LKML Archive on lore.kernel.org
 help / color / Atom feed
From: Masami Hiramatsu <mhiramat@kernel.org>
To: Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@kernel.org>
Cc: 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>,
	linux-arch@vger.kernel.org, x86@kernel.org
Subject: [PATCH -tip v6 03/27] kprobes/x86: Remove jprobe implementation
Date: Wed, 20 Jun 2018 01:05:35 +0900
Message-ID: <152942433578.15209.14034551799624757792.stgit@devbox> (raw)
In-Reply-To: <152942424698.15209.15245996287444292393.stgit@devbox>

Remove arch dependent setjump/longjump functions
and unused fields in kprobe_ctlblk for jprobes
from arch/x86.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
---
 arch/x86/include/asm/kprobes.h |    3 -
 arch/x86/kernel/kprobes/core.c |   96 +---------------------------------------
 2 files changed, 3 insertions(+), 96 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..1b2d1acba810 100644
--- a/arch/x86/kernel/kprobes/core.c
+++ b/arch/x86/kernel/kprobes/core.c
@@ -66,8 +66,6 @@
 
 #include "common.h"
 
-void jprobe_return_end(void);
-
 DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
 DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
 
@@ -690,10 +688,9 @@ int kprobe_int3_handler(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, it prepped
-			 * for calling the break_handler below on re-entry
-			 * for jprobe processing, so get out doing nothing
-			 * more here.
+			 * pre-handler and it returned non-zero, that 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, kcb, 0);
@@ -1083,93 +1080,6 @@ 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 index

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-06-19 16:04 [PATCH -tip v6 00/27] kprobes: Cleanup " Masami Hiramatsu
2018-06-19 16:04 ` [PATCH -tip v6 01/27] Documentation/kprobes: Fix to remove remaining jprobe Masami Hiramatsu
2018-06-19 16:05 ` [PATCH -tip v6 02/27] kprobes: Remove jprobe API implementation Masami Hiramatsu
2018-06-19 16:05 ` Masami Hiramatsu [this message]
2018-06-19 16:06 ` [PATCH -tip v6 04/27] ARC: kprobes: Remove jprobe implementation Masami Hiramatsu
2018-06-19 16:06 ` [PATCH -tip v6 05/27] ARM: kprobes: Remove jprobe arm implementation Masami Hiramatsu
2018-06-19 16:07 ` [PATCH -tip v6 06/27] arm64: kprobes: Remove jprobe implementation Masami Hiramatsu
2018-06-19 16:07 ` [PATCH -tip v6 07/27] powerpc/kprobes: Remove jprobe powerpc implementation Masami Hiramatsu
2018-06-19 16:08 ` [PATCH -tip v6 08/27] ia64: kprobes: Remove jprobe implementation Masami Hiramatsu
2018-06-19 16:08 ` [PATCH -tip v6 09/27] MIPS: " Masami Hiramatsu
2018-06-19 16:08 ` [PATCH -tip v6 10/27] s390/kprobes: " Masami Hiramatsu
2018-06-19 16:09 ` [PATCH -tip v6 11/27] sh: kprobes: " Masami Hiramatsu
2018-06-19 16:09 ` [PATCH -tip v6 12/27] sparc64: " Masami Hiramatsu
2018-06-19 16:10 ` [PATCH -tip v6 13/27] kprobes: Don't check the ->break_handler() in generic kprobes code Masami Hiramatsu
2018-06-19 16:10 ` [PATCH -tip v6 14/27] kprobes/x86: Don't call ->break_handler() in x86 kprobes Masami Hiramatsu
2018-06-19 16:11 ` [PATCH -tip v6 15/27] ARC: kprobes: Don't call the ->break_handler() in ARC kprobes code Masami Hiramatsu
2018-06-19 16:11 ` [PATCH -tip v6 16/27] ARM: kprobes: Don't call the ->break_handler() in arm " Masami Hiramatsu
2018-06-19 16:12 ` [PATCH -tip v6 17/27] arm64: kprobes: Don't call the ->break_handler() in arm64 " Masami Hiramatsu
2018-06-19 16:12 ` [PATCH -tip v6 18/27] powerpc/kprobes: Don't call the ->break_handler() in powerpc " Masami Hiramatsu
2018-06-19 16:13 ` [PATCH -tip v6 19/27] ia64: kprobes: Don't call the ->break_handler() in ia64 " Masami Hiramatsu
2018-06-19 16:13 ` [PATCH -tip v6 20/27] MIPS: kprobes: Don't call the ->break_handler() in MIPS " Masami Hiramatsu
2018-06-19 16:14 ` [PATCH -tip v6 21/27] s390/kprobes: Don't call the ->break_handler() in s390 " Masami Hiramatsu
2018-06-19 16:14 ` [PATCH -tip v6 22/27] sh: kprobes: Don't call the ->break_handler() in SH " Masami Hiramatsu
2018-06-19 16:15 ` [PATCH -tip v6 23/27] sparc64: kprobes: Don't call the ->break_handler() in sparc64 " Masami Hiramatsu
2018-06-19 16:15 ` [PATCH -tip v6 24/27] bpf: error-inject: kprobes: Clear current_kprobe and enable preempt in kprobe Masami Hiramatsu
2018-06-19 16:16 ` [PATCH -tip v6 25/27] kprobes/x86: Do not disable preempt on int3 path Masami Hiramatsu
2018-06-19 16:16 ` [PATCH -tip v6 26/27] Documentation: kprobes: Add how to change the execution path Masami Hiramatsu
2018-06-19 16:31   ` Randy Dunlap
2018-06-20  8:26     ` Masami Hiramatsu
2018-06-21 10:35       ` Ingo Molnar
2018-06-22  6:07         ` Masami Hiramatsu
2018-06-22  9:15           ` [tip:perf/core] kprobes/Documentation: Fix various typos tip-bot for Masami Hiramatsu
2018-06-19 16:17 ` [PATCH -tip v6 27/27] kprobes: Remove jprobe stub API Masami Hiramatsu

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=152942433578.15209.14034551799624757792.stgit@devbox \
    --to=mhiramat@kernel.org \
    --cc=akpm@linux-foundation.org \
    --cc=ananth@linux.vnet.ibm.com \
    --cc=hpa@zytor.com \
    --cc=linux-arch@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@kernel.org \
    --cc=mingo@redhat.com \
    --cc=rostedt@goodmis.org \
    --cc=tglx@linutronix.de \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

LKML Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/lkml/0 lkml/git/0.git
	git clone --mirror https://lore.kernel.org/lkml/1 lkml/git/1.git
	git clone --mirror https://lore.kernel.org/lkml/2 lkml/git/2.git
	git clone --mirror https://lore.kernel.org/lkml/3 lkml/git/3.git
	git clone --mirror https://lore.kernel.org/lkml/4 lkml/git/4.git
	git clone --mirror https://lore.kernel.org/lkml/5 lkml/git/5.git
	git clone --mirror https://lore.kernel.org/lkml/6 lkml/git/6.git
	git clone --mirror https://lore.kernel.org/lkml/7 lkml/git/7.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 lkml lkml/ https://lore.kernel.org/lkml \
		linux-kernel@vger.kernel.org
	public-inbox-index lkml

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-kernel


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git