From 454f3e132d0520472558518df61ee14db1dbef88 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Wed, 20 Jun 2018 01:06:34 +0900 Subject: [PATCH] ARM/kprobes: Remove jprobe arm implementation Remove arch dependent setjump/longjump functions and unused fields in kprobe_ctlblk for jprobes from arch/arm. Signed-off-by: Masami Hiramatsu Acked-by: Thomas Gleixner Cc: Ananth N Mavinakayanahalli Cc: Andrew Morton Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Russell King Cc: Steven Rostedt Cc: linux-arch@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Link: https://lore.kernel.org/lkml/152942439350.15209.11127640848082283736.stgit@devbox Signed-off-by: Ingo Molnar --- arch/arm/include/asm/kprobes.h | 2 - arch/arm/include/asm/probes.h | 1 - arch/arm/probes/kprobes/core.c | 114 --------------------------------- 3 files changed, 117 deletions(-) diff --git a/arch/arm/include/asm/kprobes.h b/arch/arm/include/asm/kprobes.h index 59655459da59..82290f212d8e 100644 --- a/arch/arm/include/asm/kprobes.h +++ b/arch/arm/include/asm/kprobes.h @@ -44,8 +44,6 @@ struct prev_kprobe { struct kprobe_ctlblk { unsigned int kprobe_status; struct prev_kprobe prev_kprobe; - struct pt_regs jprobe_saved_regs; - char jprobes_stack[MAX_STACK_SIZE]; }; void arch_remove_kprobe(struct kprobe *); diff --git a/arch/arm/include/asm/probes.h b/arch/arm/include/asm/probes.h index 1e5b9bb92270..991c9127c650 100644 --- a/arch/arm/include/asm/probes.h +++ b/arch/arm/include/asm/probes.h @@ -51,7 +51,6 @@ struct arch_probes_insn { * We assume one instruction can consume at most 64 bytes stack, which is * 'push {r0-r15}'. Instructions consume more or unknown stack space like * 'str r0, [sp, #-80]' and 'str r0, [sp, r1]' should be prohibit to probe. - * Both kprobe and jprobe use this macro. */ #define MAX_STACK_SIZE 64 diff --git a/arch/arm/probes/kprobes/core.c b/arch/arm/probes/kprobes/core.c index e90cc8a08186..23562111c511 100644 --- a/arch/arm/probes/kprobes/core.c +++ b/arch/arm/probes/kprobes/core.c @@ -47,9 +47,6 @@ (unsigned long)(addr) + \ (size)) -/* Used as a marker in ARM_pc to note when we're in a jprobe. */ -#define JPROBE_MAGIC_ADDR 0xffffffff - DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL; DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); @@ -521,117 +518,6 @@ void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, regs->ARM_lr = (unsigned long)&kretprobe_trampoline; } -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(); - long sp_addr = regs->ARM_sp; - long cpsr; - - kcb->jprobe_saved_regs = *regs; - memcpy(kcb->jprobes_stack, (void *)sp_addr, MIN_STACK_SIZE(sp_addr)); - regs->ARM_pc = (long)jp->entry; - - cpsr = regs->ARM_cpsr | PSR_I_BIT; -#ifdef CONFIG_THUMB2_KERNEL - /* Set correct Thumb state in cpsr */ - if (regs->ARM_pc & 1) - cpsr |= PSR_T_BIT; - else - cpsr &= ~PSR_T_BIT; -#endif - regs->ARM_cpsr = cpsr; - - preempt_disable(); - return 1; -} - -void __kprobes jprobe_return(void) -{ - struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); - - __asm__ __volatile__ ( - /* - * Setup an empty pt_regs. Fill SP and PC fields as - * they're needed by longjmp_break_handler. - * - * We allocate some slack between the original SP and start of - * our fabricated regs. To be precise we want to have worst case - * covered which is STMFD with all 16 regs so we allocate 2 * - * sizeof(struct_pt_regs)). - * - * This is to prevent any simulated instruction from writing - * over the regs when they are accessing the stack. - */ -#ifdef CONFIG_THUMB2_KERNEL - "sub r0, %0, %1 \n\t" - "mov sp, r0 \n\t" -#else - "sub sp, %0, %1 \n\t" -#endif - "ldr r0, ="__stringify(JPROBE_MAGIC_ADDR)"\n\t" - "str %0, [sp, %2] \n\t" - "str r0, [sp, %3] \n\t" - "mov r0, sp \n\t" - "bl kprobe_handler \n\t" - - /* - * Return to the context saved by setjmp_pre_handler - * and restored by longjmp_break_handler. - */ -#ifdef CONFIG_THUMB2_KERNEL - "ldr lr, [sp, %2] \n\t" /* lr = saved sp */ - "ldrd r0, r1, [sp, %5] \n\t" /* r0,r1 = saved lr,pc */ - "ldr r2, [sp, %4] \n\t" /* r2 = saved psr */ - "stmdb lr!, {r0, r1, r2} \n\t" /* push saved lr and */ - /* rfe context */ - "ldmia sp, {r0 - r12} \n\t" - "mov sp, lr \n\t" - "ldr lr, [sp], #4 \n\t" - "rfeia sp! \n\t" -#else - "ldr r0, [sp, %4] \n\t" - "msr cpsr_cxsf, r0 \n\t" - "ldmia sp, {r0 - pc} \n\t" -#endif - : - : "r" (kcb->jprobe_saved_regs.ARM_sp), - "I" (sizeof(struct pt_regs) * 2), - "J" (offsetof(struct pt_regs, ARM_sp)), - "J" (offsetof(struct pt_regs, ARM_pc)), - "J" (offsetof(struct pt_regs, ARM_cpsr)), - "J" (offsetof(struct pt_regs, ARM_lr)) - : "memory", "cc"); -} - -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.ARM_sp; - long orig_sp = regs->ARM_sp; - struct jprobe *jp = container_of(p, struct jprobe, kp); - - if (regs->ARM_pc == JPROBE_MAGIC_ADDR) { - if (orig_sp != stack_addr) { - struct pt_regs *saved_regs = - (struct pt_regs *)kcb->jprobe_saved_regs.ARM_sp; - printk("current sp %lx does not match saved sp %lx\n", - orig_sp, stack_addr); - printk("Saved registers for jprobe %p\n", jp); - show_regs(saved_regs); - printk("Current registers\n"); - show_regs(regs); - BUG(); - } - *regs = kcb->jprobe_saved_regs; - memcpy((void *)stack_addr, kcb->jprobes_stack, - MIN_STACK_SIZE(stack_addr)); - preempt_enable_no_resched(); - return 1; - } - return 0; -} - int __kprobes arch_trampoline_kprobe(struct kprobe *p) { return 0;