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| author | Siddhesh Poyarekar <siddhesh@sourceware.org> | 2022-05-13 10:01:47 +0530 |
|---|---|---|
| committer | Siddhesh Poyarekar <siddhesh@sourceware.org> | 2022-05-16 20:10:08 +0530 |
| commit | 61a87530108ec9181e1b18a9b727ec3cc3ba7532 (patch) | |
| tree | 087b65df424e96ee17fe07459dd92044ea03bdd9 /misc | |
| parent | 0b6c6750732483b4d59c2fcb45484079cd84157d (diff) | |
| download | glibc-61a87530108ec9181e1b18a9b727ec3cc3ba7532.tar.gz glibc-61a87530108ec9181e1b18a9b727ec3cc3ba7532.tar.xz glibc-61a87530108ec9181e1b18a9b727ec3cc3ba7532.zip | |
fortify: Ensure that __glibc_fortify condition is a constant [BZ #29141]
The fix c8ee1c85 introduced a -1 check for object size without also checking that object size is a constant. Because of this, the tree optimizer passes in gcc fail to fold away one of the branches in __glibc_fortify and trips on a spurious Wstringop-overflow. The warning itself is incorrect and the branch does go away eventually in DCE in the rtl passes in gcc, but the constant check is a helpful hint to simplify code early, so add it in. Resolves: BZ #29141 Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Diffstat (limited to 'misc')
| -rw-r--r-- | misc/sys/cdefs.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/misc/sys/cdefs.h b/misc/sys/cdefs.h index f1faf8292c..1c2b044a0d 100644 --- a/misc/sys/cdefs.h +++ b/misc/sys/cdefs.h @@ -164,7 +164,7 @@ /* Length is known to be safe at compile time if the __L * __S <= __OBJSZ condition can be folded to a constant and if it is true, or unknown (-1) */ #define __glibc_safe_or_unknown_len(__l, __s, __osz) \ - ((__osz) == (__SIZE_TYPE__) -1 \ + ((__builtin_constant_p (__osz) && (__osz) == (__SIZE_TYPE__) -1) \ || (__glibc_unsigned_or_positive (__l) \ && __builtin_constant_p (__glibc_safe_len_cond ((__SIZE_TYPE__) (__l), \ (__s), (__osz))) \ |