* [PATCH] mips/kprobes: flush_insn_slot should flush only if probe initialised
@ 2017-06-08 13:20 Marcin Nowakowski
2017-06-08 13:20 ` Marcin Nowakowski
2017-06-08 13:41 ` Ralf Baechle
0 siblings, 2 replies; 3+ messages in thread
From: Marcin Nowakowski @ 2017-06-08 13:20 UTC (permalink / raw)
To: Ralf Baechle; +Cc: linux-mips, Marcin Nowakowski
When ftrace is used with kprobes, it is possible for a kprobe to contain
an invalid location (ie. only initialised to 0 and not to a specific
location in the code). Trying to perform a cache flush on such location
leads to a crash r4k_flush_icache_range().
Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
---
arch/mips/include/asm/kprobes.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/mips/include/asm/kprobes.h b/arch/mips/include/asm/kprobes.h
index 291846d..ad1a999 100644
--- a/arch/mips/include/asm/kprobes.h
+++ b/arch/mips/include/asm/kprobes.h
@@ -43,7 +43,8 @@ typedef union mips_instruction kprobe_opcode_t;
#define flush_insn_slot(p) \
do { \
- flush_icache_range((unsigned long)p->addr, \
+ if (p->addr) \
+ flush_icache_range((unsigned long)p->addr, \
(unsigned long)p->addr + \
(MAX_INSN_SIZE * sizeof(kprobe_opcode_t))); \
} while (0)
--
2.7.4
^ permalink raw reply related [flat|nested] 3+ messages in thread* [PATCH] mips/kprobes: flush_insn_slot should flush only if probe initialised
2017-06-08 13:20 [PATCH] mips/kprobes: flush_insn_slot should flush only if probe initialised Marcin Nowakowski
@ 2017-06-08 13:20 ` Marcin Nowakowski
2017-06-08 13:41 ` Ralf Baechle
1 sibling, 0 replies; 3+ messages in thread
From: Marcin Nowakowski @ 2017-06-08 13:20 UTC (permalink / raw)
To: Ralf Baechle; +Cc: linux-mips, Marcin Nowakowski
When ftrace is used with kprobes, it is possible for a kprobe to contain
an invalid location (ie. only initialised to 0 and not to a specific
location in the code). Trying to perform a cache flush on such location
leads to a crash r4k_flush_icache_range().
Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
---
arch/mips/include/asm/kprobes.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/mips/include/asm/kprobes.h b/arch/mips/include/asm/kprobes.h
index 291846d..ad1a999 100644
--- a/arch/mips/include/asm/kprobes.h
+++ b/arch/mips/include/asm/kprobes.h
@@ -43,7 +43,8 @@ typedef union mips_instruction kprobe_opcode_t;
#define flush_insn_slot(p) \
do { \
- flush_icache_range((unsigned long)p->addr, \
+ if (p->addr) \
+ flush_icache_range((unsigned long)p->addr, \
(unsigned long)p->addr + \
(MAX_INSN_SIZE * sizeof(kprobe_opcode_t))); \
} while (0)
--
2.7.4
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] mips/kprobes: flush_insn_slot should flush only if probe initialised
2017-06-08 13:20 [PATCH] mips/kprobes: flush_insn_slot should flush only if probe initialised Marcin Nowakowski
2017-06-08 13:20 ` Marcin Nowakowski
@ 2017-06-08 13:41 ` Ralf Baechle
1 sibling, 0 replies; 3+ messages in thread
From: Ralf Baechle @ 2017-06-08 13:41 UTC (permalink / raw)
To: Marcin Nowakowski; +Cc: linux-mips
On Thu, Jun 08, 2017 at 03:20:32PM +0200, Marcin Nowakowski wrote:
> When ftrace is used with kprobes, it is possible for a kprobe to contain
> an invalid location (ie. only initialised to 0 and not to a specific
> location in the code). Trying to perform a cache flush on such location
> leads to a crash r4k_flush_icache_range().
Cute, 2.6.36+ ...
Applied,
Ralf
^ permalink raw reply [flat|nested] 3+ messages in thread
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2017-06-08 13:20 [PATCH] mips/kprobes: flush_insn_slot should flush only if probe initialised Marcin Nowakowski
2017-06-08 13:20 ` Marcin Nowakowski
2017-06-08 13:41 ` Ralf Baechle
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