[v4,0/8] Replace strncmp with str_has_prefix

Message

Chuhong Yuan Aug. 9, 2019, 7:10 a.m. UTC

The commit 72921427d46b
("string.h: Add str_has_prefix() helper function")
introduced str_has_prefix() to substitute error-prone
strncmp(str, const, len).

strncmp(str, const, len) is easy to have error in len
because of counting error or sizeof(const) without - 1.

These patches replace such pattern with str_has_prefix()
to avoid hard coded constant length and sizeof.

Besides, str_has_prefix() returns the length of prefix
when the comparison returns true.
We can use this return value to substitute some hard-coding.

Changelog:

v1 -> v2:
  - Revise the description.
  - Use the return value of str_has_prefix() to eliminate
    hard coding.
  - Remove possible false positives and add newly detected
    one in upstream.

v2 -> v3:
  - Revise the description.
  - Remove else uses in printk.c.

v3 -> v4:
  - Eliminate assignments in if conditions.

Chuhong Yuan (8):
  dma: debug: Replace strncmp with str_has_prefix
  module: Replace strncmp with str_has_prefix
  PM/sleep: Replace strncmp with str_has_prefix
  printk: Replace strncmp with str_has_prefix
  reboot: Replace strncmp with str_has_prefix
  sched: Replace strncmp with str_has_prefix
  userns: Replace strncmp with str_has_prefix
  watchdog: Replace strncmp with str_has_prefix

 kernel/dma/debug.c       |  2 +-
 kernel/module.c          |  2 +-
 kernel/power/main.c      |  2 +-
 kernel/printk/braille.c  | 15 +++++++++++----
 kernel/printk/printk.c   | 22 ++++++++++++++++------
 kernel/reboot.c          |  7 +++++--
 kernel/sched/debug.c     |  6 ++++--
 kernel/sched/isolation.c | 11 +++++++----
 kernel/user_namespace.c  | 20 ++++++++++++--------
 kernel/watchdog.c        |  8 ++++----
 10 files changed, 62 insertions(+), 33 deletions(-)