kernel/linux.git/lib/kstrtox.c, branch v6.19.11

lib/kstrtox: fix kstrtobool() docstring to mention enabled/disabled

2026-02-26T23:01:08+00:00

[ Upstream commit 1921044eebf1d6861a6de1a76e3f63729a45e712 ] Commit ae5b3500856f ("kstrtox: add support for enabled and disabled in kstrtobool()") added support for 'e'/'E' (enabled) and 'd'/'D' (disabled) inputs, but did not update the docstring accordingly. Update the docstring to include 'Ee' (for true) and 'Dd' (for false) in the list of accepted first characters. Link: https://lkml.kernel.org/r/20251227092229.57330-1-chaitanyamishra.ai@gmail.com Fixes: ae5b3500856f ("kstrtox: add support for enabled and disabled in kstrtobool()") Signed-off-by: Chaitanya Mishra Cc: Mario Limonciello Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin

kstrtox: add support for enabled and disabled in kstrtobool()

2025-05-12T00:54:06+00:00

In some places in the kernel there is a design pattern for sysfs attributes to use kstrtobool() in store() and str_enabled_disabled() in show(). This is counterintuitive to interact with because kstrtobool() takes on/off but str_enabled_disabled() shows enabled/disabled. Some of those sysfs uses could switch to str_on_off() but for some attributes enabled/disabled really makes more sense. Add support for kstrtobool() to accept enabled/disabled. Link: https://lkml.kernel.org/r/20250321022538.1532445-1-superm1@kernel.org Signed-off-by: Mario Limonciello Signed-off-by: Andrew Morton

kstrtox: consistently use _tolower()

2023-08-21T20:46:25+00:00

We already use _tolower() in other places, so convert the one which open codes it. Link: https://lkml.kernel.org/r/20230817145919.543251-1-andriy.shevchenko@linux.intel.com Signed-off-by: Andy Shevchenko Signed-off-by: Andrew Morton

lib/kstrtox.c: add "false"/"true" support to kstrtobool()

2022-05-13T14:20:13+00:00

At many places in kernel, It is necessary to convert sysfs input to corresponding bool value e.g. "false" or "0" need to be converted to bool false, "true" or "1" need to be converted to bool true, places where such conversion is needed currently check the input string manually, kstrtobool() can be utilized at such places but currently it doesn't have support to accept "false"/"true". Add support to accept "false"/"true" as valid string in kstrtobool(). [akpm@linux-foundation.org: undo s/iff/if/, per Matthew] Link: https://lkml.kernel.org/r/20220426180203.70782-1-jvgediya@linux.ibm.com Signed-off-by: Jagdish Gediya Reviewed-by: Matthew Wilcox (Oracle) Reviewed-by: Andy Shevchenko Cc: "Huang, Ying" Cc: Dave Hansen Cc: Jonathan Cameron Cc: Alexey Dobriyan Cc: Richard Fitzgerald Cc: Petr Mladek Signed-off-by: Andrew Morton

kstrtox: uninline everything

2022-01-20T06:52:53+00:00

I've made a mistake of looking into lib/kstrtox.o code generation. The only function remotely performance critical is _parse_integer() (via /proc/*/map_files/*), everything else is not. Uninline everything, shrink lib/kstrtox.o by ~20 % ! Space savings on x86_64: add/remove: 0/0 grow/shrink: 0/23 up/down: 0/-1269 (-1269 !!!) Function old new delta kstrtoull 16 13 -3 kstrtouint 59 48 -11 kstrtou8 60 49 -11 kstrtou16 61 50 -11 _kstrtoul 46 35 -11 kstrtoull_from_user 95 83 -12 kstrtoul_from_user 95 83 -12 kstrtoll 93 80 -13 kstrtouint_from_user 124 83 -41 kstrtou8_from_user 125 83 -42 kstrtou16_from_user 126 83 -43 kstrtos8 101 50 -51 kstrtos16 102 51 -51 kstrtoint 100 49 -51 _kstrtol 93 35 -58 kstrtobool_from_user 156 75 -81 kstrtoll_from_user 165 83 -82 kstrtol_from_user 165 83 -82 kstrtoint_from_user 172 83 -89 kstrtos8_from_user 173 83 -90 kstrtos16_from_user 174 83 -91 _parse_integer 136 10 -126 _kstrtoull 308 101 -207 Total: Before=3421236, After=3419967, chg -0.04% Link: https://lkml.kernel.org/r/YZDsFDhHst4m2Pnt@localhost.localdomain Signed-off-by: Alexey Dobriyan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'akpm' (patches from Andrew)

2021-07-02T19:08:10+00:00

Merge more updates from Andrew Morton: "190 patches. Subsystems affected by this patch series: mm (hugetlb, userfaultfd, vmscan, kconfig, proc, z3fold, zbud, ras, mempolicy, memblock, migration, thp, nommu, kconfig, madvise, memory-hotplug, zswap, zsmalloc, zram, cleanups, kfence, and hmm), procfs, sysctl, misc, core-kernel, lib, lz4, checkpatch, init, kprobes, nilfs2, hfs, signals, exec, kcov, selftests, compress/decompress, and ipc" * emailed patches from Andrew Morton : (190 commits) ipc/util.c: use binary search for max_idx ipc/sem.c: use READ_ONCE()/WRITE_ONCE() for use_global_lock ipc: use kmalloc for msg_queue and shmid_kernel ipc sem: use kvmalloc for sem_undo allocation lib/decompressors: remove set but not used variabled 'level' selftests/vm/pkeys: exercise x86 XSAVE init state selftests/vm/pkeys: refill shadow register after implicit kernel write selftests/vm/pkeys: handle negative sys_pkey_alloc() return code selftests/vm/pkeys: fix alloc_random_pkey() to make it really, really random kcov: add __no_sanitize_coverage to fix noinstr for all architectures exec: remove checks in __register_bimfmt() x86: signal: don't do sas_ss_reset() until we are certain that sigframe won't be abandoned hfsplus: report create_date to kstat.btime hfsplus: remove unnecessary oom message nilfs2: remove redundant continue statement in a while-loop kprobes: remove duplicated strong free_insn_page in x86 and s390 init: print out unknown kernel parameters checkpatch: do not complain about positive return values starting with EPOLL checkpatch: improve the indented label test checkpatch: scripts/spdxcheck.py now requires python3 ...

kernel.h: split out kstrtox() and simple_strtox() to a separate header

2021-07-01T18:06:05+00:00

kernel.h is being used as a dump for all kinds of stuff for a long time. Here is the attempt to start cleaning it up by splitting out kstrtox() and simple_strtox() helpers. At the same time convert users in header and lib folders to use new header. Though for time being include new header back to kernel.h to avoid twisted indirected includes for existing users. [andy.shevchenko@gmail.com: fix documentation references] Link: https://lkml.kernel.org/r/20210615220003.377901-1-andy.shevchenko@gmail.com Link: https://lkml.kernel.org/r/20210611185815.44103-1-andriy.shevchenko@linux.intel.com Signed-off-by: Andy Shevchenko Acked-by: Jonathan Cameron Cc: Francis Laniel Cc: Randy Dunlap Cc: Kars Mulder Cc: Trond Myklebust Cc: Anna Schumaker Cc: "J. Bruce Fields" Cc: Chuck Lever Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

lib: vsprintf: Fix handling of number field widths in vsscanf

2021-05-19T13:05:11+00:00

The existing code attempted to handle numbers by doing a strto[u]l(), ignoring the field width, and then repeatedly dividing to extract the field out of the full converted value. If the string contains a run of valid digits longer than will fit in a long or long long, this would overflow and no amount of dividing can recover the correct value. This patch fixes vsscanf() to obey number field widths when parsing the number. A new _parse_integer_limit() is added that takes a limit for the number of characters to parse. The number field conversion in vsscanf is changed to use this new function. If a number starts with a radix prefix, the field width must be long enough for at last one digit after the prefix. If not, it will be handled like this: sscanf("0x4", "%1i", &i): i=0, scanning continues with the 'x' sscanf("0x4", "%2i", &i): i=0, scanning continues with the '4' This is consistent with the observed behaviour of userland sscanf. Note that this patch does NOT fix the problem of a single field value overflowing the target type. So for example: sscanf("123456789abcdef", "%x", &i); Will not produce the correct result because the value obviously overflows INT_MAX. But sscanf will report a successful conversion. Note that where a very large number is used to mean "unlimited", the value INT_MAX is used for consistency with the behaviour of vsnprintf(). Signed-off-by: Richard Fitzgerald Reviewed-by: Petr Mladek Signed-off-by: Petr Mladek Link: https://lore.kernel.org/r/20210514161206.30821-2-rf@opensource.cirrus.com

lib: Fix fall-through warnings for Clang

2020-11-19T13:23:47+00:00

In preparation to enable -Wimplicit-fallthrough for Clang, fix multiple warnings by explicitly adding multiple break statements instead of letting the code fall through to the next case, and by replacing a number of /* fall through */ comments with the new pseudo-keyword macro fallthrough. Notice that Clang doesn't recognize /* Fall through */ comments as implicit fall-through markings. Link: https://github.com/KSPP/linux/issues/115 Signed-off-by: Gustavo A. R. Silva

kstrto: do not describe simple_strto() as obsolete/replaced

2020-08-12T17:58:00+00:00

The documentation of the kstrto*() functions describes kstrto*() as "replacements" of the "obsolete" simple_strto*() functions. Both of these terms are inaccurate: they're not replacements because they have different behaviour, and the simple_strto*() are not obsolete because there are cases where they have benefits over kstrto*(). Remove usage of the terms "replacement" and "obsolete" in reference to simple_strto*(), and instead use the term "preferred over". Fixes: 4c925d6031f71 ("kstrto*: add documentation") Fixes: 885e68e8b7b13 ("kernel.h: update comment about simple_strto() functions") Signed-off-by: Kars Mulder Signed-off-by: Andrew Morton Reviewed-by: Andy Shevchenko Cc: Eldad Zack Cc: Miguel Ojeda Cc: Geert Uytterhoeven Cc: Mans Rullgard Cc: Petr Mladek Link: http://lkml.kernel.org/r/29b9-5f234c80-13-4e3aa200@244003027 Signed-off-by: Linus Torvalds