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| author | David S. Miller <davem@davemloft.net> | 2012-10-14 17:59:40 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-10-28 10:02:13 -0700 |
| commit | 7f6df60755431d12897da745980316ad900d8b56 (patch) | |
| tree | baefecf7b4a1293789df8eb9a97c4e6a4afd4b47 /arch/sparc | |
| parent | ad88238990a8e05db4c2d393372bb95bc4be5d99 (diff) | |
| download | lwn-7f6df60755431d12897da745980316ad900d8b56.tar.gz lwn-7f6df60755431d12897da745980316ad900d8b56.zip | |
sparc64: Like x86 we should check current->mm during perf backtrace generation.
[ 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>
Diffstat (limited to 'arch/sparc')
| -rw-r--r-- | arch/sparc/kernel/perf_event.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/arch/sparc/kernel/perf_event.c b/arch/sparc/kernel/perf_event.c index 6860d40253c3..bcc3eef7f5e0 100644 --- a/arch/sparc/kernel/perf_event.c +++ b/arch/sparc/kernel/perf_event.c @@ -1380,8 +1380,6 @@ static void perf_callchain_user_64(struct perf_callchain_entry *entry, { unsigned long ufp; - perf_callchain_store(entry, regs->tpc); - ufp = regs->u_regs[UREG_I6] + STACK_BIAS; do { struct sparc_stackf *usf, sf; @@ -1402,8 +1400,6 @@ static void perf_callchain_user_32(struct perf_callchain_entry *entry, { unsigned long ufp; - perf_callchain_store(entry, regs->tpc); - ufp = regs->u_regs[UREG_I6] & 0xffffffffUL; do { struct sparc_stackf32 *usf, sf; @@ -1422,6 +1418,11 @@ static void perf_callchain_user_32(struct perf_callchain_entry *entry, 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); |