From: Michael Ellerman <mpe@ellerman.id.au>
To: Nicholas Piggin <npiggin@gmail.com>, linuxppc-dev@lists.ozlabs.org
Cc: Nicholas Piggin <npiggin@gmail.com>
Subject: Re: [PATCH] powerpc: build time sort extable
Date: Mon, 10 Oct 2016 15:13:44 +1100 [thread overview]
Message-ID: <87eg3o7sef.fsf@concordia.ellerman.id.au> (raw)
In-Reply-To: <20161007112941.20073-1-npiggin@gmail.com>
Nicholas Piggin <npiggin@gmail.com> writes:
> Can we just switch this on? Powerpc does not use relative extables
> (that's a nice exercise left for the reader), so it should just use
> the standard sort.
>
> This patch seems to work, famous last words...
Would be nice but ...
> Sorting probably only takes a few ms on any real hardware, but on on
> very large kernel configs, extable sorting can take several seconds in
> simulators and be a noticable cost to booting.
(We even carried a patch for years to speed it up.)
Blows up for me at boot:
[ OK ] Started LSB: Control pmcd (the collection daemon for PCP).
Unable to handle kernel paging request for data at address 0x00000000
Faulting instruction address: 0xc000000000062d60
cpu 0x1: Vector: 300 (Data Access) at [c0000001d6687aa0]
pc: c000000000062d60: __copy_tofrom_user_base+0x54/0x5b4
lr: c0000000000633d8: copy_from_user+0x78/0xe0
sp: c0000001d6687d20
msr: 8000000000009033
dar: 0
dsisr: 40000000
current = 0xc0000001d6601880
paca = 0xc000000007e00400 softe: 0 irq_happened: 0x01
pid = 7101, comm = docker
Linux version 4.8.0-compiler_gcc-6.2.0-11418-g4011878e4cd3 (michael@ka3.ozlabs.ibm.com) (gcc version 6.2.0 (GCC) ) #219 SMP Mon Oct 10 14:48:04 AEDT 2016
enter ? for help
[link register ] c0000000000633d8 copy_from_user+0x78/0xe0
[c0000001d6687d20] c0000001d6687d90 (unreliable)
[c0000001d6687d60] c0000000001c7358 do_seccomp+0x78/0x6d0
[c0000001d6687dd0] c0000000000dc08c SyS_prctl+0x27c/0x670
[c0000001d6687e30] c00000000000bde4 system_call+0x38/0xfc
--- Exception: c01 (System Call) at 000000001025634c
SP (c8208d6cd8) is in userspace
cheers
prev parent reply other threads:[~2016-10-10 4:13 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-07 11:29 [PATCH] powerpc: build time sort extable Nicholas Piggin
2016-10-10 4:13 ` Michael Ellerman [this message]
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