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commit 61a87530108ec9181e1b18a9b727ec3cc3ba7532
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Author: Siddhesh Poyarekar <siddhesh@sourceware.org>
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Date:   Fri May 13 10:01:47 2022 +0530
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    fortify: Ensure that __glibc_fortify condition is a constant [BZ #29141]
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    The fix c8ee1c85 introduced a -1 check for object size without also
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    checking that object size is a constant.  Because of this, the tree
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    optimizer passes in gcc fail to fold away one of the branches in
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    __glibc_fortify and trips on a spurious Wstringop-overflow.  The warning
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    itself is incorrect and the branch does go away eventually in DCE in the
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    rtl passes in gcc, but the constant check is a helpful hint to simplify
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    code early, so add it in.
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    Resolves: BZ #29141
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    Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
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diff --git a/misc/sys/cdefs.h b/misc/sys/cdefs.h
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index 404496c7d6da4fb3..f3d7efdd2a9320f7 100644
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--- a/misc/sys/cdefs.h
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+++ b/misc/sys/cdefs.h
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@@ -145,7 +145,7 @@
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 /* Length is known to be safe at compile time if the __L * __S <= __OBJSZ
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    condition can be folded to a constant and if it is true, or unknown (-1) */
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 #define __glibc_safe_or_unknown_len(__l, __s, __osz) \
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-  ((__osz) == (__SIZE_TYPE__) -1					      \
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+  ((__builtin_constant_p (__osz) && (__osz) == (__SIZE_TYPE__) -1)	      \
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    || (__glibc_unsigned_or_positive (__l)				      \
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        && __builtin_constant_p (__glibc_safe_len_cond ((__SIZE_TYPE__) (__l), \
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 						       (__s), (__osz)))	      \