Dave,
This patch is similar to the one you reviewed sometime back:
http://sourceware.org/ml/systemtap/2005-q3/msg00196.html
From: Ananth N Mavinakayanahalli <[email protected]>
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: Ananth N Mavinakayanahalli <[email protected]>
Signed-off-by: Anil S Keshavamurthy <[email protected]>
---
arch/sparc64/kernel/kprobes.c | 131 +++++++++++++++++++++---------------------
include/asm-sparc64/kprobes.h | 20 ++++++
2 files changed, 87 insertions(+), 64 deletions(-)
Index: linux-2.6.14-rc3/arch/sparc64/kernel/kprobes.c
===================================================================
--- linux-2.6.14-rc3.orig/arch/sparc64/kernel/kprobes.c 2005-10-05 15:24:09.000000000 -0400
+++ linux-2.6.14-rc3/arch/sparc64/kernel/kprobes.c 2005-10-05 16:06:10.000000000 -0400
@@ -38,6 +38,9 @@
* - 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)
{
return 0;
@@ -66,46 +69,39 @@ void __kprobes arch_remove_kprobe(struct
{
}
-static struct kprobe *current_kprobe;
-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)
+static inline void save_previous_kprobe(struct kprobe_ctlblk *kcb)
{
- kprobe_status_prev = kprobe_status;
- kprobe_orig_tnpc_prev = current_kprobe_orig_tnpc;
- kprobe_orig_tstate_pil_prev = current_kprobe_orig_tstate_pil;
- kprobe_prev = current_kprobe;
+ kcb->prev_kprobe.kp = kprobe_running();
+ kcb->prev_kprobe.status = kcb->kprobe_status;
+ kcb->prev_kprobe.orig_tnpc = kcb->kprobe_orig_tnpc;
+ 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;
- current_kprobe_orig_tnpc = kprobe_orig_tnpc_prev;
- current_kprobe_orig_tstate_pil = kprobe_orig_tstate_pil_prev;
- current_kprobe = kprobe_prev;
+ __get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp;
+ kcb->kprobe_status = kcb->prev_kprobe.status;
+ kcb->kprobe_orig_tnpc = kcb->prev_kprobe.orig_tnpc;
+ 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;
- current_kprobe_orig_tstate_pil = (regs->tstate & TSTATE_PIL);
- current_kprobe = p;
+ __get_cpu_var(current_kprobe) = p;
+ kcb->kprobe_orig_tnpc = regs->tnpc;
+ 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;
/*single step inline, if it a breakpoint instruction*/
if (p->opcode == BREAKPOINT_INSTRUCTION) {
regs->tpc = (unsigned long) p->addr;
- regs->tnpc = current_kprobe_orig_tnpc;
+ regs->tnpc = kcb->kprobe_orig_tnpc;
} else {
regs->tpc = (unsigned long) &p->ainsn.insn[0];
regs->tnpc = (unsigned long) &p->ainsn.insn[1];
@@ -117,6 +113,7 @@ static int __kprobes kprobe_handler(stru
struct kprobe *p;
void *addr = (void *) regs->tpc;
int ret = 0;
+ struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
if (kprobe_running()) {
/* We *are* holding lock here, so this is safe.
@@ -124,9 +121,9 @@ static int __kprobes kprobe_handler(stru
*/
p = get_kprobe(addr);
if (p) {
- if (kprobe_status == KPROBE_HIT_SS) {
+ if (kcb->kprobe_status == KPROBE_HIT_SS) {
regs->tstate = ((regs->tstate & ~TSTATE_PIL) |
- current_kprobe_orig_tstate_pil);
+ kcb->kprobe_orig_tstate_pil);
unlock_kprobes();
goto no_kprobe;
}
@@ -136,14 +133,14 @@ static int __kprobes kprobe_handler(stru
* just single step on the instruction of the new probe
* without calling any user handlers.
*/
- save_previous_kprobe();
- set_current_kprobe(p, regs);
+ save_previous_kprobe(kcb);
+ set_current_kprobe(p, regs, kcb);
p->nmissed++;
- kprobe_status = KPROBE_REENTER;
- prepare_singlestep(p, regs);
+ kcb->kprobe_status = KPROBE_REENTER;
+ prepare_singlestep(p, regs, kcb);
return 1;
} else {
- p = current_kprobe;
+ p = __get_cpu_var(current_kprobe);
if (p->break_handler && p->break_handler(p, regs))
goto ss_probe;
}
@@ -174,14 +171,14 @@ static int __kprobes kprobe_handler(stru
* in post_kprobes_handler()
*/
preempt_disable();
- set_current_kprobe(p, regs);
- kprobe_status = KPROBE_HIT_ACTIVE;
+ set_current_kprobe(p, regs, kcb);
+ kcb->kprobe_status = KPROBE_HIT_ACTIVE;
if (p->pre_handler && p->pre_handler(p, regs))
return 1;
ss_probe:
- prepare_singlestep(p, regs);
- kprobe_status = KPROBE_HIT_SS;
+ prepare_singlestep(p, regs, kcb);
+ kcb->kprobe_status = KPROBE_HIT_SS;
return 1;
no_kprobe:
@@ -262,11 +259,12 @@ static void __kprobes retpc_fixup(struct
* This function prepares to return from the post-single-step
* 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];
- regs->tpc = current_kprobe_orig_tnpc;
+ regs->tpc = kcb->kprobe_orig_tnpc;
regs->tnpc = relbranch_fixup(insn,
(unsigned long) p->addr,
(unsigned long) &p->ainsn.insn[0],
@@ -274,26 +272,30 @@ static void __kprobes resume_execution(s
retpc_fixup(regs, insn, (unsigned long) p->addr);
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)
{
- 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, kcb);
/*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:
preempt_enable_no_resched();
@@ -304,13 +306,16 @@ out:
/* Interrupts disabled, kprobe_lock held. */
static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
{
- if (current_kprobe->fault_handler
- && current_kprobe->fault_handler(current_kprobe, regs, trapnr))
+ struct kprobe *cur = kprobe_running();
+ struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
+
+ 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, kcb);
+ reset_current_kprobe();
unlock_kprobes();
preempt_enable_no_resched();
}
@@ -370,24 +375,21 @@ asmlinkage void __kprobes kprobe_trap(un
}
/* 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)
{
struct jprobe *jp = container_of(p, struct jprobe, kp);
+ struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
- jprobe_saved_regs_location = regs;
- memcpy(&jprobe_saved_regs, regs, sizeof(*regs));
+ kcb->jprobe_saved_regs_location = regs;
+ memcpy(&(kcb->jprobe_saved_regs), regs, sizeof(*regs));
/* Save a whole stack frame, this gets arguments
* pushed onto the stack after using up all the
* arg registers.
*/
- memcpy(&jprobe_saved_stack,
+ memcpy(&(kcb->jprobe_saved_stack),
(char *) (regs->u_regs[UREG_FP] + STACK_BIAS),
- sizeof(jprobe_saved_stack));
+ sizeof(kcb->jprobe_saved_stack));
regs->tpc = (unsigned long) jp->entry;
regs->tnpc = ((unsigned long) jp->entry) + 0x4UL;
@@ -411,14 +413,15 @@ extern void __show_regs(struct pt_regs *
int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
{
u32 *addr = (u32 *) regs->tpc;
+ struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
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 "
"saved regs (%p).\n",
- regs, jprobe_saved_regs_location);
+ regs, kcb->jprobe_saved_regs_location);
printk("JPROBE: Saved registers\n");
- __show_regs(jprobe_saved_regs_location);
+ __show_regs(kcb->jprobe_saved_regs_location);
printk("JPROBE: Current registers\n");
__show_regs(regs);
BUG();
@@ -427,11 +430,11 @@ int __kprobes longjmp_break_handler(stru
* first so that UREG_FP is the original one for
* 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),
- &jprobe_saved_stack,
- sizeof(jprobe_saved_stack));
+ &(kcb->jprobe_saved_stack),
+ sizeof(kcb->jprobe_saved_stack));
return 1;
}
Index: linux-2.6.14-rc3/include/asm-sparc64/kprobes.h
===================================================================
--- linux-2.6.14-rc3.orig/include/asm-sparc64/kprobes.h 2005-09-30 17:17:35.000000000 -0400
+++ linux-2.6.14-rc3/include/asm-sparc64/kprobes.h 2005-10-05 15:33:35.000000000 -0400
@@ -3,6 +3,7 @@
#include <linux/config.h>
#include <linux/types.h>
+#include <linux/percpu.h>
typedef u32 kprobe_opcode_t;
@@ -18,6 +19,25 @@ struct arch_specific_insn {
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
extern int kprobe_exceptions_notify(struct notifier_block *self,
unsigned long val, void *data);
-
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