Date: Wed, 22 Sep 2010 06:45:07 +0000 (UTC) From: Andriy Gapon <avg@FreeBSD.org> To: cvs-src-old@freebsd.org Subject: cvs commit: src/sys/kern kern_linker.c subr_kdb.c subr_stack.c Message-ID: <201009220645.o8M6jWUL047896@repoman.freebsd.org>
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avg 2010-09-22 06:45:07 UTC
FreeBSD src repository
Modified files:
sys/kern kern_linker.c subr_kdb.c subr_stack.c
Log:
SVN rev 212994 on 2010-09-22 06:45:07Z by avg
kdb_backtrace: use stack_print_ddb instead of stack_print
This is a followup to r212964.
stack_print call chain obtains linker sx lock and thus potentially may
lead to a deadlock depending on a kind of a panic.
stack_print_ddb doesn't acquire any locks and it doesn't use any
facilities of ddb backend.
Using stack_print_ddb outside of DDB ifdef required taking a number of
helper functions from under it as well.
It is a good idea to rename linker_ddb_* and stack_*_ddb functions to
have 'unlocked' component in their name instead of 'ddb', because those
functions do not use any DDB services, but instead they provide unlocked
access to linker symbol information. The latter was previously needed
only for DDB, hence the 'ddb' name component.
Alternative is to ditch unlocked versions altogether after implementing
proper panic handling:
1. stop other cpus upon a panic
2. make all non-spinlock lock operations (mutex, sx, rwlock) be a no-op
when panicstr != NULL
Suggested by: mdf
Discussed with: attilio
MFC after: 2 weeks
Revision Changes Path
1.180 +2 -2 src/sys/kern/kern_linker.c
1.31 +1 -1 src/sys/kern/subr_kdb.c
1.11 +1 -5 src/sys/kern/subr_stack.c
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