kernel/git/stable/linux.git/drivers/mtd/mtdoops.c, branch master

mtd: mtdoops: free page bitmap when the backing MTD is removed

2026-07-17T15:49:27+00:00

mtdoops_notify_add() allocates oops_page_used when the configured MTD device is registered. mtdoops_notify_remove() detaches from that device but leaves the bitmap allocated. If the same MTD device is later registered again, the add path allocates a new bitmap and overwrites the old pointer, leaking one vmalloc allocation per remove/add cycle. This is only visible when the backing MTD device can disappear and be registered again while mtdoops remains loaded, so the usual static MTD case does not expose it. Free the bitmap after unregistering the dumper and flushing the pending workers, then clear the pointer and page count before a later attach can allocate fresh state. Clearing the pointer also keeps the module exit path from freeing the same bitmap a second time after a remove event. Fixes: be95745f0167 ("mtd: mtdoops: keep track of used/unused pages in an array") Cc: stable@vger.kernel.org Signed-off-by: Xu Rao Signed-off-by: Miquel Raynal

mtd: mtdoops: replace simple_strtoul with kstrtouint

2026-04-27T13:12:58+00:00

Replace deprecated simple_strtoul with kstrtouint for better error handling and type safety. The kstrtouint function provides stricter validation, automatically rejecting inputs like "123abc" that simple_strtoul would partially accept. Using kstrtouint avoids unsigned long to int conversion and is more appropriate for MTD device indices which are non-negative integers. Signed-off-by: Haoyu Lu Signed-off-by: Miquel Raynal

mtd: use vmalloc_array and vcalloc to simplify code

2025-09-11T15:34:15+00:00

Remove array_size() calls and replace vmalloc(array_size()) with vmalloc_array() and vzalloc(array_size()) with vcalloc() to simplify the code. Compile-tested only. Signed-off-by: Qianfeng Rong Signed-off-by: Miquel Raynal

mtd: mtdoops: Fix kmsgdump parameter renaming.

2024-07-22T15:56:22+00:00

When the kmsg_dumper callback parameter changed, the reason variable in mtdoops_do_dump() was not updated accordingly. This breaks the build with mtdoops. Fixes: e1a261ba599e ("printk: Add a short description string to kmsg_dump()") Suggested-by: Knop Ryszard Signed-off-by: Jocelyn Falempe Acked-by: Richard Weinberger Link: https://patchwork.freedesktop.org/patch/msgid/20240719152542.1554440-1-jfalempe@redhat.com

printk: Add a short description string to kmsg_dump()

2024-07-17T10:35:24+00:00

kmsg_dump doesn't forward the panic reason string to the kmsg_dumper callback. This patch adds a new struct kmsg_dump_detail, that will hold the reason and description, and pass it to the dump() callback. To avoid updating all kmsg_dump() call, it adds a kmsg_dump_desc() function and a macro for backward compatibility. I've written this for drm_panic, but it can be useful for other kmsg_dumper. It allows to see the panic reason, like "sysrq triggered crash" or "VFS: Unable to mount root fs on xxxx" on the drm panic screen. v2: * Use a struct kmsg_dump_detail to hold the reason and description pointer, for more flexibility if we want to add other parameters. (Kees Cook) * Fix powerpc/nvram_64 build, as I didn't update the forward declaration of oops_to_nvram() Signed-off-by: Jocelyn Falempe Acked-by: Petr Mladek Acked-by: Michael Ellerman (powerpc) Acked-by: Kees Cook Link: https://patchwork.freedesktop.org/patch/msgid/20240702122639.248110-1-jfalempe@redhat.com

mtd: mtdoops: panic caused mtdoops to call mtdoops_erase function immediately

2022-11-07T16:08:00+00:00

The panic function disables the local interrupts, preemption, and all other processors. When the invoked mtdoops needs to erase a used page, calling schedule_work() to do it will not work. Instead, just call mtdoops_erase function immediately. Tested: ~# echo c > /proc/sysrq-trigger [ 171.654759] sysrq: Trigger a crash [ 171.658325] Kernel panic - not syncing: sysrq triggered crash ...... [ 172.406423] mtdoops: not ready 34, 35 (erase immediately) [ 172.432285] mtdoops: ready 34, 35 [ 172.435633] Rebooting in 10 seconds.. Signed-off-by: Ray Zhang Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20221010045549.2221965-4-sgzhang@google.com

mtd: mtdoops: add mtdoops_erase function and move mtdoops_inc_counter to after it

2022-11-07T16:07:59+00:00

Preparing for next patch with minimal code difference, add mtdoops_erase function and move mtdoops_inc_counter to after it, with no functional change. Signed-off-by: Ray Zhang Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20221010045549.2221965-3-sgzhang@google.com

mtd: mtdoops: change printk() to counterpart pr_ functions

2022-11-07T16:07:59+00:00

To comply with latest kernel code requirement, change printk() to counterpart pr_ functions in mtdoops driver: - change printk(INFO) to pr_info() - change printk(DEBUG) to pr_debug() - change printk(WARNING) to pr_warn() - change printk(ERR) to pr_err() Note that only if dynamic debugging is enabled or DEBUG is defined, printk(KERN_DEBUG) and pr_debug() are equivalent; Otherwise pr_debug() is no-op, causing different behavior. Signed-off-by: Ray Zhang Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20221010045549.2221965-2-sgzhang@google.com

mtd: mtdoops: Add a timestamp to the mtdoops header.

2022-04-26T07:27:12+00:00

On some systems, the oops only has relative time from boot. Signed-off-by: Jean-Marc Eurin Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20220425160927.3823016-1-jmeurin@google.com

mtd: mtdoops: Create a header structure for the saved mtdoops.

2022-04-26T07:27:07+00:00

Create a dump header to enable the addition of fields without having to modify the rest of the code. Reported-by: kernel test robot Signed-off-by: Jean-Marc Eurin Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20220421234244.2172003-3-jmeurin@google.com