From: Ananth N Mavinakayanahalli Date: Mon, 7 Nov 2005 09:00:09 +0000 (-0800) Subject: [PATCH] Kprobes: Track kprobe on a per_cpu basis - ia64 changes X-Git-Tag: v2.6.15-rc1~581 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8a5c4dc5e5d72b7802f5647082ccf3861a94f013;p=linux-2.6 [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: Ananth N Mavinakayanahalli Signed-off-by: Anil S Keshavamurthy Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/arch/ia64/kernel/kprobes.c b/arch/ia64/kernel/kprobes.c index 1e80ec80dd..17e70b1b8d 100644 --- a/arch/ia64/kernel/kprobes.c +++ b/arch/ia64/kernel/kprobes.c @@ -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; } diff --git a/include/asm-ia64/kprobes.h b/include/asm-ia64/kprobes.h index 573a3574a2..592abb000e 100644 --- a/include/asm-ia64/kprobes.h +++ b/include/asm-ia64/kprobes.h @@ -26,6 +26,7 @@ */ #include #include +#include #include #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