Messages in this thread | | | Subject | Re: mprotect() failed: Cannot allocate memory | From | Yann Droneaud <> | Date | Wed, 21 Apr 2010 10:22:19 +0200 |
| |
Le mercredi 21 avril 2010 à 01:44 +0200, Paweł Sikora a écrit : > On Wednesday 21 April 2010 01:17:22 Mike Frysinger wrote: > > On Tuesday 20 April 2010 19:05:20 Paweł Sikora wrote: > > > i'm trying to debug an ugly application with ElectricFence. > > > > electricfence does a lot of ugly memory tricks to do its thing, including, > > but not limited to, overriding memory related symbols. best to seek help > > from the electricfence authors. > > so, let's avoid EF and run following test: > > #include <stdio.h> > #include <stdlib.h> > #include <unistd.h> > #include <sys/mman.h> > > void* my_alloc( size_t n ) > { > size_t ps = getpagesize(); > printf( "request for %Zd bytes => ", n ); > /* alloc PAGE_SIZE + n */ > char* p = mmap( 0, ps + n, PROT_READ | PROT_WRITE, MAP_SHARED | > MAP_ANONYMOUS, -1, 0 ); > if ( p == MAP_FAILED ) > __builtin_abort(); > /* block guard page */ > int rc = mprotect( p, ps, PROT_NONE ); > if ( rc != 0 ) > __builtin_abort(); > char* q = p + ps; > printf( "guard page @ %p, allocated region @ %p\n", p, q ); > return q; > } > > int main() > { > #define N 100 > size_t NN = 4*100*100; > size_t kmax = 100; > int i; > > double **bm = (double **)my_alloc( NN * sizeof( double* ) ); > for( i = 0; i < NN; ++i ) > { > bm[ i ] = (double*)my_alloc( kmax * sizeof( double ) ); > } > // leak... > return 0; > } > > and the result is... > > (...) > mmap(NULL, 4896, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_ANONYMOUS, -1, 0) = > 0x7f5fd97df000 > mprotect(0x7f5fd97df000, 4096, PROT_NONE) = -1 ENOMEM (Cannot allocate memory)
Have you checked available memory on your system ? Or user limit ?
You test program is going to allocate 79 + 1 pages for bm 1 + 1 for each double arrays (x 40000)
So in the end your program is allocating 80080 pages, so about 312MBytes.
It not that big for a 64bits system.
Check limits such as -d the maximum size of a process's data segment -l the maximum size a process may lock into memory -m the maximum resident set size
Regards.
-- Yann Droneaud
-- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |