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ARM/kprobes: Remove jprobe arm implementation

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Remove arch dependent setjump/longjump functions
and unused fields in kprobe_ctlblk for jprobes
from arch/arm.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Steven Rostedt <rostedt@goodmis.org>
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 <mingo@kernel.org>
This commit is contained in:
Masami Hiramatsu 2018-06-20 01:06:34 +09:00 committed by Ingo Molnar
parent e00f1993e9
commit 454f3e132d
3 changed files with 0 additions and 117 deletions
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2
arch/arm/include/asm/kprobes.h
View file

@ -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 *);

1
arch/arm/include/asm/probes.h
View file

@ -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

114
arch/arm/probes/kprobes/core.c
View file

@ -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;