From: Florian Weimer <fweimer@redhat.com>
Date: Mon, 1 Aug 2022 13:49:07 +0000 (+0200)
Subject: malloc: Use __getrandom_nocancel during tcache initiailization
X-Git-Tag: glibc-2.37~462
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7187efd0aa270c83c428ea6cd0e1cffc34b41a74;p=thirdparty%2Fglibc.git

malloc: Use __getrandom_nocancel during tcache initiailization

Cancellation currently cannot happen at this point because dlopen
as used by the unwind link always performs additional allocations
for libgcc_s.so.1, even if it has been loaded already as a dependency
of the main executable.  But it seems prudent not to rely on this
quirk.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
---

diff --git a/malloc/malloc.c b/malloc/malloc.c
index bd3c76ed310..430d2041564 100644
--- a/malloc/malloc.c
+++ b/malloc/malloc.c
@@ -254,6 +254,7 @@
 /* For tcache double-free check.  */
 #include <random-bits.h>
 #include <sys/random.h>
+#include <not-cancel.h>
 
 /*
   Debugging:
@@ -3153,7 +3154,7 @@ static uintptr_t tcache_key;
 static void
 tcache_key_initialize (void)
 {
-  if (__getrandom (&tcache_key, sizeof(tcache_key), GRND_NONBLOCK)
+  if (__getrandom_nocancel (&tcache_key, sizeof(tcache_key), GRND_NONBLOCK)
       != sizeof (tcache_key))
     {
       tcache_key = random_bits ();