Jason A. Donenfeld 625d344978 Revert "kernel/printk: add kmsg SEEK_CUR handling" ... This reverts commit 8ece3b3eb5. This commit broke userspace. Bash uses ESPIPE to determine whether or not the file should be read using "unbuffered I/O", which means reading 1 byte at a time instead of 128 bytes at a time. I used to use bash to read through kmsg in a really quite nasty way: while read -t 0.1 -r line 2>/dev/null || [[ $? -ne 142 ]]; do echo "SARU $line" done < /dev/kmsg This will show all lines that can fit into the 128 byte buffer, and skip lines that don't. That's pretty awful, but at least it worked. With this change, bash now tries to do 1-byte reads, which means it skips all the lines, which is worse than before. Now, I don't really care very much about this, and I'm already look for a workaround. But I did just spend an hour trying to figure out why my scripts were broken. Either way, it makes no difference to me personally whether this is reverted, but it might be something to consider. If you declare that "trying to read /dev/kmsg with bash is terminally stupid anyway," I might be inclined to agree with you. But do note that bash uses lseek(fd, 0, SEEK_CUR)==>ESPIPE to determine whether or not it's reading from a pipe. Cc: Bruno Meneguele <bmeneg@redhat.com> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: David Laight <David.Laight@ACULAB.COM> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Petr Mladek <pmladek@suse.com> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2020-06-21 20:47:20 -07:00
..
bpf	Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net	2020-06-13 16:27:13 -07:00
cgroup
configs
debug	maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault	2020-06-17 10:57:41 -07:00
dma	dma-pool: decouple DMA_REMAP from DMA_COHERENT_POOL	2020-06-15 08:35:30 +02:00
events
gcov
irq
kcsan
livepatch
locking
power
printk	Revert "kernel/printk: add kmsg SEEK_CUR handling"	2020-06-21 20:47:20 -07:00
rcu
sched
time
trace	A few fixes and small cleanups for tracing:	2020-06-20 13:17:47 -07:00
.gitignore
acct.c
async.c
audit_fsnotify.c
audit_tree.c
audit_watch.c
audit.c
audit.h
auditfilter.c
auditsc.c
backtracetest.c
bounds.c
capability.c
compat.c
configs.c
context_tracking.c
cpu_pm.c
cpu.c
crash_core.c
crash_dump.c
cred.c
delayacct.c
dma.c
elfcore.c
exec_domain.c
exit.c
extable.c
fail_function.c
fork.c
freezer.c
futex.c
gen_kheaders.sh
groups.c
hung_task.c
iomem.c
irq_work.c
jump_label.c
kallsyms.c
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c
kexec_core.c
kexec_elf.c
kexec_file.c
kexec_internal.h
kexec.c
kheaders.c
kmod.c
kprobes.c	kretprobe: Prevent triggering kretprobe from within kprobe_flush_task	2020-06-16 21:21:01 -04:00
ksysfs.c
kthread.c	maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault	2020-06-17 10:57:41 -07:00
latencytop.c
Makefile
module_signature.c
module_signing.c
module-internal.h
module.c
notifier.c
nsproxy.c
padata.c
panic.c
params.c
pid_namespace.c
pid.c
profile.c
ptrace.c
range.c
reboot.c
relay.c
resource.c
rseq.c
scs.c
seccomp.c
signal.c
smp.c
smpboot.c
smpboot.h
softirq.c
stackleak.c
stacktrace.c
stop_machine.c
sys_ni.c
sys.c	Add additional LSM hooks for SafeSetID	2020-06-14 11:39:31 -07:00
sysctl_binary.c
sysctl-test.c
sysctl.c
task_work.c
taskstats.c
test_kprobes.c
torture.c
tracepoint.c
tsacct.c
ucount.c
uid16.c
uid16.h
umh.c
up.c
user_namespace.c
user-return-notifier.c
user.c
utsname_sysctl.c
utsname.c
watch_queue.c
watchdog_hld.c
watchdog.c
workqueue_internal.h
workqueue.c	maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault	2020-06-17 10:57:41 -07:00