[Bug sanitizer/84285] New: Fail to statically link with -fsanitize=undefined

[marcandre.lureau at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84285

Bug ID: 84285
   Summary: Fail to statically link with -fsanitize=undefined
   Product: gcc
   Version: unknown
Status: UNCONFIRMED
  Severity: normal
  Priority: P3
 Component: sanitizer
  Assignee: unassigned at gcc dot gnu.org
  Reporter: marcandre.lureau at gmail dot com
CC: dodji at gcc dot gnu.org, dvyukov at gcc dot gnu.org,
jakub at gcc dot gnu.org, kcc at gcc dot gnu.org, marxin at 
gcc dot gnu.org
  Target Milestone: ---

With gcc (GCC) 7.2.1 20170915 (Red Hat 7.2.1-2) (fedora 27)

int main(int argc, char **argv) {
  int k = 0x7fff;
  k += argc;
  return 0;
}

$ clang -static -fsanitize=undefined test.c

vs

$ gcc -static -fsanitize=undefined test.c
/usr/lib/gcc/x86_64-redhat-linux/7/libubsan.a(sanitizer_linux_libcdep.o): In
function `__sanitizer::GetThreadStackTopAndBottom(bool, unsigned long*,
unsigned long*)':
(.text+0x551): undefined reference to `pthread_attr_init'
(.text+0x556): undefined reference to `pthread_self'
(.text+0x561): undefined reference to `pthread_getattr_np'
(.text+0x599): undefined reference to `pthread_attr_destroy'
/usr/lib/gcc/x86_64-redhat-linux/7/libubsan.a(sanitizer_linux_libcdep.o): In
function `__sanitizer::SetEnv(char const*, char const*)':
(.text+0x70b): undefined reference to `dlsym'
/usr/lib/gcc/x86_64-redhat-linux/7/libubsan.a(sanitizer_linux_libcdep.o): In
function `__sanitizer::InitTlsSize()':
(.text+0x843): undefined reference to `dlsym'
/usr/lib/gcc/x86_64-redhat-linux/7/libubsan.a(sanitizer_posix_libcdep.o): In
function `__sanitizer::GetNamedMappingFd(char const*, unsigned long)':
(.text+0x747): undefined reference to `shm_open'
(.text+0x763): undefined reference to `shm_unlink'
/usr/lib/gcc/x86_64-redhat-linux/7/libubsan.a(sanitizer_posix_libcdep.o): In
function `__sanitizer::AdjustStackSize(void*)':
(.text+0xa8f): undefined reference to `pthread_attr_setstacksize'
/usr/lib/gcc/x86_64-redhat-linux/7/libubsan.a(sanitizer_posix_libcdep.o): In
function `__sanitizer::GetThreadSelf()':
(.text+0x1d1): undefined reference to `pthread_self'
/usr/lib/gcc/x86_64-redhat-linux/7/libubsan.a(sanitizer_posix_libcdep.o): In
function `__sanitizer::my_pthread_attr_getstack(void*, void**, unsigned
long*)':
(.text+0x9b1): undefined reference to `pthread_attr_getstack'
/usr/lib/gcc/x86_64-redhat-linux/7/libubsan.a(sanitizer_symbolizer_posix_libcdep.o):
In function `__sanitizer::Symbolizer::LateInitialize()':
(.text+0x7e3): undefined reference to `dlsym'
collect2: error: ld returned 1 exit status

[Bug sanitizer/84285] Fail to statically link with -fsanitize=undefined

[marcandre.lureau at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84285

--- Comment #4 from Marc-André Lureau  ---
(In reply to Jakub Jelinek from comment #3)
> Created attachment 43371 [details]
> gcc8-pr84285.patch
> 
> Untested fix.

Thanks
patch texted successfully.

[Bug c/105080] New: Bugus -Wformat-truncation

[marcandre.lureau at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105080

Bug ID: 105080
   Summary: Bugus -Wformat-truncation
   Product: gcc
   Version: 12.0
Status: UNCONFIRMED
  Severity: normal
  Priority: P3
 Component: c
  Assignee: unassigned at gcc dot gnu.org
  Reporter: marcandre.lureau at gmail dot com
  Target Milestone: ---

With Fedora gcc-12.0.1-0.12.fc36.x86_64
gcc (GCC) 12.0.1 20220308 (Red Hat 12.0.1-0)

test.c:

#include 

void main(void)
{
char foo[3];
int i;

for (i = 0; i < 16; i++) {
snprintf(foo, sizeof(foo), "%d", i);
}
}


$ gcc -Wformat-truncation test.c
test.c: In function ‘main’:
test.c:9:45: warning: ‘%d’ directive output may be truncated writing between 1
and 11 bytes into a region of size 3 [-Wformat-truncation=]
9 | snprintf(foo, sizeof(foo), "%d", i);
  | ^~
test.c:9:44: note: directive argument in the range [-2147483647, 15]
9 | snprintf(foo, sizeof(foo), "%d", i);
  |^~~~
test.c:9:17: note: ‘snprintf’ output between 2 and 12 bytes into a destination
of size 3
9 | snprintf(foo, sizeof(foo), "%d", i);
  | ^~~



The computed range seems incorrect. There are similar variants of this bug that
have been found while compiling QEMU
(https://patchew.org/QEMU/20220328084717.367993-1-marcandre.lur...@redhat.com/)

[Bug sanitizer/113304] New: zero-length array and bound checking error

[marcandre.lureau at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113304

Bug ID: 113304
   Summary: zero-length array and bound checking error
   Product: gcc
   Version: 13.2.1
Status: UNCONFIRMED
  Severity: normal
  Priority: P3
 Component: sanitizer
  Assignee: unassigned at gcc dot gnu.org
  Reporter: marcandre.lureau at gmail dot com
CC: dodji at gcc dot gnu.org, dvyukov at gcc dot gnu.org,
jakub at gcc dot gnu.org, kcc at gcc dot gnu.org, marxin at 
gcc dot gnu.org
  Target Milestone: ---

gcc (GCC) 13.2.1 20231205 (Red Hat 13.2.1-6)

gcc -fsanitize=bounds-strict -lubsan test.c

test.c:6:11: runtime error: index 3 out of bounds for type 'int [*]'

typedef struct BN {
int d[0];
} BN;

void test(BN *foo) {
foo->d[3] = 0;
}

int main(int argc, char *argv[])
{
struct BN {
int d[4];
} foo;

test((BN *)&foo);

return 0;
}



This coding style is used in bignum libraries, such as libtpms BN
implementation. Is this incompatible with bounds-strict usage?