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author | Linus Torvalds <torvalds@linux-foundation.org> | 2022-12-12 09:01:36 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-12-12 09:01:36 -0800 |
commit | 98d0052d0d9dcd5323833482712b5799ed0bbb0b (patch) | |
tree | e055e679d2aebf8b11d82b010775d96794295106 /lib | |
parent | 73fa58dca80293320f5cfeb06f5b2daeb8d97bd5 (diff) | |
parent | 6b2b0d839acaa84f05a77184370f793752e786e9 (diff) | |
download | lwn-98d0052d0d9dcd5323833482712b5799ed0bbb0b.tar.gz lwn-98d0052d0d9dcd5323833482712b5799ed0bbb0b.zip |
Merge tag 'printk-for-6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux
Pull printk updates from Petr Mladek:
- Add NMI-safe SRCU reader API. It uses atomic_inc() instead of
this_cpu_inc() on strong load-store architectures.
- Introduce new console_list_lock to synchronize a manipulation of the
list of registered consoles and their flags.
This is a first step in removing the big-kernel-lock-like behavior of
console_lock(). This semaphore still serializes console->write()
calbacks against:
- each other. It primary prevents potential races between early
and proper console drivers using the same device.
- suspend()/resume() callbacks and init() operations in some
drivers.
- various other operations in the tty/vt and framebufer
susbsystems. It is likely that console_lock() serializes even
operations that are not directly conflicting with the
console->write() callbacks here. This is the most complicated
big-kernel-lock aspect of the console_lock() that will be hard
to untangle.
- Introduce new console_srcu lock that is used to safely iterate and
access the registered console drivers under SRCU read lock.
This is a prerequisite for introducing atomic console drivers and
console kthreads. It will reduce the complexity of serialization
against normal consoles and console_lock(). Also it should remove the
risk of deadlock during critical situations, like Oops or panic, when
only atomic consoles are registered.
- Check whether the console is registered instead of enabled on many
locations. It was a historical leftover.
- Cleanly force a preferred console in xenfb code instead of a dirty
hack.
- A lot of code and comment clean ups and improvements.
* tag 'printk-for-6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: (47 commits)
printk: htmldocs: add missing description
tty: serial: sh-sci: use setup() callback for early console
printk: relieve console_lock of list synchronization duties
tty: serial: kgdboc: use console_list_lock to trap exit
tty: serial: kgdboc: synchronize tty_find_polling_driver() and register_console()
tty: serial: kgdboc: use console_list_lock for list traversal
tty: serial: kgdboc: use srcu console list iterator
proc: consoles: use console_list_lock for list iteration
tty: tty_io: use console_list_lock for list synchronization
printk, xen: fbfront: create/use safe function for forcing preferred
netconsole: avoid CON_ENABLED misuse to track registration
usb: early: xhci-dbc: use console_is_registered()
tty: serial: xilinx_uartps: use console_is_registered()
tty: serial: samsung_tty: use console_is_registered()
tty: serial: pic32_uart: use console_is_registered()
tty: serial: earlycon: use console_is_registered()
tty: hvc: use console_is_registered()
efi: earlycon: use console_is_registered()
tty: nfcon: use console_is_registered()
serial_core: replace uart_console_enabled() with uart_console_registered()
...
Diffstat (limited to 'lib')
-rw-r--r-- | lib/test_printf.c | 26 | ||||
-rw-r--r-- | lib/vsprintf.c | 2 |
2 files changed, 13 insertions, 15 deletions
diff --git a/lib/test_printf.c b/lib/test_printf.c index 5eb889679e4f..d6a5d4b5f884 100644 --- a/lib/test_printf.c +++ b/lib/test_printf.c @@ -692,31 +692,29 @@ flags(void) static void __init fwnode_pointer(void) { - const struct software_node softnodes[] = { - { .name = "first", }, - { .name = "second", .parent = &softnodes[0], }, - { .name = "third", .parent = &softnodes[1], }, - { NULL /* Guardian */ } - }; - const char * const full_name = "first/second/third"; + const struct software_node first = { .name = "first" }; + const struct software_node second = { .name = "second", .parent = &first }; + const struct software_node third = { .name = "third", .parent = &second }; + const struct software_node *group[] = { &first, &second, &third, NULL }; const char * const full_name_second = "first/second"; + const char * const full_name_third = "first/second/third"; const char * const second_name = "second"; const char * const third_name = "third"; int rval; - rval = software_node_register_nodes(softnodes); + rval = software_node_register_node_group(group); if (rval) { pr_warn("cannot register softnodes; rval %d\n", rval); return; } - test(full_name_second, "%pfw", software_node_fwnode(&softnodes[1])); - test(full_name, "%pfw", software_node_fwnode(&softnodes[2])); - test(full_name, "%pfwf", software_node_fwnode(&softnodes[2])); - test(second_name, "%pfwP", software_node_fwnode(&softnodes[1])); - test(third_name, "%pfwP", software_node_fwnode(&softnodes[2])); + test(full_name_second, "%pfw", software_node_fwnode(&second)); + test(full_name_third, "%pfw", software_node_fwnode(&third)); + test(full_name_third, "%pfwf", software_node_fwnode(&third)); + test(second_name, "%pfwP", software_node_fwnode(&second)); + test(third_name, "%pfwP", software_node_fwnode(&third)); - software_node_unregister_nodes(softnodes); + software_node_unregister_node_group(group); } static void __init fourcc_pointer(void) diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 24f37bab8bc1..5b0611c00956 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -866,7 +866,7 @@ char *restricted_pointer(char *buf, char *end, const void *ptr, * kptr_restrict==1 cannot be used in IRQ context * because its test for CAP_SYSLOG would be meaningless. */ - if (in_irq() || in_serving_softirq() || in_nmi()) { + if (in_hardirq() || in_serving_softirq() || in_nmi()) { if (spec.field_width == -1) spec.field_width = 2 * sizeof(ptr); return error_string(buf, end, "pK-error", spec); |