From: Matthew Fortune <[email protected]>
Ensure the frame barrier prevents reordering of stack pointer changes.
It is possible for a load/store accessing the stack via a copy of the
stack pointer to be moved across the epilogue meaning that it accesses
stack that is no longer allocated. This leads to a situation where the
code is unsafe in the event of an interrupt where the same stack is
used for interrupt handling.
gcc/
* config/mips/mips.cc (mips_frame_barrier): Upgrade to a full
blockage.
Cherry-picked 0c240da6f6032bd19348b97148d25c05ba2e8356
from https://github.com/MIPS/gcc
Signed-off-by: Matthew Fortune <[email protected]>
Signed-off-by: Faraz Shahbazker <[email protected]>
Signed-off-by: Aleksandar Rakic <[email protected]>
---
gcc/config/mips/mips.cc | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/gcc/config/mips/mips.cc b/gcc/config/mips/mips.cc
index dcb4b9f9f99..57a858aca39 100644
--- a/gcc/config/mips/mips.cc
+++ b/gcc/config/mips/mips.cc
@@ -13626,7 +13626,7 @@ mips_output_function_epilogue (FILE *)
static void
mips_frame_barrier (void)
{
- emit_clobber (gen_frame_mem (BLKmode, stack_pointer_rtx));
+ emit_insn (gen_blockage ());
}
--
2.34.1
