提交 f215d985 编写于 作者: A Ananth N Mavinakayanahalli 提交者: Linus Torvalds

[PATCH] Kprobes: Track kprobe on a per_cpu basis - sparc64 changes

Sparc64 changes to track kprobe execution on a per-cpu basis.  We now track
the kprobe state machine independently on each cpu using an arch specific
kprobe control block.
Signed-off-by: NAnanth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: NAnil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
上级 0dc036c9
...@@ -38,6 +38,9 @@ ...@@ -38,6 +38,9 @@
* - Mark that we are no longer actively in a kprobe. * - Mark that we are no longer actively in a kprobe.
*/ */
DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
int __kprobes arch_prepare_kprobe(struct kprobe *p) int __kprobes arch_prepare_kprobe(struct kprobe *p)
{ {
return 0; return 0;
...@@ -66,46 +69,39 @@ void __kprobes arch_remove_kprobe(struct kprobe *p) ...@@ -66,46 +69,39 @@ void __kprobes arch_remove_kprobe(struct kprobe *p)
{ {
} }
static struct kprobe *current_kprobe; static inline void save_previous_kprobe(struct kprobe_ctlblk *kcb)
static unsigned long current_kprobe_orig_tnpc;
static unsigned long current_kprobe_orig_tstate_pil;
static unsigned int kprobe_status;
static struct kprobe *kprobe_prev;
static unsigned long kprobe_orig_tnpc_prev;
static unsigned long kprobe_orig_tstate_pil_prev;
static unsigned int kprobe_status_prev;
static inline void save_previous_kprobe(void)
{ {
kprobe_status_prev = kprobe_status; kcb->prev_kprobe.kp = kprobe_running();
kprobe_orig_tnpc_prev = current_kprobe_orig_tnpc; kcb->prev_kprobe.status = kcb->kprobe_status;
kprobe_orig_tstate_pil_prev = current_kprobe_orig_tstate_pil; kcb->prev_kprobe.orig_tnpc = kcb->kprobe_orig_tnpc;
kprobe_prev = current_kprobe; kcb->prev_kprobe.orig_tstate_pil = kcb->kprobe_orig_tstate_pil;
} }
static inline void restore_previous_kprobe(void) static inline void restore_previous_kprobe(struct kprobe_ctlblk *kcb)
{ {
kprobe_status = kprobe_status_prev; __get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp;
current_kprobe_orig_tnpc = kprobe_orig_tnpc_prev; kcb->kprobe_status = kcb->prev_kprobe.status;
current_kprobe_orig_tstate_pil = kprobe_orig_tstate_pil_prev; kcb->kprobe_orig_tnpc = kcb->prev_kprobe.orig_tnpc;
current_kprobe = kprobe_prev; kcb->kprobe_orig_tstate_pil = kcb->prev_kprobe.orig_tstate_pil;
} }
static inline void set_current_kprobe(struct kprobe *p, struct pt_regs *regs) static inline void set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
struct kprobe_ctlblk *kcb)
{ {
current_kprobe_orig_tnpc = regs->tnpc; __get_cpu_var(current_kprobe) = p;
current_kprobe_orig_tstate_pil = (regs->tstate & TSTATE_PIL); kcb->kprobe_orig_tnpc = regs->tnpc;
current_kprobe = p; kcb->kprobe_orig_tstate_pil = (regs->tstate & TSTATE_PIL);
} }
static inline void prepare_singlestep(struct kprobe *p, struct pt_regs *regs) static inline void prepare_singlestep(struct kprobe *p, struct pt_regs *regs,
struct kprobe_ctlblk *kcb)
{ {
regs->tstate |= TSTATE_PIL; regs->tstate |= TSTATE_PIL;
/*single step inline, if it a breakpoint instruction*/ /*single step inline, if it a breakpoint instruction*/
if (p->opcode == BREAKPOINT_INSTRUCTION) { if (p->opcode == BREAKPOINT_INSTRUCTION) {
regs->tpc = (unsigned long) p->addr; regs->tpc = (unsigned long) p->addr;
regs->tnpc = current_kprobe_orig_tnpc; regs->tnpc = kcb->kprobe_orig_tnpc;
} else { } else {
regs->tpc = (unsigned long) &p->ainsn.insn[0]; regs->tpc = (unsigned long) &p->ainsn.insn[0];
regs->tnpc = (unsigned long) &p->ainsn.insn[1]; regs->tnpc = (unsigned long) &p->ainsn.insn[1];
...@@ -117,6 +113,7 @@ static int __kprobes kprobe_handler(struct pt_regs *regs) ...@@ -117,6 +113,7 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
struct kprobe *p; struct kprobe *p;
void *addr = (void *) regs->tpc; void *addr = (void *) regs->tpc;
int ret = 0; int ret = 0;
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
if (kprobe_running()) { if (kprobe_running()) {
/* We *are* holding lock here, so this is safe. /* We *are* holding lock here, so this is safe.
...@@ -124,9 +121,9 @@ static int __kprobes kprobe_handler(struct pt_regs *regs) ...@@ -124,9 +121,9 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
*/ */
p = get_kprobe(addr); p = get_kprobe(addr);
if (p) { if (p) {
if (kprobe_status == KPROBE_HIT_SS) { if (kcb->kprobe_status == KPROBE_HIT_SS) {
regs->tstate = ((regs->tstate & ~TSTATE_PIL) | regs->tstate = ((regs->tstate & ~TSTATE_PIL) |
current_kprobe_orig_tstate_pil); kcb->kprobe_orig_tstate_pil);
unlock_kprobes(); unlock_kprobes();
goto no_kprobe; goto no_kprobe;
} }
...@@ -136,14 +133,14 @@ static int __kprobes kprobe_handler(struct pt_regs *regs) ...@@ -136,14 +133,14 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
* just single step on the instruction of the new probe * just single step on the instruction of the new probe
* without calling any user handlers. * without calling any user handlers.
*/ */
save_previous_kprobe(); save_previous_kprobe(kcb);
set_current_kprobe(p, regs); set_current_kprobe(p, regs, kcb);
p->nmissed++; p->nmissed++;
kprobe_status = KPROBE_REENTER; kcb->kprobe_status = KPROBE_REENTER;
prepare_singlestep(p, regs); prepare_singlestep(p, regs, kcb);
return 1; return 1;
} else { } else {
p = current_kprobe; p = __get_cpu_var(current_kprobe);
if (p->break_handler && p->break_handler(p, regs)) if (p->break_handler && p->break_handler(p, regs))
goto ss_probe; goto ss_probe;
} }
...@@ -174,14 +171,14 @@ static int __kprobes kprobe_handler(struct pt_regs *regs) ...@@ -174,14 +171,14 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
* in post_kprobes_handler() * in post_kprobes_handler()
*/ */
preempt_disable(); preempt_disable();
set_current_kprobe(p, regs); set_current_kprobe(p, regs, kcb);
kprobe_status = KPROBE_HIT_ACTIVE; kcb->kprobe_status = KPROBE_HIT_ACTIVE;
if (p->pre_handler && p->pre_handler(p, regs)) if (p->pre_handler && p->pre_handler(p, regs))
return 1; return 1;
ss_probe: ss_probe:
prepare_singlestep(p, regs); prepare_singlestep(p, regs, kcb);
kprobe_status = KPROBE_HIT_SS; kcb->kprobe_status = KPROBE_HIT_SS;
return 1; return 1;
no_kprobe: no_kprobe:
...@@ -262,11 +259,12 @@ static void __kprobes retpc_fixup(struct pt_regs *regs, u32 insn, ...@@ -262,11 +259,12 @@ static void __kprobes retpc_fixup(struct pt_regs *regs, u32 insn,
* This function prepares to return from the post-single-step * This function prepares to return from the post-single-step
* breakpoint trap. * breakpoint trap.
*/ */
static void __kprobes resume_execution(struct kprobe *p, struct pt_regs *regs) static void __kprobes resume_execution(struct kprobe *p,
struct pt_regs *regs, struct kprobe_ctlblk *kcb)
{ {
u32 insn = p->ainsn.insn[0]; u32 insn = p->ainsn.insn[0];
regs->tpc = current_kprobe_orig_tnpc; regs->tpc = kcb->kprobe_orig_tnpc;
regs->tnpc = relbranch_fixup(insn, regs->tnpc = relbranch_fixup(insn,
(unsigned long) p->addr, (unsigned long) p->addr,
(unsigned long) &p->ainsn.insn[0], (unsigned long) &p->ainsn.insn[0],
...@@ -274,26 +272,30 @@ static void __kprobes resume_execution(struct kprobe *p, struct pt_regs *regs) ...@@ -274,26 +272,30 @@ static void __kprobes resume_execution(struct kprobe *p, struct pt_regs *regs)
retpc_fixup(regs, insn, (unsigned long) p->addr); retpc_fixup(regs, insn, (unsigned long) p->addr);
regs->tstate = ((regs->tstate & ~TSTATE_PIL) | regs->tstate = ((regs->tstate & ~TSTATE_PIL) |
current_kprobe_orig_tstate_pil); kcb->kprobe_orig_tstate_pil);
} }
static inline int post_kprobe_handler(struct pt_regs *regs) static inline int post_kprobe_handler(struct pt_regs *regs)
{ {
if (!kprobe_running()) struct kprobe *cur = kprobe_running();
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
if (!cur)
return 0; return 0;
if ((kprobe_status != KPROBE_REENTER) && current_kprobe->post_handler) { if ((kcb->kprobe_status != KPROBE_REENTER) && cur->post_handler) {
kprobe_status = KPROBE_HIT_SSDONE; kcb->kprobe_status = KPROBE_HIT_SSDONE;
current_kprobe->post_handler(current_kprobe, regs, 0); cur->post_handler(cur, regs, 0);
} }
resume_execution(current_kprobe, regs); resume_execution(cur, regs, kcb);
/*Restore back the original saved kprobes variables and continue. */ /*Restore back the original saved kprobes variables and continue. */
if (kprobe_status == KPROBE_REENTER) { if (kcb->kprobe_status == KPROBE_REENTER) {
restore_previous_kprobe(); restore_previous_kprobe(kcb);
goto out; goto out;
} }
reset_current_kprobe();
unlock_kprobes(); unlock_kprobes();
out: out:
preempt_enable_no_resched(); preempt_enable_no_resched();
...@@ -304,13 +306,16 @@ static inline int post_kprobe_handler(struct pt_regs *regs) ...@@ -304,13 +306,16 @@ static inline int post_kprobe_handler(struct pt_regs *regs)
/* Interrupts disabled, kprobe_lock held. */ /* Interrupts disabled, kprobe_lock held. */
static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr) static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
{ {
if (current_kprobe->fault_handler struct kprobe *cur = kprobe_running();
&& current_kprobe->fault_handler(current_kprobe, regs, trapnr)) struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
if (cur->fault_handler && cur->fault_handler(cur, regs, trapnr))
return 1; return 1;
if (kprobe_status & KPROBE_HIT_SS) { if (kcb->kprobe_status & KPROBE_HIT_SS) {
resume_execution(current_kprobe, regs); resume_execution(cur, regs, kcb);
reset_current_kprobe();
unlock_kprobes(); unlock_kprobes();
preempt_enable_no_resched(); preempt_enable_no_resched();
} }
...@@ -370,24 +375,21 @@ asmlinkage void __kprobes kprobe_trap(unsigned long trap_level, ...@@ -370,24 +375,21 @@ asmlinkage void __kprobes kprobe_trap(unsigned long trap_level,
} }
/* Jprobes support. */ /* Jprobes support. */
static struct pt_regs jprobe_saved_regs;
static struct pt_regs *jprobe_saved_regs_location;
static struct sparc_stackf jprobe_saved_stack;
int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs) int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
{ {
struct jprobe *jp = container_of(p, struct jprobe, kp); struct jprobe *jp = container_of(p, struct jprobe, kp);
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
jprobe_saved_regs_location = regs; kcb->jprobe_saved_regs_location = regs;
memcpy(&jprobe_saved_regs, regs, sizeof(*regs)); memcpy(&(kcb->jprobe_saved_regs), regs, sizeof(*regs));
/* Save a whole stack frame, this gets arguments /* Save a whole stack frame, this gets arguments
* pushed onto the stack after using up all the * pushed onto the stack after using up all the
* arg registers. * arg registers.
*/ */
memcpy(&jprobe_saved_stack, memcpy(&(kcb->jprobe_saved_stack),
(char *) (regs->u_regs[UREG_FP] + STACK_BIAS), (char *) (regs->u_regs[UREG_FP] + STACK_BIAS),
sizeof(jprobe_saved_stack)); sizeof(kcb->jprobe_saved_stack));
regs->tpc = (unsigned long) jp->entry; regs->tpc = (unsigned long) jp->entry;
regs->tnpc = ((unsigned long) jp->entry) + 0x4UL; regs->tnpc = ((unsigned long) jp->entry) + 0x4UL;
...@@ -411,14 +413,15 @@ extern void __show_regs(struct pt_regs * regs); ...@@ -411,14 +413,15 @@ extern void __show_regs(struct pt_regs * regs);
int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs) int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
{ {
u32 *addr = (u32 *) regs->tpc; u32 *addr = (u32 *) regs->tpc;
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
if (addr == (u32 *) jprobe_return_trap_instruction) { if (addr == (u32 *) jprobe_return_trap_instruction) {
if (jprobe_saved_regs_location != regs) { if (kcb->jprobe_saved_regs_location != regs) {
printk("JPROBE: Current regs (%p) does not match " printk("JPROBE: Current regs (%p) does not match "
"saved regs (%p).\n", "saved regs (%p).\n",
regs, jprobe_saved_regs_location); regs, kcb->jprobe_saved_regs_location);
printk("JPROBE: Saved registers\n"); printk("JPROBE: Saved registers\n");
__show_regs(jprobe_saved_regs_location); __show_regs(kcb->jprobe_saved_regs_location);
printk("JPROBE: Current registers\n"); printk("JPROBE: Current registers\n");
__show_regs(regs); __show_regs(regs);
BUG(); BUG();
...@@ -427,11 +430,11 @@ int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs) ...@@ -427,11 +430,11 @@ int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
* first so that UREG_FP is the original one for * first so that UREG_FP is the original one for
* the stack frame restore. * the stack frame restore.
*/ */
memcpy(regs, &jprobe_saved_regs, sizeof(*regs)); memcpy(regs, &(kcb->jprobe_saved_regs), sizeof(*regs));
memcpy((char *) (regs->u_regs[UREG_FP] + STACK_BIAS), memcpy((char *) (regs->u_regs[UREG_FP] + STACK_BIAS),
&jprobe_saved_stack, &(kcb->jprobe_saved_stack),
sizeof(jprobe_saved_stack)); sizeof(kcb->jprobe_saved_stack));
return 1; return 1;
} }
......
...@@ -3,6 +3,7 @@ ...@@ -3,6 +3,7 @@
#include <linux/config.h> #include <linux/config.h>
#include <linux/types.h> #include <linux/types.h>
#include <linux/percpu.h>
typedef u32 kprobe_opcode_t; typedef u32 kprobe_opcode_t;
...@@ -18,6 +19,25 @@ struct arch_specific_insn { ...@@ -18,6 +19,25 @@ struct arch_specific_insn {
kprobe_opcode_t insn[MAX_INSN_SIZE]; kprobe_opcode_t insn[MAX_INSN_SIZE];
}; };
struct prev_kprobe {
struct kprobe *kp;
unsigned int status;
unsigned long orig_tnpc;
unsigned long orig_tstate_pil;
};
/* per-cpu kprobe control block */
struct kprobe_ctlblk {
unsigned long kprobe_status;
unsigned long kprobe_orig_tnpc;
unsigned long kprobe_orig_tstate_pil;
long *jprobe_saved_esp;
struct pt_regs jprobe_saved_regs;
struct pt_regs *jprobe_saved_regs_location;
struct sparc_stackf jprobe_saved_stack;
struct prev_kprobe prev_kprobe;
};
#ifdef CONFIG_KPROBES #ifdef CONFIG_KPROBES
extern int kprobe_exceptions_notify(struct notifier_block *self, extern int kprobe_exceptions_notify(struct notifier_block *self,
unsigned long val, void *data); unsigned long val, void *data);
......
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