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: int strlcpytoupper(char *dst, const char *src, size_t len); int 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 v4: - rebased on 4.8-rc1; this only affects patch 6/7 (gk104) and only the patch context, not the patch itself - added an ACK to patch 4/7 (speakup) - added an ACK to patch 7/7 (power_supply)
Changes since v3: - strlcpytoupper() and strlcpytolower() return length of destination or -E2BIG (see [2]) - we use ~(size_t)0 instead of -1 to copy strings of arbitrary length in strcpyto*() and strto*() - A few ACKs added
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 [3]) - Added two new patches replacing strtoupper() implementations
[1] https://lkml.org/lkml/2016/6/30/727 [2] https://lkml.org/lkml/2016/7/10/4 [3] 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 | 46 ++++++++++++++++++++++++ 11 files changed, 98 insertions(+), 55 deletions(-)