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authorMichael Neuling <mikey@neuling.org>2013-11-25 11:12:20 +1100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-12-04 11:05:54 -0800
commit5bdecef947f289555686de327a7bd5ac9142cfa7 (patch)
tree73bd56f18f936ad0fadff67374541ef865c0ba60
parent368882d5acaad71ee5811a9e12d29688a1a490b6 (diff)
powerpc/signals: Improved mark VSX not saved with small contexts fix
commit ec67ad82814bee92251fd963bf01c7a173856555 upstream. In a recent patch: commit c13f20ac48328b05cd3b8c19e31ed6c132b44b42 Author: Michael Neuling <mikey@neuling.org> powerpc/signals: Mark VSX not saved with small contexts We fixed an issue but an improved solution was later discussed after the patch was merged. Firstly, this patch doesn't handle the 64bit signals case, which could also hit this issue (but has never been reported). Secondly, the original patch isn't clear what MSR VSX should be set to. The new approach below always clears the MSR VSX bit (to indicate no VSX is in the context) and sets it only in the specific case where VSX is available (ie. when VSX has been used and the signal context passed has space to provide the state). This reverts the original patch and replaces it with the improved solution. It also adds a 64 bit version. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--arch/powerpc/kernel/signal_32.c16
-rw-r--r--arch/powerpc/kernel/signal_64.c6
2 files changed, 13 insertions, 9 deletions
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index 36d49e6b7c4c..fea2dba1226c 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -445,6 +445,12 @@ static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
#endif /* CONFIG_ALTIVEC */
if (copy_fpr_to_user(&frame->mc_fregs, current))
return 1;
+
+ /*
+ * Clear the MSR VSX bit to indicate there is no valid state attached
+ * to this context, except in the specific case below where we set it.
+ */
+ msr &= ~MSR_VSX;
#ifdef CONFIG_VSX
/*
* Copy VSR 0-31 upper half from thread_struct to local
@@ -457,15 +463,7 @@ static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
if (copy_vsx_to_user(&frame->mc_vsregs, current))
return 1;
msr |= MSR_VSX;
- } else if (!ctx_has_vsx_region)
- /*
- * With a small context structure we can't hold the VSX
- * registers, hence clear the MSR value to indicate the state
- * was not saved.
- */
- msr &= ~MSR_VSX;
-
-
+ }
#endif /* CONFIG_VSX */
#ifdef CONFIG_SPE
/* save spe registers */
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index f93ec2835a13..1e7ba8817106 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -121,6 +121,12 @@ static long setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
flush_fp_to_thread(current);
/* copy fpr regs and fpscr */
err |= copy_fpr_to_user(&sc->fp_regs, current);
+
+ /*
+ * Clear the MSR VSX bit to indicate there is no valid state attached
+ * to this context, except in the specific case below where we set it.
+ */
+ msr &= ~MSR_VSX;
#ifdef CONFIG_VSX
/*
* Copy VSX low doubleword to local buffer for formatting,