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Diffstat (limited to 'arch/x86/kernel/kprobes.c')
-rw-r--r--arch/x86/kernel/kprobes.c127
1 files changed, 112 insertions, 15 deletions
diff --git a/arch/x86/kernel/kprobes.c b/arch/x86/kernel/kprobes.c
index 1cbd54c0df9..d91c477b3f6 100644
--- a/arch/x86/kernel/kprobes.c
+++ b/arch/x86/kernel/kprobes.c
@@ -403,7 +403,7 @@ static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb)
static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb)
{
- __get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp;
+ __this_cpu_write(current_kprobe, kcb->prev_kprobe.kp);
kcb->kprobe_status = kcb->prev_kprobe.status;
kcb->kprobe_old_flags = kcb->prev_kprobe.old_flags;
kcb->kprobe_saved_flags = kcb->prev_kprobe.saved_flags;
@@ -412,7 +412,7 @@ static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb)
static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
struct kprobe_ctlblk *kcb)
{
- __get_cpu_var(current_kprobe) = p;
+ __this_cpu_write(current_kprobe, p);
kcb->kprobe_saved_flags = kcb->kprobe_old_flags
= (regs->flags & (X86_EFLAGS_TF | X86_EFLAGS_IF));
if (is_IF_modifier(p->ainsn.insn))
@@ -586,7 +586,7 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
preempt_enable_no_resched();
return 1;
} else if (kprobe_running()) {
- p = __get_cpu_var(current_kprobe);
+ p = __this_cpu_read(current_kprobe);
if (p->break_handler && p->break_handler(p, regs)) {
setup_singlestep(p, regs, kcb, 0);
return 1;
@@ -759,11 +759,11 @@ static __used __kprobes void *trampoline_handler(struct pt_regs *regs)
orig_ret_address = (unsigned long)ri->ret_addr;
if (ri->rp && ri->rp->handler) {
- __get_cpu_var(current_kprobe) = &ri->rp->kp;
+ __this_cpu_write(current_kprobe, &ri->rp->kp);
get_kprobe_ctlblk()->kprobe_status = KPROBE_HIT_ACTIVE;
ri->ret_addr = correct_ret_addr;
ri->rp->handler(ri, regs);
- __get_cpu_var(current_kprobe) = NULL;
+ __this_cpu_write(current_kprobe, NULL);
}
recycle_rp_inst(ri, &empty_rp);
@@ -1184,6 +1184,10 @@ static void __kprobes optimized_callback(struct optimized_kprobe *op,
{
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
+ /* This is possible if op is under delayed unoptimizing */
+ if (kprobe_disabled(&op->kp))
+ return;
+
preempt_disable();
if (kprobe_running()) {
kprobes_inc_nmissed_count(&op->kp);
@@ -1198,10 +1202,10 @@ static void __kprobes optimized_callback(struct optimized_kprobe *op,
regs->ip = (unsigned long)op->kp.addr + INT3_SIZE;
regs->orig_ax = ~0UL;
- __get_cpu_var(current_kprobe) = &op->kp;
+ __this_cpu_write(current_kprobe, &op->kp);
kcb->kprobe_status = KPROBE_HIT_ACTIVE;
opt_pre_handler(&op->kp, regs);
- __get_cpu_var(current_kprobe) = NULL;
+ __this_cpu_write(current_kprobe, NULL);
}
preempt_enable_no_resched();
}
@@ -1401,10 +1405,16 @@ int __kprobes arch_prepare_optimized_kprobe(struct optimized_kprobe *op)
return 0;
}
-/* Replace a breakpoint (int3) with a relative jump. */
-int __kprobes arch_optimize_kprobe(struct optimized_kprobe *op)
+#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)
{
- unsigned char jmp_code[RELATIVEJUMP_SIZE];
s32 rel = (s32)((long)op->optinsn.insn -
((long)op->kp.addr + RELATIVEJUMP_SIZE));
@@ -1412,16 +1422,79 @@ int __kprobes arch_optimize_kprobe(struct optimized_kprobe *op)
memcpy(op->optinsn.copied_insn, op->kp.addr + INT3_SIZE,
RELATIVE_ADDR_SIZE);
- jmp_code[0] = RELATIVEJUMP_OPCODE;
- *(s32 *)(&jmp_code[1]) = rel;
+ 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(op->kp.addr, jmp_code, RELATIVEJUMP_SIZE);
- return 0;
+ 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). */
@@ -1453,11 +1526,35 @@ static int __kprobes setup_detour_execution(struct kprobe *p,
}
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 0;
+ return init_poke_params();
}
int __kprobes arch_trampoline_kprobe(struct kprobe *p)
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-11-15 02:57:30 +0000