Messages in this thread Patch in this message | | | From | Rusty Russell <> | Date | Mon, 1 Dec 2008 23:25:16 +1030 | Subject | [RFC 3/8] param: make sure charp isn't used as a core_param |
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"charp" sets a variable to point to a char string in a command line. This doesn't work if the command line isn't going to stick around. Add a compile-breaking check for this case, and make a note of it.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> --- include/linux/moduleparam.h | 3 +++ kernel/params.c | 7 +++++++ 2 files changed, 10 insertions(+)
diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h --- a/include/linux/moduleparam.h +++ b/include/linux/moduleparam.h @@ -118,11 +118,15 @@ struct kparam_array * early in boot. This is for compatibility with __setup(), and it * makes sense as truly core parameters aren't tied to the particular * file they're in. + * + * Note: You can't use 'charp' here (which keeps a pointer into our + * tmp cmdline). */ #define core_param(name, var, type, perm) \ param_check_##type(name, &(var)); \ __module_param_call("", "__core_param", name, param_set_##type, \ - param_get_##type, &var, perm) + param_get_##type, &var, perm \ + + BUILD_BUG_ON_ZERO(param_##type##_keeps_reference)) #endif /* !MODULE */ /* Actually copy string: maxlen param is usually sizeof(string). */ @@ -150,42 +154,52 @@ extern int param_set_byte(const char *va extern int param_set_byte(const char *val, struct kernel_param *kp); extern int param_get_byte(char *buffer, struct kernel_param *kp); #define param_check_byte(name, p) __param_check(name, p, unsigned char) +#define param_byte_keeps_reference 0 extern int param_set_short(const char *val, struct kernel_param *kp); extern int param_get_short(char *buffer, struct kernel_param *kp); #define param_check_short(name, p) __param_check(name, p, short) +#define param_short_keeps_reference 0 extern int param_set_ushort(const char *val, struct kernel_param *kp); extern int param_get_ushort(char *buffer, struct kernel_param *kp); #define param_check_ushort(name, p) __param_check(name, p, unsigned short) +#define param_ushort_keeps_reference 0 extern int param_set_int(const char *val, struct kernel_param *kp); extern int param_get_int(char *buffer, struct kernel_param *kp); #define param_check_int(name, p) __param_check(name, p, int) +#define param_int_keeps_reference 0 extern int param_set_uint(const char *val, struct kernel_param *kp); extern int param_get_uint(char *buffer, struct kernel_param *kp); #define param_check_uint(name, p) __param_check(name, p, unsigned int) +#define param_uint_keeps_reference 0 extern int param_set_long(const char *val, struct kernel_param *kp); extern int param_get_long(char *buffer, struct kernel_param *kp); #define param_check_long(name, p) __param_check(name, p, long) +#define param_long_keeps_reference 0 extern int param_set_ulong(const char *val, struct kernel_param *kp); extern int param_get_ulong(char *buffer, struct kernel_param *kp); #define param_check_ulong(name, p) __param_check(name, p, unsigned long) +#define param_ulong_keeps_reference 0 extern int param_set_charp(const char *val, struct kernel_param *kp); extern int param_get_charp(char *buffer, struct kernel_param *kp); #define param_check_charp(name, p) __param_check(name, p, char *) +#define param_charp_keeps_reference 1 extern int param_set_bool(const char *val, struct kernel_param *kp); extern int param_get_bool(char *buffer, struct kernel_param *kp); #define param_check_bool(name, p) __param_check(name, p, int) +#define param_bool_keeps_reference 0 extern int param_set_invbool(const char *val, struct kernel_param *kp); extern int param_get_invbool(char *buffer, struct kernel_param *kp); #define param_check_invbool(name, p) __param_check(name, p, int) +#define param_invbool_keeps_reference 0 /* Comma-separated array: *nump is set to number they actually specified. */ #define module_param_array_named(name, array, type, nump, perm) \
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