Commit-ID: d38bc89c72e7235ac889ae64fe7828e2e61a18af Gitweb: https://git.kernel.org/tip/d38bc89c72e7235ac889ae64fe7828e2e61a18af Author: Andy Lutomirski <luto@xxxxxxxxxx> AuthorDate: Wed, 21 Nov 2018 15:11:24 -0800 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitDate: Thu, 22 Nov 2018 09:23:01 +0100 x86/oops: Show the correct CS value in show_regs() 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 <luto@xxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Cc: H. Peter Anvin <hpa@xxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Rik van Riel <riel@xxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Yu-cheng Yu <yu-cheng.yu@xxxxxxxxx> Link: http://lkml.kernel.org/r/4e36812b6e1e95236a812021d35cbf22746b5af6.1542841400.git.luto@xxxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> --- 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);
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