diff mbox series

[1/1] Fix: arm: kprobes: optimized kprobes illegal instruction

Message ID 20190205152806.20340-1-mathieu.desnoyers@efficios.com (mailing list archive)
State Mainlined, archived
Commit 0ac569bf6a7983c0c5747d6df8db9dc05bc92b6c
Headers show
Series [1/1] Fix: arm: kprobes: optimized kprobes illegal instruction | expand

Commit Message

Mathieu Desnoyers Feb. 5, 2019, 3:28 p.m. UTC
commit e46daee53bb5 ("ARM: 8806/1: kprobes: Fix false positive with
FORTIFY_SOURCE") introduced a regression in optimized kprobes. It
triggers "invalid instruction" oopses when using kprobes instrumentation
through lttng and perf. This commit was introduced in kernel v4.20, and
has been backported to stable kernels 4.19 and 4.14.

This crash was also reported by Hongzhi Song on the redhat bugzilla
where the patch was originally introduced.

Link: https://bugzilla.redhat.com/show_bug.cgi?id=1639397
Link: https://bugs.lttng.org/issues/1174
Link: https://lore.kernel.org/lkml/342740659.2887.1549307721609.JavaMail.zimbra@efficios.com
Fixes: e46daee53bb5 ("ARM: 8806/1: kprobes: Fix false positive with FORTIFY_SOURCE")
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reported-by: Robert Berger <Robert.Berger@ReliableEmbeddedSystems.com>
Tested-by: Robert Berger <Robert.Berger@ReliableEmbeddedSystems.com>
Acked-by: Kees Cook <keescook@chromium.org>
CC: Robert Berger <Robert.Berger@ReliableEmbeddedSystems.com>
CC: Masami Hiramatsu <mhiramat@kernel.org>
CC: William Cohen <wcohen@redhat.com>
CC: Laura Abbott <labbott@redhat.com>
CC: Kees Cook <keescook@chromium.org>
CC: Russell King <rmk+kernel@armlinux.org.uk>
CC: <stable@vger.kernel.org> # v4.14+
CC: linux-arm-kernel@lists.infradead.org
CC: patches@armlinux.org.uk
---
 arch/arm/probes/kprobes/opt-arm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/arch/arm/probes/kprobes/opt-arm.c b/arch/arm/probes/kprobes/opt-arm.c
index 2c118a6ab358..0dc23fc227ed 100644
--- a/arch/arm/probes/kprobes/opt-arm.c
+++ b/arch/arm/probes/kprobes/opt-arm.c
@@ -247,7 +247,7 @@  int arch_prepare_optimized_kprobe(struct optimized_kprobe *op, struct kprobe *or
 	}
 
 	/* Copy arch-dep-instance from template. */
-	memcpy(code, (unsigned char *)optprobe_template_entry,
+	memcpy(code, (unsigned long *)&optprobe_template_entry,
 			TMPL_END_IDX * sizeof(kprobe_opcode_t));
 
 	/* Adjust buffer according to instruction. */