diff options
| author | Niklas Cassel <cassel@kernel.org> | 2026-09-16 15:00:32 +0200 |
|---|---|---|
| committer | Niklas Cassel <cassel@kernel.org> | 2026-09-16 16:18:00 +0200 |
| commit | 8d836581f9b1f57ceaa2b47654754ef1260b410b (patch) | |
| tree | 1dbd4d0dfb99c2e238356cbe947e5b0be3e3a571 /samples/livepatch/livepatch-shadow-fix2.c | |
| download | linux-stable-8d836581f9b1f57ceaa2b47654754ef1260b410b.tar.gz linux-stable-8d836581f9b1f57ceaa2b47654754ef1260b410b.zip | |
ata: libata-scsi: fix ata_dsm_trim_pages() kernel-docgrafted
make htmldocs fails with:
Documentation/driver-api/libata:604: ./drivers/ata/libata-scsi.c:2301:
ERROR: Unexpected indentation. [docutils]
The Return: section of ata_dsm_trim_pages() ends its first sentence with
a colon and continues with an indented bullet list. reStructuredText
requires a blank line before an indented block, so docutils chokes on
the list.
Simply adding the missing blank line does not work either: Return: is a
kernel-doc "special section", which is terminated by the first blank
line, so the bullet list would end up in the Description section,
detached from the sentence introducing it.
Spell the two bounds out as prose instead, so that the Return: section
stays self-contained. Documentation-only change.
Fixes: e64e6b5dc867 ("ata: libata-scsi: scale DSM TRIM payload by MAX PAGES PER DSM COMMAND")
Reported-by: Thomas Huth <thuth@redhat.com>
Closes: https://lore.kernel.org/linux-ide/b0a0b8e8-cc4f-4c7b-8bc5-fee0712d405a@redhat.com/
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Link: https://lore.kernel.org/r/20260916130031.29990-2-cassel@kernel.org
Signed-off-by: Niklas Cassel <cassel@kernel.org>
Diffstat (limited to 'samples/livepatch/livepatch-shadow-fix2.c')
| -rw-r--r-- | samples/livepatch/livepatch-shadow-fix2.c | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/samples/livepatch/livepatch-shadow-fix2.c b/samples/livepatch/livepatch-shadow-fix2.c new file mode 100644 index 000000000..b99122cb2 --- /dev/null +++ b/samples/livepatch/livepatch-shadow-fix2.c @@ -0,0 +1,133 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2017 Joe Lawrence <joe.lawrence@redhat.com> + */ + +/* + * livepatch-shadow-fix2.c - Shadow variables, livepatch demo + * + * Purpose + * ------- + * + * Adds functionality to livepatch-shadow-mod's in-flight data + * structures through a shadow variable. The livepatch patches a + * routine that periodically inspects data structures, incrementing a + * per-data-structure counter, creating the counter if needed. + * + * + * Usage + * ----- + * + * This module is not intended to be standalone. See the "Usage" + * section of livepatch-shadow-mod.c. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/livepatch.h> +#include <linux/slab.h> + +/* Shadow variable enums */ +#define SV_LEAK 1 +#define SV_COUNTER 2 + +struct dummy { + struct list_head list; + unsigned long jiffies_expire; +}; + +static bool livepatch_fix2_dummy_check(struct dummy *d, unsigned long jiffies) +{ + int *shadow_count; + + /* + * Patch: handle in-flight dummy structures, if they do not + * already have a SV_COUNTER shadow variable, then attach a + * new one. + */ + shadow_count = klp_shadow_get_or_alloc(d, SV_COUNTER, + sizeof(*shadow_count), GFP_NOWAIT, + NULL, NULL); + if (shadow_count) + *shadow_count += 1; + + return time_after(jiffies, d->jiffies_expire); +} + +static void livepatch_fix2_dummy_leak_dtor(void *obj, void *shadow_data) +{ + void *d = obj; + int **shadow_leak = shadow_data; + + pr_info("%s: dummy @ %p, prevented leak @ %p\n", + __func__, d, *shadow_leak); + kfree(*shadow_leak); +} + +static void livepatch_fix2_dummy_free(struct dummy *d) +{ + int **shadow_leak; + int *shadow_count; + + /* Patch: copy the memory leak patch from the fix1 module. */ + shadow_leak = klp_shadow_get(d, SV_LEAK); + if (shadow_leak) + klp_shadow_free(d, SV_LEAK, livepatch_fix2_dummy_leak_dtor); + else + pr_info("%s: dummy @ %p leaked!\n", __func__, d); + + /* + * Patch: fetch the SV_COUNTER shadow variable and display + * the final count. Detach the shadow variable. + */ + shadow_count = klp_shadow_get(d, SV_COUNTER); + if (shadow_count) { + pr_info("%s: dummy @ %p, check counter = %d\n", + __func__, d, *shadow_count); + klp_shadow_free(d, SV_COUNTER, NULL); + } + + kfree(d); +} + +static struct klp_func funcs[] = { + { + .old_name = "dummy_check", + .new_func = livepatch_fix2_dummy_check, + }, + { + .old_name = "dummy_free", + .new_func = livepatch_fix2_dummy_free, + }, { } +}; + +static struct klp_object objs[] = { + { + .name = "livepatch_shadow_mod", + .funcs = funcs, + }, { } +}; + +static struct klp_patch patch = { + .mod = THIS_MODULE, + .objs = objs, +}; + +static int livepatch_shadow_fix2_init(void) +{ + return klp_enable_patch(&patch); +} + +static void livepatch_shadow_fix2_exit(void) +{ + /* Cleanup any existing SV_COUNTER shadow variables */ + klp_shadow_free_all(SV_COUNTER, NULL); +} + +module_init(livepatch_shadow_fix2_init); +module_exit(livepatch_shadow_fix2_exit); +MODULE_DESCRIPTION("Live patching demo for shadow variables"); +MODULE_LICENSE("GPL"); +MODULE_INFO(livepatch, "Y"); |
