[PATCH v15 06/10] arm64: Treat all entry code as non-kprobe-able

From: David Long
Date: Fri Jul 08 2016 - 12:36:32 EST


From: Pratyush Anand <panand@xxxxxxxxxx>

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

Signed-off-by: Pratyush Anand <panand@xxxxxxxxxx>
Signed-off-by: David A. Long <dave.long@xxxxxxxxxx>
Acked-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
---
arch/arm64/kernel/entry.S | 3 +++
arch/arm64/kernel/probes/kprobes.c | 26 ++++++++++++++++++++++++++
arch/arm64/kernel/vmlinux.lds.S | 1 +
3 files changed, 30 insertions(+)

diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index 12e8d2b..7d99bed 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -243,6 +243,7 @@ tsk .req x28 // current thread_info
* Exception vectors.
*/

+ .pushsection ".entry.text", "ax"
.align 11
ENTRY(vectors)
ventry el1_sync_invalid // Synchronous EL1t
@@ -781,3 +782,5 @@ ENTRY(sys_rt_sigreturn_wrapper)
mov x0, sp
b sys_rt_sigreturn
ENDPROC(sys_rt_sigreturn_wrapper)
+
+ .popsection
diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c
index 4496801..0fe2b65 100644
--- a/arch/arm64/kernel/probes/kprobes.c
+++ b/arch/arm64/kernel/probes/kprobes.c
@@ -30,6 +30,7 @@
#include <asm/insn.h>
#include <asm/uaccess.h>
#include <asm/irq.h>
+#include <asm-generic/sections.h>

#include "decode-insn.h"

@@ -519,6 +520,31 @@ int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
return 1;
}

+bool arch_within_kprobe_blacklist(unsigned long addr)
+{
+ extern char __idmap_text_start[], __idmap_text_end[];
+ extern char __hyp_idmap_text_start[], __hyp_idmap_text_end[];
+
+ if ((addr >= (unsigned long)__kprobes_text_start &&
+ addr < (unsigned long)__kprobes_text_end) ||
+ (addr >= (unsigned long)__entry_text_start &&
+ addr < (unsigned long)__entry_text_end) ||
+ (addr >= (unsigned long)__idmap_text_start &&
+ addr < (unsigned long)__idmap_text_end) ||
+ !!search_exception_tables(addr))
+ return true;
+
+ if (!is_kernel_in_hyp_mode()) {
+ if ((addr >= (unsigned long)__hyp_text_start &&
+ addr < (unsigned long)__hyp_text_end) ||
+ (addr >= (unsigned long)__hyp_idmap_text_start &&
+ addr < (unsigned long)__hyp_idmap_text_end))
+ return true;
+ }
+
+ return false;
+}
+
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 075ce32..9f59394 100644
--- a/arch/arm64/kernel/vmlinux.lds.S
+++ b/arch/arm64/kernel/vmlinux.lds.S
@@ -118,6 +118,7 @@ SECTIONS
__exception_text_end = .;
IRQENTRY_TEXT
SOFTIRQENTRY_TEXT
+ ENTRY_TEXT
TEXT_TEXT
SCHED_TEXT
LOCK_TEXT
--
2.5.0