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-rw-r--r--arch/x86/kernel/kprobes.c664
1 files changed, 76 insertions, 588 deletions
diff --git a/arch/x86/kernel/kprobes.c b/arch/x86/kernel/kprobes.c
index 7da647d8b64c..e213fc8408d2 100644
--- a/arch/x86/kernel/kprobes.c
+++ b/arch/x86/kernel/kprobes.c
@@ -30,16 +30,15 @@
* <jkenisto@us.ibm.com> and Prasanna S Panchamukhi
* <prasanna@in.ibm.com> added function-return probes.
* 2005-May Rusty Lynch <rusty.lynch@intel.com>
- * Added function return probes functionality
+ * Added function return probes functionality
* 2006-Feb Masami Hiramatsu <hiramatu@sdl.hitachi.co.jp> added
- * kprobe-booster and kretprobe-booster for i386.
+ * kprobe-booster and kretprobe-booster for i386.
* 2007-Dec Masami Hiramatsu <mhiramat@redhat.com> added kprobe-booster
- * and kretprobe-booster for x86-64
+ * and kretprobe-booster for x86-64
* 2007-Dec Masami Hiramatsu <mhiramat@redhat.com>, Arjan van de Ven
- * <arjan@infradead.org> and Jim Keniston <jkenisto@us.ibm.com>
- * unified x86 kprobes code.
+ * <arjan@infradead.org> and Jim Keniston <jkenisto@us.ibm.com>
+ * unified x86 kprobes code.
*/
-
#include <linux/kprobes.h>
#include <linux/ptrace.h>
#include <linux/string.h>
@@ -59,6 +58,8 @@
#include <asm/insn.h>
#include <asm/debugreg.h>
+#include "kprobes-common.h"
+
void jprobe_return_end(void);
DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
@@ -108,6 +109,7 @@ struct kretprobe_blackpoint kretprobe_blacklist[] = {
doesn't switch kernel stack.*/
{NULL, NULL} /* Terminator */
};
+
const int kretprobe_blacklist_size = ARRAY_SIZE(kretprobe_blacklist);
static void __kprobes __synthesize_relative_insn(void *from, void *to, u8 op)
@@ -123,11 +125,17 @@ static void __kprobes __synthesize_relative_insn(void *from, void *to, u8 op)
}
/* Insert a jump instruction at address 'from', which jumps to address 'to'.*/
-static void __kprobes synthesize_reljump(void *from, void *to)
+void __kprobes synthesize_reljump(void *from, void *to)
{
__synthesize_relative_insn(from, to, RELATIVEJUMP_OPCODE);
}
+/* Insert a call instruction at address 'from', which calls address 'to'.*/
+void __kprobes synthesize_relcall(void *from, void *to)
+{
+ __synthesize_relative_insn(from, to, RELATIVECALL_OPCODE);
+}
+
/*
* Skip the prefixes of the instruction.
*/
@@ -151,7 +159,7 @@ static kprobe_opcode_t *__kprobes skip_prefixes(kprobe_opcode_t *insn)
* Returns non-zero if opcode is boostable.
* RIP relative instructions are adjusted at copying time in 64 bits mode
*/
-static int __kprobes can_boost(kprobe_opcode_t *opcodes)
+int __kprobes can_boost(kprobe_opcode_t *opcodes)
{
kprobe_opcode_t opcode;
kprobe_opcode_t *orig_opcodes = opcodes;
@@ -207,13 +215,15 @@ retry:
}
}
-/* Recover the probed instruction at addr for further analysis. */
-static int recover_probed_instruction(kprobe_opcode_t *buf, unsigned long addr)
+static unsigned long
+__recover_probed_insn(kprobe_opcode_t *buf, unsigned long addr)
{
struct kprobe *kp;
+
kp = get_kprobe((void *)addr);
+ /* There is no probe, return original address */
if (!kp)
- return -EINVAL;
+ return addr;
/*
* Basically, kp->ainsn.insn has an original instruction.
@@ -230,14 +240,29 @@ static int recover_probed_instruction(kprobe_opcode_t *buf, unsigned long addr)
*/
memcpy(buf, kp->addr, MAX_INSN_SIZE * sizeof(kprobe_opcode_t));
buf[0] = kp->opcode;
- return 0;
+ return (unsigned long)buf;
+}
+
+/*
+ * Recover the probed instruction at addr for further analysis.
+ * Caller must lock kprobes by kprobe_mutex, or disable preemption
+ * for preventing to release referencing kprobes.
+ */
+unsigned long recover_probed_instruction(kprobe_opcode_t *buf, unsigned long addr)
+{
+ unsigned long __addr;
+
+ __addr = __recover_optprobed_insn(buf, addr);
+ if (__addr != addr)
+ return __addr;
+
+ return __recover_probed_insn(buf, addr);
}
/* Check if paddr is at an instruction boundary */
static int __kprobes can_probe(unsigned long paddr)
{
- int ret;
- unsigned long addr, offset = 0;
+ unsigned long addr, __addr, offset = 0;
struct insn insn;
kprobe_opcode_t buf[MAX_INSN_SIZE];
@@ -247,26 +272,24 @@ static int __kprobes can_probe(unsigned long paddr)
/* Decode instructions */
addr = paddr - offset;
while (addr < paddr) {
- kernel_insn_init(&insn, (void *)addr);
- insn_get_opcode(&insn);
-
/*
* 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
+ * normally used, we just go through if there is no kprobe.
*/
- if (insn.opcode.bytes[0] == BREAKPOINT_INSTRUCTION) {
- ret = recover_probed_instruction(buf, addr);
- if (ret)
- /*
- * Another debugging subsystem might insert
- * this breakpoint. In that case, we can't
- * recover it.
- */
- return 0;
- kernel_insn_init(&insn, buf);
- }
+ __addr = recover_probed_instruction(buf, addr);
+ kernel_insn_init(&insn, (void *)__addr);
insn_get_length(&insn);
+
+ /*
+ * Another debugging subsystem might insert this breakpoint.
+ * In that case, we can't recover it.
+ */
+ if (insn.opcode.bytes[0] == BREAKPOINT_INSTRUCTION)
+ return 0;
addr += insn.length;
}
@@ -299,24 +322,16 @@ static int __kprobes is_IF_modifier(kprobe_opcode_t *insn)
* If not, return null.
* Only applicable to 64-bit x86.
*/
-static int __kprobes __copy_instruction(u8 *dest, u8 *src, int recover)
+int __kprobes __copy_instruction(u8 *dest, u8 *src)
{
struct insn insn;
- int ret;
kprobe_opcode_t buf[MAX_INSN_SIZE];
- kernel_insn_init(&insn, src);
- if (recover) {
- insn_get_opcode(&insn);
- if (insn.opcode.bytes[0] == BREAKPOINT_INSTRUCTION) {
- ret = recover_probed_instruction(buf,
- (unsigned long)src);
- if (ret)
- return 0;
- kernel_insn_init(&insn, buf);
- }
- }
+ kernel_insn_init(&insn, (void *)recover_probed_instruction(buf, (unsigned long)src));
insn_get_length(&insn);
+ /* Another subsystem puts a breakpoint, failed to recover */
+ if (insn.opcode.bytes[0] == BREAKPOINT_INSTRUCTION)
+ return 0;
memcpy(dest, insn.kaddr, insn.length);
#ifdef CONFIG_X86_64
@@ -337,8 +352,7 @@ static int __kprobes __copy_instruction(u8 *dest, u8 *src, int recover)
* extension of the original signed 32-bit displacement would
* have given.
*/
- newdisp = (u8 *) src + (s64) insn.displacement.value -
- (u8 *) dest;
+ newdisp = (u8 *) src + (s64) insn.displacement.value - (u8 *) dest;
BUG_ON((s64) (s32) newdisp != newdisp); /* Sanity check. */
disp = (u8 *) dest + insn_offset_displacement(&insn);
*(s32 *) disp = (s32) newdisp;
@@ -349,18 +363,20 @@ static int __kprobes __copy_instruction(u8 *dest, u8 *src, int recover)
static void __kprobes arch_copy_kprobe(struct kprobe *p)
{
+ /* Copy an instruction with recovering if other optprobe modifies it.*/
+ __copy_instruction(p->ainsn.insn, p->addr);
+
/*
- * Copy an instruction without recovering int3, because it will be
- * put by another subsystem.
+ * __copy_instruction can modify the displacement of the instruction,
+ * but it doesn't affect boostable check.
*/
- __copy_instruction(p->ainsn.insn, p->addr, 0);
-
- if (can_boost(p->addr))
+ if (can_boost(p->ainsn.insn))
p->ainsn.boostable = 0;
else
p->ainsn.boostable = -1;
- p->opcode = *p->addr;
+ /* Also, displacement change doesn't affect the first byte */
+ p->opcode = p->ainsn.insn[0];
}
int __kprobes arch_prepare_kprobe(struct kprobe *p)
@@ -442,8 +458,8 @@ static void __kprobes restore_btf(void)
}
}
-void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
- struct pt_regs *regs)
+void __kprobes
+arch_prepare_kretprobe(struct kretprobe_instance *ri, struct pt_regs *regs)
{
unsigned long *sara = stack_addr(regs);
@@ -453,16 +469,8 @@ void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
*sara = (unsigned long) &kretprobe_trampoline;
}
-#ifdef CONFIG_OPTPROBES
-static int __kprobes setup_detour_execution(struct kprobe *p,
- struct pt_regs *regs,
- int reenter);
-#else
-#define setup_detour_execution(p, regs, reenter) (0)
-#endif
-
-static void __kprobes setup_singlestep(struct kprobe *p, struct pt_regs *regs,
- struct kprobe_ctlblk *kcb, int reenter)
+static void __kprobes
+setup_singlestep(struct kprobe *p, struct pt_regs *regs, struct kprobe_ctlblk *kcb, int reenter)
{
if (setup_detour_execution(p, regs, reenter))
return;
@@ -504,8 +512,8 @@ static void __kprobes setup_singlestep(struct kprobe *p, struct pt_regs *regs,
* within the handler. We save the original kprobes variables and just single
* step on the instruction of the new probe without calling any user handlers.
*/
-static int __kprobes reenter_kprobe(struct kprobe *p, struct pt_regs *regs,
- struct kprobe_ctlblk *kcb)
+static int __kprobes
+reenter_kprobe(struct kprobe *p, struct pt_regs *regs, struct kprobe_ctlblk *kcb)
{
switch (kcb->kprobe_status) {
case KPROBE_HIT_SSDONE:
@@ -600,69 +608,6 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
return 0;
}
-#ifdef CONFIG_X86_64
-#define SAVE_REGS_STRING \
- /* Skip cs, ip, orig_ax. */ \
- " subq $24, %rsp\n" \
- " pushq %rdi\n" \
- " pushq %rsi\n" \
- " pushq %rdx\n" \
- " pushq %rcx\n" \
- " pushq %rax\n" \
- " pushq %r8\n" \
- " pushq %r9\n" \
- " pushq %r10\n" \
- " pushq %r11\n" \
- " pushq %rbx\n" \
- " pushq %rbp\n" \
- " pushq %r12\n" \
- " pushq %r13\n" \
- " pushq %r14\n" \
- " pushq %r15\n"
-#define RESTORE_REGS_STRING \
- " popq %r15\n" \
- " popq %r14\n" \
- " popq %r13\n" \
- " popq %r12\n" \
- " popq %rbp\n" \
- " popq %rbx\n" \
- " popq %r11\n" \
- " popq %r10\n" \
- " popq %r9\n" \
- " popq %r8\n" \
- " popq %rax\n" \
- " popq %rcx\n" \
- " popq %rdx\n" \
- " popq %rsi\n" \
- " popq %rdi\n" \
- /* Skip orig_ax, ip, cs */ \
- " addq $24, %rsp\n"
-#else
-#define SAVE_REGS_STRING \
- /* Skip cs, ip, orig_ax and gs. */ \
- " subl $16, %esp\n" \
- " pushl %fs\n" \
- " pushl %es\n" \
- " pushl %ds\n" \
- " pushl %eax\n" \
- " pushl %ebp\n" \
- " pushl %edi\n" \
- " pushl %esi\n" \
- " pushl %edx\n" \
- " pushl %ecx\n" \
- " pushl %ebx\n"
-#define RESTORE_REGS_STRING \
- " popl %ebx\n" \
- " popl %ecx\n" \
- " popl %edx\n" \
- " popl %esi\n" \
- " 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"
-#endif
-
/*
* When a retprobed function returns, this code saves registers and
* calls trampoline_handler() runs, which calls the kretprobe's handler.
@@ -816,8 +761,8 @@ static __used __kprobes void *trampoline_handler(struct pt_regs *regs)
* jump instruction after the copied instruction, that jumps to the next
* instruction after the probepoint.
*/
-static void __kprobes resume_execution(struct kprobe *p,
- struct pt_regs *regs, struct kprobe_ctlblk *kcb)
+static void __kprobes
+resume_execution(struct kprobe *p, struct pt_regs *regs, struct kprobe_ctlblk *kcb)
{
unsigned long *tos = stack_addr(regs);
unsigned long copy_ip = (unsigned long)p->ainsn.insn;
@@ -996,8 +941,8 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
/*
* Wrapper routine for handling exceptions.
*/
-int __kprobes kprobe_exceptions_notify(struct notifier_block *self,
- unsigned long val, void *data)
+int __kprobes
+kprobe_exceptions_notify(struct notifier_block *self, unsigned long val, void *data)
{
struct die_args *args = data;
int ret = NOTIFY_DONE;
@@ -1107,466 +1052,9 @@ int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
return 0;
}
-
-#ifdef CONFIG_OPTPROBES
-
-/* Insert a call instruction at address 'from', which calls address 'to'.*/
-static void __kprobes synthesize_relcall(void *from, void *to)
-{
- __synthesize_relative_insn(from, to, RELATIVECALL_OPCODE);
-}
-
-/* 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)
-{
- asm volatile (
- ".global optprobe_template_entry\n"
- "optprobe_template_entry: \n"
-#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"
- RESTORE_REGS_STRING
- /* Skip flags entry */
- " addq $8, %rsp\n"
- " popfq\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
- RESTORE_REGS_STRING
- " addl $4, %esp\n" /* skip cs */
- " popf\n"
-#endif
- ".global optprobe_template_end\n"
- "optprobe_template_end: \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)
-{
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
- unsigned long flags;
-
- /* This is possible if op is under delayed unoptimizing */
- if (kprobe_disabled(&op->kp))
- return;
-
- local_irq_save(flags);
- if (kprobe_running()) {
- kprobes_inc_nmissed_count(&op->kp);
- } else {
- /* Save skipped registers */
-#ifdef CONFIG_X86_64
- regs->cs = __KERNEL_CS;
-#else
- regs->cs = __KERNEL_CS | get_kernel_rpl();
- regs->gs = 0;
-#endif
- regs->ip = (unsigned long)op->kp.addr + INT3_SIZE;
- regs->orig_ax = ~0UL;
-
- __this_cpu_write(current_kprobe, &op->kp);
- kcb->kprobe_status = KPROBE_HIT_ACTIVE;
- opt_pre_handler(&op->kp, regs);
- __this_cpu_write(current_kprobe, NULL);
- }
- local_irq_restore(flags);
-}
-
-static int __kprobes copy_optimized_instructions(u8 *dest, u8 *src)
-{
- int len = 0, ret;
-
- while (len < RELATIVEJUMP_SIZE) {
- ret = __copy_instruction(dest + len, src + len, 1);
- if (!ret || !can_boost(dest + len))
- return -EINVAL;
- len += ret;
- }
- /* Check whether the address range is reserved */
- if (ftrace_text_reserved(src, src + len - 1) ||
- alternatives_text_reserved(src, src + len - 1) ||
- jump_label_text_reserved(src, src + len - 1))
- return -EBUSY;
-
- return len;
-}
-
-/* Check whether insn is indirect jump */
-static int __kprobes insn_is_indirect_jump(struct insn *insn)
-{
- return ((insn->opcode.bytes[0] == 0xff &&
- (X86_MODRM_REG(insn->modrm.value) & 6) == 4) || /* Jump */
- insn->opcode.bytes[0] == 0xea); /* Segment based jump */
-}
-
-/* Check whether insn jumps into specified address range */
-static int insn_jump_into_range(struct insn *insn, unsigned long start, int len)
-{
- unsigned long target = 0;
-
- switch (insn->opcode.bytes[0]) {
- case 0xe0: /* loopne */
- case 0xe1: /* loope */
- case 0xe2: /* loop */
- case 0xe3: /* jcxz */
- case 0xe9: /* near relative jump */
- case 0xeb: /* short relative jump */
- break;
- case 0x0f:
- if ((insn->opcode.bytes[1] & 0xf0) == 0x80) /* jcc near */
- break;
- return 0;
- default:
- if ((insn->opcode.bytes[0] & 0xf0) == 0x70) /* jcc short */
- break;
- return 0;
- }
- target = (unsigned long)insn->next_byte + insn->immediate.value;
-
- return (start <= target && target <= start + len);
-}
-
-/* Decode whole function to ensure any instructions don't jump into target */
-static int __kprobes can_optimize(unsigned long paddr)
-{
- int ret;
- unsigned long addr, size = 0, offset = 0;
- struct insn insn;
- kprobe_opcode_t buf[MAX_INSN_SIZE];
-
- /* Lookup symbol including addr */
- if (!kallsyms_lookup_size_offset(paddr, &size, &offset))
- return 0;
-
- /*
- * Do not optimize in the entry code due to the unstable
- * stack handling.
- */
- if ((paddr >= (unsigned long )__entry_text_start) &&
- (paddr < (unsigned long )__entry_text_end))
- return 0;
-
- /* Check there is enough space for a relative jump. */
- if (size - offset < RELATIVEJUMP_SIZE)
- return 0;
-
- /* Decode instructions */
- addr = paddr - offset;
- while (addr < paddr - offset + size) { /* Decode until function end */
- if (search_exception_tables(addr))
- /*
- * Since some fixup code will jumps into this function,
- * we can't optimize kprobe in this function.
- */
- return 0;
- kernel_insn_init(&insn, (void *)addr);
- insn_get_opcode(&insn);
- if (insn.opcode.bytes[0] == BREAKPOINT_INSTRUCTION) {
- ret = recover_probed_instruction(buf, addr);
- if (ret)
- return 0;
- kernel_insn_init(&insn, buf);
- }
- insn_get_length(&insn);
- /* Recover address */
- insn.kaddr = (void *)addr;
- insn.next_byte = (void *)(addr + insn.length);
- /* Check any instructions don't jump into target */
- if (insn_is_indirect_jump(&insn) ||
- insn_jump_into_range(&insn, paddr + INT3_SIZE,
- RELATIVE_ADDR_SIZE))
- return 0;
- addr += insn.length;
- }
-
- return 1;
-}
-
-/* Check optimized_kprobe can actually be optimized. */
-int __kprobes arch_check_optimized_kprobe(struct optimized_kprobe *op)
-{
- int i;
- struct kprobe *p;
-
- for (i = 1; i < op->optinsn.size; i++) {
- p = get_kprobe(op->kp.addr + i);
- if (p && !kprobe_disabled(p))
- return -EEXIST;
- }
-
- return 0;
-}
-
-/* Check the addr is within the optimized instructions. */
-int __kprobes arch_within_optimized_kprobe(struct optimized_kprobe *op,
- unsigned long addr)
-{
- return ((unsigned long)op->kp.addr <= addr &&
- (unsigned long)op->kp.addr + op->optinsn.size > addr);
-}
-
-/* Free optimized instruction slot */
-static __kprobes
-void __arch_remove_optimized_kprobe(struct optimized_kprobe *op, int dirty)
-{
- if (op->optinsn.insn) {
- free_optinsn_slot(op->optinsn.insn, dirty);
- op->optinsn.insn = NULL;
- op->optinsn.size = 0;
- }
-}
-
-void __kprobes arch_remove_optimized_kprobe(struct optimized_kprobe *op)
-{
- __arch_remove_optimized_kprobe(op, 1);
-}
-
-/*
- * Copy replacing target instructions
- * Target instructions MUST be relocatable (checked inside)
- */
-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;
-
- op->optinsn.insn = get_optinsn_slot();
- 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);
- 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,
- (u8 *)op->kp.addr + op->optinsn.size);
-
- flush_icache_range((unsigned long) buf,
- (unsigned long) buf + TMPL_END_IDX +
- 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 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.
- */
-void __kprobes arch_optimize_kprobes(struct list_head *oplist)
-{
- struct optimized_kprobe *op, *tmp;
- int c = 0;
-
- 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);
- list_del_init(&op->list);
- if (++c >= MAX_OPTIMIZE_PROBES)
- break;
- }
-
- /*
- * text_poke_smp doesn't support NMI/MCE code modifying.
- * 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);
-}
-
-static void __kprobes setup_unoptimize_kprobe(struct text_poke_param *tprm,
- u8 *insn_buf,
- struct optimized_kprobe *op)
-{
- /* 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;
-}
-
-/*
- * Recover original instructions and breakpoints from relative jumps.
- * Caller must call with locking kprobe_mutex.
- */
-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);
- list_move(&op->list, done_list);
- if (++c >= MAX_OPTIMIZE_PROBES)
- break;
- }
-
- /*
- * text_poke_smp doesn't support NMI/MCE code modifying.
- * 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);
-}
-
-/* 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);
-}
-
-static int __kprobes setup_detour_execution(struct kprobe *p,
- struct pt_regs *regs,
- int reenter)
-{
- struct optimized_kprobe *op;
-
- if (p->flags & KPROBE_FLAG_OPTIMIZED) {
- /* 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;
- if (!reenter)
- reset_current_kprobe();
- preempt_enable_no_resched();
- return 1;
- }
- return 0;
-}
-
-static int __kprobes init_poke_params(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;
-}
-#else /* !CONFIG_OPTPROBES */
-static int __kprobes init_poke_params(void)
-{
- return 0;
-}
-#endif
-
int __init arch_init_kprobes(void)
{
- return init_poke_params();
+ return arch_init_optprobes();
}
int __kprobes arch_trampoline_kprobe(struct kprobe *p)