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From: Masami Hiramatsu <mhiramat@kernel.org>
To: Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@kernel.org>
Cc: x86@kernel.org, Masami Hiramatsu <mhiramat@kernel.org>,
	Ingo Molnar <mingo@redhat.com>, "H . Peter Anvin" <hpa@zytor.com>,
	linux-kernel@vger.kernel.org,
	Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	Laura Abbott <labbott@redhat.com>, Josef Bacik <jbacik@fb.com>,
	Alexei Starovoitov <ast@kernel.org>,
	Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Subject: [PATCH -tip v3 3/7] x86: kprobes: Remove jprobe implementation
Date: Thu, 17 May 2018 08:58:05 +0900	[thread overview]
Message-ID: <152651508564.25583.15078673780465986976.stgit@devbox> (raw)
In-Reply-To: <152651499561.25583.14488389770693278906.stgit@devbox>

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

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
 arch/x86/include/asm/kprobes.h |    3 -
 arch/x86/kernel/kprobes/core.c |   87 ----------------------------------------
 2 files changed, 90 deletions(-)

diff --git a/arch/x86/include/asm/kprobes.h b/arch/x86/include/asm/kprobes.h
index 367d99cff426..06782c2efa04 100644
--- a/arch/x86/include/asm/kprobes.h
+++ b/arch/x86/include/asm/kprobes.h
@@ -111,9 +111,6 @@ struct kprobe_ctlblk {
 	unsigned long kprobe_status;
 	unsigned long kprobe_old_flags;
 	unsigned long kprobe_saved_flags;
-	unsigned long *jprobe_saved_sp;
-	struct pt_regs jprobe_saved_regs;
-	kprobe_opcode_t jprobes_stack[MAX_STACK_SIZE];
 	struct prev_kprobe prev_kprobe;
 };
 
diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c
index 6f4d42377fe5..7d4b8e870635 100644
--- a/arch/x86/kernel/kprobes/core.c
+++ b/arch/x86/kernel/kprobes/core.c
@@ -1083,93 +1083,6 @@ int kprobe_exceptions_notify(struct notifier_block *self, unsigned long val,
 }
 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);
-	unsigned long addr;
-	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
-
-	kcb->jprobe_saved_regs = *regs;
-	kcb->jprobe_saved_sp = stack_addr(regs);
-	addr = (unsigned long)(kcb->jprobe_saved_sp);
-
-	/*
-	 * As Linus pointed out, gcc assumes that the callee
-	 * owns the argument space and could overwrite it, e.g.
-	 * tailcall optimization. So, to be absolutely safe
-	 * we also save and restore enough stack bytes to cover
-	 * the argument area.
-	 * Use __memcpy() to avoid KASAN stack out-of-bounds reports as we copy
-	 * raw stack chunk with redzones:
-	 */
-	__memcpy(kcb->jprobes_stack, (kprobe_opcode_t *)addr, MIN_STACK_SIZE(addr));
-	regs->ip = (unsigned long)(jp->entry);
-
-	/*
-	 * 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)
-{
-	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
-
-	/* Unpoison stack redzones in the frames we are going to jump over. */
-	kasan_unpoison_stack_above_sp_to(kcb->jprobe_saved_sp);
-
-	asm volatile (
-#ifdef CONFIG_X86_64
-			"       xchg   %%rbx,%%rsp	\n"
-#else
-			"       xchgl   %%ebx,%%esp	\n"
-#endif
-			"       int3			\n"
-			"       .globl jprobe_return_end\n"
-			"       jprobe_return_end:	\n"
-			"       nop			\n"::"b"
-			(kcb->jprobe_saved_sp):"memory");
-}
-NOKPROBE_SYMBOL(jprobe_return);
-NOKPROBE_SYMBOL(jprobe_return_end);
-
-int longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
-{
-	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
-	u8 *addr = (u8 *) (regs->ip - 1);
-	struct jprobe *jp = container_of(p, struct jprobe, kp);
-	void *saved_sp = kcb->jprobe_saved_sp;
-
-	if ((addr > (u8 *) jprobe_return) &&
-	    (addr < (u8 *) jprobe_return_end)) {
-		if (stack_addr(regs) != saved_sp) {
-			struct pt_regs *saved_regs = &kcb->jprobe_saved_regs;
-			printk(KERN_ERR
-			       "current sp %p does not match saved sp %p\n",
-			       stack_addr(regs), saved_sp);
-			printk(KERN_ERR "Saved registers for jprobe %p\n", jp);
-			show_regs(saved_regs);
-			printk(KERN_ERR "Current registers\n");
-			show_regs(regs);
-			BUG();
-		}
-		/* It's OK to start function graph tracing again */
-		unpause_graph_tracing();
-		*regs = kcb->jprobe_saved_regs;
-		__memcpy(saved_sp, kcb->jprobes_stack, MIN_STACK_SIZE(saved_sp));
-		preempt_enable_no_resched();
-		return 1;
-	}
-	return 0;
-}
-NOKPROBE_SYMBOL(longjmp_break_handler);
-
 bool arch_within_kprobe_blacklist(unsigned long addr)
 {
 	bool is_in_entry_trampoline_section = false;

  parent reply	other threads:[~2018-05-16 23:58 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-16 23:56 [PATCH -tip v3 0/7] kprobes: x86: Cleanup jprobe implementation on x86 Masami Hiramatsu
2018-05-16 23:57 ` [PATCH -tip v3 1/7] Documentation/kprobes: Fix to remove remaining jprobe Masami Hiramatsu
2018-05-16 23:57 ` [PATCH -tip v3 2/7] kprobes: Remove jprobe API implementation Masami Hiramatsu
2018-05-16 23:58 ` Masami Hiramatsu [this message]
2018-05-16 23:58 ` [PATCH -tip v3 4/7] kprobes: Ignore break_handler Masami Hiramatsu
2018-05-18  6:16   ` Ingo Molnar
2018-05-18 13:38     ` Masami Hiramatsu
2018-05-18  6:20   ` Ingo Molnar
2018-05-18 14:14     ` Masami Hiramatsu
2018-05-16 23:59 ` [PATCH -tip v3 5/7] x86: " Masami Hiramatsu
2018-05-18  6:26   ` Ingo Molnar
2018-05-18 13:42     ` Masami Hiramatsu
2018-05-16 23:59 ` [PATCH -tip v3 6/7] bpf: error-inject: x86: Fix unbalanced preempt-count for function override Masami Hiramatsu
2018-05-17  0:00 ` [PATCH -tip v3 7/7] x86: kprobes: Do not disable preempt on int3 path Masami Hiramatsu
2018-05-18  6:23 ` [PATCH -tip v3 0/7] kprobes: x86: Cleanup jprobe implementation on x86 Ingo Molnar
2018-05-18 14:10   ` Masami Hiramatsu

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