From 4c925d6031f719fad6ea8b1c94a636f4c0fea39b Mon Sep 17 00:00:00 2001 From: Eldad Zack Date: Mon, 17 Dec 2012 16:03:04 -0800 Subject: kstrto*: add documentation As Bruce Fields pointed out, kstrto* is currently lacking kerneldoc comments. This patch adds kerneldoc comments to common variants of kstrto*: kstrto(u)l, kstrto(u)ll and kstrto(u)int. Signed-off-by: Eldad Zack Cc: J. Bruce Fields Cc: Joe Perches Cc: Randy Dunlap Cc: Alexey Dobriyan Cc: Rob Landley Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/kernel.h | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) (limited to 'include/linux/kernel.h') diff --git a/include/linux/kernel.h b/include/linux/kernel.h index d97ed5897447..d140e8fb075f 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -220,6 +220,23 @@ int __must_check _kstrtol(const char *s, unsigned int base, long *res); int __must_check kstrtoull(const char *s, unsigned int base, unsigned long long *res); int __must_check kstrtoll(const char *s, unsigned int base, long long *res); + +/** + * kstrtoul - convert a string to an unsigned long + * @s: The start of the string. The string must be null-terminated, and may also + * include a single newline before its terminating null. The first character + * may also be a plus sign, but not a minus sign. + * @base: The number base to use. The maximum supported base is 16. If base is + * given as 0, then the base of the string is automatically detected with the + * conventional semantics - If it begins with 0x the number will be parsed as a + * hexadecimal (case insensitive), if it otherwise begins with 0, it will be + * parsed as an octal number. Otherwise it will be parsed as a decimal. + * @res: Where to write the result of the conversion on success. + * + * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error. + * Used as a replacement for the obsolete simple_strtoull. Return code must + * be checked. +*/ static inline int __must_check kstrtoul(const char *s, unsigned int base, unsigned long *res) { /* @@ -233,6 +250,22 @@ static inline int __must_check kstrtoul(const char *s, unsigned int base, unsign return _kstrtoul(s, base, res); } +/** + * kstrtol - convert a string to a long + * @s: The start of the string. The string must be null-terminated, and may also + * include a single newline before its terminating null. The first character + * may also be a plus sign or a minus sign. + * @base: The number base to use. The maximum supported base is 16. If base is + * given as 0, then the base of the string is automatically detected with the + * conventional semantics - If it begins with 0x the number will be parsed as a + * hexadecimal (case insensitive), if it otherwise begins with 0, it will be + * parsed as an octal number. Otherwise it will be parsed as a decimal. + * @res: Where to write the result of the conversion on success. + * + * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error. + * Used as a replacement for the obsolete simple_strtoull. Return code must + * be checked. + */ static inline int __must_check kstrtol(const char *s, unsigned int base, long *res) { /* -- cgit v1.2.3 From c4e18497d8fd92eef2c6e7eadcc1a107ccd115ea Mon Sep 17 00:00:00 2001 From: Guenter Roeck Date: Thu, 20 Dec 2012 15:05:42 -0800 Subject: linux/kernel.h: fix DIV_ROUND_CLOSEST with unsigned divisors Commit 263a523d18bc ("linux/kernel.h: Fix warning seen with W=1 due to change in DIV_ROUND_CLOSEST") fixes a warning seen with W=1 due to change in DIV_ROUND_CLOSEST. Unfortunately, the C compiler converts divide operations with unsigned divisors to unsigned, even if the dividend is signed and negative (for example, -10 / 5U = 858993457). The C standard says "If one operand has unsigned int type, the other operand is converted to unsigned int", so the compiler is not to blame. As a result, DIV_ROUND_CLOSEST(0, 2U) and similar operations now return bad values, since the automatic conversion of expressions such as "0 - 2U/2" to unsigned was not taken into account. Fix by checking for the divisor variable type when deciding which operation to perform. This fixes DIV_ROUND_CLOSEST(0, 2U), but still returns bad values for negative dividends divided by unsigned divisors. Mark the latter case as unsupported. One observed effect of this problem is that the s2c_hwmon driver reports a value of 4198403 instead of 0 if the ADC reads 0. Other impact is unpredictable. Problem is seen if the divisor is an unsigned variable or constant and the dividend is less than (divisor/2). Signed-off-by: Guenter Roeck Reported-by: Juergen Beisert Tested-by: Juergen Beisert Cc: Jean Delvare Cc: [3.7.x] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/kernel.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'include/linux/kernel.h') diff --git a/include/linux/kernel.h b/include/linux/kernel.h index d140e8fb075f..c566927efcbd 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -77,13 +77,15 @@ /* * Divide positive or negative dividend by positive divisor and round - * to closest integer. Result is undefined for negative divisors. + * to closest integer. Result is undefined for negative divisors and + * for negative dividends if the divisor variable type is unsigned. */ #define DIV_ROUND_CLOSEST(x, divisor)( \ { \ typeof(x) __x = x; \ typeof(divisor) __d = divisor; \ - (((typeof(x))-1) > 0 || (__x) > 0) ? \ + (((typeof(x))-1) > 0 || \ + ((typeof(divisor))-1) > 0 || (__x) > 0) ? \ (((__x) + ((__d) / 2)) / (__d)) : \ (((__x) - ((__d) / 2)) / (__d)); \ } \ -- cgit v1.2.3 From 373d4d099761cb1f637bed488ab3871945882273 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Mon, 21 Jan 2013 17:17:39 +1030 Subject: taint: add explicit flag to show whether lock dep is still OK. Fix up all callers as they were before, with make one change: an unsigned module taints the kernel, but doesn't turn off lockdep. Signed-off-by: Rusty Russell --- include/linux/kernel.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'include/linux/kernel.h') diff --git a/include/linux/kernel.h b/include/linux/kernel.h index c566927efcbd..80d36874689b 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -398,7 +398,11 @@ extern int panic_on_unrecovered_nmi; extern int panic_on_io_nmi; extern int sysctl_panic_on_stackoverflow; extern const char *print_tainted(void); -extern void add_taint(unsigned flag); +enum lockdep_ok { + LOCKDEP_STILL_OK, + LOCKDEP_NOW_UNRELIABLE +}; +extern void add_taint(unsigned flag, enum lockdep_ok); extern int test_taint(unsigned flag); extern unsigned long get_taint(void); extern int root_mountflags; -- cgit v1.2.3