Re: [BUG -tip] kmemleak and stacktrace cause page faul

From: Cyrill Gorcunov
Date: Tue Oct 22 2019 - 10:56:26 EST


On Tue, Oct 22, 2019 at 05:23:25PM +0300, Cyrill Gorcunov wrote:
>
> I presume the kmemleak tries to save stack trace too early when estack_pages are not
> yet filled.

Indeed, at this stage of boot the percpu_setup_exception_stacks has not been called
yet and estack_pages full of crap

[ 0.157502] stk 0x1008 k 1 begin 0x0 end 0xd000 estack_pages 0xffffffff82014880 ep 0xffffffff82014888
[ 0.159395] estack_pages[0] = 0x0
[ 0.160046] estack_pages[1] = 0x5100000001000
[ 0.160881] estack_pages[2] = 0x0
[ 0.161530] estack_pages[3] = 0x6100000003000
[ 0.162343] estack_pages[4] = 0x0
[ 0.162962] estack_pages[5] = 0x0
[ 0.163523] estack_pages[6] = 0x0
[ 0.164065] estack_pages[7] = 0x8100000007000
[ 0.164978] estack_pages[8] = 0x0
[ 0.165624] estack_pages[9] = 0x9100000009000
[ 0.166448] estack_pages[10] = 0x0
[ 0.167064] estack_pages[11] = 0xa10000000b000
[ 0.168055] estack_pages[12] = 0x0
[ 0.168891] BUG: unable to handle page fault for address: 0000000000001ff0