diff options
Diffstat (limited to 'arch/powerpc/kernel/kprobes.c')
| -rw-r--r-- | arch/powerpc/kernel/kprobes.c | 128 |
1 files changed, 26 insertions, 102 deletions
diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c index 1c97c0f177ae..c0d9f12cb441 100644 --- a/arch/powerpc/kernel/kprobes.c +++ b/arch/powerpc/kernel/kprobes.c @@ -19,13 +19,13 @@ #include <linux/extable.h> #include <linux/kdebug.h> #include <linux/slab.h> -#include <linux/moduleloader.h> -#include <asm/code-patching.h> +#include <linux/set_memory.h> +#include <linux/execmem.h> +#include <asm/text-patching.h> #include <asm/cacheflush.h> #include <asm/sstep.h> #include <asm/sections.h> #include <asm/inst.h> -#include <asm/set_memory.h> #include <linux/uaccess.h> DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL; @@ -105,42 +105,25 @@ kprobe_opcode_t *kprobe_lookup_name(const char *name, unsigned int offset) return addr; } -static bool arch_kprobe_on_func_entry(unsigned long offset) +static bool arch_kprobe_on_func_entry(unsigned long addr, unsigned long offset) { -#ifdef CONFIG_PPC64_ELF_ABI_V2 -#ifdef CONFIG_KPROBES_ON_FTRACE - return offset <= 16; -#else - return offset <= 8; -#endif -#else + unsigned long ip = ftrace_location(addr); + + if (ip) + return offset <= (ip - addr); + if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V2) && !IS_ENABLED(CONFIG_PPC_KERNEL_PCREL)) + return offset <= 8; return !offset; -#endif } /* XXX try and fold the magic of kprobe_lookup_name() in this */ kprobe_opcode_t *arch_adjust_kprobe_addr(unsigned long addr, unsigned long offset, bool *on_func_entry) { - *on_func_entry = arch_kprobe_on_func_entry(offset); + *on_func_entry = arch_kprobe_on_func_entry(addr, offset); return (kprobe_opcode_t *)(addr + offset); } -void *alloc_insn_page(void) -{ - void *page; - - page = module_alloc(PAGE_SIZE); - if (!page) - return NULL; - - if (strict_module_rwx_enabled()) { - set_memory_ro((unsigned long)page, 1); - set_memory_x((unsigned long)page, 1); - } - return page; -} - int arch_prepare_kprobe(struct kprobe *p) { int ret = 0; @@ -158,10 +141,14 @@ int arch_prepare_kprobe(struct kprobe *p) printk("Cannot register a kprobe on the second word of prefixed instruction\n"); ret = -EINVAL; } - preempt_disable(); prev = get_kprobe(p->addr - 1); - preempt_enable_no_resched(); - if (prev && ppc_inst_prefixed(ppc_inst_read(prev->ainsn.insn))) { + + /* + * When prev is a ftrace-based kprobe, we don't have an insn, and it + * doesn't probe for prefixed instruction. + */ + if (prev && !kprobe_ftrace(prev) && + ppc_inst_prefixed(ppc_inst_read(prev->ainsn.insn))) { printk("Cannot register a kprobe on the second word of prefixed instruction\n"); ret = -EINVAL; } @@ -239,16 +226,6 @@ static nokprobe_inline void set_current_kprobe(struct kprobe *p, struct pt_regs kcb->kprobe_saved_msr = regs->msr; } -void arch_prepare_kretprobe(struct kretprobe_instance *ri, struct pt_regs *regs) -{ - ri->ret_addr = (kprobe_opcode_t *)regs->link; - ri->fp = NULL; - - /* Replace the return addr with trampoline addr */ - regs->link = (unsigned long)__kretprobe_trampoline; -} -NOKPROBE_SYMBOL(arch_prepare_kretprobe); - static int try_to_emulate(struct kprobe *p, struct pt_regs *regs) { int ret; @@ -269,7 +246,7 @@ static int try_to_emulate(struct kprobe *p, struct pt_regs *regs) * So, we should never get here... but, its still * good to catch them, just in case... */ - printk("Can't step on instruction %s\n", ppc_inst_as_str(insn)); + printk("Can't step on instruction %08lx\n", ppc_inst_as_ulong(insn)); BUG(); } else { /* @@ -365,7 +342,7 @@ int kprobe_handler(struct pt_regs *regs) if (ret > 0) { restore_previous_kprobe(kcb); - preempt_enable_no_resched(); + preempt_enable(); return 1; } } @@ -378,7 +355,7 @@ int kprobe_handler(struct pt_regs *regs) if (p->pre_handler && p->pre_handler(p, regs)) { /* handler changed execution path, so skip ss setup */ reset_current_kprobe(); - preempt_enable_no_resched(); + preempt_enable(); return 1; } @@ -391,7 +368,7 @@ int kprobe_handler(struct pt_regs *regs) kcb->kprobe_status = KPROBE_HIT_SSDONE; reset_current_kprobe(); - preempt_enable_no_resched(); + preempt_enable(); return 1; } } @@ -400,55 +377,12 @@ int kprobe_handler(struct pt_regs *regs) return 1; no_kprobe: - preempt_enable_no_resched(); + preempt_enable(); return ret; } NOKPROBE_SYMBOL(kprobe_handler); /* - * Function return probe trampoline: - * - init_kprobes() establishes a probepoint here - * - When the probed function returns, this probe - * causes the handlers to fire - */ -asm(".global __kretprobe_trampoline\n" - ".type __kretprobe_trampoline, @function\n" - "__kretprobe_trampoline:\n" - "nop\n" - "blr\n" - ".size __kretprobe_trampoline, .-__kretprobe_trampoline\n"); - -/* - * Called when the probe at kretprobe trampoline is hit - */ -static int trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) -{ - unsigned long orig_ret_address; - - orig_ret_address = __kretprobe_trampoline_handler(regs, NULL); - /* - * We get here through one of two paths: - * 1. by taking a trap -> kprobe_handler() -> here - * 2. by optprobe branch -> optimized_callback() -> opt_pre_handler() -> here - * - * When going back through (1), we need regs->nip to be setup properly - * as it is used to determine the return address from the trap. - * For (2), since nip is not honoured with optprobes, we instead setup - * the link register properly so that the subsequent 'blr' in - * __kretprobe_trampoline jumps back to the right instruction. - * - * For nip, we should set the address to the previous instruction since - * we end up emulating it in kprobe_handler(), which increments the nip - * again. - */ - regs_set_return_ip(regs, orig_ret_address - 4); - regs->link = orig_ret_address; - - return 0; -} -NOKPROBE_SYMBOL(trampoline_probe_handler); - -/* * Called after single-stepping. p->addr is the address of the * instruction whose first byte has been replaced by the "breakpoint" * instruction. To avoid the SMP problems that can occur when we @@ -486,7 +420,7 @@ int kprobe_post_handler(struct pt_regs *regs) } reset_current_kprobe(); out: - preempt_enable_no_resched(); + preempt_enable(); /* * if somebody else is singlestepping across a probe point, msr @@ -525,7 +459,7 @@ int kprobe_fault_handler(struct pt_regs *regs, int trapnr) restore_previous_kprobe(kcb); else reset_current_kprobe(); - preempt_enable_no_resched(); + preempt_enable(); break; case KPROBE_HIT_ACTIVE: case KPROBE_HIT_SSDONE: @@ -550,19 +484,9 @@ int kprobe_fault_handler(struct pt_regs *regs, int trapnr) } NOKPROBE_SYMBOL(kprobe_fault_handler); -static struct kprobe trampoline_p = { - .addr = (kprobe_opcode_t *) &__kretprobe_trampoline, - .pre_handler = trampoline_probe_handler -}; - -int __init arch_init_kprobes(void) -{ - return register_kprobe(&trampoline_p); -} - int arch_trampoline_kprobe(struct kprobe *p) { - if (p->addr == (kprobe_opcode_t *)&__kretprobe_trampoline) + if (p->addr == (kprobe_opcode_t *)&arch_rethook_trampoline) return 1; return 0; |