196779b9b4
Both dump_stack() and show_stack() are currently implemented by each architecture. show_stack(NULL, NULL) dumps the backtrace for the current task as does dump_stack(). On some archs, dump_stack() prints extra information - pid, utsname and so on - in addition to the backtrace while the two are identical on other archs. The usages in arch-independent code of the two functions indicate show_stack(NULL, NULL) should print out bare backtrace while dump_stack() is used for debugging purposes when something went wrong, so it does make sense to print additional information on the task which triggered dump_stack(). There's no reason to require archs to implement two separate but mostly identical functions. It leads to unnecessary subtle information. This patch expands the dummy fallback dump_stack() implementation in lib/dump_stack.c such that it prints out debug information (taken from x86) and invokes show_stack(NULL, NULL) and drops arch-specific dump_stack() implementations in all archs except blackfin. Blackfin's dump_stack() does something wonky that I don't understand. Debug information can be printed separately by calling dump_stack_print_info() so that arch-specific dump_stack() implementation can still emit the same debug information. This is used in blackfin. This patch brings the following behavior changes. * On some archs, an extra level in backtrace for show_stack() could be printed. This is because the top frame was determined in dump_stack() on those archs while generic dump_stack() can't do that reliably. It can be compensated by inlining dump_stack() but not sure whether that'd be necessary. * Most archs didn't use to print debug info on dump_stack(). They do now. An example WARN dump follows. WARNING: at kernel/workqueue.c:4841 init_workqueues+0x35/0x505() Hardware name: empty Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.9.0-rc1-work+ #9 0000000000000009 ffff88007c861e08 ffffffff81c614dc ffff88007c861e48 ffffffff8108f50f ffffffff82228240 0000000000000040 ffffffff8234a03c 0000000000000000 0000000000000000 0000000000000000 ffff88007c861e58 Call Trace: [<ffffffff81c614dc>] dump_stack+0x19/0x1b [<ffffffff8108f50f>] warn_slowpath_common+0x7f/0xc0 [<ffffffff8108f56a>] warn_slowpath_null+0x1a/0x20 [<ffffffff8234a071>] init_workqueues+0x35/0x505 ... v2: CPU number added to the generic debug info as requested by s390 folks and dropped the s390 specific dump_stack(). This loses %ksp from the debug message which the maintainers think isn't important enough to keep the s390-specific dump_stack() implementation. dump_stack_print_info() is moved to kernel/printk.c from lib/dump_stack.c. Because linkage is per objecct file, dump_stack_print_info() living in the same lib file as generic dump_stack() means that archs which implement custom dump_stack() - at this point, only blackfin - can't use dump_stack_print_info() as that will bring in the generic version of dump_stack() too. v1 The v1 patch broke build on blackfin due to this issue. The build breakage was reported by Fengguang Wu. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Vineet Gupta <vgupta@synopsys.com> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Acked-by: Vineet Gupta <vgupta@synopsys.com> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> [s390 bits] Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Sam Ravnborg <sam@ravnborg.org> Acked-by: Richard Kuo <rkuo@codeaurora.org> [hexagon bits] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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.. | ||
lzo | ||
mpi | ||
raid6 | ||
reed_solomon | ||
xz | ||
zlib_deflate | ||
zlib_inflate | ||
.gitignore | ||
argv_split.c | ||
asn1_decoder.c | ||
atomic64.c | ||
atomic64_test.c | ||
audit.c | ||
average.c | ||
bcd.c | ||
bch.c | ||
bitmap.c | ||
bitrev.c | ||
bsearch.c | ||
btree.c | ||
bug.c | ||
build_OID_registry | ||
bust_spinlocks.c | ||
check_signature.c | ||
checksum.c | ||
clz_tab.c | ||
cmdline.c | ||
cordic.c | ||
cpu-notifier-error-inject.c | ||
cpu_rmap.c | ||
cpumask.c | ||
crc-ccitt.c | ||
crc-itu-t.c | ||
crc-t10dif.c | ||
crc7.c | ||
crc8.c | ||
crc16.c | ||
crc32.c | ||
crc32defs.h | ||
ctype.c | ||
debug_locks.c | ||
debugobjects.c | ||
dec_and_lock.c | ||
decompress.c | ||
decompress_bunzip2.c | ||
decompress_inflate.c | ||
decompress_unlzma.c | ||
decompress_unlzo.c | ||
decompress_unxz.c | ||
devres.c | ||
digsig.c | ||
div64.c | ||
dma-debug.c | ||
dump_stack.c | ||
dynamic_debug.c | ||
dynamic_queue_limits.c | ||
earlycpio.c | ||
extable.c | ||
fault-inject.c | ||
fdt.c | ||
fdt_ro.c | ||
fdt_rw.c | ||
fdt_strerror.c | ||
fdt_sw.c | ||
fdt_wip.c | ||
find_last_bit.c | ||
find_next_bit.c | ||
flex_array.c | ||
flex_proportions.c | ||
gcd.c | ||
gen_crc32table.c | ||
genalloc.c | ||
halfmd4.c | ||
hexdump.c | ||
hweight.c | ||
idr.c | ||
inflate.c | ||
int_sqrt.c | ||
interval_tree.c | ||
interval_tree_test_main.c | ||
iomap.c | ||
iomap_copy.c | ||
iommu-helper.c | ||
ioremap.c | ||
irq_regs.c | ||
is_single_threaded.c | ||
jedec_ddr_data.c | ||
kasprintf.c | ||
Kconfig | ||
Kconfig.debug | ||
Kconfig.kgdb | ||
Kconfig.kmemcheck | ||
kfifo.c | ||
klist.c | ||
kobject.c | ||
kobject_uevent.c | ||
kstrtox.c | ||
kstrtox.h | ||
lcm.c | ||
libcrc32c.c | ||
list_debug.c | ||
list_sort.c | ||
llist.c | ||
locking-selftest-hardirq.h | ||
locking-selftest-mutex.h | ||
locking-selftest-rlock-hardirq.h | ||
locking-selftest-rlock-softirq.h | ||
locking-selftest-rlock.h | ||
locking-selftest-rsem.h | ||
locking-selftest-softirq.h | ||
locking-selftest-spin-hardirq.h | ||
locking-selftest-spin-softirq.h | ||
locking-selftest-spin.h | ||
locking-selftest-wlock-hardirq.h | ||
locking-selftest-wlock-softirq.h | ||
locking-selftest-wlock.h | ||
locking-selftest-wsem.h | ||
locking-selftest.c | ||
lru_cache.c | ||
Makefile | ||
md5.c | ||
memory-notifier-error-inject.c | ||
memweight.c | ||
nlattr.c | ||
notifier-error-inject.c | ||
notifier-error-inject.h | ||
of-reconfig-notifier-error-inject.c | ||
oid_registry.c | ||
parser.c | ||
pci_iomap.c | ||
percpu-rwsem.c | ||
percpu_counter.c | ||
plist.c | ||
pm-notifier-error-inject.c | ||
prio_heap.c | ||
proportions.c | ||
radix-tree.c | ||
random32.c | ||
ratelimit.c | ||
rational.c | ||
rbtree.c | ||
rbtree_test.c | ||
reciprocal_div.c | ||
rwsem-spinlock.c | ||
rwsem.c | ||
scatterlist.c | ||
sha1.c | ||
show_mem.c | ||
smp_processor_id.c | ||
sort.c | ||
spinlock_debug.c | ||
stmp_device.c | ||
string.c | ||
string_helpers.c | ||
strncpy_from_user.c | ||
strnlen_user.c | ||
swiotlb.c | ||
syscall.c | ||
test-kstrtox.c | ||
textsearch.c | ||
timerqueue.c | ||
ts_bm.c | ||
ts_fsm.c | ||
ts_kmp.c | ||
ucs2_string.c | ||
uuid.c | ||
vsprintf.c |