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| author | H.J. Lu <hongjiu.lu@intel.com> | 2018-07-04 03:01:33 +0000 |
|---|---|---|
| committer | H.J. Lu <hjl@gcc.gnu.org> | 2018-07-03 20:01:33 -0700 |
| commit | ebaa4deaf9f3bec32443e60fe74fce14686b4706 (patch) | |
| tree | fb0135f43e72e4ffd528ad5806930aa0f186f804 /gcc/doc/extend.texi | |
| parent | 7422f0ff39697b53ad599834647c56cb0cb3c3a3 (diff) | |
| download | gcc-ebaa4deaf9f3bec32443e60fe74fce14686b4706.zip gcc-ebaa4deaf9f3bec32443e60fe74fce14686b4706.tar.gz gcc-ebaa4deaf9f3bec32443e60fe74fce14686b4706.tar.bz2 | |
i386: Add indirect_return function attribute
On x86, swapcontext may return via indirect branch when shadow stack
is enabled. To support code instrumentation of control-flow transfers
with -fcf-protection, add indirect_return function attribute to inform
compiler that a function may return via indirect branch.
Note: Unlike setjmp, swapcontext only returns once. Mark it return
twice will unnecessarily disable compiler optimization as shown in
the testcase here.
gcc/
PR target/85620
* config/i386/i386.c (rest_of_insert_endbranch): Also generate
ENDBRANCH for non-tail call which may return via indirect branch.
* doc/extend.texi: Document indirect_return attribute.
gcc/testsuite/
PR target/85620
* gcc.target/i386/pr85620-1.c: New test.
* gcc.target/i386/pr85620-2.c: Likewise.
* gcc.target/i386/pr85620-3.c: Likewise.
* gcc.target/i386/pr85620-4.c: Likewise.
From-SVN: r262370
Diffstat (limited to 'gcc/doc/extend.texi')
| -rw-r--r-- | gcc/doc/extend.texi | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi index 19c2da2..071d0ff 100644 --- a/gcc/doc/extend.texi +++ b/gcc/doc/extend.texi @@ -5886,6 +5886,12 @@ foo (void) @} @end smallexample +@item indirect_return +@cindex @code{indirect_return} function attribute, x86 + +The @code{indirect_return} attribute on a function is used to inform +the compiler that the function may return via indirect branch. + @end table On the x86, the inliner does not inline a |