Hi James, On 2018/6/21 9:38, James Morse wrote: > Hi Will, Wei, > > On 20/06/18 17:25, Wei Xu wrote: >> On 2018/6/20 23:54, James Morse wrote: >> I have disabled CONFIG_ARM64_RAS_EXTN and reverted that commit. >> But I still got the stack overflow issue sometimes. >> Do you have more hint? > >> The log is as below: >> [ 0.000000] Booting Linux on physical CPU 0x0000000000 [0x480fd010] >> [ 0.000000] Linux version 4.17.0-45865-g2b31fe7-dirty > > Could you reproduce this with v4.17? This says there are ~45,000 extra > patches, > and un-committed changes. None of the hashes so far have been commits in > mainline, so we have no idea what this tree is. >
I have tried v4.17 and log is as below and also it can be found in the first mail of this thread. [ 0.000000] Linux version 4.17.0-45864-g29dcea8-dirty (joyx@Turing-Arch-b) (gcc version 4.9.1 20140505 (prerelease) (crosstool-NG linaro-1.13.1-4.9-2014.05 - Linaro GCC 4.9-2014.05)) #6 SMP PREEMPT Fri Jun 15 21:39:52 CST 2018 I will try v4.17.2 and v4.18-rc1. > >> (joyx@Turing-Arch-b) (gcc version 4.9.1 20140505 (prerelease) (crosstool-NG >> linaro-1.13.1-4.9-2014.05 - Linaro GCC 4.9-2014.05)) #10 SMP PREEMPT Wed Jun >> 20 >> 23:59:05 CST 2018 > >> [ 0.000000] CPU0: using LPI pending table @0x000000007d860000 >> [ 0.000000] GIC: PPI11 is secure or misconfigured >> [ 0.000000] arch_timer: WARNING: Invalid trigger for IRQ3, assuming >> level >> low >> [ 0.000000] arch_timer: WARNING: Please fix your firmware >> [ 0.000000] arch_timer: cp15 timer(s) running at 100.00MHz (virt). > > (No idea what these mean, but I doubt they are relevant) > I will try with mainline qemu 2.12.0. Thanks! Best Regards, Wei > >> [ 0.042421] Insufficient stack space to handle exception! >> [ 0.042423] ESR: 0x96000046 -- DABT (current EL) >> [ 0.043730] FAR: 0xffff0000093a80e0 >> [ 0.044714] Task stack: [0xffff0000093a8000..0xffff0000093ac000] > > This was a level 2 translation fault on a write, to an address that is within > the stack.... > > >> [ 0.051113] IRQ stack: [0xffff000008000000..0xffff000008004000] >> [ 0.057610] Overflow stack: [0xffff80003efce2f0..0xffff80003efcf2f0] >> [ 0.064003] CPU: 0 PID: 12 Comm: migration/0 Not tainted >> 4.17.0-45865-g2b31fe7-dirty #10 >> [ 0.072201] Hardware name: linux,dummy-virt (DT) > >> [ 0.076797] pstate: 604003c5 (nZCv DAIF +PAN -UAO) >> [ 0.081727] pc : el1_sync+0x0/0xb0 > > ... from the vectors. > > >> [ 0.085217] lr : kpti_install_ng_mappings+0x120/0x214 > > What I think is happening is: we come out of the kpti idmap with the stack > unmapped. Shortly after we access the stack, which faults. el1_sync faults as > well when it tries to push the registers to the stack, and we keep going until > we overflow the stack. > > I can't reproduce this with kvmtool or qemu in the model. > > > Thanks, > > James > > . >