pstore/platform: Pass max_reason to kmesg dump (3524e688) · Commits · 戴 / test

Add a new member to struct pstore_info for passing information about kmesg dump maximum reason. This allows a finer control of what kmesg dumps are sent to pstore storage backends. Those backends that do not explicitly set this field (keeping it equal to 0), get the default behavior: store only Oopses and Panics, or everything if the printk.always_kmsg_dump boot param is set. Signed-off-by:

Pavel Tatashin <pasha.tatashin@soleen.com> Link: https://lore.kernel.org/lkml/20200515184434.8470-5-keescook@chromium.org/ Co-developed-by:

Kees Cook <keescook@chromium.org> Signed-off-by:

Kees Cook <keescook@chromium.org>

fs/pstore/platform.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -595,8 +595,10 @@ int pstore_register(struct pstore_info *psi)

		pstore_get_records(0);

		if (psi->flags & PSTORE_FLAGS_DMESG)
		if (psi->flags & PSTORE_FLAGS_DMESG) {
		pstore_dumper.max_reason = psinfo->max_reason;
		pstore_register_kmsg();
		}
		if (psi->flags & PSTORE_FLAGS_CONSOLE)
		pstore_register_console();
		if (psi->flags & PSTORE_FLAGS_FTRACE)

include/linux/pstore.h

+7 −0

Original line number	Diff line number	Diff line
		@@ -96,6 +96,12 @@ struct pstore_record {
		*
		* @read_mutex: serializes @open, @read, @close, and @erase callbacks
		* @flags: bitfield of frontends the backend can accept writes for
		* @max_reason: Used when PSTORE_FLAGS_DMESG is set. Contains the
		* kmsg_dump_reason enum value. KMSG_DUMP_UNDEF means
		* "use existing kmsg_dump() filtering, based on the
		* printk.always_kmsg_dump boot param" (which is either
		* KMSG_DUMP_OOPS when false, or KMSG_DUMP_MAX when
		* true); see printk.always_kmsg_dump for more details.
		* @data: backend-private pointer passed back during callbacks
		*
		* Callbacks:
		@@ -179,6 +185,7 @@ struct pstore_info {
		struct mutex read_mutex;

		int flags;
		int max_reason;
		void *data;

		int (open)(struct pstore_info psi);

Admin message