diff options
Diffstat (limited to 'arch/powerpc/kernel/kprobes.c')
| -rw-r--r-- | arch/powerpc/kernel/kprobes.c | 107 |
1 files changed, 11 insertions, 96 deletions
diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c index bbca90a5e2ec..c0d9f12cb441 100644 --- a/arch/powerpc/kernel/kprobes.c +++ b/arch/powerpc/kernel/kprobes.c @@ -19,9 +19,9 @@ #include <linux/extable.h> #include <linux/kdebug.h> #include <linux/slab.h> -#include <linux/moduleloader.h> #include <linux/set_memory.h> -#include <asm/code-patching.h> +#include <linux/execmem.h> +#include <asm/text-patching.h> #include <asm/cacheflush.h> #include <asm/sstep.h> #include <asm/sections.h> @@ -105,47 +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()) { - int err = set_memory_rox((unsigned long)page, 1); - - if (err) - goto error; - } - return page; -error: - module_memfree(page); - return NULL; -} - int arch_prepare_kprobe(struct kprobe *p) { int ret = 0; @@ -248,16 +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; @@ -415,49 +383,6 @@ no_kprobe: 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 @@ -559,19 +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; |