| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <20120510115401.18125.93504.stgit@localhost.localdomain>
Date: Thu, 10 May 2012 20:54:01 +0900
From: Masami Hiramatsu <masami.hiramatsu.pt@...achi.com>
To: Steven Rostedt <rostedt@...dmis.org>
Cc: "Frank Ch. Eigler" <fche@...hat.com>, linux-kernel@...r.kernel.org,
Ingo Molnar <mingo@...e.hu>,
Andrew Morton <akpm@...ux-foundation.org>,
Frederic Weisbecker <fweisbec@...il.com>,
"H. Peter Anvin" <hpa@...or.com>, yrl.pp-manager.tt@...achi.com,
Steven Rostedt <rostedt@...dmis.org>,
Masami Hiramatsu <masami.hiramatsu.pt@...achi.com>
Subject: [RFC PATCH -tip ] x86/kprobes: kprobes call optimization
Note: this code is still under development, but it will
be useful for the discussion to show this.
Use relative call instead of relative jump for optimizing
kprobes. This reduces x86-depend magic code and runtime
memory size.
Current jump-based optimization copies below regions
into an out-of-line buffer and add some portions to make
a detour path for each optimized probe.
ffffffff815f7009 T optprobe_template_entry
ffffffff815f7029 T optprobe_template_val
ffffffff815f7033 T optprobe_template_call
ffffffff815f7068 T optprobe_template_end
This actually consumes 0x5f == 95 bytes + copied
instructions(20bytes) + jump back (5bytes).
Since call-based optimization can share above templates
of trampoline code, it just requires 25bytes for each
optimized probe.
Steven, I saw your ftrace-based optimization code. And
this will do similar thing but a different way. I'd like
to reuse this code for getting pt_regs in both i386/x86-64.
So, that will be done as follows;
- ftrace-call calls mcount
- mcount calls ftrace handlers
- mcount checks if there is a kprobe
if so, it jumps into trampoline code
- trampoline code does same way if it is called from
probe point directly. But if it is called from mcount,
it directly returns into the ftrace-caller site.
Thank you,
Cc: Steven Rostedt <rostedt@...dmis.org>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@...achi.com>
---
Documentation/kprobes.txt | 39 +++++---
arch/x86/include/asm/kprobes.h | 15 +--
arch/x86/kernel/kprobes-common.h | 31 ++++--
arch/x86/kernel/kprobes-opt.c | 191 ++++++++++++++++----------------------
arch/x86/kernel/kprobes.c | 4 -
kernel/kprobes.c | 6 -
6 files changed, 131 insertions(+), 155 deletions(-)
diff --git a/Documentation/kprobes.txt b/Documentation/kprobes.txt
index 0cfb00f..316d5d2 100644
--- a/Documentation/kprobes.txt
+++ b/Documentation/kprobes.txt
@@ -45,7 +45,7 @@ can speed up unregistration process when you have to unregister
a lot of probes at once.
The next four subsections explain how the different types of
-probes work and how jump optimization works. They explain certain
+probes work and how call optimization works. They explain certain
things that you'll need to know in order to make the best use of
Kprobes -- e.g., the difference between a pre_handler and
a post_handler, and how to use the maxactive and nmissed fields of
@@ -163,12 +163,12 @@ In case probed function is entered but there is no kretprobe_instance
object available, then in addition to incrementing the nmissed count,
the user entry_handler invocation is also skipped.
-1.4 How Does Jump Optimization Work?
+1.4 How Does Call Optimization Work?
If your kernel is built with CONFIG_OPTPROBES=y (currently this flag
is automatically set 'y' on x86/x86-64, non-preemptive kernel) and
the "debug.kprobes_optimization" kernel parameter is set to 1 (see
-sysctl(8)), Kprobes tries to reduce probe-hit overhead by using a jump
+sysctl(8)), Kprobes tries to reduce probe-hit overhead by using a call
instruction instead of a breakpoint instruction at each probepoint.
1.4.1 Init a Kprobe
@@ -182,9 +182,9 @@ probepoint, there'll be a probe there.
Before optimizing a probe, Kprobes performs the following safety checks:
-- Kprobes verifies that the region that will be replaced by the jump
+- Kprobes verifies that the region that will be replaced by the call
instruction (the "optimized region") lies entirely within one function.
-(A jump instruction is multiple bytes, and so may overlay multiple
+(A call instruction is multiple bytes, and so may overlay multiple
instructions.)
- Kprobes analyzes the entire function and verifies that there is no
@@ -204,9 +204,6 @@ the instruction can be executed out of line.
Next, Kprobes prepares a "detour" buffer, which contains the following
instruction sequence:
-- code to push the CPU's registers (emulating a breakpoint trap)
-- a call to the trampoline code which calls user's probe handlers.
-- code to restore registers
- the instructions from the optimized region
- a jump back to the original execution path.
@@ -231,7 +228,7 @@ the CPU's instruction pointer to the copied code in the detour buffer
1.4.5 Optimization
-The Kprobe-optimizer doesn't insert the jump instruction immediately;
+The Kprobe-optimizer doesn't insert the call instruction immediately;
rather, it calls synchronize_sched() for safety first, because it's
possible for a CPU to be interrupted in the middle of executing the
optimized region(*). As you know, synchronize_sched() can ensure
@@ -240,10 +237,20 @@ was called are done, but only if CONFIG_PREEMPT=n. So, this version
of kprobe optimization supports only kernels with CONFIG_PREEMPT=n.(**)
After that, the Kprobe-optimizer calls stop_machine() to replace
-the optimized region with a jump instruction to the detour buffer,
-using text_poke_smp().
+the optimized region with a call instruction to the trampoline code,
+by using text_poke_smp().
-1.4.6 Unoptimization
+1.4.6 Trampoline code
+
+The trampoline code doing as follows;
+- save all registers (to make pt_regs on stack)
+- pass call-address (which was on the top of original stack)
+ and pt_regs to optprobe_callback
+- optprobe callback finding kprobes on the call address and
+ returns the address of detour buffer
+- restore all registers and return to the address
+
+1.4.7 Unoptimization
When an optimized kprobe is unregistered, disabled, or blocked by
another kprobe, it will be unoptimized. If this happens before
@@ -571,7 +578,7 @@ reason, Kprobes doesn't support return probes (or kprobes or jprobes)
on the x86_64 version of __switch_to(); the registration functions
return -EINVAL.
-On x86/x86-64, since the Jump Optimization of Kprobes modifies
+On x86/x86-64, since the Call Optimization of Kprobes modifies
instructions widely, there are some limitations to optimization. To
explain it, we introduce some terminology. Imagine a 3-instruction
sequence consisting of a two 2-byte instructions and one 3-byte
@@ -593,7 +600,7 @@ DCR: Detoured Code Region
The instructions in DCR are copied to the out-of-line buffer
of the kprobe, because the bytes in DCR are replaced by
-a 5-byte jump instruction. So there are several limitations.
+a 5-byte call instruction. So there are several limitations.
a) The instructions in DCR must be relocatable.
b) The instructions in DCR must not include a call instruction.
@@ -704,8 +711,8 @@ Appendix B: The kprobes sysctl interface
/proc/sys/debug/kprobes-optimization: Turn kprobes optimization ON/OFF.
When CONFIG_OPTPROBES=y, this sysctl interface appears and it provides
-a knob to globally and forcibly turn jump optimization (see section
-1.4) ON or OFF. By default, jump optimization is allowed (ON).
+a knob to globally and forcibly turn the call optimization (see section
+1.4) ON or OFF. By default, call optimization is allowed (ON).
If you echo "0" to this file or set "debug.kprobes_optimization" to
0 via sysctl, all optimized probes will be unoptimized, and any new
probes registered after that will not be optimized. Note that this
diff --git a/arch/x86/include/asm/kprobes.h b/arch/x86/include/asm/kprobes.h
index 5478825..c6e0dec 100644
--- a/arch/x86/include/asm/kprobes.h
+++ b/arch/x86/include/asm/kprobes.h
@@ -36,6 +36,7 @@ typedef u8 kprobe_opcode_t;
#define RELATIVEJUMP_OPCODE 0xe9
#define RELATIVEJUMP_SIZE 5
#define RELATIVECALL_OPCODE 0xe8
+#define RELATIVECALL_SIZE 5
#define RELATIVE_ADDR_SIZE 4
#define MAX_STACK_SIZE 64
#define MIN_STACK_SIZE(ADDR) \
@@ -47,16 +48,10 @@ typedef u8 kprobe_opcode_t;
#define flush_insn_slot(p) do { } while (0)
-/* optinsn template addresses */
-extern kprobe_opcode_t optprobe_template_entry;
-extern kprobe_opcode_t optprobe_template_val;
-extern kprobe_opcode_t optprobe_template_call;
-extern kprobe_opcode_t optprobe_template_end;
-#define MAX_OPTIMIZED_LENGTH (MAX_INSN_SIZE + RELATIVE_ADDR_SIZE)
-#define MAX_OPTINSN_SIZE \
- (((unsigned long)&optprobe_template_end - \
- (unsigned long)&optprobe_template_entry) + \
- MAX_OPTIMIZED_LENGTH + RELATIVEJUMP_SIZE)
+/* optprobe trampoline addresses */
+void optprobe_trampoline(void);
+#define MAX_OPTIMIZED_LENGTH (MAX_INSN_SIZE + RELATIVE_ADDR_SIZE)
+#define MAX_OPTINSN_SIZE (MAX_OPTIMIZED_LENGTH + RELATIVEJUMP_SIZE)
extern const int kretprobe_blacklist_size;
diff --git a/arch/x86/kernel/kprobes-common.h b/arch/x86/kernel/kprobes-common.h
index 3230b68..fedc8a3 100644
--- a/arch/x86/kernel/kprobes-common.h
+++ b/arch/x86/kernel/kprobes-common.h
@@ -4,9 +4,8 @@
/* Kprobes and Optprobes common header */
#ifdef CONFIG_X86_64
-#define SAVE_REGS_STRING \
- /* Skip cs, ip, orig_ax. */ \
- " subq $24, %rsp\n" \
+#define SAVE_REGS_STRING_OFF(offs) \
+ " subq $" #offs ", %rsp\n" \
" pushq %rdi\n" \
" pushq %rsi\n" \
" pushq %rdx\n" \
@@ -22,7 +21,7 @@
" pushq %r13\n" \
" pushq %r14\n" \
" pushq %r15\n"
-#define RESTORE_REGS_STRING \
+#define RESTORE_REGS_STRING_OFF(offs) \
" popq %r15\n" \
" popq %r14\n" \
" popq %r13\n" \
@@ -38,12 +37,15 @@
" popq %rdx\n" \
" popq %rsi\n" \
" popq %rdi\n" \
- /* Skip orig_ax, ip, cs */ \
- " addq $24, %rsp\n"
+ " addq $" #offs ", %rsp\n"
+
+/* skip cs, ip, orig_ax */
+#define SAVE_REGS_STRING SAVE_REGS_STRING_OFF(24)
+#define RESTORE_REGS_STRING RESTORE_REGS_STRING_OFF(24)
+
#else
-#define SAVE_REGS_STRING \
- /* Skip cs, ip, orig_ax and gs. */ \
- " subl $16, %esp\n" \
+#define SAVE_REGS_STRING_OFF(offs) \
+ " subl $" #offs ", %esp\n" \
" pushl %fs\n" \
" pushl %es\n" \
" pushl %ds\n" \
@@ -54,7 +56,7 @@
" pushl %edx\n" \
" pushl %ecx\n" \
" pushl %ebx\n"
-#define RESTORE_REGS_STRING \
+#define RESTORE_REGS_STRING_OFF(offs) \
" popl %ebx\n" \
" popl %ecx\n" \
" popl %edx\n" \
@@ -62,8 +64,13 @@
" popl %edi\n" \
" popl %ebp\n" \
" popl %eax\n" \
- /* Skip ds, es, fs, gs, orig_ax, and ip. Note: don't pop cs here*/\
- " addl $24, %esp\n"
+ " addl $" #offs ", %esp\n"
+
+/* skip cs, ip, orig_ax and gs. */
+#define SAVE_REGS_STRING SAVE_REGS_STRING_OFF(16)
+/* skip ds, es, fs, gs, orig_ax, and ip. Note: don't pop cs here*/
+#define RESTORE_REGS_STRING RESTORE_REGS_STRING_OFF(24)
+
#endif
/* Ensure if the instruction can be boostable */
diff --git a/arch/x86/kernel/kprobes-opt.c b/arch/x86/kernel/kprobes-opt.c
index c5e410e..0b0a382 100644
--- a/arch/x86/kernel/kprobes-opt.c
+++ b/arch/x86/kernel/kprobes-opt.c
@@ -1,5 +1,5 @@
/*
- * Kernel Probes Jump Optimization (Optprobes)
+ * Kernel Probes Call Optimization (Optprobes)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
@@ -46,9 +46,9 @@ unsigned long __recover_optprobed_insn(kprobe_opcode_t *buf, unsigned long addr)
long offs;
int i;
- for (i = 0; i < RELATIVEJUMP_SIZE; i++) {
+ for (i = 0; i < RELATIVECALL_SIZE; i++) {
kp = get_kprobe((void *)addr - i);
- /* This function only handles jump-optimized kprobe */
+ /* This function only handles call-optimized kprobe */
if (kp && kprobe_optimized(kp)) {
op = container_of(kp, struct optimized_kprobe, kp);
/* If op->list is not empty, op is under optimizing */
@@ -61,7 +61,7 @@ unsigned long __recover_optprobed_insn(kprobe_opcode_t *buf, unsigned long addr)
found:
/*
* If the kprobe can be optimized, original bytes which can be
- * overwritten by jump destination address. In this case, original
+ * overwritten by call destination address. In this case, original
* bytes must be recovered from op->optinsn.copied_insn buffer.
*/
memcpy(buf, (void *)addr, MAX_INSN_SIZE * sizeof(kprobe_opcode_t));
@@ -76,83 +76,69 @@ found:
return (unsigned long)buf;
}
-/* Insert a move instruction which sets a pointer to eax/rdi (1st arg). */
-static void __kprobes synthesize_set_arg1(kprobe_opcode_t *addr, unsigned long val)
-{
-#ifdef CONFIG_X86_64
- *addr++ = 0x48;
- *addr++ = 0xbf;
-#else
- *addr++ = 0xb8;
-#endif
- *(unsigned long *)addr = val;
-}
-
-static void __used __kprobes kprobes_optinsn_template_holder(void)
+static void __used __kprobes optprobe_trampoline_holder(void)
{
asm volatile (
- ".global optprobe_template_entry\n"
- "optprobe_template_entry:\n"
+ ".global optprobe_trampoline\n"
+ "optprobe_trampoline:\n"
+ /* When call to here, the stack has call address+5 */
#ifdef CONFIG_X86_64
/* We don't bother saving the ss register */
" pushq %rsp\n"
" pushfq\n"
SAVE_REGS_STRING
- " movq %rsp, %rsi\n"
- ".global optprobe_template_val\n"
- "optprobe_template_val:\n"
- ASM_NOP5
- ASM_NOP5
- ".global optprobe_template_call\n"
- "optprobe_template_call:\n"
- ASM_NOP5
- /* Move flags to rsp */
- " movq 144(%rsp), %rdx\n"
- " movq %rdx, 152(%rsp)\n"
+ " movq %rsp, %rsi\n" /* pt_regs */
+ " movq 160(%rsp), %rdi\n" /* call address */
+ " call optimized_callback\n"
+ /* Replace call address with stub address */
+ " movq %rax, 160(%rsp)\n"
RESTORE_REGS_STRING
- /* Skip flags entry */
- " addq $8, %rsp\n"
" popfq\n"
+ /* Skip rsp entry */
+ " addq $8, %rsp\n"
#else /* CONFIG_X86_32 */
" pushf\n"
- SAVE_REGS_STRING
- " movl %esp, %edx\n"
- ".global optprobe_template_val\n"
- "optprobe_template_val:\n"
- ASM_NOP5
- ".global optprobe_template_call\n"
- "optprobe_template_call:\n"
- ASM_NOP5
+ /* skip only ip, orig_ax, and gs (flags saved on cs) */
+ SAVE_REGS_STRING_OFF(12)
+ " movl 56(%esp), %eax\n" /* call address */
+ /* recover flags from cs */
+ " movl 52(%esp), %edx\n"
+ " movl %edx, 56(%esp)\n"
+ " movl %esp, %edx\n" /* pt_regs */
+ " call optimized_callback\n"
+ /* Move flags to cs */
+ " movl 56(%esp), %edx\n"
+ " movl %edx, 52(%esp)\n"
+ /* Replace flags with stub address */
+ " movl %eax, 56(%esp)\n"
RESTORE_REGS_STRING
- " addl $4, %esp\n" /* skip cs */
" popf\n"
#endif
- ".global optprobe_template_end\n"
- "optprobe_template_end:\n");
+ " ret\n");
}
-#define TMPL_MOVE_IDX \
- ((long)&optprobe_template_val - (long)&optprobe_template_entry)
-#define TMPL_CALL_IDX \
- ((long)&optprobe_template_call - (long)&optprobe_template_entry)
-#define TMPL_END_IDX \
- ((long)&optprobe_template_end - (long)&optprobe_template_entry)
-
#define INT3_SIZE sizeof(kprobe_opcode_t)
/* Optimized kprobe call back function: called from optinsn */
-static void __kprobes optimized_callback(struct optimized_kprobe *op, struct pt_regs *regs)
+static __used __kprobes kprobe_opcode_t *optimized_callback(kprobe_opcode_t *addr, struct pt_regs *regs)
{
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
+ struct optimized_kprobe *op;
+ struct kprobe_ctlblk *kcb;
unsigned long flags;
+ struct kprobe *p;
+
+ local_irq_save(flags);
+
+ kcb = get_kprobe_ctlblk();
+ p = get_kprobe(addr - RELATIVECALL_SIZE);
+ BUG_ON(!p);
/* This is possible if op is under delayed unoptimizing */
- if (kprobe_disabled(&op->kp))
- return;
+ if (kprobe_disabled(p))
+ goto end;
- local_irq_save(flags);
if (kprobe_running()) {
- kprobes_inc_nmissed_count(&op->kp);
+ kprobes_inc_nmissed_count(p);
} else {
/* Save skipped registers */
#ifdef CONFIG_X86_64
@@ -161,22 +147,26 @@ static void __kprobes optimized_callback(struct optimized_kprobe *op, struct pt_
regs->cs = __KERNEL_CS | get_kernel_rpl();
regs->gs = 0;
#endif
- regs->ip = (unsigned long)op->kp.addr + INT3_SIZE;
+ regs->ip = (unsigned long)p->addr + INT3_SIZE;
regs->orig_ax = ~0UL;
- __this_cpu_write(current_kprobe, &op->kp);
+ __this_cpu_write(current_kprobe, p);
kcb->kprobe_status = KPROBE_HIT_ACTIVE;
- opt_pre_handler(&op->kp, regs);
+ opt_pre_handler(p, regs);
__this_cpu_write(current_kprobe, NULL);
}
+end:
+ op = container_of(p, struct optimized_kprobe, kp);
+ addr = (kprobe_opcode_t *)(op->optinsn.insn);
local_irq_restore(flags);
+ return addr;
}
static int __kprobes copy_optimized_instructions(u8 *dest, u8 *src)
{
int len = 0, ret;
- while (len < RELATIVEJUMP_SIZE) {
+ while (len < RELATIVECALL_SIZE) {
ret = __copy_instruction(dest + len, src + len);
if (!ret || !can_boost(dest + len))
return -EINVAL;
@@ -245,8 +235,8 @@ static int __kprobes can_optimize(unsigned long paddr)
(paddr < (unsigned long)__entry_text_end))
return 0;
- /* Check there is enough space for a relative jump. */
- if (size - offset < RELATIVEJUMP_SIZE)
+ /* Check there is enough space for a relative call. */
+ if (size - offset < RELATIVECALL_SIZE)
return 0;
/* Decode instructions */
@@ -325,7 +315,6 @@ int __kprobes arch_prepare_optimized_kprobe(struct optimized_kprobe *op)
{
u8 *buf;
int ret;
- long rel;
if (!can_optimize((unsigned long)op->kp.addr))
return -EILSEQ;
@@ -334,70 +323,52 @@ int __kprobes arch_prepare_optimized_kprobe(struct optimized_kprobe *op)
if (!op->optinsn.insn)
return -ENOMEM;
- /*
- * Verify if the address gap is in 2GB range, because this uses
- * a relative jump.
- */
- rel = (long)op->optinsn.insn - (long)op->kp.addr + RELATIVEJUMP_SIZE;
- if (abs(rel) > 0x7fffffff)
- return -ERANGE;
-
buf = (u8 *)op->optinsn.insn;
/* Copy instructions into the out-of-line buffer */
- ret = copy_optimized_instructions(buf + TMPL_END_IDX, op->kp.addr);
+ ret = copy_optimized_instructions(buf, op->kp.addr);
if (ret < 0) {
__arch_remove_optimized_kprobe(op, 0);
return ret;
}
op->optinsn.size = ret;
- /* Copy arch-dep-instance from template */
- memcpy(buf, &optprobe_template_entry, TMPL_END_IDX);
-
- /* Set probe information */
- synthesize_set_arg1(buf + TMPL_MOVE_IDX, (unsigned long)op);
-
- /* Set probe function call */
- synthesize_relcall(buf + TMPL_CALL_IDX, optimized_callback);
-
/* Set returning jmp instruction at the tail of out-of-line buffer */
- synthesize_reljump(buf + TMPL_END_IDX + op->optinsn.size,
+ synthesize_reljump(buf + op->optinsn.size,
(u8 *)op->kp.addr + op->optinsn.size);
- flush_icache_range((unsigned long) buf,
- (unsigned long) buf + TMPL_END_IDX +
+ flush_icache_range((unsigned long) buf, (unsigned long) buf +
op->optinsn.size + RELATIVEJUMP_SIZE);
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 struct text_poke_param *call_poke_params;
+static struct call_poke_buffer {
+ u8 buf[RELATIVECALL_SIZE];
+} *call_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));
+ s32 rel = (s32)((long)&optprobe_trampoline -
+ ((long)op->kp.addr + RELATIVECALL_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;
+ insn_buf[0] = RELATIVECALL_OPCODE;
*(s32 *)(&insn_buf[1]) = rel;
tprm->addr = op->kp.addr;
tprm->opcode = insn_buf;
- tprm->len = RELATIVEJUMP_SIZE;
+ tprm->len = RELATIVECALL_SIZE;
}
/*
- * Replace breakpoints (int3) with relative jumps.
+ * Replace breakpoints (int3) with relative calls.
* Caller must call with locking kprobe_mutex and text_mutex.
*/
void __kprobes arch_optimize_kprobes(struct list_head *oplist)
@@ -408,8 +379,8 @@ void __kprobes arch_optimize_kprobes(struct list_head *oplist)
list_for_each_entry_safe(op, tmp, oplist, list) {
WARN_ON(kprobe_disabled(&op->kp));
/* Setup param */
- setup_optimize_kprobe(&jump_poke_params[c],
- jump_poke_bufs[c].buf, op);
+ setup_optimize_kprobe(&call_poke_params[c],
+ call_poke_bufs[c].buf, op);
list_del_init(&op->list);
if (++c >= MAX_OPTIMIZE_PROBES)
break;
@@ -420,7 +391,7 @@ void __kprobes arch_optimize_kprobes(struct list_head *oplist)
* However, since kprobes itself also doesn't support NMI/MCE
* code probing, it's not a problem.
*/
- text_poke_smp_batch(jump_poke_params, c);
+ text_poke_smp_batch(call_poke_params, c);
}
static void __kprobes setup_unoptimize_kprobe(struct text_poke_param *tprm,
@@ -433,11 +404,11 @@ static void __kprobes setup_unoptimize_kprobe(struct text_poke_param *tprm,
tprm->addr = op->kp.addr;
tprm->opcode = insn_buf;
- tprm->len = RELATIVEJUMP_SIZE;
+ tprm->len = RELATIVECALL_SIZE;
}
/*
- * Recover original instructions and breakpoints from relative jumps.
+ * Recover original instructions and breakpoints from relative calls.
* Caller must call with locking kprobe_mutex.
*/
extern void arch_unoptimize_kprobes(struct list_head *oplist,
@@ -448,8 +419,8 @@ extern void arch_unoptimize_kprobes(struct list_head *oplist,
list_for_each_entry_safe(op, tmp, oplist, list) {
/* Setup param */
- setup_unoptimize_kprobe(&jump_poke_params[c],
- jump_poke_bufs[c].buf, op);
+ setup_unoptimize_kprobe(&call_poke_params[c],
+ call_poke_bufs[c].buf, op);
list_move(&op->list, done_list);
if (++c >= MAX_OPTIMIZE_PROBES)
break;
@@ -460,18 +431,18 @@ extern void arch_unoptimize_kprobes(struct list_head *oplist,
* However, since kprobes itself also doesn't support NMI/MCE
* code probing, it's not a problem.
*/
- text_poke_smp_batch(jump_poke_params, c);
+ text_poke_smp_batch(call_poke_params, c);
}
/* Replace a relative jump with a breakpoint (int3). */
void __kprobes arch_unoptimize_kprobe(struct optimized_kprobe *op)
{
- u8 buf[RELATIVEJUMP_SIZE];
+ u8 buf[RELATIVECALL_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);
+ text_poke_smp(op->kp.addr, buf, RELATIVECALL_SIZE);
}
int __kprobes
@@ -483,7 +454,7 @@ setup_detour_execution(struct kprobe *p, struct pt_regs *regs, int reenter)
/* This kprobe is really able to run optimized path. */
op = container_of(p, struct optimized_kprobe, kp);
/* Detour through copied instructions */
- regs->ip = (unsigned long)op->optinsn.insn + TMPL_END_IDX;
+ regs->ip = (unsigned long)op->optinsn.insn;
if (!reenter)
reset_current_kprobe();
preempt_enable_no_resched();
@@ -495,16 +466,16 @@ setup_detour_execution(struct kprobe *p, struct pt_regs *regs, int reenter)
int __kprobes arch_init_optprobes(void)
{
/* Allocate code buffer and parameter array */
- jump_poke_bufs = kmalloc(sizeof(struct jump_poke_buffer) *
+ call_poke_bufs = kmalloc(sizeof(struct call_poke_buffer) *
MAX_OPTIMIZE_PROBES, GFP_KERNEL);
- if (!jump_poke_bufs)
+ if (!call_poke_bufs)
return -ENOMEM;
- jump_poke_params = kmalloc(sizeof(struct text_poke_param) *
+ call_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;
+ if (!call_poke_params) {
+ kfree(call_poke_bufs);
+ call_poke_bufs = NULL;
return -ENOMEM;
}
diff --git a/arch/x86/kernel/kprobes.c b/arch/x86/kernel/kprobes.c
index e2f751e..2fe982c 100644
--- a/arch/x86/kernel/kprobes.c
+++ b/arch/x86/kernel/kprobes.c
@@ -276,8 +276,8 @@ static int __kprobes can_probe(unsigned long paddr)
* Check if the instruction has been modified by another
* kprobe, in which case we replace the breakpoint by the
* original instruction in our buffer.
- * Also, jump optimization will change the breakpoint to
- * relative-jump. Since the relative-jump itself is
+ * Also, call optimization will change the breakpoint to
+ * relative-call. Since the relative-call itself is
* normally used, we just go through if there is no kprobe.
*/
__addr = recover_probed_instruction(buf, addr);
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index c62b854..b1552dd 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -290,7 +290,7 @@ void __kprobes free_insn_slot(kprobe_opcode_t * slot, int dirty)
static DEFINE_MUTEX(kprobe_optinsn_mutex); /* Protects kprobe_optinsn_slots */
static struct kprobe_insn_cache kprobe_optinsn_slots = {
.pages = LIST_HEAD_INIT(kprobe_optinsn_slots.pages),
- /* .insn_size is initialized later */
+ .insn_size = MAX_OPTINSN_SIZE,
.nr_garbage = 0,
};
/* Get a slot for optimized_kprobe buffer */
@@ -2002,10 +2002,6 @@ static int __init init_kprobes(void)
}
#if defined(CONFIG_OPTPROBES)
-#if defined(__ARCH_WANT_KPROBES_INSN_SLOT)
- /* Init kprobe_optinsn_slots */
- kprobe_optinsn_slots.insn_size = MAX_OPTINSN_SIZE;
-#endif
/* By default, kprobes can be optimized */
kprobes_allow_optimization = true;
#endif
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists