From 563ca40ddf400dbf8c6254077f9b6887101d0f08 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Fri, 8 May 2020 09:16:02 -0700 Subject: pstore/platform: Switch pstore_info::name to const In order to more cleanly pass around backend names, make the "name" member const. This means the module param needs to be dynamic (technically, it was before, so this actually cleans up a minor memory leak if a backend was specified and then gets unloaded.) Link: https://lore.kernel.org/lkml/20200510202436.63222-3-keescook@chromium.org/ Signed-off-by: Kees Cook --- include/linux/pstore.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/pstore.h b/include/linux/pstore.h index e779441e6d26..f6f22b13e04f 100644 --- a/include/linux/pstore.h +++ b/include/linux/pstore.h @@ -170,7 +170,7 @@ struct pstore_record { */ struct pstore_info { struct module *owner; - char *name; + const char *name; struct semaphore buf_lock; char *buf; -- cgit v1.2.3 From 6d3cf962dd1a95df868c547b090bfc4c7977f4be Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Fri, 15 May 2020 11:05:43 -0700 Subject: printk: Collapse shutdown types into a single dump reason To turn the KMSG_DUMP_* reasons into a more ordered list, collapse the redundant KMSG_DUMP_(RESTART|HALT|POWEROFF) reasons into KMSG_DUMP_SHUTDOWN. The current users already don't meaningfully distinguish between them, so there's no need to, as discussed here: https://lore.kernel.org/lkml/CA+CK2bAPv5u1ih5y9t5FUnTyximtFCtDYXJCpuyjOyHNOkRdqw@mail.gmail.com/ Link: https://lore.kernel.org/lkml/20200515184434.8470-2-keescook@chromium.org/ Reviewed-by: Pavel Tatashin Reviewed-by: Petr Mladek Acked-by: Michael Ellerman (powerpc) Signed-off-by: Kees Cook --- include/linux/kmsg_dump.h | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'include/linux') diff --git a/include/linux/kmsg_dump.h b/include/linux/kmsg_dump.h index 2e7a1e032c71..3f82b5cb2d82 100644 --- a/include/linux/kmsg_dump.h +++ b/include/linux/kmsg_dump.h @@ -25,9 +25,7 @@ enum kmsg_dump_reason { KMSG_DUMP_PANIC, KMSG_DUMP_OOPS, KMSG_DUMP_EMERG, - KMSG_DUMP_RESTART, - KMSG_DUMP_HALT, - KMSG_DUMP_POWEROFF, + KMSG_DUMP_SHUTDOWN, }; /** -- cgit v1.2.3 From b1f6f161b236d0e5a9222fb8b482e65aaff13689 Mon Sep 17 00:00:00 2001 From: Pavel Tatashin Date: Tue, 5 May 2020 11:45:06 -0400 Subject: printk: honor the max_reason field in kmsg_dumper 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", but it was getting ignored when set to any "reason" higher than KMSG_DUMP_OOPS unless "always_kmsg_dump" was passed as kernel parameter. Allow clients to actually control their "max_reason", and keep the current behavior when "max_reason" is not set. Signed-off-by: Pavel Tatashin Link: https://lore.kernel.org/lkml/20200515184434.8470-3-keescook@chromium.org/ Reviewed-by: Petr Mladek Signed-off-by: Kees Cook --- include/linux/kmsg_dump.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') 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 }; /** -- cgit v1.2.3 From fb13cb8a0482105a415e24042209d02a684255e2 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Thu, 7 May 2020 19:36:22 -0700 Subject: printk: Introduce kmsg_dump_reason_str() The pstore subsystem already had a private version of this function. With the coming addition of the pstore/zone driver, this needs to be shared. As it really should live with printk, move it there instead. Link: https://lore.kernel.org/lkml/20200515184434.8470-4-keescook@chromium.org/ Acked-by: Petr Mladek Acked-by: Sergey Senozhatsky Reviewed-by: Pavel Tatashin Signed-off-by: Kees Cook --- include/linux/kmsg_dump.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'include/linux') diff --git a/include/linux/kmsg_dump.h b/include/linux/kmsg_dump.h index 9826014771ab..3378bcbe585e 100644 --- a/include/linux/kmsg_dump.h +++ b/include/linux/kmsg_dump.h @@ -70,6 +70,8 @@ void kmsg_dump_rewind(struct kmsg_dumper *dumper); int kmsg_dump_register(struct kmsg_dumper *dumper); int kmsg_dump_unregister(struct kmsg_dumper *dumper); + +const char *kmsg_dump_reason_str(enum kmsg_dump_reason reason); #else static inline void kmsg_dump(enum kmsg_dump_reason reason) { @@ -111,6 +113,11 @@ static inline int kmsg_dump_unregister(struct kmsg_dumper *dumper) { return -EINVAL; } + +static inline const char *kmsg_dump_reason_str(enum kmsg_dump_reason reason) +{ + return "Disabled"; +} #endif #endif /* _LINUX_KMSG_DUMP_H */ -- cgit v1.2.3 From 3524e688b8ee50b0edc76f0e020727eb6c684dbc Mon Sep 17 00:00:00 2001 From: Pavel Tatashin Date: Tue, 5 May 2020 11:45:07 -0400 Subject: pstore/platform: Pass max_reason to kmesg dump 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 Link: https://lore.kernel.org/lkml/20200515184434.8470-5-keescook@chromium.org/ Co-developed-by: Kees Cook Signed-off-by: Kees Cook --- include/linux/pstore.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'include/linux') diff --git a/include/linux/pstore.h b/include/linux/pstore.h index f6f22b13e04f..eb93a54cff31 100644 --- a/include/linux/pstore.h +++ b/include/linux/pstore.h @@ -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); -- cgit v1.2.3 From 791205e3ec6081a8da6f00621e3453d622dc41e7 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Wed, 13 May 2020 14:35:03 -0700 Subject: pstore/ram: Introduce max_reason and convert dump_oops Now that pstore_register() can correctly pass max_reason to the kmesg dump facility, introduce a new "max_reason" module parameter and "max-reason" Device Tree field. The "dump_oops" module parameter and "dump-oops" Device Tree field are now considered deprecated, but are now automatically converted to their corresponding max_reason values when present, though the new max_reason setting has precedence. For struct ramoops_platform_data, the "dump_oops" member is entirely replaced by a new "max_reason" member, with the only existing user updated in place. Additionally remove the "reason" filter logic from ramoops_pstore_write(), as that is not specifically needed anymore, though technically this is a change in behavior for any ramoops users also setting the printk.always_kmsg_dump boot param, which will cause ramoops to behave as if max_reason was set to KMSG_DUMP_MAX. Co-developed-by: Pavel Tatashin Signed-off-by: Pavel Tatashin Link: https://lore.kernel.org/lkml/20200515184434.8470-6-keescook@chromium.org/ Signed-off-by: Kees Cook --- include/linux/pstore_ram.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/pstore_ram.h b/include/linux/pstore_ram.h index 9cb9b9067298..9f16afec7290 100644 --- a/include/linux/pstore_ram.h +++ b/include/linux/pstore_ram.h @@ -133,7 +133,7 @@ struct ramoops_platform_data { unsigned long console_size; unsigned long ftrace_size; unsigned long pmsg_size; - int dump_oops; + int max_reason; u32 flags; struct persistent_ram_ecc_info ecc_info; }; -- cgit v1.2.3 From d26c3321fe18dc74517dc1f518d584aa33b0a851 Mon Sep 17 00:00:00 2001 From: WeiXiong Liao Date: Wed, 25 Mar 2020 16:54:56 +0800 Subject: pstore/zone: Introduce common layer to manage storage zones Implement a common set of APIs needed to support pstore storage zones, based on how ramoops is designed. This will be used by pstore/blk with the intention of migrating pstore/ram in the future. Signed-off-by: WeiXiong Liao Link: https://lore.kernel.org/lkml/20200511233229.27745-2-keescook@chromium.org/ Co-developed-by: Kees Cook Signed-off-by: Kees Cook --- include/linux/pstore_zone.h | 44 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) create mode 100644 include/linux/pstore_zone.h (limited to 'include/linux') diff --git a/include/linux/pstore_zone.h b/include/linux/pstore_zone.h new file mode 100644 index 000000000000..eb005d9ae40c --- /dev/null +++ b/include/linux/pstore_zone.h @@ -0,0 +1,44 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef __PSTORE_ZONE_H_ +#define __PSTORE_ZONE_H_ + +#include + +typedef ssize_t (*pstore_zone_read_op)(char *, size_t, loff_t); +typedef ssize_t (*pstore_zone_write_op)(const char *, size_t, loff_t); +/** + * struct pstore_zone_info - pstore/zone back-end driver structure + * + * @owner: Module which is responsible for this back-end driver. + * @name: Name of the back-end driver. + * @total_size: The total size in bytes pstore/zone can use. It must be greater + * than 4096 and be multiple of 4096. + * @kmsg_size: The size of oops/panic zone. Zero means disabled, otherwise, + * it must be multiple of SECTOR_SIZE(512 Bytes). + * @max_reason: Maximum kmsg dump reason to store. + * @read: The general read operation. Both of the function parameters + * @size and @offset are relative value to storage. + * On success, the number of bytes should be returned, others + * means error. + * @write: The same as @read. + * @panic_write:The write operation only used for panic case. It's optional + * if you do not care panic log. The parameters and return value + * are the same as @read. + */ +struct pstore_zone_info { + struct module *owner; + const char *name; + + unsigned long total_size; + unsigned long kmsg_size; + int max_reason; + pstore_zone_read_op read; + pstore_zone_write_op write; + pstore_zone_write_op panic_write; +}; + +extern int register_pstore_zone(struct pstore_zone_info *info); +extern void unregister_pstore_zone(struct pstore_zone_info *info); + +#endif -- cgit v1.2.3 From 17639f67c1d61aba3c05e7703f75cd468f9d484f Mon Sep 17 00:00:00 2001 From: WeiXiong Liao Date: Wed, 25 Mar 2020 16:54:57 +0800 Subject: pstore/blk: Introduce backend for block devices pstore/blk is similar to pstore/ram, but uses a block device as the storage rather than persistent ram. The pstore/blk backend solves two common use-cases that used to preclude using pstore/ram: - not all devices have a battery that could be used to persist regular RAM across power failures. - most embedded intelligent equipment have no persistent ram, which increases costs, instead preferring cheaper solutions, like block devices. pstore/blk provides separate configurations for the end user and for the block drivers. User configuration determines how pstore/blk operates, such as record sizes, max kmsg dump reasons, etc. These can be set by Kconfig and/or module parameters, but module parameter have priority over Kconfig. Driver configuration covers all the details about the target block device, such as total size of the device and how to perform read/write operations. These are provided by block drivers, calling pstore_register_blkdev(), including an optional panic_write callback used to bypass regular IO APIs in an effort to avoid potentially destabilized kernel code during a panic. Signed-off-by: WeiXiong Liao Link: https://lore.kernel.org/lkml/20200511233229.27745-3-keescook@chromium.org/ Co-developed-by: Kees Cook Signed-off-by: Kees Cook --- include/linux/pstore_blk.h | 51 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+) create mode 100644 include/linux/pstore_blk.h (limited to 'include/linux') diff --git a/include/linux/pstore_blk.h b/include/linux/pstore_blk.h new file mode 100644 index 000000000000..4501977b1336 --- /dev/null +++ b/include/linux/pstore_blk.h @@ -0,0 +1,51 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef __PSTORE_BLK_H_ +#define __PSTORE_BLK_H_ + +#include +#include +#include + +/** + * typedef pstore_blk_panic_write_op - panic write operation to block device + * + * @buf: the data to write + * @start_sect: start sector to block device + * @sects: sectors count on buf + * + * Return: On success, zero should be returned. Others mean error. + * + * Panic write to block device must be aligned to SECTOR_SIZE. + */ +typedef int (*pstore_blk_panic_write_op)(const char *buf, sector_t start_sect, + sector_t sects); + +/** + * struct pstore_blk_info - pstore/blk registration details + * + * @major: Which major device number to support with pstore/blk + * @flags: The supported PSTORE_FLAGS_* from linux/pstore.h. + * @panic_write:The write operation only used for the panic case. + * This can be NULL, but is recommended to avoid losing + * crash data if the kernel's IO path or work queues are + * broken during a panic. + * @devt: The dev_t that pstore/blk has attached to. + * @nr_sects: Number of sectors on @devt. + * @start_sect: Starting sector on @devt. + */ +struct pstore_blk_info { + unsigned int major; + unsigned int flags; + pstore_blk_panic_write_op panic_write; + + /* Filled in by pstore/blk after registration. */ + dev_t devt; + sector_t nr_sects; + sector_t start_sect; +}; + +int register_pstore_blk(struct pstore_blk_info *info); +void unregister_pstore_blk(unsigned int major); + +#endif -- cgit v1.2.3 From 0dc068265a1c5923ffebf40388fbe93050a77ad1 Mon Sep 17 00:00:00 2001 From: WeiXiong Liao Date: Wed, 25 Mar 2020 16:54:59 +0800 Subject: pstore/zone,blk: Add support for pmsg frontend Add pmsg support to pstore/blk (through pstore/zone). To enable, pmsg_size must be greater than 0 and a multiple of 4096. Signed-off-by: WeiXiong Liao Link: https://lore.kernel.org/lkml/20200511233229.27745-4-keescook@chromium.org/ Co-developed-by: Colin Ian King Signed-off-by: Colin Ian King Link: https://lore.kernel.org/lkml/20200512171932.222102-1-colin.king@canonical.com Co-developed-by: Kees Cook Signed-off-by: Kees Cook --- include/linux/pstore_zone.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux') diff --git a/include/linux/pstore_zone.h b/include/linux/pstore_zone.h index eb005d9ae40c..29c367a3bd80 100644 --- a/include/linux/pstore_zone.h +++ b/include/linux/pstore_zone.h @@ -17,6 +17,7 @@ typedef ssize_t (*pstore_zone_write_op)(const char *, size_t, loff_t); * @kmsg_size: The size of oops/panic zone. Zero means disabled, otherwise, * it must be multiple of SECTOR_SIZE(512 Bytes). * @max_reason: Maximum kmsg dump reason to store. + * @pmsg_size: The size of pmsg zone which is the same as @kmsg_size. * @read: The general read operation. Both of the function parameters * @size and @offset are relative value to storage. * On success, the number of bytes should be returned, others @@ -33,6 +34,7 @@ struct pstore_zone_info { unsigned long total_size; unsigned long kmsg_size; int max_reason; + unsigned long pmsg_size; pstore_zone_read_op read; pstore_zone_write_op write; pstore_zone_write_op panic_write; -- cgit v1.2.3 From cc9c4d1b5597167f8e8c92f6b61e1cda6d01884d Mon Sep 17 00:00:00 2001 From: WeiXiong Liao Date: Wed, 25 Mar 2020 16:55:00 +0800 Subject: pstore/zone,blk: Add console frontend support Support backend for console. To enable console backend, just make console_size be greater than 0 and a multiple of 4096. Signed-off-by: WeiXiong Liao Link: https://lore.kernel.org/lkml/20200511233229.27745-5-keescook@chromium.org/ Signed-off-by: Kees Cook --- include/linux/pstore_zone.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/pstore_zone.h b/include/linux/pstore_zone.h index 29c367a3bd80..904ee67f4ba2 100644 --- a/include/linux/pstore_zone.h +++ b/include/linux/pstore_zone.h @@ -18,11 +18,12 @@ typedef ssize_t (*pstore_zone_write_op)(const char *, size_t, loff_t); * it must be multiple of SECTOR_SIZE(512 Bytes). * @max_reason: Maximum kmsg dump reason to store. * @pmsg_size: The size of pmsg zone which is the same as @kmsg_size. + * @console_size:The size of console zone which is the same as @kmsg_size. * @read: The general read operation. Both of the function parameters * @size and @offset are relative value to storage. * On success, the number of bytes should be returned, others * means error. - * @write: The same as @read. + * @write: The same as @read, but -EBUSY means try to write again later. * @panic_write:The write operation only used for panic case. It's optional * if you do not care panic log. The parameters and return value * are the same as @read. @@ -35,6 +36,7 @@ struct pstore_zone_info { unsigned long kmsg_size; int max_reason; unsigned long pmsg_size; + unsigned long console_size; pstore_zone_read_op read; pstore_zone_write_op write; pstore_zone_write_op panic_write; -- cgit v1.2.3 From 34327e9fd213414b35eb70aa512c4e39b2095907 Mon Sep 17 00:00:00 2001 From: WeiXiong Liao Date: Wed, 25 Mar 2020 16:55:01 +0800 Subject: pstore/zone,blk: Add ftrace frontend support Support backend for ftrace. To enable ftrace backend, just make ftrace_size be greater than 0 and a multiple of 4096. Signed-off-by: WeiXiong Liao Link: https://lore.kernel.org/lkml/20200511233229.27745-6-keescook@chromium.org/ Co-developed-by: Colin Ian King Signed-off-by: Colin Ian King Link: https://lore.kernel.org/lkml/20200512170719.221514-1-colin.king@canonical.com Signed-off-by: Kees Cook --- include/linux/pstore_zone.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux') diff --git a/include/linux/pstore_zone.h b/include/linux/pstore_zone.h index 904ee67f4ba2..6f16b0dd834a 100644 --- a/include/linux/pstore_zone.h +++ b/include/linux/pstore_zone.h @@ -19,6 +19,7 @@ typedef ssize_t (*pstore_zone_write_op)(const char *, size_t, loff_t); * @max_reason: Maximum kmsg dump reason to store. * @pmsg_size: The size of pmsg zone which is the same as @kmsg_size. * @console_size:The size of console zone which is the same as @kmsg_size. + * @ftrace_size:The size of ftrace zone which is the same as @kmsg_size. * @read: The general read operation. Both of the function parameters * @size and @offset are relative value to storage. * On success, the number of bytes should be returned, others @@ -37,6 +38,7 @@ struct pstore_zone_info { int max_reason; unsigned long pmsg_size; unsigned long console_size; + unsigned long ftrace_size; pstore_zone_read_op read; pstore_zone_write_op write; pstore_zone_write_op panic_write; -- cgit v1.2.3 From 335426c6dcdd338d6b7c939c2da15fc9c5dd4959 Mon Sep 17 00:00:00 2001 From: WeiXiong Liao Date: Wed, 25 Mar 2020 16:55:03 +0800 Subject: pstore/zone: Provide way to skip "broken" zone for MTD devices One requirement to support MTD devices in pstore/zone is having a way to declare certain regions as broken. Add this support to pstore/zone. The MTD driver should return -ENOMSG when encountering a bad region, which tells pstore/zone to skip and try the next one. Signed-off-by: WeiXiong Liao Link: https://lore.kernel.org/lkml/20200511233229.27745-8-keescook@chromium.org/ Co-developed-by: Colin Ian King Signed-off-by: Colin Ian King Link: //lore.kernel.org/lkml/20200512173801.222666-1-colin.king@canonical.com Signed-off-by: Kees Cook --- include/linux/pstore_blk.h | 3 ++- include/linux/pstore_zone.h | 12 ++++++++---- 2 files changed, 10 insertions(+), 5 deletions(-) (limited to 'include/linux') diff --git a/include/linux/pstore_blk.h b/include/linux/pstore_blk.h index 4501977b1336..ccba8c068752 100644 --- a/include/linux/pstore_blk.h +++ b/include/linux/pstore_blk.h @@ -14,7 +14,8 @@ * @start_sect: start sector to block device * @sects: sectors count on buf * - * Return: On success, zero should be returned. Others mean error. + * Return: On success, zero should be returned. Others excluding -ENOMSG + * mean error. -ENOMSG means to try next zone. * * Panic write to block device must be aligned to SECTOR_SIZE. */ diff --git a/include/linux/pstore_zone.h b/include/linux/pstore_zone.h index 6f16b0dd834a..e79a18e41064 100644 --- a/include/linux/pstore_zone.h +++ b/include/linux/pstore_zone.h @@ -23,11 +23,15 @@ typedef ssize_t (*pstore_zone_write_op)(const char *, size_t, loff_t); * @read: The general read operation. Both of the function parameters * @size and @offset are relative value to storage. * On success, the number of bytes should be returned, others - * means error. - * @write: The same as @read, but -EBUSY means try to write again later. + * mean error. + * @write: The same as @read, but the following error number: + * -EBUSY means try to write again later. + * -ENOMSG means to try next zone. * @panic_write:The write operation only used for panic case. It's optional - * if you do not care panic log. The parameters and return value - * are the same as @read. + * if you do not care panic log. The parameters are relative + * value to storage. + * On success, the number of bytes should be returned, others + * excluding -ENOMSG mean error. -ENOMSG means to try next zone. */ struct pstore_zone_info { struct module *owner; -- cgit v1.2.3 From 1525fb3bb6d69028b3941d34363397c28345ffab Mon Sep 17 00:00:00 2001 From: WeiXiong Liao Date: Wed, 25 Mar 2020 16:55:04 +0800 Subject: pstore/blk: Provide way to query pstore configuration In order to configure itself, the MTD backend needs to be able to query the current pstore configuration. Introduce pstore_blk_get_config() for this purpose. Signed-off-by: WeiXiong Liao Link: https://lore.kernel.org/lkml/20200511233229.27745-9-keescook@chromium.org/ Co-developed-by: Kees Cook Signed-off-by: Kees Cook --- include/linux/pstore_blk.h | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) (limited to 'include/linux') diff --git a/include/linux/pstore_blk.h b/include/linux/pstore_blk.h index ccba8c068752..0c40774e71e0 100644 --- a/include/linux/pstore_blk.h +++ b/include/linux/pstore_blk.h @@ -49,4 +49,32 @@ struct pstore_blk_info { int register_pstore_blk(struct pstore_blk_info *info); void unregister_pstore_blk(unsigned int major); +/** + * struct pstore_blk_config - the pstore_blk backend configuration + * + * @device: Name of the desired block device + * @max_reason: Maximum kmsg dump reason to store to block device + * @kmsg_size: Total size of for kmsg dumps + * @pmsg_size: Total size of the pmsg storage area + * @console_size: Total size of the console storage area + * @ftrace_size: Total size for ftrace logging data (for all CPUs) + */ +struct pstore_blk_config { + char device[80]; + enum kmsg_dump_reason max_reason; + unsigned long kmsg_size; + unsigned long pmsg_size; + unsigned long console_size; + unsigned long ftrace_size; +}; + +/** + * pstore_blk_get_config - get a copy of the pstore_blk backend configuration + * + * @info: The sturct pstore_blk_config to be filled in + * + * Failure returns negative error code, and success returns 0. + */ +int pstore_blk_get_config(struct pstore_blk_config *info); + #endif -- cgit v1.2.3 From 7dcb7848ba110ff192efc917d1a6de66b4c9ca4f Mon Sep 17 00:00:00 2001 From: WeiXiong Liao Date: Wed, 25 Mar 2020 16:55:05 +0800 Subject: pstore/blk: Support non-block storage devices Add support for non-block devices (e.g. MTD). A non-block driver calls pstore_blk_register_device() to register iself. In addition, pstore/zone is updated to handle non-block devices, where an erase must be done before a write. Without this, there is no way to remove records stored to an MTD. Signed-off-by: WeiXiong Liao Link: https://lore.kernel.org/lkml/20200511233229.27745-10-keescook@chromium.org/ Co-developed-by: Kees Cook Signed-off-by: Kees Cook --- include/linux/pstore_blk.h | 38 ++++++++++++++++++++++++++++++++++++++ include/linux/pstore_zone.h | 6 ++++++ 2 files changed, 44 insertions(+) (limited to 'include/linux') diff --git a/include/linux/pstore_blk.h b/include/linux/pstore_blk.h index 0c40774e71e0..61e914522b01 100644 --- a/include/linux/pstore_blk.h +++ b/include/linux/pstore_blk.h @@ -49,6 +49,44 @@ struct pstore_blk_info { int register_pstore_blk(struct pstore_blk_info *info); void unregister_pstore_blk(unsigned int major); +/** + * struct pstore_device_info - back-end pstore/blk driver structure. + * + * @total_size: The total size in bytes pstore/blk can use. It must be greater + * than 4096 and be multiple of 4096. + * @flags: Refer to macro starting with PSTORE_FLAGS defined in + * linux/pstore.h. It means what front-ends this device support. + * Zero means all backends for compatible. + * @read: The general read operation. Both of the function parameters + * @size and @offset are relative value to bock device (not the + * whole disk). + * On success, the number of bytes should be returned, others + * means error. + * @write: The same as @read, but the following error number: + * -EBUSY means try to write again later. + * -ENOMSG means to try next zone. + * @erase: The general erase operation for device with special removing + * job. Both of the function parameters @size and @offset are + * relative value to storage. + * Return 0 on success and others on failure. + * @panic_write:The write operation only used for panic case. It's optional + * if you do not care panic log. The parameters are relative + * value to storage. + * On success, the number of bytes should be returned, others + * excluding -ENOMSG mean error. -ENOMSG means to try next zone. + */ +struct pstore_device_info { + unsigned long total_size; + unsigned int flags; + pstore_zone_read_op read; + pstore_zone_write_op write; + pstore_zone_erase_op erase; + pstore_zone_write_op panic_write; +}; + +int register_pstore_device(struct pstore_device_info *dev); +void unregister_pstore_device(struct pstore_device_info *dev); + /** * struct pstore_blk_config - the pstore_blk backend configuration * diff --git a/include/linux/pstore_zone.h b/include/linux/pstore_zone.h index e79a18e41064..1e35eaa33e5e 100644 --- a/include/linux/pstore_zone.h +++ b/include/linux/pstore_zone.h @@ -7,6 +7,7 @@ typedef ssize_t (*pstore_zone_read_op)(char *, size_t, loff_t); typedef ssize_t (*pstore_zone_write_op)(const char *, size_t, loff_t); +typedef ssize_t (*pstore_zone_erase_op)(size_t, loff_t); /** * struct pstore_zone_info - pstore/zone back-end driver structure * @@ -27,6 +28,10 @@ typedef ssize_t (*pstore_zone_write_op)(const char *, size_t, loff_t); * @write: The same as @read, but the following error number: * -EBUSY means try to write again later. * -ENOMSG means to try next zone. + * @erase: The general erase operation for device with special removing + * job. Both of the function parameters @size and @offset are + * relative value to storage. + * Return 0 on success and others on failure. * @panic_write:The write operation only used for panic case. It's optional * if you do not care panic log. The parameters are relative * value to storage. @@ -45,6 +50,7 @@ struct pstore_zone_info { unsigned long ftrace_size; pstore_zone_read_op read; pstore_zone_write_op write; + pstore_zone_erase_op erase; pstore_zone_write_op panic_write; }; -- cgit v1.2.3