From d015a092989d673df44a5ad6866dc5d5006b7a2a Mon Sep 17 00:00:00 2001 From: Pekka Enberg Date: Mon, 28 Dec 2009 10:26:59 +0200 Subject: x86: Use KERN_DEFAULT log-level in __show_regs() Andrew Morton reported a strange looking kmemcheck warning: WARNING: kmemcheck: Caught 32-bit read from uninitialized memory (ffff88004fba6c20) 0000000000000000310000000000000000000000000000002413000000c9ffff u u u u u u u u u u u u u u u u i i i i i i i i u u u u u u u u [] kmemleak_scan+0x25a/0x540 [] kmemleak_scan_thread+0x5b/0xe0 [] kthread+0x9e/0xb0 [] kernel_thread_helper+0x4/0x10 [] 0xffffffffffffffff The above printout is missing register dump completely. The problem here is that the output comes from syslog which doesn't show KERN_INFO log-level messages. We didn't see this before because both of us were testing on 32-bit kernels which use the _default_ log-level. Fix that up by explicitly using KERN_DEFAULT log-level for __show_regs() printks. Signed-off-by: Pekka Enberg Cc: Vegard Nossum Cc: Andrew Morton Cc: Arjan van de Ven Cc: Linus Torvalds LKML-Reference: <1261988819.4641.2.camel@penberg-laptop> Signed-off-by: Ingo Molnar --- arch/x86/kernel/process.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/x86/kernel/process.c') diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 98c2cdeb599..c6ee241c8a9 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -103,8 +103,8 @@ void show_regs_common(void) if (!product) product = ""; - printk("\n"); - printk(KERN_INFO "Pid: %d, comm: %.20s %s %s %.*s %s/%s\n", + printk(KERN_CONT "\n"); + printk(KERN_DEFAULT "Pid: %d, comm: %.20s %s %s %.*s %s/%s\n", current->pid, current->comm, print_tainted(), init_utsname()->release, (int)strcspn(init_utsname()->version, " "), -- cgit v1.2.3-70-g09d2 From 864a0922dd128392467611d9857e5138c6a91999 Mon Sep 17 00:00:00 2001 From: Cyrill Gorcunov Date: Wed, 13 Jan 2010 10:16:07 +0000 Subject: x86: kernel_thread() -- initialize SS to a known state Before the kernel_thread was converted into "C" we had pt_regs::ss set to __KERNEL_DS (by SAVE_ALL asm macro). Though I must admit I didn't find any *explicit* load of %ss from this structure the better to be on a safe side and set it to a known value. Signed-off-by: Cyrill Gorcunov Signed-off-by: Ian Campbell Cc: Christian Kujau Cc: Jeremy Fitzhardinge Cc: Brian Gerst LKML-Reference: <1263377768-19600-1-git-send-email-ian.campbell@citrix.com> Signed-off-by: Ingo Molnar --- arch/x86/kernel/process.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/x86/kernel/process.c') diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index c6ee241c8a9..02c3ee013cc 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -288,6 +288,8 @@ int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) regs.es = __USER_DS; regs.fs = __KERNEL_PERCPU; regs.gs = __KERNEL_STACK_CANARY; +#else + regs.ss = __KERNEL_DS; #endif regs.orig_ax = -1; -- cgit v1.2.3-70-g09d2