Commit 8a5c4dc5 authored by Ananth N Mavinakayanahalli's avatar Ananth N Mavinakayanahalli Committed by Linus Torvalds
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[PATCH] Kprobes: Track kprobe on a per_cpu basis - ia64 changes



IA64 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: default avatarAnanth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: default avatarAnil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 9a0e3a86
......@@ -38,13 +38,8 @@
extern void jprobe_inst_return(void);
/* kprobe_status settings */
#define KPROBE_HIT_ACTIVE 0x00000001
#define KPROBE_HIT_SS 0x00000002
static struct kprobe *current_kprobe, *kprobe_prev;
static unsigned long kprobe_status, kprobe_status_prev;
static struct pt_regs jprobe_saved_regs;
DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
enum instruction_type {A, I, M, F, B, L, X, u};
static enum instruction_type bundle_encoding[32][3] = {
......@@ -313,21 +308,22 @@ static int __kprobes valid_kprobe_addr(int template, int slot,
return 0;
}
static inline void save_previous_kprobe(void)
static inline void save_previous_kprobe(struct kprobe_ctlblk *kcb)
{
kprobe_prev = current_kprobe;
kprobe_status_prev = kprobe_status;
kcb->prev_kprobe.kp = kprobe_running();
kcb->prev_kprobe.status = kcb->kprobe_status;
}
static inline void restore_previous_kprobe(void)
static inline void restore_previous_kprobe(struct kprobe_ctlblk *kcb)
{
current_kprobe = kprobe_prev;
kprobe_status = kprobe_status_prev;
__get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp;
kcb->kprobe_status = kcb->prev_kprobe.status;
}
static inline void set_current_kprobe(struct kprobe *p)
static inline void set_current_kprobe(struct kprobe *p,
struct kprobe_ctlblk *kcb)
{
current_kprobe = p;
__get_cpu_var(current_kprobe) = p;
}
static void kretprobe_trampoline(void)
......@@ -389,6 +385,7 @@ int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
BUG_ON(!orig_ret_address || (orig_ret_address == trampoline_address));
regs->cr_iip = orig_ret_address;
reset_current_kprobe();
unlock_kprobes();
preempt_enable_no_resched();
......@@ -606,12 +603,13 @@ static int __kprobes pre_kprobes_handler(struct die_args *args)
int ret = 0;
struct pt_regs *regs = args->regs;
kprobe_opcode_t *addr = (kprobe_opcode_t *)instruction_pointer(regs);
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
/* Handle recursion cases */
if (kprobe_running()) {
p = get_kprobe(addr);
if (p) {
if ( (kprobe_status == KPROBE_HIT_SS) &&
if ((kcb->kprobe_status == KPROBE_HIT_SS) &&
(p->ainsn.inst_flag == INST_FLAG_BREAK_INST)) {
ia64_psr(regs)->ss = 0;
unlock_kprobes();
......@@ -623,17 +621,17 @@ static int __kprobes pre_kprobes_handler(struct die_args *args)
* just single step on the instruction of the new probe
* without calling any user handlers.
*/
save_previous_kprobe();
set_current_kprobe(p);
save_previous_kprobe(kcb);
set_current_kprobe(p, kcb);
p->nmissed++;
prepare_ss(p, regs);
kprobe_status = KPROBE_REENTER;
kcb->kprobe_status = KPROBE_REENTER;
return 1;
} else if (args->err == __IA64_BREAK_JPROBE) {
/*
* jprobe instrumented function just completed
*/
p = current_kprobe;
p = __get_cpu_var(current_kprobe);
if (p->break_handler && p->break_handler(p, regs)) {
goto ss_probe;
}
......@@ -668,8 +666,8 @@ static int __kprobes pre_kprobes_handler(struct die_args *args)
* in post_kprobes_handler()
*/
preempt_disable();
kprobe_status = KPROBE_HIT_ACTIVE;
set_current_kprobe(p);
set_current_kprobe(p, kcb);
kcb->kprobe_status = KPROBE_HIT_ACTIVE;
if (p->pre_handler && p->pre_handler(p, regs))
/*
......@@ -681,7 +679,7 @@ static int __kprobes pre_kprobes_handler(struct die_args *args)
ss_probe:
prepare_ss(p, regs);
kprobe_status = KPROBE_HIT_SS;
kcb->kprobe_status = KPROBE_HIT_SS;
return 1;
no_kprobe:
......@@ -690,22 +688,25 @@ no_kprobe:
static int __kprobes post_kprobes_handler(struct pt_regs *regs)
{
if (!kprobe_running())
struct kprobe *cur = kprobe_running();
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
if (!cur)
return 0;
if ((kprobe_status != KPROBE_REENTER) && current_kprobe->post_handler) {
kprobe_status = KPROBE_HIT_SSDONE;
current_kprobe->post_handler(current_kprobe, regs, 0);
if ((kcb->kprobe_status != KPROBE_REENTER) && cur->post_handler) {
kcb->kprobe_status = KPROBE_HIT_SSDONE;
cur->post_handler(cur, regs, 0);
}
resume_execution(current_kprobe, regs);
resume_execution(cur, regs);
/*Restore back the original saved kprobes variables and continue. */
if (kprobe_status == KPROBE_REENTER) {
restore_previous_kprobe();
if (kcb->kprobe_status == KPROBE_REENTER) {
restore_previous_kprobe(kcb);
goto out;
}
reset_current_kprobe();
unlock_kprobes();
out:
......@@ -715,15 +716,18 @@ out:
static int __kprobes kprobes_fault_handler(struct pt_regs *regs, int trapnr)
{
if (!kprobe_running())
struct kprobe *cur = kprobe_running();
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
if (!cur)
return 0;
if (current_kprobe->fault_handler &&
current_kprobe->fault_handler(current_kprobe, regs, trapnr))
if (cur->fault_handler && cur->fault_handler(cur, regs, trapnr))
return 1;
if (kprobe_status & KPROBE_HIT_SS) {
resume_execution(current_kprobe, regs);
if (kcb->kprobe_status & KPROBE_HIT_SS) {
resume_execution(cur, regs);
reset_current_kprobe();
unlock_kprobes();
preempt_enable_no_resched();
}
......@@ -761,9 +765,10 @@ int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
{
struct jprobe *jp = container_of(p, struct jprobe, kp);
unsigned long addr = ((struct fnptr *)(jp->entry))->ip;
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
/* save architectural state */
jprobe_saved_regs = *regs;
kcb->jprobe_saved_regs = *regs;
/* after rfi, execute the jprobe instrumented function */
regs->cr_iip = addr & ~0xFULL;
......@@ -781,7 +786,9 @@ int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
{
*regs = jprobe_saved_regs;
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
*regs = kcb->jprobe_saved_regs;
return 1;
}
......
......@@ -26,6 +26,7 @@
*/
#include <linux/types.h>
#include <linux/ptrace.h>
#include <linux/percpu.h>
#include <asm/break.h>
#define MAX_INSN_SIZE 16
......@@ -62,6 +63,18 @@ typedef struct _bundle {
} quad1;
} __attribute__((__aligned__(16))) bundle_t;
struct prev_kprobe {
struct kprobe *kp;
unsigned long status;
};
/* per-cpu kprobe control block */
struct kprobe_ctlblk {
unsigned long kprobe_status;
struct pt_regs jprobe_saved_regs;
struct prev_kprobe prev_kprobe;
};
#define JPROBE_ENTRY(pentry) (kprobe_opcode_t *)pentry
#define ARCH_SUPPORTS_KRETPROBES
......
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