Home Home > GIT Browse
summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorChuck Ebbert <cebbert@redhat.com>2007-08-10 22:31:11 +0200
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-08-11 15:58:14 -0700
commit3dab307e527f2a9bbb4f9d00240374bb93d1945f (patch)
tree3e9a83d6cc1cee1dcfedff700c0b4aeebaa2f8d5
parent5fe4486c79cdc8dbbb2a9c3f884a5ad0830a5a23 (diff)
i386: Fix double fault handler
The new percpu code has apparently broken the doublefault handler when CONFIG_DEBUG_SPINLOCK is set. Doublefault is handled by a hardware task, making the check SPIN_BUG_ON(lock->owner == current, lock, "recursion"); fault because it uses the FS register to access the percpu data for current, and that register is zero in the new TSS. (The trace I saw was on 2.6.20 where it was GS, but it looks like this will still happen with FS on 2.6.22.) Initializing FS in the doublefault_tss should fix it. AK: Also fix broken ptr_ok() and turn printks into KERN_EMERG AK: And add a PANIC prefix to make clear the system will hang AK: (e.g. x86-64 will recover) Signed-off-by: Chuck Ebbert <cebbert@redhat.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--arch/i386/kernel/doublefault.c13
1 files changed, 7 insertions, 6 deletions
diff --git a/arch/i386/kernel/doublefault.c b/arch/i386/kernel/doublefault.c
index 265c5597efb0..40978af630e7 100644
--- a/arch/i386/kernel/doublefault.c
+++ b/arch/i386/kernel/doublefault.c
@@ -13,7 +13,7 @@
static unsigned long doublefault_stack[DOUBLEFAULT_STACKSIZE];
#define STACK_START (unsigned long)(doublefault_stack+DOUBLEFAULT_STACKSIZE)
-#define ptr_ok(x) ((x) > PAGE_OFFSET && (x) < PAGE_OFFSET + 0x1000000)
+#define ptr_ok(x) ((x) > PAGE_OFFSET && (x) < PAGE_OFFSET + MAXMEM)
static void doublefault_fn(void)
{
@@ -23,23 +23,23 @@ static void doublefault_fn(void)
store_gdt(&gdt_desc);
gdt = gdt_desc.address;
- printk("double fault, gdt at %08lx [%d bytes]\n", gdt, gdt_desc.size);
+ printk(KERN_EMERG "PANIC: double fault, gdt at %08lx [%d bytes]\n", gdt, gdt_desc.size);
if (ptr_ok(gdt)) {
gdt += GDT_ENTRY_TSS << 3;
tss = *(u16 *)(gdt+2);
tss += *(u8 *)(gdt+4) << 16;
tss += *(u8 *)(gdt+7) << 24;
- printk("double fault, tss at %08lx\n", tss);
+ printk(KERN_EMERG "double fault, tss at %08lx\n", tss);
if (ptr_ok(tss)) {
struct i386_hw_tss *t = (struct i386_hw_tss *)tss;
- printk("eip = %08lx, esp = %08lx\n", t->eip, t->esp);
+ printk(KERN_EMERG "eip = %08lx, esp = %08lx\n", t->eip, t->esp);
- printk("eax = %08lx, ebx = %08lx, ecx = %08lx, edx = %08lx\n",
+ printk(KERN_EMERG "eax = %08lx, ebx = %08lx, ecx = %08lx, edx = %08lx\n",
t->eax, t->ebx, t->ecx, t->edx);
- printk("esi = %08lx, edi = %08lx\n",
+ printk(KERN_EMERG "esi = %08lx, edi = %08lx\n",
t->esi, t->edi);
}
}
@@ -63,6 +63,7 @@ struct tss_struct doublefault_tss __cacheline_aligned = {
.cs = __KERNEL_CS,
.ss = __KERNEL_DS,
.ds = __USER_DS,
+ .fs = __KERNEL_PERCPU,
.__cr3 = __pa(swapper_pg_dir)
}