gemv no check on internal buffer size

[juliantaylor]

following script exceeds the internal buffer (16MB on x86, 32MB on x86_64) and just segfaults on x86 and x86_64
there is no check if the number of rows exceeds the internal buffer in interface/gemv.c

#include <math.h>
#include <assert.h>
#include <stdlib.h>
#include <stdio.h>
typedef long blasint;
void sgemv_(char *, blasint *, blasint *, float *, float *, blasint *,  
            float *, blasint *, float *, float *, blasint *); 


int main(int argc, const char *argv[])
{   
    // increase here to exceed your archs buffer
    blasint row = 17*1024*1024/sizeof(float);
    blasint col = 1;
    blasint stride1 = 1;
    float al2 = 1;
    float bl2 = 0;
    float * a2 = malloc(row*col*sizeof(float));
    float * b2 = malloc(row*sizeof(float));
    float * v2 = malloc(row*sizeof(float));
    assert(a2);
    assert(b2);
    assert(v2);
    for (int i = 0; i < row*col; i++)
        a2[i] = 1;
    for (int i = 0; i < row; i++) {
        b2[i] = 1;
        v2[i] = 0;
    }   
    printf("%d %gMB\n", row*sizeof(float), row*sizeof(float)/1024./1024.);
    sgemv_("T", &row, &col, &al2, a2, &row,  
            b2, &stride1, &bl2, v2, &stride1); 
    printf("%g\n",v2[0] - (float)row*col);
    return 0;
}   

[juliantaylor]

seems to be similar to gh-154

[juliantaylor]

on x86_64 only seems to crash when threads are used (in kernel/x86_64/sgemv_t.S)
on 32bit x86 it crashes with and without threads in kernel/x86/gemv_t_sse.S

[xianyi]

Hi @juliantaylor ,

Could you test it ?

Thank you

Xianyi

[juliantaylor]

64bit seems to work now but 32 bit still crashes with a segmentation fault in kernel/x86/gemv_t_sse.S:214

[xianyi]

Hi @juliantaylor ,

We fixed sgemv_t bug on x86. Now, it can pass your codes. Meanwhile, we also fixed the similar bug in gemv_n

XIanyi

[juliantaylor]

thanks, it now also works in 32bit

[juliantaylor]

see gh-154 for a testcase that still crashes on i386