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[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: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Ananth N Mavinakayanahalli 2005-11-07 01:00:11 -08:00 committed by Linus Torvalds
parent 0dc036c91a
commit f215d985e9
2 changed files with 87 additions and 64 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

131
arch/sparc64/kernel/kprobes.c
View File

@ -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 kprobe *p)
{
}
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(struct pt_regs *regs)
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(struct pt_regs *regs)
*/
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(struct pt_regs *regs)
* 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(struct pt_regs *regs)
* 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 pt_regs *regs, u32 insn,
* 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(struct kprobe *p, struct pt_regs *regs)
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(unsigned long trap_level,
}
/* 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 * 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(struct kprobe *p, struct pt_regs *regs)
* 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;
}

20
include/asm-sparc64/kprobes.h
View File

@ -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);