Messages in this thread | | | Date | Tue, 8 Dec 2015 19:19:08 +0100 (CET) | From | Thomas Gleixner <> | Subject | Re: [PATCH 21/34] x86, pkeys: dump PKRU with other kernel registers |
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On Thu, 3 Dec 2015, Dave Hansen wrote:
> > From: Dave Hansen <dave.hansen@linux.intel.com> > > I'm a bit ambivalent about whether this is needed or not. > > Protection Keys never affect kernel mappings. But, they can > affect whether the kernel will fault when it touches a user > mapping. But, the kernel doesn't touch user mappings without > some careful choreography and these accesses don't generally > result in oopses.
Well, if we miss some careful choreography at some place, this information is going to be helpful.
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> > --- > > b/arch/x86/kernel/process_64.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff -puN arch/x86/kernel/process_64.c~pkeys-30-kernel-error-dumps arch/x86/kernel/process_64.c > --- a/arch/x86/kernel/process_64.c~pkeys-30-kernel-error-dumps 2015-12-03 16:21:27.874773264 -0800 > +++ b/arch/x86/kernel/process_64.c 2015-12-03 16:21:27.877773400 -0800 > @@ -116,6 +116,8 @@ void __show_regs(struct pt_regs *regs, i > printk(KERN_DEFAULT "DR0: %016lx DR1: %016lx DR2: %016lx\n", d0, d1, d2); > printk(KERN_DEFAULT "DR3: %016lx DR6: %016lx DR7: %016lx\n", d3, d6, d7); > > + if (boot_cpu_has(X86_FEATURE_OSPKE)) > + printk(KERN_DEFAULT "PKRU: %08x\n", read_pkru()); > } > > void release_thread(struct task_struct *dead_task) > _ >
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