On 2019-07-10 15:28 +0200, Jiri Kosina wrote: > On Wed, 10 Jul 2019, Jiri Kosina wrote:
> > > > > BUG: unable to handle page fault for address: ffffffff9edc1598 > > > > > #PF: supervisor write access in kernel mode > > > > > #PF: error_code(0x0003) - permissions violation > > Hm, and it seems to explode on dereferencing the static_key* in %rsi > > ^^^ %rdi of > course > > > 21: 48 8b 37 mov (%rdi),%rsi > > 24: 83 e6 03 and $0x3,%esi > > 27: 48 09 c6 or %rax,%rsi > > 2a:* 48 89 37 mov %rsi,(%rdi) <-- trapping > > instruction > > > > which looks odd, as it derefenced it successfully just 3 instructions ago. It seems the MMU (I guess ?) allows to read it, but disallows to write it: "supervisor write access in kernel mode". -- Xi Ruoyao <xry...@mengyan1223.wang> School of Aerospace Science and Technology, Xidian University
