From: Masami Hiramatsu <mhiramat@kernel.org>
To: Ingo Molnar <mingo@kernel.org>
Cc: mhiramat@kernel.org,
Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>,
Steven Rostedt <rostedt@goodmis.org>,
linux-kernel@vger.kernel.org, Ingo Molnar <mingo@redhat.com>,
Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>,
Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>,
"David S . Miller" <davem@davemloft.net>,
Thomas Gleixner <tglx@linutronix.de>, Josef Bacik <jbacik@fb.com>,
Alexei Starovoitov <ast@kernel.org>
Subject: [RFC PATCH -tip 3/4] kprobes: x86: Remove jprobe x86 port
Date: Tue, 8 May 2018 22:37:52 +0900 [thread overview]
Message-ID: <152578667261.31022.14252779586668860292.stgit@devbox> (raw)
In-Reply-To: <152578658468.31022.8952561651556318637.stgit@devbox>
Remove jprobe related functions and ignore break_handler
since the break_handler is used only from jprobe.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
arch/x86/include/asm/kprobes.h | 3 -
arch/x86/kernel/kprobes/core.c | 94 ----------------------------------------
2 files changed, 97 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 0715f827607c..29c11c8d79ab 100644
--- a/arch/x86/kernel/kprobes/core.c
+++ b/arch/x86/kernel/kprobes/core.c
@@ -708,13 +708,6 @@ int kprobe_int3_handler(struct pt_regs *regs)
regs->ip = (unsigned long)addr;
preempt_enable_no_resched();
return 1;
- } else if (kprobe_running()) {
- p = __this_cpu_read(current_kprobe);
- if (p->break_handler && p->break_handler(p, regs)) {
- if (!skip_singlestep(p, regs, kcb))
- setup_singlestep(p, regs, kcb, 0);
- return 1;
- }
} /* else: not a kprobe fault; let the kernel handle it */
preempt_enable_no_resched();
@@ -1079,93 +1072,6 @@ 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;
next prev parent reply other threads:[~2018-05-08 13:38 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-08 13:36 [RFC PATCH -tip 0/4] kprobes: x86: Remove jprobes related code Masami Hiramatsu
2018-05-08 13:36 ` [RFC PATCH -tip 1/4] Documentation/kprobes: Fix to remove remaining jprobe Masami Hiramatsu
2018-05-08 13:37 ` [RFC PATCH -tip 2/4] kprobes: Remove jprobe generic code Masami Hiramatsu
2018-05-13 19:55 ` Thomas Gleixner
2018-05-14 0:03 ` Masami Hiramatsu
2018-05-08 13:37 ` Masami Hiramatsu [this message]
2018-05-08 13:38 ` [RFC PATCH -tip 4/4] bpf: error-inject: x86: Fix unbalanced preempt-count for function override Masami Hiramatsu
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