From: Siddhesh Poyarekar <siddhesh@sourceware.org>
Date: Mon, 15 Mar 2021 14:54:45 +0000 (+0530)
Subject: Build get-cpuid-feature-leaf.c without stack-protector [BZ #27555]
X-Git-Tag: glibc-2.34~831
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=941ea10f8099cb4fcc98c65249fc17a63fcff6a4;p=thirdparty%2Fglibc.git

Build get-cpuid-feature-leaf.c without stack-protector [BZ #27555]

__x86_get_cpuid_feature_leaf is called during early startup, before
the stack check guard is initialized and is hence not safe to build
with stack-protector.

Additionally, IFUNC resolvers for static tst-ifunc-isa tests get
called too early for stack protector to be useful, so fix them to
disable stack protector for the resolver functions.

This fixes all failures seen with --enable-stack-protector=all
configuration.

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

diff --git a/sysdeps/x86/Makefile b/sysdeps/x86/Makefile
index 06c9f84f517..3ca7bfefe48 100644
--- a/sysdeps/x86/Makefile
+++ b/sysdeps/x86/Makefile
@@ -7,6 +7,8 @@ sysdep_routines += get-cpuid-feature-leaf
 sysdep-dl-routines += dl-get-cpu-features
 sysdep_headers += sys/platform/x86.h
 
+CFLAGS-get-cpuid-feature-leaf.o += $(no-stack-protector)
+
 tests += tst-get-cpu-features tst-get-cpu-features-static \
 	 tst-cpu-features-cpuinfo tst-cpu-features-cpuinfo-static \
 	 tst-cpu-features-supports tst-cpu-features-supports-static
diff --git a/sysdeps/x86/tst-ifunc-isa.h b/sysdeps/x86/tst-ifunc-isa.h
index 60aa1cea6af..6d906966a79 100644
--- a/sysdeps/x86/tst-ifunc-isa.h
+++ b/sysdeps/x86/tst-ifunc-isa.h
@@ -29,6 +29,7 @@ enum isa
 };
 
 enum isa
+__attribute__ ((__optimize__ ("-fno-stack-protector")))
 get_isa (void)
 {
   if (CPU_FEATURE_USABLE (AVX512F))
@@ -83,6 +84,7 @@ isa_none (void)
 int foo (void) __attribute__ ((ifunc ("foo_ifunc")));
 
 void *
+__attribute__ ((__optimize__ ("-fno-stack-protector")))
 foo_ifunc (void)
 {
   switch (get_isa ())