From 2efb75cd712d8311a2d0c1ba041ded191398bca7 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Wed, 20 Jun 2018 01:07:03 +0900 Subject: arm64/kprobes: Remove jprobe implementation Remove arch dependent setjump/longjump functions and unused fields in kprobe_ctlblk for jprobes from arch/arm64. Signed-off-by: Masami Hiramatsu Acked-by: Thomas Gleixner Acked-by: Will Deacon Cc: Ananth N Mavinakayanahalli Cc: Andrew Morton Cc: Catalin Marinas Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Steven Rostedt Cc: linux-arch@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Link: https://lore.kernel.org/lkml/152942442318.15209.17767976282305601884.stgit@devbox Signed-off-by: Ingo Molnar --- arch/arm64/include/asm/kprobes.h | 1 - arch/arm64/kernel/probes/kprobes.c | 68 -------------------------------------- 2 files changed, 69 deletions(-) diff --git a/arch/arm64/include/asm/kprobes.h b/arch/arm64/include/asm/kprobes.h index 6deb8d726041..d5a44cf859e9 100644 --- a/arch/arm64/include/asm/kprobes.h +++ b/arch/arm64/include/asm/kprobes.h @@ -48,7 +48,6 @@ struct kprobe_ctlblk { unsigned long saved_irqflag; struct prev_kprobe prev_kprobe; struct kprobe_step_ctx ss_ctx; - struct pt_regs jprobe_saved_regs; }; void arch_remove_kprobe(struct kprobe *); diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c index d849d9804011..3ca2351109a6 100644 --- a/arch/arm64/kernel/probes/kprobes.c +++ b/arch/arm64/kernel/probes/kprobes.c @@ -465,74 +465,6 @@ kprobe_breakpoint_handler(struct pt_regs *regs, unsigned int esr) return DBG_HOOK_HANDLED; } -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(); - - kcb->jprobe_saved_regs = *regs; - /* - * Since we can't be sure where in the stack frame "stacked" - * pass-by-value arguments are stored we just don't try to - * duplicate any of the stack. Do not use jprobes on functions that - * use more than 64 bytes (after padding each to an 8 byte boundary) - * of arguments, or pass individual arguments larger than 16 bytes. - */ - - instruction_pointer_set(regs, (unsigned long) jp->entry); - preempt_disable(); - pause_graph_tracing(); - return 1; -} - -void __kprobes jprobe_return(void) -{ - struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); - - /* - * Jprobe handler return by entering break exception, - * encoded same as kprobe, but with following conditions - * -a special PC to identify it from the other kprobes. - * -restore stack addr to original saved pt_regs - */ - asm volatile(" mov sp, %0 \n" - "jprobe_return_break: brk %1 \n" - : - : "r" (kcb->jprobe_saved_regs.sp), - "I" (BRK64_ESR_KPROBES) - : "memory"); - - unreachable(); -} - -int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs) -{ - struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); - long stack_addr = kcb->jprobe_saved_regs.sp; - long orig_sp = kernel_stack_pointer(regs); - struct jprobe *jp = container_of(p, struct jprobe, kp); - extern const char jprobe_return_break[]; - - if (instruction_pointer(regs) != (u64) jprobe_return_break) - return 0; - - if (orig_sp != stack_addr) { - struct pt_regs *saved_regs = - (struct pt_regs *)kcb->jprobe_saved_regs.sp; - pr_err("current sp %lx does not match saved sp %lx\n", - orig_sp, stack_addr); - pr_err("Saved registers for jprobe %p\n", jp); - __show_regs(saved_regs); - pr_err("Current registers\n"); - __show_regs(regs); - BUG(); - } - unpause_graph_tracing(); - *regs = kcb->jprobe_saved_regs; - preempt_enable_no_resched(); - return 1; -} - bool arch_within_kprobe_blacklist(unsigned long addr) { if ((addr >= (unsigned long)__kprobes_text_start && -- cgit v1.2.3-59-g8ed1b