[PATCH -tip v6 04/27] ARC: kprobes: Remove jprobe implementation

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

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

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: linux-snps-arc@lists.infradead.org
---
arch/arc/include/asm/kprobes.h | 2 --
arch/arc/kernel/kprobes.c | 38 ++------------------------------------
2 files changed, 2 insertions(+), 38 deletions(-)

diff --git a/arch/arc/include/asm/kprobes.h b/arch/arc/include/asm/kprobes.h
index 2e52d18e6bc7..2c1b479d5aea 100644
--- a/arch/arc/include/asm/kprobes.h
+++ b/arch/arc/include/asm/kprobes.h
@@ -45,8 +45,6 @@ struct prev_kprobe {

struct kprobe_ctlblk {
unsigned int kprobe_status;
- struct pt_regs jprobe_saved_regs;
- char jprobes_stack[MAX_STACK_SIZE];
struct prev_kprobe prev_kprobe;
};

diff --git a/arch/arc/kernel/kprobes.c b/arch/arc/kernel/kprobes.c
index 42b05046fad9..7811a6bbe8f0 100644
--- a/arch/arc/kernel/kprobes.c
+++ b/arch/arc/kernel/kprobes.c
@@ -225,10 +225,8 @@ int __kprobes arc_kprobe_handler(unsigned long addr, struct pt_regs *regs)

/* If we have no pre-handler or it returned 0, we continue with
* normal processing. If we have a pre-handler and it returned
- * non-zero - which is expected from setjmp_pre_handler for
- * jprobe, we return without single stepping and leave that to
- * the break-handler which is invoked by a kprobe from
- * jprobe_return
+ * non-zero - which means user handler setup registers to exit
+ * to another instruction, we must skip the single stepping.
*/
if (!p->pre_handler || !p->pre_handler(p, regs)) {
setup_singlestep(p, regs);
@@ -386,38 +384,6 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self,
return ret;
}

-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();
- unsigned long sp_addr = regs->sp;
-
- kcb->jprobe_saved_regs = *regs;
- memcpy(kcb->jprobes_stack, (void *)sp_addr, MIN_STACK_SIZE(sp_addr));
- regs->ret = (unsigned long)(jp->entry);
-
- return 1;
-}
-
-void __kprobes jprobe_return(void)
-{
- __asm__ __volatile__("unimp_s");
- return;
-}
-
-int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
-{
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
- unsigned long sp_addr;
-
- *regs = kcb->jprobe_saved_regs;
- sp_addr = regs->sp;
- memcpy((void *)sp_addr, kcb->jprobes_stack, MIN_STACK_SIZE(sp_addr));
- preempt_enable_no_resched();
-
- return 1;
-}
-
static void __used kretprobe_trampoline_holder(void)
{
__asm__ __volatile__(".global kretprobe_trampoline\n"