Sumit Garg 5946d1f5b3 kdb: Switch to use safer dbg_io_ops over console APIs ... In kgdb context, calling console handlers aren't safe due to locks used in those handlers which could in turn lead to a deadlock. Although, using oops_in_progress increases the chance to bypass locks in most console handlers but it might not be sufficient enough in case a console uses more locks (VT/TTY is good example). Currently when a driver provides both polling I/O and a console then kdb will output using the console. We can increase robustness by using the currently active polling I/O driver (which should be lockless) instead of the corresponding console. For several common cases (e.g. an embedded system with a single serial port that is used both for console output and debugger I/O) this will result in no console handler being used. In order to achieve this we need to reverse the order of preference to use dbg_io_ops (uses polling I/O mode) over console APIs. So we just store "struct console" that represents debugger I/O in dbg_io_ops and while emitting kdb messages, skip console that matches dbg_io_ops console in order to avoid duplicate messages. After this change, "is_console" param becomes redundant and hence removed. Suggested-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Sumit Garg <sumit.garg@linaro.org> Link: https://lore.kernel.org/r/1591264879-25920-5-git-send-email-sumit.garg@linaro.org Reviewed-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>		2020-06-26 15:40:16 +01:00
..
bpf	Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net	2020-06-13 16:27:13 -07:00
cgroup	mmap locking API: convert mmap_sem comments	2020-06-09 09:39:14 -07:00
configs
debug	kdb: Switch to use safer dbg_io_ops over console APIs	2020-06-26 15:40:16 +01:00
dma	dma-pool: decouple DMA_REMAP from DMA_COHERENT_POOL	2020-06-15 08:35:30 +02:00
events	Merge branch 'akpm' (patches from Andrew)	2020-06-09 09:54:46 -07:00
gcov	treewide: replace '---help---' in Kconfig files with 'help'	2020-06-14 01:57:21 +09:00
irq	treewide: replace '---help---' in Kconfig files with 'help'	2020-06-14 01:57:21 +09:00
kcsan	kcsan: Support distinguishing volatile accesses	2020-06-11 20:04:01 +02:00
livepatch	livepatch: Make klp_apply_object_relocs static	2020-05-11 00:31:38 +02:00
locking	The X86 entry, exception and interrupt code rework	2020-06-13 10:05:47 -07:00
power	treewide: replace '---help---' in Kconfig files with 'help'	2020-06-14 01:57:21 +09:00
printk	One more printk change for 5.8	2020-06-12 12:13:36 -07:00
rcu	TTY/Serial driver updates for 5.8-rc1	2020-06-07 09:52:36 -07:00
sched	Rebase locking/kcsan to locking/urgent	2020-06-11 20:02:46 +02:00
time	The X86 entry, exception and interrupt code rework	2020-06-13 10:05:47 -07:00
trace	A few fixes and small cleanups for tracing:	2020-06-20 13:17:47 -07:00
.gitignore
acct.c	mmap locking API: convert mmap_sem comments	2020-06-09 09:39:14 -07:00
async.c
audit_fsnotify.c
audit_tree.c
audit_watch.c
audit.c	audit/stable-5.8 PR 20200601	2020-06-02 17:13:37 -07:00
audit.h	audit: fix a net reference leak in audit_list_rules_send()	2020-04-22 15:23:10 -04:00
auditfilter.c	audit: fix a net reference leak in audit_list_rules_send()	2020-04-22 15:23:10 -04:00
auditsc.c	audit: add subj creds to NETFILTER_CFG record to	2020-05-20 18:09:19 -04:00
backtracetest.c
bounds.c
capability.c
compat.c	uaccess: Selectively open read or write user access	2020-05-01 12:35:21 +10:00
configs.c
context_tracking.c	context_tracking: Ensure that the critical path cannot be instrumented	2020-06-11 15:14:36 +02:00
cpu_pm.c	kernel/cpu_pm: Fix uninitted local in cpu_pm	2020-05-15 11:44:34 -07:00
cpu.c	The changes in this cycle are:	2020-06-03 13:06:42 -07:00
crash_core.c
crash_dump.c
cred.c	exec: Teach prepare_exec_creds how exec treats uids & gids	2020-05-20 14:44:21 -05:00
delayacct.c
dma.c
elfcore.c
exec_domain.c
exit.c	mmap locking API: convert mmap_sem comments	2020-06-09 09:39:14 -07:00
extable.c
fail_function.c
fork.c	mmap locking API: convert nested write lock sites	2020-06-09 09:39:14 -07:00
freezer.c
futex.c	mmap locking API: use coccinelle to convert mmap_sem rwsem call sites	2020-06-09 09:39:14 -07:00
gen_kheaders.sh	kbuild: add variables for compression tools	2020-06-06 23:42:01 +09:00
groups.c	mm: remove the pgprot argument to __vmalloc	2020-06-02 10:59:11 -07:00
hung_task.c	kernel/hung_task.c: introduce sysctl to print all traces when a hung task is detected	2020-06-08 11:05:56 -07:00
iomem.c
irq_work.c	irq_work, smp: Allow irq_work on call_single_queue	2020-05-28 10:54:15 +02:00
jump_label.c
kallsyms.c
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c	kcov: check kcov_softirq in kcov_remote_stop()	2020-06-10 19:14:17 -07:00
kexec_core.c
kexec_elf.c
kexec_file.c	kexec_file: don't place kexec images on IORESOURCE_MEM_DRIVER_MANAGED	2020-06-04 19:06:23 -07:00
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	sysctl: pass kernel pointers to ->proc_handler	2020-04-27 02:07:40 -04:00
Makefile	Notifications over pipes + Keyring notifications	2020-06-13 09:56:21 -07:00
module_signature.c
module_signing.c
module-internal.h
module.c	module: move the set_fs hack for flush_icache_range to m68k	2020-06-08 11:05:58 -07:00
notifier.c	mm: remove vmalloc_sync_(un)mappings()	2020-06-02 10:59:12 -07:00
nsproxy.c	nsproxy: attach to namespaces via pidfds	2020-05-13 11:41:22 +02:00
padata.c	padata: add basic support for multithreaded jobs	2020-06-03 20:09:45 -07:00
panic.c	bug: Annotate WARN/BUG/stackfail as noinstr safe	2020-06-11 15:14:36 +02:00
params.c
pid_namespace.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next	2020-06-03 16:27:18 -07:00
pid.c	remove the no longer needed pid_alive() check in __task_pid_nr_ns()	2020-04-30 06:40:14 -05:00
profile.c
ptrace.c
range.c
reboot.c	printk: Collapse shutdown types into a single dump reason	2020-05-30 10:34:03 -07:00
relay.c	mmap locking API: convert mmap_sem comments	2020-06-09 09:39:14 -07:00
resource.c	/dev/mem: Revoke mappings when a driver claims the region	2020-05-27 11:10:05 +02:00
rseq.c
scs.c	scs: Report SCS usage in bytes rather than number of entries	2020-06-04 16:14:56 +01:00
seccomp.c	sysctl: pass kernel pointers to ->proc_handler	2020-04-27 02:07:40 -04:00
signal.c	Merge branch 'work.set_fs-exec' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2020-06-01 16:21:46 -07:00
smp.c	The changes in this cycle are:	2020-06-03 13:06:42 -07:00
smpboot.c
smpboot.h
softirq.c	x86/entry: Clarify irq_{enter,exit}_rcu()	2020-06-11 15:15:24 +02:00
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	kernel/sysctl.c: ignore out-of-range taint bits introduced via kernel.tainted	2020-06-08 11:05:56 -07:00
task_work.c
taskstats.c
test_kprobes.c
torture.c
tracepoint.c
tsacct.c
ucount.c
uid16.c
uid16.h
umh.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net	2020-05-15 13:48:59 -07:00
up.c
user_namespace.c	nsproxy: add struct nsset	2020-05-09 13:57:12 +02:00
user-return-notifier.c
user.c	user.c: make uidhash_table static	2020-06-04 19:06:24 -07:00
utsname_sysctl.c	sysctl: pass kernel pointers to ->proc_handler	2020-04-27 02:07:40 -04:00
utsname.c	nsproxy: add struct nsset	2020-05-09 13:57:12 +02:00
watch_queue.c	Notifications over pipes + Keyring notifications	2020-06-13 09:56:21 -07:00
watchdog_hld.c
watchdog.c	kernel/watchdog.c: convert {soft/hard}lockup boot parameters to sysctl aliases	2020-06-08 11:05:56 -07:00
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