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bpf, selftests: Fix cast to smaller integer type 'int' warning in raw_tp #124

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Pull request for series with
subject: bpf, selftests: Fix cast to smaller integer type 'int' warning in raw_tp
version: 1
url: https://patchwork.ozlabs.org/project/netdev/list/?series=204714

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Master branch: 98b972d
series: https://patchwork.ozlabs.org/project/netdev/list/?series=204714
version: 1

kernel-patches-bot and others added 2 commits September 28, 2020 19:35
Fix warning in bpf selftests,

progs/test_raw_tp_test_run.c:18:10: warning: cast to smaller integer type 'int' from 'struct task_struct *' [-Wpointer-to-int-cast]

Change int type cast to long to fix. Discovered with gcc-9 and llvm-11+
where llvm was recent main branch.

Fixes: 09d8ad1 ("selftests/bpf: Add raw_tp_test_run")
Signed-off-by: John Fastabend <[email protected]>
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Master branch: bc60090
series: https://patchwork.ozlabs.org/project/netdev/list/?series=204714
version: 1

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At least one diff in series https://patchwork.ozlabs.org/project/netdev/list/?series=204714 irrelevant now. Closing PR.

@kernel-patches-bot kernel-patches-bot deleted the series/204714=>bpf-next branch September 30, 2020 16:13
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Jun 25, 2023
[BUG]
David reported an ASSERT() get triggered during fio load on 8 devices
with data/raid6 and metadata/raid1c3:

  fio --rw=randrw --randrepeat=1 --size=3000m \
	  --bsrange=512b-64k --bs_unaligned \
	  --ioengine=libaio --fsync=1024 \
	  --name=job0 --name=job1 \

The ASSERT() is from rbio_add_bio() of raid56.c:

	ASSERT(orig_logical >= full_stripe_start &&
	       orig_logical + orig_len <= full_stripe_start +
	       rbio->nr_data * BTRFS_STRIPE_LEN);

Which is checking if the target rbio is crossing the full stripe
boundary.

  [100.789] assertion failed: orig_logical >= full_stripe_start && orig_logical + orig_len <= full_stripe_start + rbio->nr_data * BTRFS_STRIPE_LEN, in fs/btrfs/raid56.c:1622
  [100.795] ------------[ cut here ]------------
  [100.796] kernel BUG at fs/btrfs/raid56.c:1622!
  [100.797] invalid opcode: 0000 [#1] PREEMPT SMP KASAN
  [100.798] CPU: 1 PID: 100 Comm: kworker/u8:4 Not tainted 6.4.0-rc6-default+ #124
  [100.799] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552-rebuilt.opensuse.org 04/01/2014
  [100.802] Workqueue: writeback wb_workfn (flush-btrfs-1)
  [100.803] RIP: 0010:rbio_add_bio+0x204/0x210 [btrfs]
  [100.806] RSP: 0018:ffff888104a8f300 EFLAGS: 00010246
  [100.808] RAX: 00000000000000a1 RBX: ffff8881075907e0 RCX: ffffed1020951e01
  [100.809] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000001
  [100.811] RBP: 0000000141d20000 R08: 0000000000000001 R09: ffff888104a8f04f
  [100.813] R10: ffffed1020951e09 R11: 0000000000000003 R12: ffff88810e87f400
  [100.815] R13: 0000000041d20000 R14: 0000000144529000 R15: ffff888101524000
  [100.817] FS:  0000000000000000(0000) GS:ffff88811ac00000(0000) knlGS:0000000000000000
  [100.821] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [100.822] CR2: 000055d54e44c270 CR3: 000000010a9a1006 CR4: 00000000003706a0
  [100.824] Call Trace:
  [100.825]  <TASK>
  [100.825]  ? die+0x32/0x80
  [100.826]  ? do_trap+0x12d/0x160
  [100.827]  ? rbio_add_bio+0x204/0x210 [btrfs]
  [100.827]  ? rbio_add_bio+0x204/0x210 [btrfs]
  [100.829]  ? do_error_trap+0x90/0x130
  [100.830]  ? rbio_add_bio+0x204/0x210 [btrfs]
  [100.831]  ? handle_invalid_op+0x2c/0x30
  [100.833]  ? rbio_add_bio+0x204/0x210 [btrfs]
  [100.835]  ? exc_invalid_op+0x29/0x40
  [100.836]  ? asm_exc_invalid_op+0x16/0x20
  [100.837]  ? rbio_add_bio+0x204/0x210 [btrfs]
  [100.837]  raid56_parity_write+0x64/0x270 [btrfs]
  [100.838]  btrfs_submit_chunk+0x26e/0x800 [btrfs]
  [100.840]  ? btrfs_bio_init+0x80/0x80 [btrfs]
  [100.841]  ? release_pages+0x503/0x6d0
  [100.842]  ? folio_unlock+0x2f/0x60
  [100.844]  ? __folio_put+0x60/0x60
  [100.845]  ? btrfs_do_readpage+0xae0/0xae0 [btrfs]
  [100.847]  btrfs_submit_bio+0x21/0x60 [btrfs]
  [100.847]  submit_one_bio+0x6a/0xb0 [btrfs]
  [100.849]  extent_write_cache_pages+0x395/0x680 [btrfs]
  [100.850]  ? __extent_writepage+0x520/0x520 [btrfs]
  [100.851]  ? mark_usage+0x190/0x190
  [100.852]  extent_writepages+0xdb/0x130 [btrfs]
  [100.853]  ? extent_write_locked_range+0x480/0x480 [btrfs]
  [100.854]  ? mark_usage+0x190/0x190
  [100.854]  ? attach_extent_buffer_page+0x220/0x220 [btrfs]
  [100.855]  ? reacquire_held_locks+0x178/0x280
  [100.856]  ? writeback_sb_inodes+0x245/0x7f0
  [100.857]  do_writepages+0x102/0x2e0
  [100.858]  ? page_writeback_cpu_online+0x10/0x10
  [100.859]  ? __lock_release.isra.0+0x14a/0x4d0
  [100.860]  ? reacquire_held_locks+0x280/0x280
  [100.861]  ? __lock_acquired+0x1e9/0x3d0
  [100.862]  ? do_raw_spin_lock+0x1b0/0x1b0
  [100.863]  __writeback_single_inode+0x94/0x450
  [100.864]  writeback_sb_inodes+0x372/0x7f0
  [100.864]  ? lock_sync+0xd0/0xd0
  [100.865]  ? do_raw_spin_unlock+0x93/0xf0
  [100.866]  ? sync_inode_metadata+0xc0/0xc0
  [100.867]  ? rwsem_optimistic_spin+0x340/0x340
  [100.868]  __writeback_inodes_wb+0x70/0x130
  [100.869]  wb_writeback+0x2d1/0x530
  [100.869]  ? __writeback_inodes_wb+0x130/0x130
  [100.870]  ? lockdep_hardirqs_on_prepare.part.0+0xf1/0x1c0
  [100.870]  wb_do_writeback+0x3eb/0x480
  [100.871]  ? wb_writeback+0x530/0x530
  [100.871]  ? mark_lock_irq+0xcd0/0xcd0
  [100.872]  wb_workfn+0xe0/0x3f0<

[CAUSE]
Commit a97699d ("btrfs: replace map_lookup->stripe_len by
BTRFS_STRIPE_LEN") changes how we calculate the map length, to reduce
u64 division.

Function btrfs_max_io_len() is to get the length to the stripe boundary.

It calculates the full stripe start offset (inside the chunk) by the
following code:

		*full_stripe_start =
			rounddown(*stripe_nr, nr_data_stripes(map)) <<
			BTRFS_STRIPE_LEN_SHIFT;

The calculation itself is fine, but the value returned by rounddown() is
dependent on both @stripe_nr (which is u32) and nr_data_stripes() (which
returned int).

Thus the result is also u32, then we do the left shift, which can
overflow u32.

If such overflow happens, @full_stripe_start will be a value way smaller
than @offset, causing later "full_stripe_len - (offset -
*full_stripe_start)" to underflow, thus make later length calculation to
have no stripe boundary limit, resulting a write bio to exceed stripe
boundary.

There are some other locations like this, with a u32 @stripe_nr got left
shift, which can lead to a similar overflow.

[FIX]
Fix all @stripe_nr with left shift with a type cast to u64 before the
left shift.

Those involved @stripe_nr or similar variables are recording the stripe
number inside the chunk, which is small enough to be contained by u32,
but their offset inside the chunk can not fit into u32.

Thus for those specific left shifts, a type cast to u64 is necessary so
this patch does not touch them and the code will be cleaned up in the
future to keep the fix minimal.

Reported-by: David Sterba <[email protected]>
Fixes: a97699d ("btrfs: replace map_lookup->stripe_len by BTRFS_STRIPE_LEN")
Tested-by: David Sterba <[email protected]>
Signed-off-by: Qu Wenruo <[email protected]>
Signed-off-by: David Sterba <[email protected]>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Jan 26, 2024
Like commit 1cf3bfc ("bpf: Support 64-bit pointers to kfuncs")
for s390x, add support for 64-bit pointers to kfuncs for LoongArch.
Since the infrastructure is already implemented in BPF core, the only
thing need to be done is to override bpf_jit_supports_far_kfunc_call().

Before this change, several test_verifier tests failed:

  # ./test_verifier | grep # | grep FAIL
  #119/p calls: invalid kfunc call: ptr_to_mem to struct with non-scalar FAIL
  #120/p calls: invalid kfunc call: ptr_to_mem to struct with nesting depth > 4 FAIL
  #121/p calls: invalid kfunc call: ptr_to_mem to struct with FAM FAIL
  #122/p calls: invalid kfunc call: reg->type != PTR_TO_CTX FAIL
  #123/p calls: invalid kfunc call: void * not allowed in func proto without mem size arg FAIL
  #124/p calls: trigger reg2btf_ids[reg->type] for reg->type > __BPF_REG_TYPE_MAX FAIL
  #125/p calls: invalid kfunc call: reg->off must be zero when passed to release kfunc FAIL
  #126/p calls: invalid kfunc call: don't match first member type when passed to release kfunc FAIL
  #127/p calls: invalid kfunc call: PTR_TO_BTF_ID with negative offset FAIL
  #128/p calls: invalid kfunc call: PTR_TO_BTF_ID with variable offset FAIL
  #129/p calls: invalid kfunc call: referenced arg needs refcounted PTR_TO_BTF_ID FAIL
  #130/p calls: valid kfunc call: referenced arg needs refcounted PTR_TO_BTF_ID FAIL
  #486/p map_kptr: ref: reference state created and released on xchg FAIL

This is because the kfuncs in the loaded module are far away from
__bpf_call_base:

  ffff800002009440 t bpf_kfunc_call_test_fail1    [bpf_testmod]
  9000000002e128d8 T __bpf_call_base

The offset relative to __bpf_call_base does NOT fit in s32, which breaks
the assumption in BPF core. Enable bpf_jit_supports_far_kfunc_call() lifts
this limit.

Note that to reproduce the above result, tools/testing/selftests/bpf/config
should be applied, and run the test with JIT enabled, unpriv BPF enabled.

With this change, the test_verifier tests now all passed:

  # ./test_verifier
  ...
  Summary: 777 PASSED, 0 SKIPPED, 0 FAILED

Tested-by: Tiezhu Yang <[email protected]>
Signed-off-by: Hengqi Chen <[email protected]>
Signed-off-by: Huacai Chen <[email protected]>
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