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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /samples/livepatch/livepatch-sample.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'samples/livepatch/livepatch-sample.c')
-rw-r--r-- | samples/livepatch/livepatch-sample.c | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/samples/livepatch/livepatch-sample.c b/samples/livepatch/livepatch-sample.c new file mode 100644 index 000000000..cd76d7ebe --- /dev/null +++ b/samples/livepatch/livepatch-sample.c @@ -0,0 +1,70 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * livepatch-sample.c - Kernel Live Patching Sample Module + * + * Copyright (C) 2014 Seth Jennings <sjenning@redhat.com> + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/livepatch.h> + +/* + * This (dumb) live patch overrides the function that prints the + * kernel boot cmdline when /proc/cmdline is read. + * + * Example: + * + * $ cat /proc/cmdline + * <your cmdline> + * + * $ insmod livepatch-sample.ko + * $ cat /proc/cmdline + * this has been live patched + * + * $ echo 0 > /sys/kernel/livepatch/livepatch_sample/enabled + * $ cat /proc/cmdline + * <your cmdline> + */ + +#include <linux/seq_file.h> +static int livepatch_cmdline_proc_show(struct seq_file *m, void *v) +{ + seq_printf(m, "%s\n", "this has been live patched"); + return 0; +} + +static struct klp_func funcs[] = { + { + .old_name = "cmdline_proc_show", + .new_func = livepatch_cmdline_proc_show, + }, { } +}; + +static struct klp_object objs[] = { + { + /* name being NULL means vmlinux */ + .funcs = funcs, + }, { } +}; + +static struct klp_patch patch = { + .mod = THIS_MODULE, + .objs = objs, +}; + +static int livepatch_init(void) +{ + return klp_enable_patch(&patch); +} + +static void livepatch_exit(void) +{ +} + +module_init(livepatch_init); +module_exit(livepatch_exit); +MODULE_LICENSE("GPL"); +MODULE_INFO(livepatch, "Y"); |