diff options
author | Rodrigo Rebello <rprebello@gmail.com> | 2015-11-16 08:58:18 -0200 |
---|---|---|
committer | Thomas Petazzoni <thomas.petazzoni@free-electrons.com> | 2015-11-18 22:01:46 +0100 |
commit | 694fa0e332f8b3894a606619263c6ae38e4f6e20 (patch) | |
tree | cb8072903684f12c2af3085fa02dc439f3e45dc1 /package/qemu | |
parent | e9b415ace06b416a5743c97e13f4fd7df9666d85 (diff) |
qemu: add patch to fix SSP support detection
The QEMU configure script incorrectly assumes SSP is supported by the
toolchain in some cases where the compiler accepts -fstack-protector*
flags but the C library does not provide the necessary __stack_chk_*()
functions.
Even though a full compile and link test is performed by the script,
this is done with a code fragment which does not actually meet any of
the conditions required to cause the compiler to emit canary code when
the -fstack-protector-strong variant is used. As no compile or link
failure occurs in this case, a false positive is generated and a
subsequent error is seen when the probe for pthreads is performed.
The fix consists in patching the configure script to use a more
appropriate test program for the SSP support checks.
Fixes:
http://autobuild.buildroot.net/results/efb/efbb4e940543894b8745bb405478a096c90a5ae2/
http://autobuild.buildroot.net/results/32d/32d6d984febad2dee1f0d31c5fa0aea823297096/
http://autobuild.buildroot.net/results/aa6/aa6e71c957fb6f07e7bded35a8e47be4dadd042c/
...and many others.
Signed-off-by: Rodrigo Rebello <rprebello@gmail.com>
Acked-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Reviewed-by: Vicente Olivert Riera <Vincent.Riera@imgtec.com>
Tested-by: Vicente Olivert Riera <Vincent.Riera@imgtec.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Diffstat (limited to 'package/qemu')
-rw-r--r-- | package/qemu/0001-configure-use-appropriate-code-fragment-for-fstack-p.patch | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/package/qemu/0001-configure-use-appropriate-code-fragment-for-fstack-p.patch b/package/qemu/0001-configure-use-appropriate-code-fragment-for-fstack-p.patch new file mode 100644 index 000000000..9ebe334ff --- /dev/null +++ b/package/qemu/0001-configure-use-appropriate-code-fragment-for-fstack-p.patch @@ -0,0 +1,58 @@ +From 7b93e98143c376ed09bfd30658b8641d4a36e77e Mon Sep 17 00:00:00 2001 +From: Rodrigo Rebello <rprebello@gmail.com> +Date: Thu, 12 Nov 2015 12:04:28 -0200 +Subject: [PATCH] configure: use appropriate code fragment for + -fstack-protector checks +Cc: qemu-trivial@nongnu.org + +The check for stack-protector support consisted in compiling and linking +the test program below (output by function write_c_skeleton()) with the +compiler flag -fstack-protector-strong first and then with +-fstack-protector-all if the first one failed to work: + + int main(void) { return 0; } + +This caused false positives when using certain toolchains in which the +compiler accepts -fstack-protector-strong but no support is provided by +the C library, since in this stack-protector variant the compiler emits +canary code only for functions that meet specific conditions (local +arrays, memory references to local variables, etc.) and the code +fragment under test included none of them (hence no stack protection +code generated, no link failure). + +This fix modifies the test program used for -fstack-protector checks to +meet conditions which cause the compiler to generate canary code in all +variants. + +Upstream status: sent +https://patchwork.ozlabs.org/patch/543357/ + +Signed-off-by: Rodrigo Rebello <rprebello@gmail.com> +--- + configure | 10 ++++++++++ + 1 file changed, 10 insertions(+) + +diff --git a/configure b/configure +index cd219d8..27d7b3c 100755 +--- a/configure ++++ b/configure +@@ -1471,6 +1471,16 @@ for flag in $gcc_flags; do + done + + if test "$stack_protector" != "no"; then ++ cat > $TMPC << EOF ++int main(int argc, char *argv[]) ++{ ++ char arr[64], *p = arr, *c = argv[0]; ++ while (*c) { ++ *p++ = *c++; ++ } ++ return 0; ++} ++EOF + gcc_flags="-fstack-protector-strong -fstack-protector-all" + sp_on=0 + for flag in $gcc_flags; do +-- +2.1.4 + |