x0 // #0
20: bti j
24: sub sp, sp, #0x90
28: add x19, x0, #0x0
2c: mov x0, #0x0 // #0
30: mov x10, #0xffffffffffffff78 // #-136
34: str x0, [x25, x10]
38: mov x10, #0xffffffffffffff80 // #-128
3c: str x0, [x25, x10]
40: mov x10, #0xffffffffffffff88 // #-120
44: str x0, [x25, x10]
48: mov x10, #0xffffffffffffff90 // #-112
4c: str x0, [x25, x10]
50: mov x10, #0xffffffffffffff98 // #-104
54: str x0, [x25, x10]
58: mov x10, #0xffffffffffffffa0 // #-96
5c: str x0, [x25, x10]
60: mov x10, #0xffffffffffffffa8 // #-88
64: str x0, [x25, x10]
68: mov x10, #0xffffffffffffffb0 // #-80
6c: str x0, [x25, x10]
70: mov x10, #0xffffffffffffffb8 // #-72
74: str x0, [x25, x10]
78: mov x10, #0xffffffffffffffc0 // #-64
7c: str x0, [x25, x10]
80: mov x10, #0xffffffffffffffc8 // #-56
84: str x0, [x25, x10]
88: mov x10, #0xffffffffffffffd0 // #-48
8c: str x0, [x25, x10]
90: mov x10, #0xffffffffffffffd8 // #-40
94: str x0, [x25, x10]
98: mov x10, #0xffffffffffffffe0 // #-32
9c: str x0, [x25, x10]
a0: mov x10, #0xffffffffffffffe8 // #-24
a4: str x0, [x25, x10]
a8: mov x10, #0xfffffffffffffff0 // #-16
ac: str x0, [x25, x10]
b0: mov x10, #0xfffffffffffffff8 // #-8
b4: str x0, [x25, x10]
b8: mov x10, #0x8 // #8
bc: ldr x2, [x19, x10]
[...]
With this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: stp x27, x28, [sp, #-16]!
1c: mov x25, sp
20: sub x27, x25, #0x88
24: mov x26, #0x0 // #0
28: bti j
2c: sub sp, sp, #0x90
30: add x19, x0, #0x0
34: mov x0, #0x0 // #0
38: str x0, [x27]
3c: str x0, [x27, #8]
40: str x0, [x27, #16]
44: str x0, [x27, #24]
48: str x0, [x27, #32]
4c: str x0, [x27, #40]
50: str x0, [x27, #48]
54: str x0, [x27, #56]
58: str x0, [x27, #64]
5c: str x0, [x27, #72]
60: str x0, [x27, #80]
64: str x0, [x27, #88]
68: str x0, [x27, #96]
6c: str x0, [x27, #104]
70: str x0, [x27, #112]
74: str x0, [x27, #120]
78: str x0, [x27, #128]
7c: ldr x2, [x19, #8]
[...]
Signed-off-by: Xu Kuohai <[email protected]>
kernel-patches-bot
pushed a commit
that referenced
this pull request
Mar 31, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number. Therefore, this patch tries to
convert the offsets.
The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.
FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.
Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.
For example, for the following bpftrace command:
bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'
Without this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: mov x25, sp
1c: mov x26, #0x0 // #0
20: bti j
24: sub sp, sp, #0x90
28: add x19, x0, #0x0
2c: mov x0, #0x0 // #0
30: mov x10, #0xffffffffffffff78 // #-136
34: str x0, [x25, x10]
38: mov x10, #0xffffffffffffff80 // #-128
3c: str x0, [x25, x10]
40: mov x10, #0xffffffffffffff88 // #-120
44: str x0, [x25, x10]
48: mov x10, #0xffffffffffffff90 // #-112
4c: str x0, [x25, x10]
50: mov x10, #0xffffffffffffff98 // #-104
54: str x0, [x25, x10]
58: mov x10, #0xffffffffffffffa0 // #-96
5c: str x0, [x25, x10]
60: mov x10, #0xffffffffffffffa8 // #-88
64: str x0, [x25, x10]
68: mov x10, #0xffffffffffffffb0 // #-80
6c: str x0, [x25, x10]
70: mov x10, #0xffffffffffffffb8 // #-72
74: str x0, [x25, x10]
78: mov x10, #0xffffffffffffffc0 // #-64
7c: str x0, [x25, x10]
80: mov x10, #0xffffffffffffffc8 // #-56
84: str x0, [x25, x10]
88: mov x10, #0xffffffffffffffd0 // #-48
8c: str x0, [x25, x10]
90: mov x10, #0xffffffffffffffd8 // #-40
94: str x0, [x25, x10]
98: mov x10, #0xffffffffffffffe0 // #-32
9c: str x0, [x25, x10]
a0: mov x10, #0xffffffffffffffe8 // #-24
a4: str x0, [x25, x10]
a8: mov x10, #0xfffffffffffffff0 // #-16
ac: str x0, [x25, x10]
b0: mov x10, #0xfffffffffffffff8 // #-8
b4: str x0, [x25, x10]
b8: mov x10, #0x8 // #8
bc: ldr x2, [x19, x10]
[...]
With this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: stp x27, x28, [sp, #-16]!
1c: mov x25, sp
20: sub x27, x25, #0x88
24: mov x26, #0x0 // #0
28: bti j
2c: sub sp, sp, #0x90
30: add x19, x0, #0x0
34: mov x0, #0x0 // #0
38: str x0, [x27]
3c: str x0, [x27, #8]
40: str x0, [x27, #16]
44: str x0, [x27, #24]
48: str x0, [x27, #32]
4c: str x0, [x27, #40]
50: str x0, [x27, #48]
54: str x0, [x27, #56]
58: str x0, [x27, #64]
5c: str x0, [x27, #72]
60: str x0, [x27, #80]
64: str x0, [x27, #88]
68: str x0, [x27, #96]
6c: str x0, [x27, #104]
70: str x0, [x27, #112]
74: str x0, [x27, #120]
78: str x0, [x27, #128]
7c: ldr x2, [x19, #8]
[...]
Signed-off-by: Xu Kuohai <[email protected]>
kernel-patches-bot
pushed a commit
that referenced
this pull request
Mar 31, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number. Therefore, this patch tries to
convert the offsets.
The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.
FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.
Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.
For example, for the following bpftrace command:
bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'
Without this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: mov x25, sp
1c: mov x26, #0x0 // #0
20: bti j
24: sub sp, sp, #0x90
28: add x19, x0, #0x0
2c: mov x0, #0x0 // #0
30: mov x10, #0xffffffffffffff78 // #-136
34: str x0, [x25, x10]
38: mov x10, #0xffffffffffffff80 // #-128
3c: str x0, [x25, x10]
40: mov x10, #0xffffffffffffff88 // #-120
44: str x0, [x25, x10]
48: mov x10, #0xffffffffffffff90 // #-112
4c: str x0, [x25, x10]
50: mov x10, #0xffffffffffffff98 // #-104
54: str x0, [x25, x10]
58: mov x10, #0xffffffffffffffa0 // #-96
5c: str x0, [x25, x10]
60: mov x10, #0xffffffffffffffa8 // #-88
64: str x0, [x25, x10]
68: mov x10, #0xffffffffffffffb0 // #-80
6c: str x0, [x25, x10]
70: mov x10, #0xffffffffffffffb8 // #-72
74: str x0, [x25, x10]
78: mov x10, #0xffffffffffffffc0 // #-64
7c: str x0, [x25, x10]
80: mov x10, #0xffffffffffffffc8 // #-56
84: str x0, [x25, x10]
88: mov x10, #0xffffffffffffffd0 // #-48
8c: str x0, [x25, x10]
90: mov x10, #0xffffffffffffffd8 // #-40
94: str x0, [x25, x10]
98: mov x10, #0xffffffffffffffe0 // #-32
9c: str x0, [x25, x10]
a0: mov x10, #0xffffffffffffffe8 // #-24
a4: str x0, [x25, x10]
a8: mov x10, #0xfffffffffffffff0 // #-16
ac: str x0, [x25, x10]
b0: mov x10, #0xfffffffffffffff8 // #-8
b4: str x0, [x25, x10]
b8: mov x10, #0x8 // #8
bc: ldr x2, [x19, x10]
[...]
With this patch, jited code(fragment):
0: bti c
4: stp x29, x30, [sp, #-16]!
8: mov x29, sp
c: stp x19, x20, [sp, #-16]!
10: stp x21, x22, [sp, #-16]!
14: stp x25, x26, [sp, #-16]!
18: stp x27, x28, [sp, #-16]!
1c: mov x25, sp
20: sub x27, x25, #0x88
24: mov x26, #0x0 // #0
28: bti j
2c: sub sp, sp, #0x90
30: add x19, x0, #0x0
34: mov x0, #0x0 // #0
38: str x0, [x27]
3c: str x0, [x27, #8]
40: str x0, [x27, #16]
44: str x0, [x27, #24]
48: str x0, [x27, #32]
4c: str x0, [x27, #40]
50: str x0, [x27, #48]
54: str x0, [x27, #56]
58: str x0, [x27, #64]
5c: str x0, [x27, #72]
60: str x0, [x27, #80]
64: str x0, [x27, #88]
68: str x0, [x27, #96]
6c: str x0, [x27, #104]
70: str x0, [x27, #112]
74: str x0, [x27, #120]
78: str x0, [x27, #128]
7c: ldr x2, [x19, #8]
[...]
Signed-off-by: Xu Kuohai <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
kernel-patches-daemon-bpf-rc bot
pushed a commit
that referenced
this pull request
Apr 11, 2023
powerpc sets up PF_KTHREAD and PF_IO_WORKER with a NULL pt_regs, which from my (arguably very short) checking is not commonly done for other archs. This is fine, except when PF_IO_WORKER's have been created and the task does something that causes a coredump to be generated. Then we get this crash: Kernel attempted to read user page (160) - exploit attempt? (uid: 1000) BUG: Kernel NULL pointer dereference on read at 0x00000160 Faulting instruction address: 0xc0000000000c3a60 Oops: Kernel access of bad area, sig: 11 [#1] LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=32 NUMA pSeries Modules linked in: bochs drm_vram_helper drm_kms_helper xts binfmt_misc ecb ctr syscopyarea sysfillrect cbc sysimgblt drm_ttm_helper aes_generic ttm sg libaes evdev joydev virtio_balloon vmx_crypto gf128mul drm dm_mod fuse loop configfs drm_panel_orientation_quirks ip_tables x_tables autofs4 hid_generic usbhid hid xhci_pci xhci_hcd usbcore usb_common sd_mod CPU: 1 PID: 1982 Comm: ppc-crash Not tainted 6.3.0-rc2+ #88 Hardware name: IBM pSeries (emulated by qemu) POWER9 (raw) 0x4e1202 0xf000005 of:SLOF,HEAD hv:linux,kvm pSeries NIP: c0000000000c3a60 LR: c000000000039944 CTR: c0000000000398e0 REGS: c0000000041833b0 TRAP: 0300 Not tainted (6.3.0-rc2+) MSR: 800000000280b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE> CR: 88082828 XER: 200400f8 ... NIP memcpy_power7+0x200/0x7d0 LR ppr_get+0x64/0xb0 Call Trace: ppr_get+0x40/0xb0 (unreliable) __regset_get+0x180/0x1f0 regset_get_alloc+0x64/0x90 elf_core_dump+0xb98/0x1b60 do_coredump+0x1c34/0x24a0 get_signal+0x71c/0x1410 do_notify_resume+0x140/0x6f0 interrupt_exit_user_prepare_main+0x29c/0x320 interrupt_exit_user_prepare+0x6c/0xa0 interrupt_return_srr_user+0x8/0x138 Because ppr_get() is trying to copy from a PF_IO_WORKER with a NULL pt_regs. Check for a valid pt_regs in both ppc_get/ppr_set, and return an error if not set. The actual error value doesn't seem to be important here, so just pick -EINVAL. Fixes: fa43981 ("powerpc/ptrace: Enable support for NT_PPPC_TAR, NT_PPC_PPR, NT_PPC_DSCR") Cc: [email protected] # v4.8+ Signed-off-by: Jens Axboe <[email protected]> [mpe: Trim oops in change log, add Fixes & Cc stable] Signed-off-by: Michael Ellerman <[email protected]> Link: https://msgid.link/[email protected]
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Pull request for series with
subject: libbpf: ensure F_DUPFD_CLOEXEC is defined
version: 1
url: https://patchwork.kernel.org/project/netdevbpf/list/?series=618422