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 <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>

diff --git a/arch/arm/include/asm/kprobes.h b/arch/arm/include/asm/kprobes.h
index 5965545..82290f2 100644 (file)
--- 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 1e5b9bb..991c912 100644 (file)
--- 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 e90cc8a..2356211 100644 (file)
--- 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;