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Message-ID: <Pine.LNX.4.64.0707051847030.617@internets.corp.google.com>
Date: Thu, 5 Jul 2007 18:52:27 -0700 (PDT)
From: Joshua Wise <jwise@...gle.com>
To: linux-kernel@...r.kernel.org
cc: Tim Hockin <thockin@...gle.com>, Mike Waychison <mikew@...gle.com>,
Masoud Asgharifard Sharbiani <masouds@...gle.com>,
Andrew Morton <akpm@...gle.com>
Subject: [PATCH] Print utsname on Oops on all architectures
Hopefully this patch has not been munged by pine; I have, minimally,
unchecked the mung-patches-sent-to-lkml option in pine's config. In the case
that it has been munged, I have also attached it.
--
From: Joshua Wise <jwise@...gle.com>
Background:
This patch is a follow-on to "Info dump on Oops or panic()" [1].
On some architectures, the kernel printed some information on the running
kernel, but not on all architectures. The information printed was generally
the version and build number, but it was not located in a consistant place,
and some architectures did not print it at all.
Description:
This patch uses the already-existing die_chain to print utsname information
on Oops. This patch also removes the architecture-specific utsname
printers. To avoid crashing the system further (and hence not printing the
Oops) in the case where the system is so hopelessly smashed that utsname
might be destroyed, we vsprintf the utsname data into a static buffer
first, and then just print that on crash.
Testing:
I wrote a module that does a *(int*)0 = 0; and observed that I got my
utsname data printed.
Potential impact:
This adds another line to the Oops output, causing the first few lines to
potentially scroll off the screen. This also adds a few more pointer
dereferences in the Oops path, because it adds to the die_chain notifier
chain, reducing the likelihood that the Oops will be printed if there is
very bad memory corruption.
Patch:
This patch is against git 0471448f4d017470995d8a2272dc8c06dbed3b77.
Signed-Off-By: Joshua Wise <jwise@...gle.com>
[1] http://lkml.org/lkml/2007/6/28/316
--
diff --git a/arch/alpha/kernel/process.c b/arch/alpha/kernel/process.c
index 92b6162..13f342e 100644
--- a/arch/alpha/kernel/process.c
+++ b/arch/alpha/kernel/process.c
@@ -20,7 +20,6 @@ #include <linux/ptrace.h>
#include <linux/slab.h>
#include <linux/user.h>
#include <linux/a.out.h>
-#include <linux/utsname.h>
#include <linux/time.h>
#include <linux/major.h>
#include <linux/stat.h>
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 8423617..e4448f0 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -28,7 +28,6 @@ #include <linux/cpu.h>
#include <linux/elfcore.h>
#include <linux/pm.h>
#include <linux/tick.h>
-#include <linux/utsname.h>
#include <asm/leds.h>
#include <asm/processor.h>
@@ -203,10 +202,8 @@ void __show_regs(struct pt_regs *regs)
unsigned long flags;
char buf[64];
- printk("CPU: %d %s (%s %.*s)\n",
- smp_processor_id(), print_tainted(), init_utsname()->release,
- (int)strcspn(init_utsname()->version, " "),
- init_utsname()->version);
+ printk("CPU: %d %s\n",
+ smp_processor_id(), print_tainted());
print_symbol("PC is at %s\n", instruction_pointer(regs));
print_symbol("LR is at %s\n", regs->ARM_lr);
printk("pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n"
diff --git a/arch/i386/kernel/process.c b/arch/i386/kernel/process.c
index 06dfa65..1703243 100644
--- a/arch/i386/kernel/process.c
+++ b/arch/i386/kernel/process.c
@@ -27,7 +27,6 @@ #include <linux/vmalloc.h>
#include <linux/user.h>
#include <linux/a.out.h>
#include <linux/interrupt.h>
-#include <linux/utsname.h>
#include <linux/delay.h>
#include <linux/reboot.h>
#include <linux/init.h>
@@ -308,10 +307,8 @@ void show_regs(struct pt_regs * regs)
if (user_mode_vm(regs))
printk(" ESP: %04x:%08lx",0xffff & regs->xss,regs->esp);
- printk(" EFLAGS: %08lx %s (%s %.*s)\n",
- regs->eflags, print_tainted(), init_utsname()->release,
- (int)strcspn(init_utsname()->version, " "),
- init_utsname()->version);
+ printk(" EFLAGS: %08lx %s\n",
+ regs->eflags, print_tainted());
printk("EAX: %08lx EBX: %08lx ECX: %08lx EDX: %08lx\n",
regs->eax,regs->ebx,regs->ecx,regs->edx);
printk("ESI: %08lx EDI: %08lx EBP: %08lx",
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 6e2f035..04c4abd 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -32,7 +32,6 @@ #include <linux/module.h>
#include <linux/kallsyms.h>
#include <linux/mqueue.h>
#include <linux/hardirq.h>
-#include <linux/utsname.h>
#include <asm/pgtable.h>
#include <asm/uaccess.h>
@@ -414,8 +413,8 @@ void show_regs(struct pt_regs * regs)
printk("NIP: "REG" LR: "REG" CTR: "REG"\n",
regs->nip, regs->link, regs->ctr);
- printk("REGS: %p TRAP: %04lx %s (%s)\n",
- regs, regs->trap, print_tainted(), init_utsname()->release);
+ printk("REGS: %p TRAP: %04lx %s\n",
+ regs, regs->trap, print_tainted());
printk("MSR: "REG" ", regs->msr);
printbits(regs->msr, msr_bits);
printk(" CR: %08lx XER: %08lx\n", regs->ccr, regs->xer);
diff --git a/arch/x86_64/kernel/process.c b/arch/x86_64/kernel/process.c
index 5909039..94fb7e3 100644
--- a/arch/x86_64/kernel/process.c
+++ b/arch/x86_64/kernel/process.c
@@ -32,7 +32,6 @@ #include <linux/a.out.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/ptrace.h>
-#include <linux/utsname.h>
#include <linux/random.h>
#include <linux/notifier.h>
#include <linux/kprobes.h>
@@ -310,11 +309,8 @@ void __show_regs(struct pt_regs * regs)
printk("\n");
print_modules();
- printk("Pid: %d, comm: %.20s %s %s %.*s\n",
- current->pid, current->comm, print_tainted(),
- init_utsname()->release,
- (int)strcspn(init_utsname()->version, " "),
- init_utsname()->version);
+ printk("Pid: %d, comm: %.20s %s\n",
+ current->pid, current->comm, print_tainted());
printk("RIP: %04lx:[<%016lx>] ", regs->cs & 0xffff, regs->rip);
printk_address(regs->rip);
printk("RSP: %04lx:%016lx EFLAGS: %08lx\n", regs->ss, regs->rsp,
diff --git a/kernel/sys.c b/kernel/sys.c
index 872271c..6e01085 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -31,6 +31,7 @@ #include <linux/signal.h>
#include <linux/cn_proc.h>
#include <linux/getcpu.h>
#include <linux/task_io_accounting_ops.h>
+#include <linux/kdebug.h>
#include <linux/compat.h>
#include <linux/syscalls.h>
@@ -98,6 +99,36 @@ struct pid *cad_pid;
EXPORT_SYMBOL(cad_pid);
/*
+ * Dump out UTS info on oops / panic. We pregenerate utsname_info so that
+ * we don't access utsname() if the machine is in a potentially bad state.
+ */
+
+static char *utsname_info;
+
+static int dump_utsname(struct notifier_block *self, unsigned long diecode,
+ void *p)
+{
+ printk(KERN_EMERG "%s\n", utsname_info);
+ return 0;
+}
+
+static struct notifier_block utsname_notifier = {
+ .notifier_call = dump_utsname
+};
+
+static int __init register_utsname_dump(void)
+{
+ utsname_info = kasprintf(GFP_KERNEL, "%s %s %s %s",
+ utsname()->sysname,
+ utsname()->release,
+ utsname()->version,
+ utsname()->machine);
+ register_die_notifier(&utsname_notifier);
+ return 0;
+}
+module_init(register_utsname_dump);
+
+/*
* Notifier list for kernel code which wants to be called
* at shutdown. This is used to stop any idling DMA operations
* and the like.
View attachment "utsname-on-all-arches.diff" of type "TEXT/plain" (6974 bytes)
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