From: David Long <dave.long@linaro.org>
To: linux-arm-kernel@lists.infradead.org
Cc: Rabin Vincent <rabin@rab.in>,
"Jon Medhurst (Tixy)" <tixy@linaro.org>,
linux-kernel@vger.kernel.org
Subject: [PATCH 2/9] uprobes: allow ignoring of probe hits
Date: Thu, 1 Aug 2013 19:45:46 -0400 [thread overview]
Message-ID: <1375400753-3454-3-git-send-email-dave.long@linaro.org> (raw)
In-Reply-To: <1375400753-3454-1-git-send-email-dave.long@linaro.org>
From: Rabin Vincent <rabin@rab.in>
Allow arches to decided to ignore a probe hit. ARM will use this to
only call handlers if the conditions to execute a conditionally executed
instruction are satisfied.
Upleveled for v3.10-rc7.
Signed-off-by: David A. Long <dave.long@linaro.org>
---
include/linux/uprobes.h | 1 +
kernel/events/uprobes.c | 17 ++++++++++++-----
2 files changed, 13 insertions(+), 5 deletions(-)
diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h
index 4e3b847..7a7c035 100644
--- a/include/linux/uprobes.h
+++ b/include/linux/uprobes.h
@@ -133,6 +133,7 @@ extern int arch_uprobe_post_xol(struct arch_uprobe *aup, struct pt_regs *regs);
extern bool arch_uprobe_xol_was_trapped(struct task_struct *tsk);
extern int arch_uprobe_exception_notify(struct notifier_block *self, unsigned long val, void *data);
extern void arch_uprobe_abort_xol(struct arch_uprobe *aup, struct pt_regs *regs);
+extern bool __weak arch_uprobe_ignore(struct arch_uprobe *aup, struct pt_regs *regs);
#else /* !CONFIG_UPROBES */
struct uprobes_state {
};
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index f356974..2f3a4cb 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -1734,9 +1734,6 @@ static void handle_swbp(struct pt_regs *regs)
return;
}
- /* change it in advance for ->handler() and restart */
- instruction_pointer_set(regs, bp_vaddr);
-
/*
* TODO: move copy_insn/etc into _register and remove this hack.
* After we hit the bp, _unregister + _register can install the
@@ -1744,16 +1741,26 @@ static void handle_swbp(struct pt_regs *regs)
*/
smp_rmb(); /* pairs with wmb() in install_breakpoint() */
if (unlikely(!test_bit(UPROBE_COPY_INSN, &uprobe->flags)))
- goto out;
+ goto restart;
handler_chain(uprobe, regs);
+
+ if (arch_uprobe_ignore(&uprobe->arch, regs))
+ goto out;
+
if (can_skip_sstep(uprobe, regs))
goto out;
if (!pre_ssout(uprobe, regs, bp_vaddr))
return;
- /* can_skip_sstep() succeeded, or restart if can't singlestep */
+restart:
+ /*
+ * cannot singlestep; cannot skip instruction;
+ * re-execute the instruction.
+ */
+ instruction_pointer_set(regs, bp_vaddr);
+
out:
put_uprobe(uprobe);
}
--
1.8.1.2
next prev parent reply other threads:[~2013-08-01 23:49 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-01 23:45 [PATCH 0/9] uprobes: Add uprobes support for ARM David Long
2013-08-01 23:45 ` [PATCH 1/9] uprobes: move function declarations out of arch David Long
2013-08-01 23:45 ` David Long [this message]
2013-08-01 23:45 ` [PATCH 3/9] uprobes: allow arch access to xol slot David Long
2013-08-01 23:45 ` [PATCH 4/9] uprobes: allow arch-specific initialization David Long
2013-08-01 23:45 ` [PATCH 5/9] uprobes: add arch write opcode hook David Long
2013-08-01 23:45 ` [PATCH 6/9] ARM: move shared uprobe/kprobe definitions into new include file David Long
2013-08-01 23:45 ` [PATCH 7/9] ARM: Move uprobes/kprobes shared functions to common file David Long
2013-08-29 14:08 ` Jon Medhurst (Tixy)
2013-08-01 23:45 ` [PATCH 8/9] ARM: Add "action" table for kprobes/uprobes instruction David Long
2013-08-29 14:09 ` Jon Medhurst (Tixy)
2013-08-01 23:45 ` [PATCH 9/9] ARM: add uprobes support David Long
2013-08-29 14:54 ` Jon Medhurst (Tixy)
Reply instructions:
You may reply publicly 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=1375400753-3454-3-git-send-email-dave.long@linaro.org \
--to=dave.long@linaro.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=rabin@rab.in \
--cc=tixy@linaro.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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).