LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Chuck Ebbert <cebbert@redhat.com>
To: linux-kernel <linux-kernel@vger.kernel.org>
Cc: Andrew Morton <akpm@osdl.org>, Andi Kleen <ak@suse.de>,
	Dave Jones <davej@redhat.com>
Subject: [patch] i386: add option to show more code in oops reports
Date: Mon, 29 Jan 2007 15:11:23 -0500	[thread overview]
Message-ID: <45BE54EB.4070200@redhat.com> (raw)

[-- Attachment #1: Type: text/plain, Size: 206 bytes --]

Sometimes developers need to see more object code in an oops report,
e.g. when kernel may be corrupted at runtime.

Add the "code_bytes" option for this.

Signed-off-by: Chuck Ebbert <cebbert@redhat.com>



[-- Attachment #2: i386_show_more_code.patch --]
[-- Type: text/plain, Size: 2187 bytes --]

 Documentation/kernel-parameters.txt |    5 +++++
 arch/i386/kernel/traps.c            |   20 ++++++++++++++++----
 2 files changed, 21 insertions(+), 4 deletions(-)

--- 2.6.20-rc6.1-32smp.orig/Documentation/kernel-parameters.txt
+++ 2.6.20-rc6.1-32smp/Documentation/kernel-parameters.txt
@@ -361,6 +361,11 @@ and is between 256 and 4096 characters. 
 			clocksource is not available, it defaults to PIT.
 			Format: { pit | tsc | cyclone | pmtmr }
 
+	code_bytes	[IA32] How many bytes of object code to print in an
+			oops report.
+			Range: 0 - 8192
+			Default: 64
+
 	disable_8254_timer
 	enable_8254_timer
 			[IA32/X86_64] Disable/Enable interrupt 0 timer routing
--- 2.6.20-rc6.1-32smp.orig/arch/i386/kernel/traps.c
+++ 2.6.20-rc6.1-32smp/arch/i386/kernel/traps.c
@@ -94,6 +94,7 @@ asmlinkage void spurious_interrupt_bug(v
 asmlinkage void machine_check(void);
 
 int kstack_depth_to_print = 24;
+static unsigned int code_bytes = 64;
 ATOMIC_NOTIFIER_HEAD(i386die_chain);
 
 int register_die_notifier(struct notifier_block *nb)
@@ -324,7 +325,8 @@ void show_registers(struct pt_regs *regs
 	 */
 	if (in_kernel) {
 		u8 *eip;
-		int code_bytes = 64;
+		unsigned int code_prologue = code_bytes * 43 / 64;
+		unsigned int code_len = code_bytes;
 		unsigned char c;
 
 		printk("\n" KERN_EMERG "Stack: ");
@@ -332,14 +334,14 @@ void show_registers(struct pt_regs *regs
 
 		printk(KERN_EMERG "Code: ");
 
-		eip = (u8 *)regs->eip - 43;
+		eip = (u8 *)regs->eip - code_prologue;
 		if (eip < (u8 *)PAGE_OFFSET ||
 			probe_kernel_address(eip, c)) {
 			/* try starting at EIP */
 			eip = (u8 *)regs->eip;
-			code_bytes = 32;
+			code_len = code_len - code_prologue + 1;
 		}
-		for (i = 0; i < code_bytes; i++, eip++) {
+		for (i = 0; i < code_len; i++, eip++) {
 			if (eip < (u8 *)PAGE_OFFSET ||
 				probe_kernel_address(eip, c)) {
 				printk(" Bad EIP value.");
@@ -1191,3 +1193,13 @@ static int __init kstack_setup(char *s)
 	return 1;
 }
 __setup("kstack=", kstack_setup);
+
+static int __init code_bytes_setup(char *s)
+{
+	code_bytes = simple_strtoul(s, NULL, 0);
+	if (code_bytes > 8192)
+		code_bytes = 8192;
+
+	return 1;
+}
+__setup("code_bytes=", code_bytes_setup);

             reply	other threads:[~2007-01-29 20:11 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-01-29 20:11 Chuck Ebbert [this message]
  -- strict thread matches above, loose matches on Subject: below --
2007-01-24 20:22 Chuck Ebbert
2007-01-25 22:55 ` Andrew Morton
2007-01-25 23:56   ` Chuck Ebbert
2007-01-29  3:44     ` Andi Kleen
2007-01-29 15:40       ` Chuck Ebbert
2007-01-29 18:03         ` Andi Kleen

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=45BE54EB.4070200@redhat.com \
    --to=cebbert@redhat.com \
    --cc=ak@suse.de \
    --cc=akpm@osdl.org \
    --cc=davej@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --subject='Re: [patch] i386: add option to show more code in oops reports' \
    /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

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).