[PATCH -tip v6 10/27] s390/kprobes: Remove jprobe implementation

Masami Hiramatsu
2018-06-19T16:09:27Z

Remove arch dependent setjump/longjump functions
and unused fields in kprobe_ctlblk for jprobes
from arch/s390.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux-s390@vger.kernel.org
---
arch/s390/include/asm/kprobes.h | 2 -
arch/s390/kernel/kprobes.c | 59 +--------------------------------------
2 files changed, 2 insertions(+), 59 deletions(-)

diff --git a/arch/s390/include/asm/kprobes.h b/arch/s390/include/asm/kprobes.h
index 13de80cf741c..b106aa29bf55 100644
--- a/arch/s390/include/asm/kprobes.h
+++ b/arch/s390/include/asm/kprobes.h
@@ -68,8 +68,6 @@ struct kprobe_ctlblk {
unsigned long kprobe_saved_imask;
unsigned long kprobe_saved_ctl[3];
struct prev_kprobe prev_kprobe;
- struct pt_regs jprobe_saved_regs;
- kprobe_opcode_t jprobes_stack[MAX_STACK_SIZE];
};

void arch_remove_kprobe(struct kprobe *p);
diff --git a/arch/s390/kernel/kprobes.c b/arch/s390/kernel/kprobes.c
index 60f60afa645c..0967de19f53d 100644
--- a/arch/s390/kernel/kprobes.c
+++ b/arch/s390/kernel/kprobes.c
@@ -321,9 +321,8 @@ static int kprobe_handler(struct pt_regs *regs)
* If we have no pre-handler or it returned 0, we
* continue with single stepping. If we have a
* pre-handler and it returned non-zero, it prepped
- * for calling the break_handler below on re-entry
- * for jprobe processing, so get out doing nothing
- * more here.
+ * for changing execution path, so get out doing
+ * nothing more here.
*/
push_kprobe(kcb, p);
kcb->kprobe_status = KPROBE_HIT_ACTIVE;
@@ -661,60 +660,6 @@ int kprobe_exceptions_notify(struct notifier_block *self,
}
NOKPROBE_SYMBOL(kprobe_exceptions_notify);

-int 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 stack;
-
- memcpy(&kcb->jprobe_saved_regs, regs, sizeof(struct pt_regs));
-
- /* setup return addr to the jprobe handler routine */
- regs->psw.addr = (unsigned long) jp->entry;
- regs->psw.mask &= ~(PSW_MASK_IO | PSW_MASK_EXT);
-
- /* r15 is the stack pointer */
- stack = (unsigned long) regs->gprs[15];
-
- memcpy(kcb->jprobes_stack, (void *) stack, MIN_STACK_SIZE(stack));
-
- /*
- * jprobes use jprobe_return() which skips the normal return
- * path of the function, and this messes up the accounting of the
- * function graph tracer to get messed up.
- *
- * Pause function graph tracing while performing the jprobe function.
- */
- pause_graph_tracing();
- return 1;
-}
-NOKPROBE_SYMBOL(setjmp_pre_handler);
-
-void jprobe_return(void)
-{
- asm volatile(".word 0x0002");
-}
-NOKPROBE_SYMBOL(jprobe_return);
-
-int longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
-{
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
- unsigned long stack;
-
- /* It's OK to start function graph tracing again */
- unpause_graph_tracing();
-
- stack = (unsigned long) kcb->jprobe_saved_regs.gprs[15];
-
- /* Put the regs back */
- memcpy(regs, &kcb->jprobe_saved_regs, sizeof(struct pt_regs));
- /* put the stack back */
- memcpy((void *) stack, kcb->jprobes_stack, MIN_STACK_SIZE(stack));
- preempt_enable_no_resched();
- return 1;
-}
-NOKPROBE_SYMBOL(longjmp_break_handler);
-
static struct kprobe trampoline = {
.addr = (kprobe_opcode_t *) &kretprobe_trampoline,
.pre_handler = trampoline_probe_handler