[PATCH -tip v6 06/27] arm64: kprobes: Remove jprobe implementation

Masami Hiramatsu
2018-06-19T16:07:33Z

Remove arch dependent setjump/longjump functions
and unused fields in kprobe_ctlblk for jprobes
from arch/arm64.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
---
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 &&