Re: ERLITE frozen in rc script after switching to GCC 5.4

[Rin Okuyama <rokuyama%rk.phys.keio.ac.jp@localhost>]

On 2016/10/22 6:56, Rin Okuyama wrote:
> These results indicate that the problem does not simply come from the
> optimization errors nor mips/syscall.c. Now I'm worried if there are
> much more serious regressions in GCC5 than I imagined.

In order to examine whether this is a problem with GCC5, I tested
kernels compiled by GCC 4.8.5 from netbsd-7 branch.

(1) Kernel compiled with -O2 seems to work well.

(2) Kernel compiled with -O1 fails into random freezes.

(3) Kernel compiled with -O0 panics due to assertion failure in
mips/syscall.c:

    init: copying out path `/sbin/init' 11
    pid 1(init): ABI set to N32 (e_flags=0x20000027)
    panic: kernel diagnostic assertion "l->l_blcnt == 0" failed: file "../../../../arch/mips/mips/syscall.c", line 364
    kernel: breakpoint trap
    Stopped in pid 4.1 (sh) at      netbsd:cpu_Debugger+0x10:       or      sp,s8,zero

(4) Kernel compiled with "-O0 -DMIPS_SYSCALL_DEBUG" panics due
to address error in kernel mode:

    pid 1(init): ABI set to N32 (e_flags=0x20000027)
    syscall 197: [0]=0 [1]=0x8000 [2]=0x3 [3]=0x1002 [4]=0xffffffffffffffff [5]=0 [6]=0
    ...(snip)...
    syscall 197: return v0=0x78770000 v1=0xffffffffffffffff
    pid 0(system): trap: cpu0, address error (load or I-fetch) in kernel mode
    status=0xffa3, cause=0x10, epc=0xffffffff804504b0, vaddr=0x3002c000feaee68
    tf=0x980000041093bca0 ksp=0x980000041093bde0 ra=0xffffffff804504b0 ppl=0x3002c00
    kernel: address error (load or I-fetch) trap
    Stopped in pid 0.28 (system) at netbsd:sleepq_block+0x154:      lw      v0,48(s8)

May this mean kernel compiled by GCC 4.8.5 with -O2 flag works
just accidentally?

Thanks,
Rin