59 lines
1.8 KiB
Diff
59 lines
1.8 KiB
Diff
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From 7b93e98143c376ed09bfd30658b8641d4a36e77e Mon Sep 17 00:00:00 2001
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From: Rodrigo Rebello <rprebello@gmail.com>
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Date: Thu, 12 Nov 2015 12:04:28 -0200
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Subject: [PATCH] configure: use appropriate code fragment for
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-fstack-protector checks
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Cc: qemu-trivial@nongnu.org
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The check for stack-protector support consisted in compiling and linking
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the test program below (output by function write_c_skeleton()) with the
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compiler flag -fstack-protector-strong first and then with
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-fstack-protector-all if the first one failed to work:
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int main(void) { return 0; }
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This caused false positives when using certain toolchains in which the
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compiler accepts -fstack-protector-strong but no support is provided by
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the C library, since in this stack-protector variant the compiler emits
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canary code only for functions that meet specific conditions (local
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arrays, memory references to local variables, etc.) and the code
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fragment under test included none of them (hence no stack protection
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code generated, no link failure).
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This fix modifies the test program used for -fstack-protector checks to
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meet conditions which cause the compiler to generate canary code in all
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variants.
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Upstream status: sent
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https://patchwork.ozlabs.org/patch/543357/
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Signed-off-by: Rodrigo Rebello <rprebello@gmail.com>
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---
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configure | 10 ++++++++++
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1 file changed, 10 insertions(+)
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diff --git a/configure b/configure
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index cd219d8..27d7b3c 100755
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--- a/configure
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+++ b/configure
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@@ -1471,6 +1471,16 @@ for flag in $gcc_flags; do
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done
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if test "$stack_protector" != "no"; then
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+ cat > $TMPC << EOF
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+int main(int argc, char *argv[])
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+{
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+ char arr[64], *p = arr, *c = argv[0];
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+ while (*c) {
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+ *p++ = *c++;
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+ }
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+ return 0;
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+}
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+EOF
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gcc_flags="-fstack-protector-strong -fstack-protector-all"
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sp_on=0
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for flag in $gcc_flags; do
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--
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2.1.4
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