[PATCH 2/2] arm64: Make all entry code as non-kprobe-able

From: Pratyush Anand
Date: Mon Jul 06 2015 - 01:04:25 EST


Entry symbols are not kprobe safe. So blacklist them for kprobing.

Signed-off-by: Pratyush Anand <panand@xxxxxxxxxx>
---
arch/arm64/kernel/entry.S | 3 +++
arch/arm64/kernel/kprobes.c | 9 +++++++++
arch/arm64/kernel/vmlinux.lds.S | 1 +
3 files changed, 13 insertions(+)

diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index a7691a378668..2ea24f6bc06b 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -202,6 +202,7 @@ tsk .req x28 // current thread_info
* Exception vectors.
*/

+ .section ".entry.text", "ax"
.align 11
ENTRY(vectors)
ventry el1_sync_invalid // Synchronous EL1t
@@ -737,3 +738,5 @@ ENTRY(sys_rt_sigreturn_wrapper)
mov x0, sp
b sys_rt_sigreturn
ENDPROC(sys_rt_sigreturn_wrapper)
+
+ .section ".text", "ax"
diff --git a/arch/arm64/kernel/kprobes.c b/arch/arm64/kernel/kprobes.c
index 6c9f8b5f04ce..9bc02c151f7f 100644
--- a/arch/arm64/kernel/kprobes.c
+++ b/arch/arm64/kernel/kprobes.c
@@ -28,6 +28,7 @@
#include <asm/debug-monitors.h>
#include <asm/system_misc.h>
#include <asm/insn.h>
+#include <asm-generic/sections.h>

#include "kprobes.h"
#include "kprobes-arm64.h"
@@ -661,6 +662,14 @@ int __kprobes arch_trampoline_kprobe(struct kprobe *p)
return 0;
}

+bool arch_within_kprobe_blacklist(unsigned long addr)
+{
+ return (addr >= (unsigned long)__kprobes_text_start &&
+ addr < (unsigned long)__kprobes_text_end) ||
+ (addr >= (unsigned long)__entry_text_start &&
+ addr < (unsigned long)__entry_text_end);
+}
+
int __init arch_init_kprobes(void)
{
return 0;
diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S
index 1fa6adc7aa83..11fb2b0117d0 100644
--- a/arch/arm64/kernel/vmlinux.lds.S
+++ b/arch/arm64/kernel/vmlinux.lds.S
@@ -97,6 +97,7 @@ SECTIONS
*(.exception.text)
__exception_text_end = .;
IRQENTRY_TEXT
+ ENTRY_TEXT
TEXT_TEXT
SCHED_TEXT
LOCK_TEXT
--
2.4.3

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