linux-arm-kernel.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
From: tixy@yxit.co.uk (Tixy)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] ARM: kprobes: Change testcase with unpredictable STRD instruction
Date: Sun, 27 Nov 2011 12:11:25 +0000	[thread overview]
Message-ID: <1322395885.2408.1.camel@computer2> (raw)

There is a kprobes testcase for the instruction "strd r2, [r3], r4".
This has unpredictable behaviour as it uses r3 for register writeback
addressing and also stores it to memory.

On a cortex A9, this testcase would fail because the instruction writes
the updated value of r3 to memory, whereas the kprobes emulation code
writes the original value.

Fix this by changing testcase to used r5 instead of r3.

Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
---
 arch/arm/kernel/kprobes-test-arm.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/arm/kernel/kprobes-test-arm.c b/arch/arm/kernel/kprobes-test-arm.c
index fc82de8..edf9ad8 100644
--- a/arch/arm/kernel/kprobes-test-arm.c
+++ b/arch/arm/kernel/kprobes-test-arm.c
@@ -550,7 +550,7 @@ void kprobe_arm_test_cases(void)
 	TEST_RPR(  "strccd	r",8, VAL2,", [r",13,0, ", r",12,48,"]")
 	TEST_RPR(  "strd	r",4, VAL1,", [r",2, 24,", r",3, 48,"]!")
 	TEST_RPR(  "strcsd	r",12,VAL2,", [r",11,48,", -r",10,24,"]!")
-	TEST_RPR(  "strd	r",2, VAL1,", [r",3, 24,"], r",4,48,"")
+	TEST_RPR(  "strd	r",2, VAL1,", [r",5, 24,"], r",4,48,"")
 	TEST_RPR(  "strd	r",10,VAL2,", [r",9, 48,"], -r",7,24,"")
 	TEST_UNSUPPORTED(".word 0xe1afc0fa	@ strd r12, [pc, r10]!")
 
-- 
1.7.2.5

             reply	other threads:[~2011-11-27 12:11 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-11-27 12:11 Tixy [this message]
2011-11-28 16:29 ` [PATCH] ARM: kprobes: Change testcase with unpredictable STRD instruction Nicolas Pitre
2011-11-30 23:56 ` Russell King - ARM Linux
2011-12-01  7:33   ` 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=1322395885.2408.1.camel@computer2 \
    --to=tixy@yxit.co.uk \
    --cc=linux-arm-kernel@lists.infradead.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).