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authorRodrigo Rebello <rprebello@gmail.com>2015-11-12 12:04:28 -0200
committerMichael Tokarev <mjt@tls.msk.ru>2015-12-04 09:39:55 +0300
commitfccd35a04640a728f979e6d72b2c7d02c05549f0 (patch)
parent0e1d02452bf2c3486406dd48524a5b1de3c0eba8 (diff)
configure: use appropriate code fragment for -fstack-protector checks
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 accepted -fstack-protector-strong but no support was provided by the C library, since for 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 changes the test program used for -fstack-protector checks to include a function that meets conditions which cause the compiler to generate canary code in all variants. Signed-off-by: Rodrigo Rebello <rprebello@gmail.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
1 files changed, 10 insertions, 0 deletions
diff --git a/configure b/configure
index 2e8a672ae..b9552fda6 100755
--- a/configure
+++ b/configure
@@ -1491,6 +1491,16 @@ for flag in $gcc_flags; do
if test "$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;
gcc_flags="-fstack-protector-strong -fstack-protector-all"
for flag in $gcc_flags; do