Messages in this thread Patch in this message | | | From | Michal Schmidt <> | Subject | [PATCH] params: make dashes and underscores in parameter names truly equal | Date | Mon, 10 Oct 2011 00:03:37 +0200 |
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The user may use "foo-bar" for a kernel parameter defined as "foo_bar". Make sure it works the other way around too.
Apply the equality of dashes and underscores on early_params and __setup params as well.
The example given in Documentation/kernel-parameters.txt indicates that this is the intended behaviour.
With the patch the kernel accepts "log-buf-len=1M" as expected. https://bugzilla.redhat.com/show_bug.cgi?id=744545
Signed-off-by: Michal Schmidt <mschmidt@redhat.com> --- include/linux/moduleparam.h | 20 ++++++++++++++++++++ init/main.c | 4 ++-- kernel/params.c | 34 +++++++++++++++++++++++++++------- 3 files changed, 49 insertions(+), 9 deletions(-)
diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h index 56bda92..609f89c 100644 --- a/include/linux/moduleparam.h +++ b/include/linux/moduleparam.h @@ -267,6 +267,26 @@ static inline void __kernel_param_unlock(void) .str = &__param_string_##name, 0, perm); \ __MODULE_PARM_TYPE(name, "string") +/** + * parameq - checks if two parameter names match + * @name1: parameter name 1 + * @name2: parameter name 2 + * + * Returns true if the two parameter names are equal. + * Dashes (-) are considered equal to underscores (_). + */ +extern bool parameq(const char *name1, const char *name2); + +/** + * parameqn - checks if two parameter names match + * @name1: parameter name 1 + * @name2: parameter name 2 + * @n: the maximum length to compare + * + * Similar to parameq(), except it compares at most @n characters. + */ +extern bool parameqn(const char *name1, const char *name2, size_t n); + /* Called on module insert or kernel boot */ extern int parse_args(const char *name, char *args, diff --git a/init/main.c b/init/main.c index 03b408d..63f5f6f 100644 --- a/init/main.c +++ b/init/main.c @@ -163,7 +163,7 @@ static int __init obsolete_checksetup(char *line) p = __setup_start; do { int n = strlen(p->str); - if (!strncmp(line, p->str, n)) { + if (parameqn(line, p->str, n)) { if (p->early) { /* Already done in parse_early_param? * (Needs exact match on param part). @@ -392,7 +392,7 @@ static int __init do_early_param(char *param, char *val) const struct obs_kernel_param *p; for (p = __setup_start; p < __setup_end; p++) { - if ((p->early && strcmp(param, p->str) == 0) || + if ((p->early && parameq(param, p->str)) || (strcmp(param, "console") == 0 && strcmp(p->str, "earlycon") == 0) ) { diff --git a/kernel/params.c b/kernel/params.c index 1d1c01b..aa8933c 100644 --- a/kernel/params.c +++ b/kernel/params.c @@ -67,20 +67,40 @@ static void maybe_kfree_parameter(void *param) } } -static inline char dash2underscore(char c) +static char dash2underscore(char c) { if (c == '-') return '_'; return c; } -static inline int parameq(const char *input, const char *paramname) +bool parameq(const char *name1, const char *name2) { - unsigned int i; - for (i = 0; dash2underscore(input[i]) == paramname[i]; i++) - if (input[i] == '\0') - return 1; - return 0; + char c1, c2; + while (1) { + c1 = dash2underscore(*name1++); + c2 = dash2underscore(*name2++); + if (c1 != c2) + return false; + if (c1 == '\0') + break; + } + return true; +} + +bool parameqn(const char *name1, const char *name2, size_t n) +{ + char c1, c2; + while (n) { + c1 = dash2underscore(*name1++); + c2 = dash2underscore(*name2++); + if (c1 != c2) + return false; + if (c1 == '\0') + break; + n--; + } + return true; } static int parse_one(char *param, -- 1.7.4.4
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