From patchwork Thu Dec 13 13:58:54 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [169/241] sparc64: Like x86 we should check current->mm during perf backtrace generation. Date: Thu, 13 Dec 2012 03:58:54 -0000 From: Herton Ronaldo Krzesinski X-Patchwork-Id: 206016 Message-Id: <1355407206-17100-170-git-send-email-herton.krzesinski@canonical.com> To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: "David S. Miller" 3.5.7.2 -stable review patch. If anyone has any objections, please let me know. ------------------ From: "David S. Miller" commit 08280e6c4c2e8049ac61d9e8e3536ec1df629c0d upstream. 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 Signed-off-by: Herton Ronaldo Krzesinski --- arch/sparc/kernel/perf_event.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/arch/sparc/kernel/perf_event.c b/arch/sparc/kernel/perf_event.c index 5713957..b0cce26 100644 --- a/arch/sparc/kernel/perf_event.c +++ b/arch/sparc/kernel/perf_event.c @@ -1426,8 +1426,6 @@ 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; @@ -1448,8 +1446,6 @@ 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; @@ -1468,6 +1464,11 @@ 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);