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* kdb: fix ctrl+e/a/f/b/d/p/n broken in keyboard modeNir Lichtman4 days1-9/+24
| | | | | | | | | | | | | | | | | | Problem: When using kdb via keyboard it does not react to control characters which are supported in serial mode. Example: Chords such as ctrl+a/e/d/p do not work in keyboard mode Solution: Before disregarding non-printable key characters, check if they are one of the supported control characters, I have took the control characters from the switch case upwards in this function that translates scan codes of arrow keys/backspace/home/.. to the control characters. Suggested-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Nir Lichtman <nir@lichtman.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20241111215622.GA161253@lichtman.org Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
* kdb: Fix breakpoint enable to be silent if already enabledNir Lichtman2024-11-021-2/+4
| | | | | | | | | | | | Fix the breakpoint enable command (be) to a logic that is inline with the breakpoint disable command (bd) in which if the breakpoint is already in an enabled state, do not print the message of enabled again to the user. Also a small nit fix of the new line in a separate print. Signed-off-by: Nir Lichtman <nir@lichtman.org> Link: https://lore.kernel.org/r/20241027204729.GA907155@lichtman.org Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
* kdb: Remove fallback interpretation of arbitrary numbers as hexNir Lichtman2024-11-021-12/+4
| | | | | | | | | | | | Remove logic that enables a fallback of interpreting numbers supplied in KDB CLI to be interpreted as hex without explicit "0x" prefix as this can be confusing for the end users. Suggested-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Nir Lichtman <nir@lichtman.org> Link: https://lore.kernel.org/r/20241028192228.GC918454@lichtman.org Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
* kdb: Replace the use of simple_strto with safer kstrto in kdb_mainYuran Pereira2024-11-021-48/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The simple_str* family of functions perform no error checking in scenarios where the input value overflows the intended output variable. This results in these functions successfully returning even when the output does not match the input string. Or as it was mentioned [1], "...simple_strtol(), simple_strtoll(), simple_strtoul(), and simple_strtoull() functions explicitly ignore overflows, which may lead to unexpected results in callers." Hence, the use of those functions is discouraged. This patch replaces all uses of the simple_strto* series of functions with their safer kstrto* alternatives. Side effects of this patch: - Every string to long or long long conversion using kstrto* is now checked for failure. - kstrto* errors are handled with appropriate `KDB_BADINT` wherever applicable. - A good side effect is that we end up saving a few lines of code since unlike in simple_strto* functions, kstrto functions do not need an additional "end pointer" variable, and the return values of the latter can be directly checked in an "if" statement without the need to define additional `ret` or `err` variables. This, of course, results in cleaner, yet still easy to understand code. [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#simple-strtol-simple-strtoll-simple-strtoul-simple-strtoull Signed-off-by: Yuran Pereira <yuran.pereira@hotmail.com> [nir: addressed review comments by fixing styling, invalid conversion and a missing error return] Signed-off-by: Nir Lichtman <nir@lichtman.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20241028191916.GA918454@lichtman.org Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
* move asm/unaligned.h to linux/unaligned.hAl Viro2024-10-021-1/+1
| | | | | | | | | | | | | | | | | | | asm/unaligned.h is always an include of asm-generic/unaligned.h; might as well move that thing to linux/unaligned.h and include that - there's nothing arch-specific in that header. auto-generated by the following: for i in `git grep -l -w asm/unaligned.h`; do sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i done for i in `git grep -l -w asm-generic/unaligned.h`; do sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i done git mv include/asm-generic/unaligned.h include/linux/unaligned.h git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h
* kdb: Get rid of redundant kdb_curr_task()Zheng Zengkai2024-06-213-17/+5
| | | | | | | | | | | | | | Commit cf8e8658100d ("arch: Remove Itanium (IA-64) architecture") removed the only definition of macro _TIF_MCA_INIT, so kdb_curr_task() is actually the same as curr_task() now and becomes redundant. Let's remove the definition of kdb_curr_task() and replace remaining calls with curr_task(). Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> Reviewed-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20240620142132.157518-1-zhengzengkai@huawei.com Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
* kdb: Use the passed prompt in kdb_position_cursor()Douglas Anderson2024-06-211-1/+1
| | | | | | | | | | | | | | | The function kdb_position_cursor() takes in a "prompt" parameter but never uses it. This doesn't _really_ matter since all current callers of the function pass the same value and it's a global variable, but it's a bit ugly. Let's clean it up. Found by code inspection. This patch is expected to functionally be a no-op. Fixes: 09b35989421d ("kdb: Use format-strings rather than '\0' injection in kdb_read()") Signed-off-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20240528071144.1.I0feb49839c6b6f4f2c4bf34764f5e95de3f55a66@changeid Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
* kdb: address -Wformat-security warningsArnd Bergmann2024-06-211-2/+2
| | | | | | | | | | | | | | | | | | | | | | When -Wformat-security is not disabled, using a string pointer as a format causes a warning: kernel/debug/kdb/kdb_io.c: In function 'kdb_read': kernel/debug/kdb/kdb_io.c:365:36: error: format not a string literal and no format arguments [-Werror=format-security] 365 | kdb_printf(kdb_prompt_str); | ^~~~~~~~~~~~~~ kernel/debug/kdb/kdb_io.c: In function 'kdb_getstr': kernel/debug/kdb/kdb_io.c:456:20: error: format not a string literal and no format arguments [-Werror=format-security] 456 | kdb_printf(kdb_prompt_str); | ^~~~~~~~~~~~~~ Use an explcit "%s" format instead. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Fixes: 5d5314d6795f ("kdb: core for kgdb back end (1 of 2)") Reviewed-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20240528121154.3662553-1-arnd@kernel.org Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
* kdb: Simplify management of tmpbuffer in kdb_read()Daniel Thompson2024-04-261-23/+18
| | | | | | | | | | | | | | | | | | | | | The current approach to filling tmpbuffer with completion candidates is confusing, with the buffer management being especially hard to reason about. That's because it doesn't copy the completion canidate into tmpbuffer, instead of copies a whole bunch of other nonsense and then runs the completion search from the middle of tmpbuffer! Change this to copy nothing but the completion candidate into tmpbuffer. Pretty much everything else in this patch is renaming to reflect the above change: s/p_tmp/tmpbuffer/ s/buf_size/sizeof(tmpbuffer)/ Reviewed-by: Douglas Anderson <dianders@chromium.org> Tested-by: Justin Stitt <justinstitt@google.com> Link: https://lore.kernel.org/r/20240424-kgdb_read_refactor-v3-7-f236dbe9828d@linaro.org Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
* kdb: Replace double memcpy() with memmove() in kdb_read()Daniel Thompson2024-04-261-12/+7
| | | | | | | | | | | | | | | | | | | | | | | At several points in kdb_read() there are variants of the following code pattern (with offsets slightly altered): memcpy(tmpbuffer, cp, lastchar - cp); memcpy(cp-1, tmpbuffer, lastchar - cp); *(--lastchar) = '\0'; There is no need to use tmpbuffer here, since we can use memmove() instead so refactor in the obvious way. Additionally the strings that are being copied are already properly terminated so let's also change the code so that the library calls also move the terminator. Changing how the terminators are managed has no functional effect for now but might allow us to retire lastchar at a later point. lastchar, although stored as a pointer, is functionally equivalent to caching strlen(buffer). Reviewed-by: Douglas Anderson <dianders@chromium.org> Tested-by: Justin Stitt <justinstitt@google.com> Link: https://lore.kernel.org/r/20240424-kgdb_read_refactor-v3-6-f236dbe9828d@linaro.org Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
* kdb: Use format-specifiers rather than memset() for padding in kdb_read()Daniel Thompson2024-04-261-5/+3
| | | | | | | | | | | | | | | | | | Currently when the current line should be removed from the display kdb_read() uses memset() to fill a temporary buffer with spaces. The problem is not that this could be trivially implemented using a format string rather than open coding it. The real problem is that it is possible, on systems with a long kdb_prompt_str, to write past the end of the tmpbuffer. Happily, as mentioned above, this can be trivially implemented using a format string. Make it so! Cc: stable@vger.kernel.org Reviewed-by: Douglas Anderson <dianders@chromium.org> Tested-by: Justin Stitt <justinstitt@google.com> Link: https://lore.kernel.org/r/20240424-kgdb_read_refactor-v3-5-f236dbe9828d@linaro.org Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
* kdb: Merge identical case statements in kdb_read()Daniel Thompson2024-04-261-9/+1
| | | | | | | | | | | The code that handles case 14 (down) and case 16 (up) has been copy and pasted despite being byte-for-byte identical. Combine them. Cc: stable@vger.kernel.org # Not a bug fix but it is needed for later bug fixes Reviewed-by: Douglas Anderson <dianders@chromium.org> Tested-by: Justin Stitt <justinstitt@google.com> Link: https://lore.kernel.org/r/20240424-kgdb_read_refactor-v3-4-f236dbe9828d@linaro.org Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
* kdb: Fix console handling when editing and tab-completing commandsDaniel Thompson2024-04-261-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, if the cursor position is not at the end of the command buffer and the user uses the Tab-complete functions, then the console does not leave the cursor in the correct position. For example consider the following buffer with the cursor positioned at the ^: md kdb_pro 10 ^ Pressing tab should result in: md kdb_prompt_str 10 ^ However this does not happen. Instead the cursor is placed at the end (after then 10) and further cursor movement redraws incorrectly. The same problem exists when we double-Tab but in a different part of the code. Fix this by sending a carriage return and then redisplaying the text to the left of the cursor. Cc: stable@vger.kernel.org Reviewed-by: Douglas Anderson <dianders@chromium.org> Tested-by: Justin Stitt <justinstitt@google.com> Link: https://lore.kernel.org/r/20240424-kgdb_read_refactor-v3-3-f236dbe9828d@linaro.org Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
* kdb: Use format-strings rather than '\0' injection in kdb_read()Daniel Thompson2024-04-261-21/+34
| | | | | | | | | | | | | | | | | | Currently when kdb_read() needs to reposition the cursor it uses copy and paste code that works by injecting an '\0' at the cursor position before delivering a carriage-return and reprinting the line (which stops at the '\0'). Tidy up the code by hoisting the copy and paste code into an appropriately named function. Additionally let's replace the '\0' injection with a proper field width parameter so that the string will be abridged during formatting instead. Cc: stable@vger.kernel.org # Not a bug fix but it is needed for later bug fixes Tested-by: Justin Stitt <justinstitt@google.com> Reviewed-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20240424-kgdb_read_refactor-v3-2-f236dbe9828d@linaro.org Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
* kdb: Fix buffer overflow during tab-completeDaniel Thompson2024-04-261-8/+13
| | | | | | | | | | | | | | | | | | | | | | | Currently, when the user attempts symbol completion with the Tab key, kdb will use strncpy() to insert the completed symbol into the command buffer. Unfortunately it passes the size of the source buffer rather than the destination to strncpy() with predictably horrible results. Most obviously if the command buffer is already full but cp, the cursor position, is in the middle of the buffer, then we will write past the end of the supplied buffer. Fix this by replacing the dubious strncpy() calls with memmove()/memcpy() calls plus explicit boundary checks to make sure we have enough space before we start moving characters around. Reported-by: Justin Stitt <justinstitt@google.com> Closes: https://lore.kernel.org/all/CAFhGd8qESuuifuHsNjFPR-Va3P80bxrw+LqvC8deA8GziUJLpw@mail.gmail.com/ Cc: stable@vger.kernel.org Reviewed-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Justin Stitt <justinstitt@google.com> Tested-by: Justin Stitt <justinstitt@google.com> Link: https://lore.kernel.org/r/20240424-kgdb_read_refactor-v3-1-f236dbe9828d@linaro.org Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
* kdb: Use str_plural() to fix Coccinelle warningThorsten Blum2024-04-221-1/+1
| | | | | | | | | | | | Fixes the following Coccinelle/coccicheck warning reported by string_choices.cocci: opportunity for str_plural(days) Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com> Reviewed-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20240328140015.388654-3-thorsten.blum@toblux.com Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
* kdb: Fix a potential buffer overflow in kdb_local()Christophe JAILLET2024-01-171-2/+0
| | | | | | | | | | | | | | | | | | When appending "[defcmd]" to 'kdb_prompt_str', the size of the string already in the buffer should be taken into account. An option could be to switch from strncat() to strlcat() which does the correct test to avoid such an overflow. However, this actually looks as dead code, because 'defcmd_in_progress' can't be true here. See a more detailed explanation at [1]. [1]: https://lore.kernel.org/all/CAD=FV=WSh7wKN7Yp-3wWiDgX4E3isQ8uh0LCzTmd1v9Cg9j+nQ@mail.gmail.com/ Fixes: 5d5314d6795f ("kdb: core for kgdb back end (1 of 2)") Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Reviewed-by: Douglas Anderson <dianders@chromium.org>
* kdb: Corrects comment for kdballocenvYuran Pereira2023-11-061-4/+3
| | | | | | | | | | | This patch corrects the comment for the kdballocenv function. The previous comment incorrectly described the function's parameters and return values. Signed-off-by: Yuran Pereira <yuran.pereira@hotmail.com> Link: https://lore.kernel.org/r/DB3PR10MB6835B383B596133EDECEA98AE8ABA@DB3PR10MB6835.EURPRD10.PROD.OUTLOOK.COM [daniel.thompson@linaro.org: fixed whitespace alignment in new lines] Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
* kgdb: Flush console before entering kgdb on panicDouglas Anderson2023-10-151-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When entering kdb/kgdb on a kernel panic, it was be observed that the console isn't flushed before the `kdb` prompt came up. Specifically, when using the buddy lockup detector on arm64 and running: echo HARDLOCKUP > /sys/kernel/debug/provoke-crash/DIRECT I could see: [ 26.161099] lkdtm: Performing direct entry HARDLOCKUP [ 32.499881] watchdog: Watchdog detected hard LOCKUP on cpu 6 [ 32.552865] Sending NMI from CPU 5 to CPUs 6: [ 32.557359] NMI backtrace for cpu 6 ... [backtrace for cpu 6] ... [ 32.558353] NMI backtrace for cpu 5 ... [backtrace for cpu 5] ... [ 32.867471] Sending NMI from CPU 5 to CPUs 0-4,7: [ 32.872321] NMI backtrace forP cpuANC: Hard LOCKUP Entering kdb (current=..., pid 0) on processor 5 due to Keyboard Entry [5]kdb> As you can see, backtraces for the other CPUs start printing and get interleaved with the kdb PANIC print. Let's replicate the commands to flush the console in the kdb panic entry point to avoid this. Signed-off-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20230822131945.1.I5b460ae8f954e4c4f628a373d6e74713c06dd26f@changeid Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
* Merge tag 'printk-for-6.6' of ↵Linus Torvalds2023-09-041-0/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux Pull printk updates from Petr Mladek: - Do not try to get the console lock when it is not need or useful in panic() - Replace the global console_suspended state by a per-console flag - Export symbols needed for dumping the raw printk buffer in panic() - Fix documentation of printf formats for integer types - Moved Sergey Senozhatsky to the reviewer role - Misc cleanups * tag 'printk-for-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: printk: export symbols for debug modules lib: test_scanf: Add explicit type cast to result initialization in test_number_prefix() printk: ringbuffer: Fix truncating buffer size min_t cast printk: Rename abandon_console_lock_in_panic() to other_cpu_in_panic() printk: Add per-console suspended state printk: Consolidate console deferred printing printk: Do not take console lock for console_flush_on_panic() printk: Keep non-panic-CPUs out of console lock printk: Reduce console_unblank() usage in unsafe scenarios kdb: Do not assume write() callback available docs: printk-formats: Treat char as always unsigned docs: printk-formats: Fix hex printing of signed values MAINTAINERS: adjust printk/vsprintf entries
| * kdb: Do not assume write() callback availableJohn Ogness2023-07-201-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It is allowed for consoles to not provide a write() callback. For example ttynull does this. Check if a write() callback is available before using it. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org> Acked-by: Daniel Thompson <daniel.thompson@linaro.org> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20230717194607.145135-2-john.ogness@linutronix.de
* | tty: sysrq: switch sysrq handlers from int to u8Jiri Slaby2023-07-251-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The passed parameter to sysrq handlers is a key (a character). So change the type from 'int' to 'u8'. Let it specifically be 'u8' for two reasons: * unsigned: unsigned values come from the upper layers (devices) and the tty layer assumes unsigned on most places, and * 8-bit: as that what's supposed to be one day in all the layers built on the top of tty. (Currently, we use mostly 'unsigned char' and somewhere still only 'char'. (But that also translates to the former thanks to -funsigned-char.)) Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Cc: Richard Henderson <richard.henderson@linaro.org> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: "David S. Miller" <davem@davemloft.net> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Maxime Ripard <mripard@kernel.org> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: David Airlie <airlied@gmail.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Daniel Thompson <daniel.thompson@linaro.org> Cc: Douglas Anderson <dianders@chromium.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Len Brown <len.brown@intel.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: Frederic Weisbecker <frederic@kernel.org> Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Zqiang <qiang.zhang1211@gmail.com> Acked-by: Thomas Zimmermann <tzimmermann@suse.de> # DRM Acked-by: WANG Xuerui <git@xen0n.name> # loongarch Acked-by: Paul E. McKenney <paulmck@kernel.org> Acked-by: Daniel Thompson <daniel.thompson@linaro.org> Link: https://lore.kernel.org/r/20230712081811.29004-3-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | kdb: move kdb_send_sig() declaration to a better header fileDaniel Thompson2023-07-031-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | kdb_send_sig() is defined in the signal code and called from kdb, but the declaration is part of the kdb internal code. Move the declaration to the shared header to avoid the warning: kernel/signal.c:4789:6: error: no previous prototype for 'kdb_send_sig' [-Werror=missing-prototypes] Reported-by: Arnd Bergmann <arnd@arndb.de> Closes: https://lore.kernel.org/lkml/20230517125423.930967-1-arnd@kernel.org/ Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Link: https://lore.kernel.org/r/20230630201206.2396930-1-daniel.thompson@linaro.org
* | kdb: Handle LF in the command parserDouglas Anderson2023-06-301-1/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The main kdb command parser only handles CR (ASCII 13 AKA '\r') today, but not LF (ASCII 10 AKA '\n'). That means that the kdb command parser can handle terminals that send just CR or that send CR+LF but can't handle terminals that send just LF. The fact that kdb didn't handle LF in the command parser tripped up a tool I tried to use with it. Specifically, I was trying to send a command to my device to resume it from kdb using a ChromeOS tool like: dut-control cpu_uart_cmd:"g" That tool only terminates lines with LF, not CR+LF. Arguably the ChromeOS tool should be fixed. After all, officially kdb seems to be designed such that CR+LF is the official line ending transmitted over the wire and that internally a line ending is just '\n' (LF). Some evidence: * uart_poll_put_char(), which is used by kdb, notices a '\n' and converts it to '\r\n'. * kdb functions specifically use '\r' to get a carriage return without a newline. You can see this in the pager where kdb will write a '\r' and then write over the pager prompt. However, all that being said there's no real harm in accepting LF as a command terminator in the kdb parser and doing so seems like it would improve compatibility. After this, I'd expect that things would work OK-ish with a remote terminal that used any of CR, CR+LF, or LF as a line ending. Someone using CR as a line ending might get some ugliness where kdb wasn't able to overwrite the last line, but basic commands would work. Someone using just LF as a line ending would probably also work OK. A few other notes: - It can be noted that "bash" running on an "agetty" handles LF as a line termination with no complaints. - Historically, kdb's "pager" actually handled either CR or LF fine. A very quick inspection would make one think that kdb's pager actually could have paged down two lines instead of one for anyone using CR+LF, but this is generally avoided because of kdb_input_flush(). - Conceivably one could argue that some of this special case logic belongs in uart_poll_get_char() since uart_poll_put_char() handles the '\n' => '\r\n' conversion. I would argue that perhaps we should eventually do the opposite and move the '\n' => '\r\n' out of uart_poll_put_char(). Having that conversion at such a low level could interfere if we ever want to transfer binary data. In addition, if we truly made uart_poll_get_char() the inverse of uart_poll_put_char() it would convert back to '\n' and (ironically) kdb's parser currently only looks for '\r' to find the end of a command. Signed-off-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20230628125612.1.I5cc6c3d916195f5bcfdf5b75d823f2037707f5dc@changeid Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
* | kdb: include kdb_private.h for function prototypesArnd Bergmann2023-06-291-0/+2
|/ | | | | | | | | | | | The kdb_kbd_cleanup_state() is called from another file through the kdb_private.h file, but that is not included before the definition, causing a W=1 warning: kernel/debug/kdb/kdb_keyboard.c:198:6: error: no previous prototype for 'kdb_kbd_cleanup_state' [-Werror=missing-prototypes] Signed-off-by: Arnd Bergmann <arnd@arndb.de> Link: https://lore.kernel.org/r/20230517124802.929751-1-arnd@kernel.org Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
* kdb: use srcu console list iteratorJohn Ogness2022-12-021-2/+16
| | | | | | | | | | | Guarantee safe iteration of the console list by using SRCU. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Aaron Tomlin <atomlin@atomlin.com> Reviewed-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20221116162152.193147-15-john.ogness@linutronix.de
* mm: remove vmacacheLiam R. Howlett2022-09-261-12/+0
| | | | | | | | | | | | | | | | | | | | By using the maple tree and the maple tree state, the vmacache is no longer beneficial and is complicating the VMA code. Remove the vmacache to reduce the work in keeping it up to date and code complexity. Link: https://lkml.kernel.org/r/20220906194824.2110408-26-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Tested-by: Yu Zhao <yuzhao@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: SeongJae Park <sj@kernel.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* Merge tag 'modules-5.19-rc1' of ↵Linus Torvalds2022-05-265-56/+0
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux Pull modules updates from Luis Chamberlain: - It was time to tidy up kernel/module.c and one way of starting with that effort was to split it up into files. At my request Aaron Tomlin spearheaded that effort with the goal to not introduce any functional at all during that endeavour. The penalty for the split is +1322 bytes total, +112 bytes in data, +1210 bytes in text while bss is unchanged. One of the benefits of this other than helping make the code easier to read and review is summoning more help on review for changes with livepatching so kernel/module/livepatch.c is now pegged as maintained by the live patching folks. The before and after with just the move on a defconfig on x86-64: $ size kernel/module.o text data bss dec hex filename 38434 4540 104 43078 a846 kernel/module.o $ size -t kernel/module/*.o text data bss dec hex filename 4785 120 0 4905 1329 kernel/module/kallsyms.o 28577 4416 104 33097 8149 kernel/module/main.o 1158 8 0 1166 48e kernel/module/procfs.o 902 108 0 1010 3f2 kernel/module/strict_rwx.o 3390 0 0 3390 d3e kernel/module/sysfs.o 832 0 0 832 340 kernel/module/tree_lookup.o 39644 4652 104 44400 ad70 (TOTALS) - Aaron added module unload taint tracking (MODULE_UNLOAD_TAINT_TRACKING), to enable tracking unloaded modules which did taint the kernel. - Christophe Leroy added CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC which lets architectures to request having modules data in vmalloc area instead of module area. There are three reasons why an architecture might want this: a) On some architectures (like book3s/32) it is not possible to protect against execution on a page basis. The exec stuff can be mapped by different arch segment sizes (on book3s/32 that is 256M segments). By default the module area is in an Exec segment while vmalloc area is in a NoExec segment. Using vmalloc lets you muck with module data as NoExec on those architectures whereas before you could not. b) By pushing more module data to vmalloc you also increase the probability of module text to remain within a closer distance from kernel core text and this reduces trampolines, this has been reported on arm first and powerpc folks are following that lead. c) Free'ing module_alloc() (Exec by default) area leaves this exposed as Exec by default, some architectures have some security enhancements to set this as NoExec on free, and splitting module data with text let's future generic special allocators be added to the kernel without having developers try to grok the tribal knowledge per arch. Work like Rick Edgecombe's permission vmalloc interface [0] becomes easier to address over time. [0] https://lore.kernel.org/lkml/20201120202426.18009-1-rick.p.edgecombe@intel.com/#r - Masahiro Yamada's symbol search enhancements * tag 'modules-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: (33 commits) module: merge check_exported_symbol() into find_exported_symbol_in_section() module: do not binary-search in __ksymtab_gpl if fsa->gplok is false module: do not pass opaque pointer for symbol search module: show disallowed symbol name for inherit_taint() module: fix [e_shstrndx].sh_size=0 OOB access module: Introduce module unload taint tracking module: Move module_assert_mutex_or_preempt() to internal.h module: Make module_flags_taint() accept a module's taints bitmap and usable outside core code module.h: simplify MODULE_IMPORT_NS powerpc: Select ARCH_WANTS_MODULES_DATA_IN_VMALLOC on book3s/32 and 8xx module: Remove module_addr_min and module_addr_max module: Add CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC module: Introduce data_layout module: Prepare for handling several RB trees module: Always have struct mod_tree_root module: Rename debug_align() as strict_align() module: Rework layout alignment to avoid BUG_ON()s module: Move module_enable_x() and frob_text() in strict_rwx.c module: Make module_enable_x() independent of CONFIG_ARCH_HAS_STRICT_MODULE_RWX module: Move version support into a separate file ...
| * module: Move kdb module related code out of main kdb codeAaron Tomlin2022-04-055-56/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | No functional change. This patch migrates the kdb 'lsmod' command support out of main kdb code into its own file under kernel/module. In addition to the above, a minor style warning i.e. missing a blank line after declarations, was resolved too. The new file was added to MAINTAINERS. Finally we remove linux/module.h as it is entirely redundant. Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org> Acked-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Aaron Tomlin <atomlin@redhat.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
* | lockdown: also lock down previous kgdb useDaniel Thompson2022-05-242-3/+83
|/ | | | | | | | | | | | | | | | | | | | | | | | | | KGDB and KDB allow read and write access to kernel memory, and thus should be restricted during lockdown. An attacker with access to a serial port (for example, via a hypervisor console, which some cloud vendors provide over the network) could trigger the debugger so it is important that the debugger respect the lockdown mode when/if it is triggered. Fix this by integrating lockdown into kdb's existing permissions mechanism. Unfortunately kgdb does not have any permissions mechanism (although it certainly could be added later) so, for now, kgdb is simply and brutally disabled by immediately exiting the gdb stub without taking any action. For lockdowns established early in the boot (e.g. the normal case) then this should be fine but on systems where kgdb has set breakpoints before the lockdown is enacted than "bad things" will happen. CVE: CVE-2022-21499 Co-developed-by: Stephen Brennan <stephen.s.brennan@oracle.com> Signed-off-by: Stephen Brennan <stephen.s.brennan@oracle.com> Reviewed-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kdb: Fix the putarea helper functionDaniel Thompson2022-03-241-1/+1
| | | | | | | | | | | | | | | | | | | | Currently kdb_putarea_size() uses copy_from_kernel_nofault() to write *to* arbitrary kernel memory. This is obviously wrong and means the memory modify ('mm') command is a serious risk to debugger stability: if we poke to a bad address we'll double-fault and lose our debug session. Fix this the (very) obvious way. Note that there are two Fixes: tags because the API was renamed and this patch will only trivially backport as far as the rename (and this is probably enough). Nevertheless Christoph's rename did not introduce this problem so I wanted to record that! Fixes: fe557319aa06 ("maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault") Fixes: 5d5314d6795f ("kdb: core for kgdb back end (1 of 2)") Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20220128144055.207267-1-daniel.thompson@linaro.org
* kdb: Adopt scheduler's task classificationDaniel Thompson2021-11-034-122/+53
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently kdb contains some open-coded routines to generate a summary character for each task. This code currently issues warnings, is almost certainly broken and won't make sense to any kernel dev who has ever used /proc to examine task states. Fix both the warning and the potential for confusion by adopting the scheduler's task classification. Whilst doing this we also simplify the filtering by using mask strings directly (which means we don't have to guess all the characters the scheduler might give us). Unfortunately we can't quite match the scheduler classification completely. We add four extra states: - for idle loops and i, m and s for sleeping system daemons (which means kthreads in one of the I, M and S states). These extra states are used to manage the filters for tools to make the output of ps and bta less noisy. Note: The Fixes below is the last point the original dubious code was moved; it was not introduced by that patch. However it gives us the last point to which this patch can be easily backported. Happily that should be enough to cover the introduction of CONFIG_WERROR! Fixes: 2f064a59a11f ("sched: Change task_struct::state") Link: https://lore.kernel.org/r/20211102173158.3315227-1-daniel.thompson@linaro.org Reviewed-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
* Merge tag 'kgdb-5.15-rc1' of ↵Linus Torvalds2021-09-077-704/+352
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux Pull kgdb updates from Daniel Thompson: "Changes for kgdb/kdb this cycle are dominated by a change from Sumit that removes as small (256K) private heap from kdb. This is change I've hoped for ever since I discovered how few users of this heap remained in the kernel, so many thanks to Sumit for hunting these down. The other change is an incremental step towards SPDX headers" * tag 'kgdb-5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux: kernel: debug: Convert to SPDX identifier kdb: Rename members of struct kdbtab_t kdb: Simplify kdb_defcmd macro logic kdb: Get rid of redundant kdb_register_flags() kdb: Rename struct defcmd_set to struct kdb_macro kdb: Get rid of custom debug heap allocator
| * kernel: debug: Convert to SPDX identifierCai Huoqing2021-09-062-8/+2
| | | | | | | | | | | | | | | | use SPDX-License-Identifier instead of a verbose license text Signed-off-by: Cai Huoqing <caihuoqing@baidu.com> Link: https://lore.kernel.org/r/20210906112302.937-1-caihuoqing@baidu.com Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
| * kdb: Rename members of struct kdbtab_tSumit Garg2021-07-272-239/+237
| | | | | | | | | | | | | | | | | | | | | | Remove redundant prefix "cmd_" from name of members in struct kdbtab_t for better readibility. Suggested-by: Doug Anderson <dianders@chromium.org> Signed-off-by: Sumit Garg <sumit.garg@linaro.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20210712134620.276667-5-sumit.garg@linaro.org Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
| * kdb: Simplify kdb_defcmd macro logicSumit Garg2021-07-271-49/+58
| | | | | | | | | | | | | | | | | | | | | | | | Switch to use a linked list instead of dynamic array which makes allocation of kdb macro and traversing the kdb macro commands list simpler. Suggested-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Sumit Garg <sumit.garg@linaro.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20210712134620.276667-4-sumit.garg@linaro.org Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
| * kdb: Get rid of redundant kdb_register_flags()Sumit Garg2021-07-272-127/+53
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit e4f291b3f7bb ("kdb: Simplify kdb commands registration") allowed registration of pre-allocated kdb commands with pointer to struct kdbtab_t. Lets switch other users as well to register pre- allocated kdb commands via: - Changing prototype for kdb_register() to pass a pointer to struct kdbtab_t instead. - Embed kdbtab_t structure in kdb_macro_t rather than individual params. With these changes kdb_register_flags() becomes redundant and hence removed. Also, since we have switched all users to register pre-allocated commands, "is_dynamic" flag in struct kdbtab_t becomes redundant and hence removed as well. Suggested-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Sumit Garg <sumit.garg@linaro.org> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20210712134620.276667-3-sumit.garg@linaro.org Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
| * kdb: Rename struct defcmd_set to struct kdb_macroSumit Garg2021-07-271-20/+20
| | | | | | | | | | | | | | | | | | | | | | Rename struct defcmd_set to struct kdb_macro as that sounds more appropriate given its purpose. Suggested-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Sumit Garg <sumit.garg@linaro.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20210712134620.276667-2-sumit.garg@linaro.org Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
| * kdb: Get rid of custom debug heap allocatorSumit Garg2021-07-273-307/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently the only user for debug heap is kdbnearsym() which can be modified to rather use statically allocated buffer for symbol name as per it's current usage. So do that and hence remove custom debug heap allocator. Note that this change puts a restriction on kdbnearsym() callers to carefully use shared namebuf such that a caller should consume the symbol returned immediately prior to another call to fetch a different symbol. Also, this change uses standard KSYM_NAME_LEN macro for namebuf allocation instead of local variable: knt1_size which should avoid any conflicts caused by changes to KSYM_NAME_LEN macro value. This change has been tested using kgdbtest on arm64 which doesn't show any regressions. Suggested-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Sumit Garg <sumit.garg@linaro.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20210714055620.369915-1-sumit.garg@linaro.org Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
* | isystem: trim/fixup stdarg.h and other headersAlexey Dobriyan2021-08-191-1/+0
|/ | | | | | | | | | | | Delete/fixup few includes in anticipation of global -isystem compile option removal. Note: crypto/aegis128-neon-inner.c keeps <stddef.h> due to redefinition of uintptr_t error (one definition comes from <stddef.h>, another from <linux/types.h>). Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
* kernel: debug: Fix unreachable code in gdb_serial_stub()Gustavo A. R. Silva2021-07-121-1/+1
| | | | | | | | | | | | | | | Fix the following warning: kernel/debug/gdbstub.c:1049:4: warning: fallthrough annotation in unreachable code [-Wimplicit-fallthrough] fallthrough; ^ include/linux/compiler_attributes.h:210:41: note: expanded from macro 'fallthrough' # define fallthrough __attribute__((__fallthrough__) by placing the fallthrough; statement inside ifdeffery. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
* Merge tag 'kgdb-5.14-rc1' of ↵Linus Torvalds2021-07-063-6/+7
|\ | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux Pull kgdb updates from Daniel Thompson: "This was a extremely quiet cycle for kgdb. This consists of two patches that between them address spelling errors and a switch fallthrough warning" * tag 'kgdb-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux: kgdb: Fix fall-through warning for Clang kgdb: Fix spelling mistakes
| * kgdb: Fix fall-through warning for ClangGustavo A. R. Silva2021-06-011-0/+1
| | | | | | | | | | | | | | | | | | | | | | In preparation to enable -Wimplicit-fallthrough for Clang, fix a fall-through warning by explicitly adding a goto statement instead of letting the code fall through to the next case. Link: https://github.com/KSPP/linux/issues/115 Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Link: https://lore.kernel.org/r/20210528200222.GA39201@embeddedor Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
| * kgdb: Fix spelling mistakesZhen Lei2021-06-013-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix some spelling mistakes in comments: initalization ==> initialization detatch ==> detach represntation ==> representation hexidecimal ==> hexadecimal delimeter ==> delimiter architecure ==> architecture Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Link: https://lore.kernel.org/r/20210529110305.9446-3-thunder.leizhen@huawei.com Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
* | Merge tag 'printk-for-5.14' of ↵Linus Torvalds2021-06-291-8/+1
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux Pull printk updates from Petr Mladek: - Add %pt[RT]s modifier to vsprintf(). It overrides ISO 8601 separator by using ' ' (space). It produces "YYYY-mm-dd HH:MM:SS" instead of "YYYY-mm-ddTHH:MM:SS". - Correctly parse long row of numbers by sscanf() when using the field width. Add extensive sscanf() selftest. - Generalize re-entrant CPU lock that has already been used to serialize dump_stack() output. It is part of the ongoing printk rework. It will allow to remove the obsoleted printk_safe buffers and introduce atomic consoles. - Some code clean up and sparse warning fixes. * tag 'printk-for-5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: printk: fix cpu lock ordering lib/dump_stack: move cpu lock to printk.c printk: Remove trailing semicolon in macros random32: Fix implicit truncation warning in prandom_seed_state() lib: test_scanf: Remove pointless use of type_min() with unsigned types selftests: lib: Add wrapper script for test_scanf lib: test_scanf: Add tests for sscanf number conversion lib: vsprintf: Fix handling of number field widths in vsscanf lib: vsprintf: scanf: Negative number must have field width > 1 usb: host: xhci-tegra: Switch to use %ptTs nilfs2: Switch to use %ptTs kdb: Switch to use %ptTs lib/vsprintf: Allow to override ISO 8601 date and time separator
| * | kdb: Switch to use %ptTsAndy Shevchenko2021-05-171-8/+1
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use %ptTs instead of open-coded variant to print contents of time64_t type in human readable form. Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Daniel Thompson <daniel.thompson@linaro.org> Cc: kgdb-bugreport@lists.sourceforge.net Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org> Acked-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20210511153958.34527-2-andriy.shevchenko@linux.intel.com
* / sched: Change task_struct::statePeter Zijlstra2021-06-181-8/+10
|/ | | | | | | | | | | | Change the type and name of task_struct::state. Drop the volatile and shrink it to an 'unsigned int'. Rename it in order to find all uses such that we can use READ_ONCE/WRITE_ONCE as appropriate. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com> Acked-by: Will Deacon <will@kernel.org> Acked-by: Daniel Thompson <daniel.thompson@linaro.org> Link: https://lore.kernel.org/r/20210611082838.550736351@infradead.org
* Merge tag 'printk-for-5.13' of ↵Linus Torvalds2021-04-271-5/+5
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux Pull printk updates from Petr Mladek: - Stop synchronizing kernel log buffer readers by logbuf_lock. As a result, the access to the buffer is fully lockless now. Note that printk() itself still uses locks because it tries to flush the messages to the console immediately. Also the per-CPU temporary buffers are still there because they prevent infinite recursion and serialize backtraces from NMI. All this is going to change in the future. - kmsg_dump API rework and cleanup as a side effect of the logbuf_lock removal. - Make bstr_printf() aware that %pf and %pF formats could deference the given pointer. - Show also page flags by %pGp format. - Clarify the documentation for plain pointer printing. - Do not show no_hash_pointers warning multiple times. - Update Senozhatsky email address. - Some clean up. * tag 'printk-for-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: (24 commits) lib/vsprintf.c: remove leftover 'f' and 'F' cases from bstr_printf() printk: clarify the documentation for plain pointer printing kernel/printk.c: Fixed mundane typos printk: rename vprintk_func to vprintk vsprintf: dump full information of page flags in pGp mm, slub: don't combine pr_err with INFO mm, slub: use pGp to print page flags MAINTAINERS: update Senozhatsky email address lib/vsprintf: do not show no_hash_pointers message multiple times printk: console: remove unnecessary safe buffer usage printk: kmsg_dump: remove _nolock() variants printk: remove logbuf_lock printk: introduce a kmsg_dump iterator printk: kmsg_dumper: remove @active field printk: add syslog_lock printk: use atomic64_t for devkmsg_user.seq printk: use seqcount_latch for clear_seq printk: introduce CONSOLE_LOG_MAX printk: consolidate kmsg_dump_get_buffer/syslog_print_all code printk: refactor kmsg_dump_get_buffer() ...
| * printk: kmsg_dump: remove _nolock() variantsJohn Ogness2021-03-081-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | kmsg_dump_rewind() and kmsg_dump_get_line() are lockless, so there is no need for _nolock() variants. Remove these functions and switch all callers of the _nolock() variants. The functions without _nolock() were chosen because they are already exported to kernel modules. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20210303101528.29901-15-john.ogness@linutronix.de
| * printk: introduce a kmsg_dump iteratorJohn Ogness2021-03-081-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rather than storing the iterator information in the registered kmsg_dumper structure, create a separate iterator structure. The kmsg_dump_iter structure can reside on the stack of the caller, thus allowing lockless use of the kmsg_dump functions. Update code that accesses the kernel logs using the kmsg_dumper structure to use the new kmsg_dump_iter structure. For kmsg_dumpers, this also means adding a call to kmsg_dump_rewind() to initialize the iterator. All this is in preparation for removal of @logbuf_lock. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Kees Cook <keescook@chromium.org> # pstore Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20210303101528.29901-13-john.ogness@linutronix.de
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