[Bug general/29141] New: _FORTIFY_SOURCE=3 fail for gcc 12/glibc 2.35

[ptr--- via Elfutils-devel]

https://sourceware.org/bugzilla/show_bug.cgi?id=29141

Bug ID: 29141
   Summary: _FORTIFY_SOURCE=3 fail for gcc 12/glibc 2.35
   Product: elfutils
   Version: unspecified
Status: UNCONFIRMED
  Severity: normal
  Priority: P2
 Component: general
  Assignee: unassigned at sourceware dot org
  Reporter: p...@void-ptr.info
CC: elfutils-devel at sourceware dot org
  Target Milestone: ---

Hi,

_FORTIFY_SOURCE=3 fail to compile with gcc 12/glibc 2.35.

Used:
  (GCC) 12.0.1 20220504 (prerelease)
  glibc ec5b79aac768 (release/2.35/master)


In file included from /x86_64-unknown-linux-gnu/usr/include/features.h:490,
 from .../x86_64-unknown-linux-gnu/usr/include/assert.h:35,
 from elf_getarsym.c:34:
In function ‘pread’,
inlined from ‘pread_retry’ at ../lib/system.h:188:21,
inlined from ‘read_number_entries’ at elf_getarsym.c:63:21,
inlined from ‘elf_getarsym’ at elf_getarsym.c:172:11:
/x86_64-unknown-linux-gnu/usr/include/bits/unistd.h:74:10: error:
‘__pread_alias’ specified size between 9223372036854775813 and
18446744073709551615 exceeds maximum object size 9223372036854775807
[-Werror=stringop-overflow=]
   74 |   return __glibc_fortify (pread, __nbytes, sizeof (char),
  |  ^~~
elf_getarsym.c: In function ‘elf_getarsym’:
elf_getarsym.c:56:5: note: destination object allocated here
   56 |   } u;
  | ^
/x86_64-unknown-linux-gnu/usr/include/bits/unistd.h:50:16: note: in a call
to function ‘__pread_alias’ declared with attribute ‘access (write_only, 2, 3)’
   50 | extern ssize_t __REDIRECT (__pread_alias,
  |^~


In file included from /x86_64-unknown-linux-gnu/usr/include/features.h:490,
 from /x86_64-unknown-linux-gnu/usr/include/assert.h:35,
 from elf_getarsym.c:34:
In function ‘pread’,
inlined from ‘pread_retry’ at ../lib/system.h:188:21,
inlined from ‘read_number_entries’ at elf_getarsym.c:63:21,
inlined from ‘elf_getarsym’ at elf_getarsym.c:172:11:
.../x86_64-unknown-linux-gnu/usr/include/bits/unistd.h:74:10: error:
‘__pread_alias’ specified size between 9223372036854775813 and
18446744073709551615 exceeds maximum object size 9223372036854775807
[-Werror=stringop-overflow=]
   74 |   return __glibc_fortify (pread, __nbytes, sizeof (char),
  |  ^~~
elf_getarsym.c: In function ‘elf_getarsym’:
elf_getarsym.c:56:5: note: destination object allocated here
   56 |   } u;
  | ^
.../x86_64-unknown-linux-gnu/usr/include/bits/unistd.h:50:16: note: in a call
to function ‘__pread_alias’ declared with attribute ‘access (write_only, 2, 3)’
   50 | extern ssize_t __REDIRECT (__pread_alias,


Lower level (_FORTIFY_SOURCE=2) compiled fine.

Tricks similar to suggested in
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91397
not help: warning disappear only when I set wrong condition

  if (w >= sizeof(u))
__builtin_unreachable();

(should be w > sizeof(u)).

--

   - ptr

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[Bug libc/29141] _FORTIFY_SOURCE=3 fail for gcc 12/glibc 2.35

[ptr--- via Elfutils-devel]

https://sourceware.org/bugzilla/show_bug.cgi?id=29141

Petr Ovtchenkov  changed:

   What|Removed |Added

Version|2.36|2.35

--- Comment #4 from Petr Ovtchenkov  ---
The glibc in this issue is ec5b79aac768, so c8ee1c85c07b already here.

Don't worry about distros, VCS is primary source.

glibc is on release/2.35/master, so reference to 2.36 is not correct, IMO.

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[Bug libc/29141] _FORTIFY_SOURCE=3 fail for gcc 12/glibc 2.35

[ptr--- via Elfutils-devel]

https://sourceware.org/bugzilla/show_bug.cgi?id=29141

--- Comment #5 from Petr Ovtchenkov  ---
Hmm. c8ee1c8 not correspond to diff you show above.

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