user/sven/linux.git/kernel/debug/kdb, branch v5.13.16

Merge tag 'printk-for-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux

2021-04-28T01:09:44Z

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() ...

kdb: Refactor env variables get/set code

2021-04-14T12:47:09Z

Add two new kdb environment access methods as kdb_setenv() and kdb_printenv() in order to abstract out environment access code from kdb command functions. Also, replace (char *)0 with NULL as an initializer for environment variables array. Signed-off-by: Sumit Garg Reviewed-by: Douglas Anderson Link: https://lore.kernel.org/r/1612771342-16883-1-git-send-email-sumit.garg@linaro.org [daniel.thompson@linaro.org: Replaced (char *)0/NULL initializers with an array size] Signed-off-by: Daniel Thompson

kdb: Simplify kdb commands registration

2021-03-19T16:51:59Z

Simplify kdb commands registration via using linked list instead of static array for commands storage. Signed-off-by: Sumit Garg Link: https://lore.kernel.org/r/20210224070827.408771-1-sumit.garg@linaro.org Reviewed-by: Douglas Anderson [daniel.thompson@linaro.org: Removed a bunch of .cmd_minline = 0 initializers] Signed-off-by: Daniel Thompson

kdb: Remove redundant function definitions/prototypes

2021-03-19T16:34:52Z

Cleanup kdb code to get rid of unused function definitions/prototypes. Signed-off-by: Sumit Garg Link: https://lore.kernel.org/r/20210224071653.409150-1-sumit.garg@linaro.org Reviewed-by: Douglas Anderson Signed-off-by: Daniel Thompson

printk: kmsg_dump: remove _nolock() variants

2021-03-08T10:43:35Z

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 Reviewed-by: Petr Mladek Signed-off-by: Petr Mladek Link: https://lore.kernel.org/r/20210303101528.29901-15-john.ogness@linutronix.de

printk: introduce a kmsg_dump iterator

2021-03-08T10:43:27Z

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 Reviewed-by: Kees Cook # pstore Reviewed-by: Petr Mladek Signed-off-by: Petr Mladek Link: https://lore.kernel.org/r/20210303101528.29901-13-john.ogness@linutronix.de

printk: kmsg_dumper: remove @active field

2021-03-08T10:43:23Z

All 6 kmsg_dumpers do not benefit from the @active flag: (provide their own synchronization) - arch/powerpc/kernel/nvram_64.c - arch/um/kernel/kmsg_dump.c - drivers/mtd/mtdoops.c - fs/pstore/platform.c (only dump on KMSG_DUMP_PANIC, which does not require synchronization) - arch/powerpc/platforms/powernv/opal-kmsg.c - drivers/hv/vmbus_drv.c The other 2 kmsg_dump users also do not rely on @active: (hard-code @active to always be true) - arch/powerpc/xmon/xmon.c - kernel/debug/kdb/kdb_main.c Therefore, @active can be removed. Signed-off-by: John Ogness Reviewed-by: Petr Mladek Signed-off-by: Petr Mladek Link: https://lore.kernel.org/r/20210303101528.29901-12-john.ogness@linutronix.de

kdb: Make memory allocations more robust

2021-02-08T13:42:50Z

Currently kdb uses in_interrupt() to determine whether its library code has been called from the kgdb trap handler or from a saner calling context such as driver init. This approach is broken because in_interrupt() alone isn't able to determine kgdb trap handler entry from normal task context. This can happen during normal use of basic features such as breakpoints and can also be trivially reproduced using: echo g > /proc/sysrq-trigger We can improve this by adding check for in_dbg_master() instead which explicitly determines if we are running in debugger context. Cc: stable@vger.kernel.org Signed-off-by: Sumit Garg Link: https://lore.kernel.org/r/1611313556-4004-1-git-send-email-sumit.garg@linaro.org Signed-off-by: Daniel Thompson

kdb: kdb_support: Fix debugging information problem

2021-02-04T15:55:04Z

There are several common patterns. 0: kdb_printf("...",...); which is the normal one. 1: kdb_printf("%s: "...,__func__,...) We could improve '1' to this : #define kdb_func_printf(format, args...) \ kdb_printf("%s: " format, __func__, ## args) 2: if(KDB_DEBUG(AR)) kdb_printf("%s "...,__func__,...); We could improve '2' to this : #define kdb_dbg_printf(mask, format, args...) \ do { \ if (KDB_DEBUG(mask)) \ kdb_func_printf(format, ## args); \ } while (0) In addition, we changed the format code of size_t to %zu. Signed-off-by: Stephen Zhang Link: https://lore.kernel.org/r/1612440429-6391-1-git-send-email-stephenzhangzsd@gmail.com Reviewed-by: Douglas Anderson [daniel.thompson@linaro.org: Minor typo and line length fixes in the patch description] Signed-off-by: Daniel Thompson

kdb: Fix pager search for multi-line strings

2020-10-01T13:44:08Z

Currently using forward search doesn't handle multi-line strings correctly. The search routine replaces line breaks with \0 during the search and, for regular searches ("help | grep Common\n"), there is code after the line has been discarded or printed to replace the break character. However during a pager search ("help\n" followed by "/Common\n") when the string is matched we will immediately return to normal output and the code that should restore the \n becomes unreachable. Fix this by restoring the replaced character when we disable the search mode and update the comment accordingly. Fixes: fb6daa7520f9d ("kdb: Provide forward search at more prompt") Link: https://lore.kernel.org/r/20200909141708.338273-1-daniel.thompson@linaro.org Reviewed-by: Douglas Anderson Signed-off-by: Daniel Thompson