From: Kees Cook <keescook@chromium.org> To: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Kees Cook <keescook@chromium.org>, Petr Mladek <pmladek@suse.com>, Anton Vorontsov <anton@enomsg.org>, Colin Cross <ccross@android.com>, Tony Luck <tony.luck@intel.com>, Jonathan Corbet <corbet@lwn.net>, Benson Leung <bleung@chromium.org>, Rob Herring <robh+dt@kernel.org>, Michael Ellerman <mpe@ellerman.id.au>, Benjamin Herrenschmidt <benh@kernel.crashing.org>, Paul Mackerras <paulus@samba.org>, Enric Balletbo i Serra <enric.balletbo@collabora.com>, Sergey Senozhatsky <sergey.senozhatsky@gmail.com>, Steven Rostedt <rostedt@goodmis.org>, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: [PATCH v4 2/6] printk: honor the max_reason field in kmsg_dumper Date: Fri, 15 May 2020 11:44:30 -0700 [thread overview] Message-ID: <20200515184434.8470-3-keescook@chromium.org> (raw) In-Reply-To: <20200515184434.8470-1-keescook@chromium.org> From: Pavel Tatashin <pasha.tatashin@soleen.com> kmsg_dump() allows to dump kmesg buffer for various system events: oops, panic, reboot, etc. It provides an interface to register a callback call for clients, and in that callback interface there is a field "max_reason" which gets ignored unless always_kmsg_dump is passed as kernel parameter. Allow clients to decide max_reason, and keep the current behavior when max_reason is not set. Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com> Link: https://lore.kernel.org/lkml/20200506211523.15077-2-keescook@chromium.org/ Signed-off-by: Kees Cook <keescook@chromium.org> --- include/linux/kmsg_dump.h | 1 + kernel/printk/printk.c | 15 +++++++++++---- 2 files changed, 12 insertions(+), 4 deletions(-) diff --git a/include/linux/kmsg_dump.h b/include/linux/kmsg_dump.h index 3f82b5cb2d82..9826014771ab 100644 --- a/include/linux/kmsg_dump.h +++ b/include/linux/kmsg_dump.h @@ -26,6 +26,7 @@ enum kmsg_dump_reason { KMSG_DUMP_OOPS, KMSG_DUMP_EMERG, KMSG_DUMP_SHUTDOWN, + KMSG_DUMP_MAX }; /** diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 9a9b6156270b..a121c2255737 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -3157,12 +3157,19 @@ void kmsg_dump(enum kmsg_dump_reason reason) struct kmsg_dumper *dumper; unsigned long flags; - if ((reason > KMSG_DUMP_OOPS) && !always_kmsg_dump) - return; - rcu_read_lock(); list_for_each_entry_rcu(dumper, &dump_list, list) { - if (dumper->max_reason && reason > dumper->max_reason) + enum kmsg_dump_reason max_reason = dumper->max_reason; + + /* + * If client has not provided a specific max_reason, default + * to KMSG_DUMP_OOPS, unless always_kmsg_dump was set. + */ + if (max_reason == KMSG_DUMP_UNDEF) { + max_reason = always_kmsg_dump ? KMSG_DUMP_MAX : + KMSG_DUMP_OOPS; + } + if (reason > max_reason) continue; /* initialize iterator with data about the stored records */ -- 2.20.1
WARNING: multiple messages have this Message-ID (diff)
From: Kees Cook <keescook@chromium.org> To: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Petr Mladek <pmladek@suse.com>, Tony Luck <tony.luck@intel.com>, Kees Cook <keescook@chromium.org>, Jonathan Corbet <corbet@lwn.net>, Anton Vorontsov <anton@enomsg.org>, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, Steven Rostedt <rostedt@goodmis.org>, Sergey Senozhatsky <sergey.senozhatsky@gmail.com>, devicetree@vger.kernel.org, Rob Herring <robh+dt@kernel.org>, Paul Mackerras <paulus@samba.org>, Colin Cross <ccross@android.com>, Enric Balletbo i Serra <enric.balletbo@collabora.com>, linuxppc-dev@lists.ozlabs.org, Benson Leung <bleung@chromium.org> Subject: [PATCH v4 2/6] printk: honor the max_reason field in kmsg_dumper Date: Fri, 15 May 2020 11:44:30 -0700 [thread overview] Message-ID: <20200515184434.8470-3-keescook@chromium.org> (raw) In-Reply-To: <20200515184434.8470-1-keescook@chromium.org> From: Pavel Tatashin <pasha.tatashin@soleen.com> kmsg_dump() allows to dump kmesg buffer for various system events: oops, panic, reboot, etc. It provides an interface to register a callback call for clients, and in that callback interface there is a field "max_reason" which gets ignored unless always_kmsg_dump is passed as kernel parameter. Allow clients to decide max_reason, and keep the current behavior when max_reason is not set. Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com> Link: https://lore.kernel.org/lkml/20200506211523.15077-2-keescook@chromium.org/ Signed-off-by: Kees Cook <keescook@chromium.org> --- include/linux/kmsg_dump.h | 1 + kernel/printk/printk.c | 15 +++++++++++---- 2 files changed, 12 insertions(+), 4 deletions(-) diff --git a/include/linux/kmsg_dump.h b/include/linux/kmsg_dump.h index 3f82b5cb2d82..9826014771ab 100644 --- a/include/linux/kmsg_dump.h +++ b/include/linux/kmsg_dump.h @@ -26,6 +26,7 @@ enum kmsg_dump_reason { KMSG_DUMP_OOPS, KMSG_DUMP_EMERG, KMSG_DUMP_SHUTDOWN, + KMSG_DUMP_MAX }; /** diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 9a9b6156270b..a121c2255737 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -3157,12 +3157,19 @@ void kmsg_dump(enum kmsg_dump_reason reason) struct kmsg_dumper *dumper; unsigned long flags; - if ((reason > KMSG_DUMP_OOPS) && !always_kmsg_dump) - return; - rcu_read_lock(); list_for_each_entry_rcu(dumper, &dump_list, list) { - if (dumper->max_reason && reason > dumper->max_reason) + enum kmsg_dump_reason max_reason = dumper->max_reason; + + /* + * If client has not provided a specific max_reason, default + * to KMSG_DUMP_OOPS, unless always_kmsg_dump was set. + */ + if (max_reason == KMSG_DUMP_UNDEF) { + max_reason = always_kmsg_dump ? KMSG_DUMP_MAX : + KMSG_DUMP_OOPS; + } + if (reason > max_reason) continue; /* initialize iterator with data about the stored records */ -- 2.20.1
next prev parent reply other threads:[~2020-05-15 18:44 UTC|newest] Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-05-15 18:44 [PATCH v4 0/6] allow ramoops to collect all kmesg_dump events Kees Cook 2020-05-15 18:44 ` Kees Cook 2020-05-15 18:44 ` [PATCH v4 1/6] printk: Collapse shutdown types into a single dump reason Kees Cook 2020-05-15 18:44 ` Kees Cook 2020-05-15 19:17 ` Pavel Tatashin 2020-05-15 19:17 ` Pavel Tatashin 2020-05-22 16:21 ` Petr Mladek 2020-05-22 16:21 ` Petr Mladek 2020-05-23 11:16 ` Michael Ellerman 2020-05-23 11:16 ` Michael Ellerman 2020-05-15 18:44 ` Kees Cook [this message] 2020-05-15 18:44 ` [PATCH v4 2/6] printk: honor the max_reason field in kmsg_dumper Kees Cook 2020-05-22 16:51 ` Petr Mladek 2020-05-22 16:51 ` Petr Mladek 2020-05-22 17:34 ` Kees Cook 2020-05-22 17:34 ` Kees Cook 2020-05-15 18:44 ` [PATCH v4 3/6] printk: Introduce kmsg_dump_reason_str() Kees Cook 2020-05-15 18:44 ` Kees Cook 2020-05-15 19:23 ` Pavel Tatashin 2020-05-15 19:23 ` Pavel Tatashin 2020-05-15 18:44 ` [PATCH v4 4/6] pstore/platform: Pass max_reason to kmesg dump Kees Cook 2020-05-15 18:44 ` Kees Cook 2020-05-15 18:44 ` [PATCH v4 5/6] pstore/ram: Introduce max_reason and convert dump_oops Kees Cook 2020-05-15 18:44 ` Kees Cook 2020-05-15 19:30 ` Pavel Tatashin 2020-05-15 19:30 ` Pavel Tatashin 2020-05-15 19:48 ` Kees Cook 2020-05-15 19:48 ` Kees Cook 2020-05-15 19:40 ` Pavel Tatashin 2020-05-15 19:40 ` Pavel Tatashin 2020-05-15 19:53 ` Kees Cook 2020-05-15 19:53 ` Kees Cook 2020-05-15 18:44 ` [PATCH v4 6/6] ramoops: Add max_reason optional field to ramoops DT node Kees Cook 2020-05-15 18:44 ` Kees Cook 2020-05-18 22:45 ` Rob Herring 2020-05-18 22:45 ` Rob Herring 2020-05-18 23:04 ` Kees Cook 2020-05-18 23:04 ` Kees Cook 2020-05-15 19:13 ` [PATCH v4 0/6] allow ramoops to collect all kmesg_dump events Pavel Tatashin 2020-05-15 19:13 ` Pavel Tatashin
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