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authorJani Nikula <jani.nikula@intel.com>2014-08-27 06:22:23 +0930
committerRusty Russell <rusty@rustcorp.com.au>2014-08-27 21:54:08 +0930
commit91f9d330cc14932084c37751997213cb0e7ea882 (patch)
tree8a7494e64787ea72ce4ed86c5298a1b1b7195111 /kernel/params.c
parent6a4c264313c4ae32dc53821a9c57e0dc9696fb81 (diff)
downloadlwn-91f9d330cc14932084c37751997213cb0e7ea882.tar.gz
lwn-91f9d330cc14932084c37751997213cb0e7ea882.zip
module: make it possible to have unsafe, tainting module params
Add flags field to struct kernel_params, and add the first flag: unsafe parameter. Modifying a kernel parameter with the unsafe flag set, either via the kernel command line or sysfs, will issue a warning and taint the kernel. Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jean Delvare <khali@linux-fr.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Jon Mason <jon.mason@intel.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Jani Nikula <jani.nikula@intel.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Diffstat (limited to 'kernel/params.c')
-rw-r--r--kernel/params.c11
1 files changed, 11 insertions, 0 deletions
diff --git a/kernel/params.c b/kernel/params.c
index 8a484fc8bde8..ad8d04563c3a 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -233,6 +233,7 @@ char *parse_args(const char *doing,
#define STANDARD_PARAM_DEF(name, type, format, strtolfn) \
int param_set_##name(const char *val, const struct kernel_param *kp) \
{ \
+ param_check_unsafe(kp); \
return strtolfn(val, 0, (type *)kp->arg); \
} \
int param_get_##name(char *buffer, const struct kernel_param *kp) \
@@ -265,6 +266,8 @@ int param_set_charp(const char *val, const struct kernel_param *kp)
return -ENOSPC;
}
+ param_check_unsafe(kp);
+
maybe_kfree_parameter(*(char **)kp->arg);
/* This is a hack. We can't kmalloc in early boot, and we
@@ -302,6 +305,8 @@ EXPORT_SYMBOL(param_ops_charp);
/* Actually could be a bool or an int, for historical reasons. */
int param_set_bool(const char *val, const struct kernel_param *kp)
{
+ param_check_unsafe(kp);
+
/* No equals means "set"... */
if (!val) val = "1";
@@ -331,6 +336,8 @@ int param_set_invbool(const char *val, const struct kernel_param *kp)
bool boolval;
struct kernel_param dummy;
+ param_check_unsafe(kp);
+
dummy.arg = &boolval;
ret = param_set_bool(val, &dummy);
if (ret == 0)
@@ -357,6 +364,8 @@ int param_set_bint(const char *val, const struct kernel_param *kp)
bool v;
int ret;
+ param_check_unsafe(kp);
+
/* Match bool exactly, by re-using it. */
boolkp = *kp;
boolkp.arg = &v;
@@ -476,6 +485,8 @@ int param_set_copystring(const char *val, const struct kernel_param *kp)
{
const struct kparam_string *kps = kp->str;
+ param_check_unsafe(kp);
+
if (strlen(val)+1 > kps->maxlen) {
pr_err("%s: string doesn't fit in %u chars.\n",
kp->name, kps->maxlen-1);