diff options
| -rw-r--r-- | arch/ia64/kernel/jprobes.S | 27 | ||||
| -rw-r--r-- | arch/ia64/kernel/kprobes.c | 57 | ||||
| -rw-r--r-- | include/asm-ia64/kprobes.h | 6 |
3 files changed, 90 insertions, 0 deletions
diff --git a/arch/ia64/kernel/jprobes.S b/arch/ia64/kernel/jprobes.S index 2323377..5cd6226f 100644 --- a/arch/ia64/kernel/jprobes.S +++ b/arch/ia64/kernel/jprobes.S @@ -60,3 +60,30 @@ END(jprobe_break) GLOBAL_ENTRY(jprobe_inst_return) br.call.sptk.many b0=jprobe_break END(jprobe_inst_return) + +GLOBAL_ENTRY(invalidate_stacked_regs) + movl r16=invalidate_restore_cfm + ;; + mov b6=r16 + ;; + br.ret.sptk.many b6 + ;; +invalidate_restore_cfm: + mov r16=ar.rsc + ;; + mov ar.rsc=r0 + ;; + loadrs + ;; + mov ar.rsc=r16 + ;; + br.cond.sptk.many rp +END(invalidate_stacked_regs) + +GLOBAL_ENTRY(flush_register_stack) + // flush dirty regs to backing store (must be first in insn group) + flushrs + ;; + br.ret.sptk.many rp +END(flush_register_stack) + diff --git a/arch/ia64/kernel/kprobes.c b/arch/ia64/kernel/kprobes.c index 346fedf..50ae8c7 100644 --- a/arch/ia64/kernel/kprobes.c +++ b/arch/ia64/kernel/kprobes.c @@ -766,11 +766,56 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, return ret; } +struct param_bsp_cfm { + unsigned long ip; + unsigned long *bsp; + unsigned long cfm; +}; + +static void ia64_get_bsp_cfm(struct unw_frame_info *info, void *arg) +{ + unsigned long ip; + struct param_bsp_cfm *lp = arg; + + do { + unw_get_ip(info, &ip); + if (ip == 0) + break; + if (ip == lp->ip) { + unw_get_bsp(info, (unsigned long*)&lp->bsp); + unw_get_cfm(info, (unsigned long*)&lp->cfm); + return; + } + } while (unw_unwind(info) >= 0); + lp->bsp = 0; + lp->cfm = 0; + return; +} + 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(); + struct param_bsp_cfm pa; + int bytes; + + /* + * Callee owns the argument space and could overwrite it, eg + * tail call optimization. So to be absolutely safe + * we save the argument space before transfering the control + * to instrumented jprobe function which runs in + * the process context + */ + pa.ip = regs->cr_iip; + unw_init_running(ia64_get_bsp_cfm, &pa); + bytes = (char *)ia64_rse_skip_regs(pa.bsp, pa.cfm & 0x3f) + - (char *)pa.bsp; + memcpy( kcb->jprobes_saved_stacked_regs, + pa.bsp, + bytes ); + kcb->bsp = pa.bsp; + kcb->cfm = pa.cfm; /* save architectural state */ kcb->jprobe_saved_regs = *regs; @@ -792,8 +837,20 @@ int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs) int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs) { struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); + int bytes; + /* restoring architectural state */ *regs = kcb->jprobe_saved_regs; + + /* restoring the original argument space */ + flush_register_stack(); + bytes = (char *)ia64_rse_skip_regs(kcb->bsp, kcb->cfm & 0x3f) + - (char *)kcb->bsp; + memcpy( kcb->bsp, + kcb->jprobes_saved_stacked_regs, + bytes ); + invalidate_stacked_regs(); + preempt_enable_no_resched(); return 1; } diff --git a/include/asm-ia64/kprobes.h b/include/asm-ia64/kprobes.h index a74b681..8c0fc22 100644 --- a/include/asm-ia64/kprobes.h +++ b/include/asm-ia64/kprobes.h @@ -68,10 +68,14 @@ struct prev_kprobe { unsigned long status; }; +#define MAX_PARAM_RSE_SIZE (0x60+0x60/0x3f) /* per-cpu kprobe control block */ struct kprobe_ctlblk { unsigned long kprobe_status; struct pt_regs jprobe_saved_regs; + unsigned long jprobes_saved_stacked_regs[MAX_PARAM_RSE_SIZE]; + unsigned long *bsp; + unsigned long cfm; struct prev_kprobe prev_kprobe; }; @@ -118,5 +122,7 @@ extern int kprobe_exceptions_notify(struct notifier_block *self, static inline void jprobe_return(void) { } +extern void invalidate_stacked_regs(void); +extern void flush_register_stack(void); #endif /* _ASM_KPROBES_H */ |