[tip:perf/core] kprobes/x86: Use text_poke_bp() instead of text_poke_smp*()
From: tip-bot for Masami Hiramatsu
Date: Sun Jul 21 2013 - 09:44:45 EST
Commit-ID: a7b0133ea94e4421a81702d5c0e6dcdbbbab8f6b
Gitweb: http://git.kernel.org/tip/a7b0133ea94e4421a81702d5c0e6dcdbbbab8f6b
Author: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
AuthorDate: Thu, 18 Jul 2013 20:47:50 +0900
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Fri, 19 Jul 2013 09:57:04 +0200
kprobes/x86: Use text_poke_bp() instead of text_poke_smp*()
Use text_poke_bp() for optimizing kprobes instead of
text_poke_smp*(). Since the number of kprobes is usually not so
large (<100) and text_poke_bp() is much lighter than
text_poke_smp() [which uses stop_machine()], this just stops
using batch processing.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
Reviewed-by: Jiri Kosina <jkosina@xxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Jason Baron <jbaron@xxxxxxxxxx>
Cc: yrl.pp-manager.tt@xxxxxxxxxxx
Cc: Borislav Petkov <bpetkov@xxxxxxx>
Link: 20130718114750.26675.9174.stgit@mhiramat-M0-7522">http://lkml.kernel.org/r/20130718114750.26675.9174.stgit@mhiramat-M0-7522
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/kernel/kprobes/common.h | 5 --
arch/x86/kernel/kprobes/core.c | 2 +-
arch/x86/kernel/kprobes/opt.c | 100 +++++++++------------------------------
3 files changed, 23 insertions(+), 84 deletions(-)
diff --git a/arch/x86/kernel/kprobes/common.h b/arch/x86/kernel/kprobes/common.h
index 2e9d4b5..c6ee63f 100644
--- a/arch/x86/kernel/kprobes/common.h
+++ b/arch/x86/kernel/kprobes/common.h
@@ -82,14 +82,9 @@ extern void synthesize_reljump(void *from, void *to);
extern void synthesize_relcall(void *from, void *to);
#ifdef CONFIG_OPTPROBES
-extern int arch_init_optprobes(void);
extern int setup_detour_execution(struct kprobe *p, struct pt_regs *regs, int reenter);
extern unsigned long __recover_optprobed_insn(kprobe_opcode_t *buf, unsigned long addr);
#else /* !CONFIG_OPTPROBES */
-static inline int arch_init_optprobes(void)
-{
- return 0;
-}
static inline int setup_detour_execution(struct kprobe *p, struct pt_regs *regs, int reenter)
{
return 0;
diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c
index 211bce4..cd49b2c 100644
--- a/arch/x86/kernel/kprobes/core.c
+++ b/arch/x86/kernel/kprobes/core.c
@@ -1068,7 +1068,7 @@ int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
int __init arch_init_kprobes(void)
{
- return arch_init_optprobes();
+ return 0;
}
int __kprobes arch_trampoline_kprobe(struct kprobe *p)
diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c
index d7d8a8c..d71e994 100644
--- a/arch/x86/kernel/kprobes/opt.c
+++ b/arch/x86/kernel/kprobes/opt.c
@@ -371,31 +371,6 @@ int __kprobes arch_prepare_optimized_kprobe(struct optimized_kprobe *op)
return 0;
}
-#define MAX_OPTIMIZE_PROBES 256
-static struct text_poke_param *jump_poke_params;
-static struct jump_poke_buffer {
- u8 buf[RELATIVEJUMP_SIZE];
-} *jump_poke_bufs;
-
-static void __kprobes setup_optimize_kprobe(struct text_poke_param *tprm,
- u8 *insn_buf,
- struct optimized_kprobe *op)
-{
- s32 rel = (s32)((long)op->optinsn.insn -
- ((long)op->kp.addr + RELATIVEJUMP_SIZE));
-
- /* Backup instructions which will be replaced by jump address */
- memcpy(op->optinsn.copied_insn, op->kp.addr + INT3_SIZE,
- RELATIVE_ADDR_SIZE);
-
- insn_buf[0] = RELATIVEJUMP_OPCODE;
- *(s32 *)(&insn_buf[1]) = rel;
-
- tprm->addr = op->kp.addr;
- tprm->opcode = insn_buf;
- tprm->len = RELATIVEJUMP_SIZE;
-}
-
/*
* Replace breakpoints (int3) with relative jumps.
* Caller must call with locking kprobe_mutex and text_mutex.
@@ -403,32 +378,38 @@ static void __kprobes setup_optimize_kprobe(struct text_poke_param *tprm,
void __kprobes arch_optimize_kprobes(struct list_head *oplist)
{
struct optimized_kprobe *op, *tmp;
- int c = 0;
+ u8 insn_buf[RELATIVEJUMP_SIZE];
list_for_each_entry_safe(op, tmp, oplist, list) {
+ s32 rel = (s32)((long)op->optinsn.insn -
+ ((long)op->kp.addr + RELATIVEJUMP_SIZE));
+
WARN_ON(kprobe_disabled(&op->kp));
- /* Setup param */
- setup_optimize_kprobe(&jump_poke_params[c],
- jump_poke_bufs[c].buf, op);
+
+ /* Backup instructions which will be replaced by jump address */
+ memcpy(op->optinsn.copied_insn, op->kp.addr + INT3_SIZE,
+ RELATIVE_ADDR_SIZE);
+
+ insn_buf[0] = RELATIVEJUMP_OPCODE;
+ *(s32 *)(&insn_buf[1]) = rel;
+
+ text_poke_bp(op->kp.addr, insn_buf, RELATIVEJUMP_SIZE,
+ op->optinsn.insn);
+
list_del_init(&op->list);
- if (++c >= MAX_OPTIMIZE_PROBES)
- break;
}
-
- text_poke_smp_batch(jump_poke_params, c);
}
-static void __kprobes setup_unoptimize_kprobe(struct text_poke_param *tprm,
- u8 *insn_buf,
- struct optimized_kprobe *op)
+/* Replace a relative jump with a breakpoint (int3). */
+void __kprobes arch_unoptimize_kprobe(struct optimized_kprobe *op)
{
+ u8 insn_buf[RELATIVEJUMP_SIZE];
+
/* Set int3 to first byte for kprobes */
insn_buf[0] = BREAKPOINT_INSTRUCTION;
memcpy(insn_buf + 1, op->optinsn.copied_insn, RELATIVE_ADDR_SIZE);
-
- tprm->addr = op->kp.addr;
- tprm->opcode = insn_buf;
- tprm->len = RELATIVEJUMP_SIZE;
+ text_poke_bp(op->kp.addr, insn_buf, RELATIVEJUMP_SIZE,
+ op->optinsn.insn);
}
/*
@@ -439,29 +420,11 @@ extern void arch_unoptimize_kprobes(struct list_head *oplist,
struct list_head *done_list)
{
struct optimized_kprobe *op, *tmp;
- int c = 0;
list_for_each_entry_safe(op, tmp, oplist, list) {
- /* Setup param */
- setup_unoptimize_kprobe(&jump_poke_params[c],
- jump_poke_bufs[c].buf, op);
+ arch_unoptimize_kprobe(op);
list_move(&op->list, done_list);
- if (++c >= MAX_OPTIMIZE_PROBES)
- break;
}
-
- text_poke_smp_batch(jump_poke_params, c);
-}
-
-/* Replace a relative jump with a breakpoint (int3). */
-void __kprobes arch_unoptimize_kprobe(struct optimized_kprobe *op)
-{
- u8 buf[RELATIVEJUMP_SIZE];
-
- /* Set int3 to first byte for kprobes */
- buf[0] = BREAKPOINT_INSTRUCTION;
- memcpy(buf + 1, op->optinsn.copied_insn, RELATIVE_ADDR_SIZE);
- text_poke_smp(op->kp.addr, buf, RELATIVEJUMP_SIZE);
}
int __kprobes
@@ -481,22 +444,3 @@ setup_detour_execution(struct kprobe *p, struct pt_regs *regs, int reenter)
}
return 0;
}
-
-int __kprobes arch_init_optprobes(void)
-{
- /* Allocate code buffer and parameter array */
- jump_poke_bufs = kmalloc(sizeof(struct jump_poke_buffer) *
- MAX_OPTIMIZE_PROBES, GFP_KERNEL);
- if (!jump_poke_bufs)
- return -ENOMEM;
-
- jump_poke_params = kmalloc(sizeof(struct text_poke_param) *
- MAX_OPTIMIZE_PROBES, GFP_KERNEL);
- if (!jump_poke_params) {
- kfree(jump_poke_bufs);
- jump_poke_bufs = NULL;
- return -ENOMEM;
- }
-
- return 0;
-}
--
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