| Date | Tue, 30 Mar 2010 15:42:30 -0700 | From | Greg KH <> | Subject | [116/156] sparc64: Properly truncate pt_regs framepointer in perf callback. |
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2.6.33-stable review patch. If anyone has any objections, please let us know.
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From: David S. Miller <davem@davemloft.net>
[ Upstream commit 9e8307ecaf9f8c8b5b3b22145021204c4e73114a ]
For 32-bit processes, we save the full 64-bits of the regs in pt_regs.
But unlike when the userspace actually does load and store instructions, the top 32-bits don't get automatically truncated by the cpu in kernel mode (because the kernel doesn't execute with PSTATE_AM address masking enabled).
So we have to do it by hand.
Reported-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- arch/sparc/kernel/perf_event.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/sparc/kernel/perf_event.c +++ b/arch/sparc/kernel/perf_event.c @@ -1337,7 +1337,7 @@ static void perf_callchain_user_32(struc callchain_store(entry, PERF_CONTEXT_USER); callchain_store(entry, regs->tpc); - ufp = regs->u_regs[UREG_I6]; + ufp = regs->u_regs[UREG_I6] & 0xffffffffUL; do { struct sparc_stackf32 *usf, sf; unsigned long pc;
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