Markus Mayer
2016-Jul-08 22:43 UTC
[Nouveau] [PATCH v3 0/7] lib: string: add functions to case-convert strings
This series introduces a family of generic string case conversion functions. This kind of functionality is needed in several places in the kernel. Right now, everybody seems to be implementing their own copy of this functionality. Based on the discussion of the previous version of this series[1] and the use cases found in the kernel, it does look like having several flavours of case conversion functions is beneficial. The use cases fall into three categories: - copying a string and converting the case while specifying a maximum length to mimic strlcpy() - copying a string and converting the case without specifying a length to mimic strcpy() - converting the case of a string in-place (i.e. modifying the string that was passed in) Consequently, I am proposing these new functions: void strlcpytoupper(char *dst, const char *src, size_t len); void strlcpytolower(char *dst, const char *src, size_t len); void strcpytoupper(char *dst, const char *src); void strcpytolower(char *dst, const char *src); void strtoupper(char *s); void strtolower(char *s); Several drivers are being modified to make use of the functions above. Another driver that also makes use of this functionality will be submitted upstream shortly, which prompted this whole exercise. The changes made here have been compile-tested, but not tried out, due to lack of required hardware. Changes since v2: - use strlcpy() semantics not strncpy() semantics, i.e. guarantee NULL termination - as a result strncpyto<upper|lower> are now called strlcpyto<upper|lower> - make functions void - use len == -1 (SIZE_MAX) as no-limit indicator rather then len == 0 - change PATCH 2/7 to match strlcpy() semantics - change PATCH 4/7 to match strlcpy() semantics Changes since v1: - expanded strtolower() into a family of functions that cover use cases when a length argument is or isn't required and that support copying the string into a new buffer or changing it in-place - changed the function semantics to return a pointer to the terminating '\0' character of the modified string - added strtoupper() functionality mirroring the above - dropped the ACPICA patch, since that code is OS independent and can't rely on a Linux library function (see [2]) - Added two new patches replacing strtoupper() implementations [1] https://lkml.org/lkml/2016/6/30/727 [2] https://lkml.org/lkml/2016/7/1/9 Markus Mayer (7): lib: string: add functions to case-convert strings drm/nouveau/core: make use of new strlcpytolower() function ACPI / device_sysfs: make use of new strtolower() function staging: speakup: replace spk_strlwr() with strlcpytolower() iscsi-target: replace iscsi_initiatorname_tolower() with strtolower() drm/nouveau/fifo/gk104: make use of new strcpytoupper() function power_supply: make use of new strcpytoupper() function drivers/acpi/device_sysfs.c | 4 +-- drivers/gpu/drm/nouveau/nvkm/core/firmware.c | 9 +----- drivers/gpu/drm/nouveau/nvkm/engine/fifo/gk104.c | 5 +-- drivers/power/power_supply_sysfs.c | 13 +++----- drivers/staging/speakup/kobjects.c | 3 +- drivers/staging/speakup/main.c | 3 +- drivers/staging/speakup/speakup.h | 1 - drivers/staging/speakup/varhandlers.c | 12 ------- drivers/target/iscsi/iscsi_target_nego.c | 17 +--------- include/linux/string.h | 40 ++++++++++++++++++++++++ lib/string.c | 38 ++++++++++++++++++++++ 11 files changed, 90 insertions(+), 55 deletions(-) -- 2.7.4
Markus Mayer
2016-Jul-08 22:43 UTC
[Nouveau] [PATCH v3 1/7] lib: string: add functions to case-convert strings
Add a collection of generic functions to convert strings to lowercase or uppercase. Changing the case of a string (with or without copying it first) seems to be a recurring requirement in the kernel that is currently being solved by several duplicated implementations doing the same thing. This change aims at reducing this code duplication. The new functions are void strlcpytoupper(char *dst, const char *src, size_t len); void strlcpytolower(char *dst, const char *src, size_t len); void strcpytoupper(char *dst, const char *src); void strcpytolower(char *dst, const char *src); void strtoupper(char *s); void strtolower(char *s); The "str[l]cpyto*" versions of the function take a destination string and a source string as arguments. The "strlcpyto*" versions additionally take a length argument like strlcpy() itself. Lastly, the strto* functions take a single string argument and modify the passed-in string. Like strlcpy(), and unlike strncpy(), the functions guarantee NULL termination of the destination string. Signed-off-by: Markus Mayer <mmayer at broadcom.com> --- include/linux/string.h | 40 ++++++++++++++++++++++++++++++++++++++++ lib/string.c | 38 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 78 insertions(+) diff --git a/include/linux/string.h b/include/linux/string.h index 26b6f6a..36c9d14 100644 --- a/include/linux/string.h +++ b/include/linux/string.h @@ -116,6 +116,8 @@ extern void * memchr(const void *,int,__kernel_size_t); #endif void *memchr_inv(const void *s, int c, size_t n); char *strreplace(char *s, char old, char new); +extern void strlcpytoupper(char *dst, const char *src, size_t len); +extern void strlcpytolower(char *dst, const char *src, size_t len); extern void kfree_const(const void *x); @@ -169,4 +171,42 @@ static inline const char *kbasename(const char *path) return tail ? tail + 1 : path; } +/** + * strcpytoupper - Copy string and convert to uppercase. + * @dst: The buffer to store the result. + * @src: The string to convert to uppercase. + */ +static inline void strcpytoupper(char *dst, const char *src) +{ + strlcpytoupper(dst, src, -1); +} + +/** + * strcpytolower - Copy string and convert to lowercase. + * @dst: The buffer to store the result. + * @src: The string to convert to lowercase. + */ +static inline void strcpytolower(char *dst, const char *src) +{ + strlcpytolower(dst, src, -1); +} + +/** + * strtoupper - Convert string to uppercase. + * @s: The string to operate on. + */ +static inline void strtoupper(char *s) +{ + strlcpytoupper(s, s, -1); +} + +/** + * strtolower - Convert string to lowercase. + * @s: The string to operate on. + */ +static inline void strtolower(char *s) +{ + strlcpytolower(s, s, -1); +} + #endif /* _LINUX_STRING_H_ */ diff --git a/lib/string.c b/lib/string.c index ed83562..fd8c427 100644 --- a/lib/string.c +++ b/lib/string.c @@ -952,3 +952,41 @@ char *strreplace(char *s, char old, char new) return s; } EXPORT_SYMBOL(strreplace); + +/** + * strlcpytoupper - Copy a length-limited string and convert to uppercase. + * @dst: The buffer to store the result. + * @src: The string to convert to uppercase. + * @len: Maximum string length. May be SIZE_MAX (-1) to set no limit. + */ +void strlcpytoupper(char *dst, const char *src, size_t len) +{ + size_t i; + + if (!len) + return; + + for (i = 0; i < len && src[i]; ++i) + dst[i] = toupper(src[i]); + dst[i < len ? i : i - 1] = '\0'; +} +EXPORT_SYMBOL(strlcpytoupper); + +/** + * strlcpytolower - Copy a length-limited string and convert to lowercase. + * @dst: The buffer to store the result. + * @src: The string to convert to lowercase. + * @len: Maximum string length. May be SIZE_MAX (-1) to set no limit. + */ +void strlcpytolower(char *dst, const char *src, size_t len) +{ + size_t i; + + if (!len) + return; + + for (i = 0; i < len && src[i]; ++i) + dst[i] = tolower(src[i]); + dst[i < len ? i : i - 1] = '\0'; +} +EXPORT_SYMBOL(strlcpytolower); -- 2.7.4
Markus Mayer
2016-Jul-08 22:43 UTC
[Nouveau] [PATCH v3 2/7] drm/nouveau/core: make use of new strlcpytolower() function
Call strlcpytolower() rather than copying the string explicitly and then walking it to convert it to lowercase. Signed-off-by: Markus Mayer <mmayer at broadcom.com> --- The semantics of the new function has changed, so this patch has been updated since v2 to match the new strlcpy() semantics (no explicit NULL terminating is required). See https://patchwork.kernel.org/patch/9215207/ for the previous version. drivers/gpu/drm/nouveau/nvkm/core/firmware.c | 9 +-------- 1 file changed, 1 insertion(+), 8 deletions(-) diff --git a/drivers/gpu/drm/nouveau/nvkm/core/firmware.c b/drivers/gpu/drm/nouveau/nvkm/core/firmware.c index 34ecd4a..982601e 100644 --- a/drivers/gpu/drm/nouveau/nvkm/core/firmware.c +++ b/drivers/gpu/drm/nouveau/nvkm/core/firmware.c @@ -36,16 +36,9 @@ nvkm_firmware_get(struct nvkm_device *device, const char *fwname, { char f[64]; char cname[16]; - int i; /* Convert device name to lowercase */ - strncpy(cname, device->chip->name, sizeof(cname)); - cname[sizeof(cname) - 1] = '\0'; - i = strlen(cname); - while (i) { - --i; - cname[i] = tolower(cname[i]); - } + strlcpytolower(cname, device->chip->name, sizeof(cname)); snprintf(f, sizeof(f), "nvidia/%s/%s.bin", cname, fwname); return request_firmware(fw, f, device->dev); -- 2.7.4
Markus Mayer
2016-Jul-08 22:43 UTC
[Nouveau] [PATCH v3 6/7] drm/nouveau/fifo/gk104: make use of new strcpytoupper() function
Call strcpytoupper() rather than copying the string explicitly and then walking it to convert it to uppercase. Signed-off-by: Markus Mayer <mmayer at broadcom.com> --- drivers/gpu/drm/nouveau/nvkm/engine/fifo/gk104.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gk104.c b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gk104.c index 743f3a1..8d01032 100644 --- a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gk104.c +++ b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gk104.c @@ -332,10 +332,7 @@ gk104_fifo_intr_fault(struct gk104_fifo *fifo, int unit) enum nvkm_devidx engidx = nvkm_top_fault(device->top, unit); if (engidx < NVKM_SUBDEV_NR) { const char *src = nvkm_subdev_name[engidx]; - char *dst = en; - do { - *dst++ = toupper(*src++); - } while(*src); + strcpytoupper(en, src); engine = nvkm_device_engine(device, engidx); } } else { -- 2.7.4
Luis de Bethencourt
2016-Jul-09 12:04 UTC
[Nouveau] [PATCH v3 1/7] lib: string: add functions to case-convert strings
On 08/07/16 23:43, Markus Mayer wrote:> Add a collection of generic functions to convert strings to lowercase > or uppercase. > > Changing the case of a string (with or without copying it first) seems > to be a recurring requirement in the kernel that is currently being > solved by several duplicated implementations doing the same thing. This > change aims at reducing this code duplication. > > The new functions are > void strlcpytoupper(char *dst, const char *src, size_t len); > void strlcpytolower(char *dst, const char *src, size_t len); > void strcpytoupper(char *dst, const char *src); > void strcpytolower(char *dst, const char *src); > void strtoupper(char *s); > void strtolower(char *s); > > The "str[l]cpyto*" versions of the function take a destination string > and a source string as arguments. The "strlcpyto*" versions additionally > take a length argument like strlcpy() itself. Lastly, the strto* > functions take a single string argument and modify the passed-in string. > > Like strlcpy(), and unlike strncpy(), the functions guarantee NULL > termination of the destination string. > > Signed-off-by: Markus Mayer <mmayer at broadcom.com> > --- > include/linux/string.h | 40 ++++++++++++++++++++++++++++++++++++++++ > lib/string.c | 38 ++++++++++++++++++++++++++++++++++++++ > 2 files changed, 78 insertions(+) > > diff --git a/include/linux/string.h b/include/linux/string.h > index 26b6f6a..36c9d14 100644 > --- a/include/linux/string.h > +++ b/include/linux/string.h > @@ -116,6 +116,8 @@ extern void * memchr(const void *,int,__kernel_size_t); > #endif > void *memchr_inv(const void *s, int c, size_t n); > char *strreplace(char *s, char old, char new); > +extern void strlcpytoupper(char *dst, const char *src, size_t len); > +extern void strlcpytolower(char *dst, const char *src, size_t len); > > extern void kfree_const(const void *x); > > @@ -169,4 +171,42 @@ static inline const char *kbasename(const char *path) > return tail ? tail + 1 : path; > } > > +/** > + * strcpytoupper - Copy string and convert to uppercase. > + * @dst: The buffer to store the result. > + * @src: The string to convert to uppercase. > + */ > +static inline void strcpytoupper(char *dst, const char *src) > +{ > + strlcpytoupper(dst, src, -1); > +} > +Why not use SIZE_MAX instead of -1?> +/** > + * strcpytolower - Copy string and convert to lowercase. > + * @dst: The buffer to store the result. > + * @src: The string to convert to lowercase. > + */ > +static inline void strcpytolower(char *dst, const char *src) > +{ > + strlcpytolower(dst, src, -1); > +} > +Same here, and the 2 below :) Thanks Markus, Luis> +/** > + * strtoupper - Convert string to uppercase. > + * @s: The string to operate on. > + */ > +static inline void strtoupper(char *s) > +{ > + strlcpytoupper(s, s, -1); > +} > + > +/** > + * strtolower - Convert string to lowercase. > + * @s: The string to operate on. > + */ > +static inline void strtolower(char *s) > +{ > + strlcpytolower(s, s, -1); > +} > + > #endif /* _LINUX_STRING_H_ */ > diff --git a/lib/string.c b/lib/string.c > index ed83562..fd8c427 100644 > --- a/lib/string.c > +++ b/lib/string.c > @@ -952,3 +952,41 @@ char *strreplace(char *s, char old, char new) > return s; > } > EXPORT_SYMBOL(strreplace); > + > +/** > + * strlcpytoupper - Copy a length-limited string and convert to uppercase. > + * @dst: The buffer to store the result. > + * @src: The string to convert to uppercase. > + * @len: Maximum string length. May be SIZE_MAX (-1) to set no limit. > + */ > +void strlcpytoupper(char *dst, const char *src, size_t len) > +{ > + size_t i; > + > + if (!len) > + return; > + > + for (i = 0; i < len && src[i]; ++i) > + dst[i] = toupper(src[i]); > + dst[i < len ? i : i - 1] = '\0'; > +} > +EXPORT_SYMBOL(strlcpytoupper); > + > +/** > + * strlcpytolower - Copy a length-limited string and convert to lowercase. > + * @dst: The buffer to store the result. > + * @src: The string to convert to lowercase. > + * @len: Maximum string length. May be SIZE_MAX (-1) to set no limit. > + */ > +void strlcpytolower(char *dst, const char *src, size_t len) > +{ > + size_t i; > + > + if (!len) > + return; > + > + for (i = 0; i < len && src[i]; ++i) > + dst[i] = tolower(src[i]); > + dst[i < len ? i : i - 1] = '\0'; > +} > +EXPORT_SYMBOL(strlcpytolower); >
Chris Metcalf
2016-Jul-10 03:13 UTC
[Nouveau] [PATCH v3 0/7] lib: string: add functions to case-convert strings
On 7/8/2016 6:43 PM, Markus Mayer wrote:> This series introduces a family of generic string case conversion > functions. This kind of functionality is needed in several places in > the kernel. Right now, everybody seems to be implementing their own > copy of this functionality. > > Based on the discussion of the previous version of this series[1] and > the use cases found in the kernel, it does look like having several > flavours of case conversion functions is beneficial. The use cases fall > into three categories: > - copying a string and converting the case while specifying a > maximum length to mimic strlcpy() > - copying a string and converting the case without specifying a > length to mimic strcpy() > - converting the case of a string in-place (i.e. modifying the > string that was passed in) > > Consequently, I am proposing these new functions: > void strlcpytoupper(char *dst, const char *src, size_t len); > void strlcpytolower(char *dst, const char *src, size_t len); > void strcpytoupper(char *dst, const char *src); > void strcpytolower(char *dst, const char *src); > void strtoupper(char *s); > void strtolower(char *s);You may want to read the article here: https://lwn.net/Articles/659214/ and follow up some of the discussion threads on LKML about the best semantics to advertise for the strlcpy/strscpy variants. It might be helpful to return some kind of overflow/truncation error from your copy functions so people can error-check the result. -- Chris Metcalf, Mellanox Technologies http://www.mellanox.com
Markus Mayer
2016-Jul-10 04:11 UTC
[Nouveau] [PATCH v3 0/7] lib: string: add functions to case-convert strings
On 9 July 2016 at 20:13, Chris Metcalf <cmetcalf at mellanox.com> wrote:> On 7/8/2016 6:43 PM, Markus Mayer wrote: >> >> This series introduces a family of generic string case conversion >> functions. This kind of functionality is needed in several places in >> the kernel. Right now, everybody seems to be implementing their own >> copy of this functionality. >> >> Based on the discussion of the previous version of this series[1] and >> the use cases found in the kernel, it does look like having several >> flavours of case conversion functions is beneficial. The use cases fall >> into three categories: >> - copying a string and converting the case while specifying a >> maximum length to mimic strlcpy() >> - copying a string and converting the case without specifying a >> length to mimic strcpy() >> - converting the case of a string in-place (i.e. modifying the >> string that was passed in) >> >> Consequently, I am proposing these new functions: >> void strlcpytoupper(char *dst, const char *src, size_t len); >> void strlcpytolower(char *dst, const char *src, size_t len); >> void strcpytoupper(char *dst, const char *src); >> void strcpytolower(char *dst, const char *src); >> void strtoupper(char *s); >> void strtolower(char *s); > > > You may want to read the article here: > > https://lwn.net/Articles/659214/I'll read that. Thanks.> and follow up some of the discussion threads on LKML about the best > semantics to advertise for the strlcpy/strscpy variants. It might be > helpful to return some kind of overflow/truncation error from your > copy functions so people can error-check the result.I am inclined to agree. However, everybody has been telling me that these functions should be void. Originally they weren't. Regards, -Markus
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