show_regs() shows the CS in the CPU register instead of the value in
regs. This means that we'll probably print "CS: 0010" almost all
the time regardless of what was actually in CS when the kernel
malfunctioned. This gives a particularly confusing result if we
OOPSed due to an implicit supervisor access from user mode.
Signed-off-by: Andy Lutomirski <l...@kernel.org>
---
arch/x86/kernel/process_64.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 0e0b4288a4b2..2b8e6324fa20 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -66,7 +66,7 @@ void __show_regs(struct pt_regs *regs, enum show_regs_mode
mode)
unsigned long cr0 = 0L, cr2 = 0L, cr3 = 0L, cr4 = 0L, fs, gs, shadowgs;
unsigned long d0, d1, d2, d3, d6, d7;
unsigned int fsindex, gsindex;
- unsigned int ds, cs, es;
+ unsigned int ds, es;
show_iret_regs(regs);
@@ -98,7 +98,6 @@ void __show_regs(struct pt_regs *regs, enum show_regs_mode
mode)
}
asm("movl %%ds,%0" : "=r" (ds));
- asm("movl %%cs,%0" : "=r" (cs));
asm("movl %%es,%0" : "=r" (es));
asm("movl %%fs,%0" : "=r" (fsindex));
asm("movl %%gs,%0" : "=r" (gsindex));
@@ -114,7 +113,7 @@ void __show_regs(struct pt_regs *regs, enum show_regs_mode
mode)
printk(KERN_DEFAULT "FS: %016lx(%04x) GS:%016lx(%04x) knlGS:%016lx\n",
fs, fsindex, gs, gsindex, shadowgs);
- printk(KERN_DEFAULT "CS: %04x DS: %04x ES: %04x CR0: %016lx\n", cs, ds,
+ printk(KERN_DEFAULT "CS: %04lx DS: %04x ES: %04x CR0: %016lx\n",
regs->cs, ds,
es, cr0);
printk(KERN_DEFAULT "CR2: %016lx CR3: %016lx CR4: %016lx\n", cr2, cr3,
cr4);
--
2.17.2
