[PATCH 3.16.y-ckt 108/168] MIPS: fix EVA & non-SMP non-FPU FP context signal handling
From: Luis Henriques
Date: Mon Dec 15 2014 - 09:28:55 EST
3.16.7-ckt3 -stable review patch. If anyone has any objections, please let me know.
------------------
From: Paul Burton <paul.burton@xxxxxxxxxx>
commit 14fa12df1d6bc1d3389a0fa842e0ebd8e8a9af26 upstream.
The save_fp_context & restore_fp_context pointers were being assigned
to the wrong variables if either:
- The kernel is configured for UP & runs on a system without an FPU,
since b2ead5282885 "MIPS: Move & rename
fpu_emulator_{save,restore}_context".
- The kernel is configured for EVA, since ca750649e08c "MIPS: kernel:
signal: Prevent save/restore FPU context in user memory".
This would lead to FP context being clobbered incorrectly when setting
up a sigcontext, then the garbage values being saved uselessly when
returning from the signal.
Fix by swapping the pointer assignments appropriately.
Signed-off-by: Paul Burton <paul.burton@xxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxx
Patchwork: https://patchwork.linux-mips.org/patch/8230/
Signed-off-by: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
---
arch/mips/kernel/signal.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c
index 9e60d117e41e..394e2b12a3ba 100644
--- a/arch/mips/kernel/signal.c
+++ b/arch/mips/kernel/signal.c
@@ -676,13 +676,13 @@ static int signal_setup(void)
save_fp_context = _save_fp_context;
restore_fp_context = _restore_fp_context;
} else {
- save_fp_context = copy_fp_from_sigcontext;
- restore_fp_context = copy_fp_to_sigcontext;
+ save_fp_context = copy_fp_to_sigcontext;
+ restore_fp_context = copy_fp_from_sigcontext;
}
#endif /* CONFIG_SMP */
#else
- save_fp_context = copy_fp_from_sigcontext;;
- restore_fp_context = copy_fp_to_sigcontext;
+ save_fp_context = copy_fp_to_sigcontext;
+ restore_fp_context = copy_fp_from_sigcontext;
#endif
return 0;
--
2.1.3
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