void-packages/srcpkgs/glibc/patches/glibc-upstream-07.patch

72 lines
2.3 KiB
Diff

From c55ad6452e2d63ebf6fcaabb00bfd27aae02ffb6 Mon Sep 17 00:00:00 2001
From: Florian Weimer <fweimer@redhat.com>
Date: Thu, 10 Aug 2017 15:58:28 +0200
Subject: [PATCH 07] malloc: Avoid optimizer warning with GCC 7 and -O3
(cherry picked from commit eac43cbb8d808a40004aa0a4a286f5c5155beccb)
---
ChangeLog | 5 +++++
malloc/malloc.c | 20 ++++++++++++++++----
2 files changed, 21 insertions(+), 4 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index 3127648626..5ea9b8baa7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2017-08-10 Florian Weimer <fweimer@redhat.com>
+
+ * malloc/malloc.c (get_max_fast): Reimplement as an inline
+ function which calls __builtin_unreachable.
+
2017-08-09 Florian Weimer <fweimer@redhat.com>
[BZ #21932]
diff --git a/malloc/malloc.c b/malloc/malloc.c
index 54e406bcb6..e3ff778113 100644
--- a/malloc/malloc.c
+++ b/malloc/malloc.c
@@ -1658,6 +1658,9 @@ typedef struct malloc_chunk *mfastbinptr;
#define arena_is_corrupt(A) (((A)->flags & ARENA_CORRUPTION_BIT))
#define set_arena_corrupt(A) ((A)->flags |= ARENA_CORRUPTION_BIT)
+/* Maximum size of memory handled in fastbins. */
+static INTERNAL_SIZE_T global_max_fast;
+
/*
Set value of max_fast.
Use impossibly small value if 0.
@@ -1668,8 +1671,20 @@ typedef struct malloc_chunk *mfastbinptr;
#define set_max_fast(s) \
global_max_fast = (((s) == 0) \
? SMALLBIN_WIDTH : ((s + SIZE_SZ) & ~MALLOC_ALIGN_MASK))
-#define get_max_fast() global_max_fast
+static inline INTERNAL_SIZE_T
+get_max_fast (void)
+{
+ /* Tell the GCC optimizers that global_max_fast is never larger
+ than MAX_FAST_SIZE. This avoids out-of-bounds array accesses in
+ _int_malloc after constant propagation of the size parameter.
+ (The code never executes because malloc preserves the
+ global_max_fast invariant, but the optimizers may not recognize
+ this.) */
+ if (global_max_fast > MAX_FAST_SIZE)
+ __builtin_unreachable ();
+ return global_max_fast;
+}
/*
----------- Internal state representation and initialization -----------
@@ -1797,9 +1812,6 @@ static struct malloc_par mp_ =
#endif
};
-/* Maximum size of memory handled in fastbins. */
-static INTERNAL_SIZE_T global_max_fast;
-
/*
Initialize a malloc_state struct.