From 88fc241f54459ac3d86c5e13b449730199f66061 Mon Sep 17 00:00:00 2001 From: Doug Chapman Date: Thu, 15 Jan 2009 10:38:56 -0800 Subject: [PATCH] [IA64] dump stack on kernel unaligned warnings Often the cause of kernel unaligned access warnings is not obvious from just the ip displayed in the warning. This adds the option via proc to dump the stack in addition to the warning. The default is off (just display the 1 line warning). To enable the stack to be shown: echo 1 > /proc/sys/kernel/unaligned-dump-stack Signed-off-by: Doug Chapman Signed-off-by: Tony Luck --- arch/ia64/kernel/unaligned.c | 6 +++++- kernel/sysctl.c | 9 +++++++++ 2 files changed, 14 insertions(+), 1 deletion(-) diff --git a/arch/ia64/kernel/unaligned.c b/arch/ia64/kernel/unaligned.c index ff0e7c10faa..6db08599ebb 100644 --- a/arch/ia64/kernel/unaligned.c +++ b/arch/ia64/kernel/unaligned.c @@ -59,6 +59,7 @@ dump (const char *str, void *vp, size_t len) * (i.e. don't allow attacker to fill up logs with unaligned accesses). */ int no_unaligned_warning; +int unaligned_dump_stack; static int noprint_warning; /* @@ -1371,9 +1372,12 @@ ia64_handle_unaligned (unsigned long ifa, struct pt_regs *regs) } } } else { - if (within_logging_rate_limit()) + if (within_logging_rate_limit()) { printk(KERN_WARNING "kernel unaligned access to 0x%016lx, ip=0x%016lx\n", ifa, regs->cr_iip + ipsr->ri); + if (unaligned_dump_stack) + dump_stack(); + } set_fs(KERNEL_DS); } diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 3e38b74b612..368d1638ee7 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -144,6 +144,7 @@ extern int acct_parm[]; #ifdef CONFIG_IA64 extern int no_unaligned_warning; +extern int unaligned_dump_stack; #endif #ifdef CONFIG_RT_MUTEXES @@ -781,6 +782,14 @@ static struct ctl_table kern_table[] = { .mode = 0644, .proc_handler = &proc_dointvec, }, + { + .ctl_name = CTL_UNNUMBERED, + .procname = "unaligned-dump-stack", + .data = &unaligned_dump_stack, + .maxlen = sizeof (int), + .mode = 0644, + .proc_handler = &proc_dointvec, + }, #endif #ifdef CONFIG_DETECT_SOFTLOCKUP { -- 2.41.1