[ 38/42] sparc64: Like x86 we should check current->mm during perf backtrace generation.
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2012-10-26 00:36:57
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lkml
3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: "David S. Miller" <davem@davemloft.net> [ Upstream commit 08280e6c4c2e8049ac61d9e8e3536ec1df629c0d ] If the MM is not active, only report the top-level PC. Do not try to access the address space. Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- arch/sparc/kernel/perf_event.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)
--- a/arch/sparc/kernel/perf_event.c
+++ b/arch/sparc/kernel/perf_event.c@@ -1428,8 +1428,6 @@ static void perf_callchain_user_64(struc { unsigned long ufp; - perf_callchain_store(entry, regs->tpc); - ufp = regs->u_regs[UREG_I6] + STACK_BIAS; do { struct sparc_stackf *usf, sf;
@@ -1450,8 +1448,6 @@ static void perf_callchain_user_32(struc { unsigned long ufp; - perf_callchain_store(entry, regs->tpc); - ufp = regs->u_regs[UREG_I6] & 0xffffffffUL; do { struct sparc_stackf32 *usf, sf;
@@ -1470,6 +1466,11 @@ static void perf_callchain_user_32(struc void perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs) { + perf_callchain_store(entry, regs->tpc); + + if (!current->mm) + return; + flushw_user(); if (test_thread_flag(TIF_32BIT)) perf_callchain_user_32(entry, regs);