Eric Lee / linux-smarc-t335x-v3.2

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Commit af9379c7121d5543722c00bbd1adf7dcaa0b6448

Authored by David Brownell
Committed by Linus Torvalds
1 parent 5f820f648c
Exists in master and in 4 other branches v3.2_AM335xPSP_04.06.00.11, v3.2_NEWT335xPSP_04.06.00.11, v3.2_SBC_SMARTMEN, v3.2_SMARCT335xPSP_04.06.00.11

documentation: when to BUG(), and when to not BUG() 

Provide some basic advice about when to use BUG()/BUG_ON(): never, unless
there's really no better option.

This matches my understanding of the standard policy ...  which seems not
to be written down so far, outside of LKML messages that I haven't
bookmarked.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Hans Verkuil <hverkuil@xs4all.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Showing 1 changed file with 17 additions and 0 deletions Side-by-side Diff

include/asm-generic/bug.h
Diff comments   View file @ af9379c
... ... @@ -28,6 +28,17 @@
28 28 #define BUGFLAG_WARNING (1<<0)
29 29 #endif /* CONFIG_GENERIC_BUG */
30 30  
  31 +/*
  32 + * Don't use BUG() or BUG_ON() unless there's really no way out; one
  33 + * example might be detecting data structure corruption in the middle
  34 + * of an operation that can't be backed out of. If the (sub)system
  35 + * can somehow continue operating, perhaps with reduced functionality,
  36 + * it's probably not BUG-worthy.
  37 + *
  38 + * If you're tempted to BUG(), think again: is completely giving up
  39 + * really the *only* solution? There are usually better options, where
  40 + * users don't need to reboot ASAP and can mostly shut down cleanly.
  41 + */
31 42 #ifndef HAVE_ARCH_BUG
32 43 #define BUG() do { \
33 44 printk("BUG: failure at %s:%d/%s()!\n", __FILE__, __LINE__, __func__); \
... ... @@ -39,6 +50,12 @@
39 50 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while(0)
40 51 #endif
41 52  
  53 +/*
  54 + * WARN(), WARN_ON(), WARN_ON_ONCE, and so on can be used to report
  55 + * significant issues that need prompt attention if they should ever
  56 + * appear at runtime. Use the versions with printk format strings
  57 + * to provide better diagnostics.
  58 + */
42 59 #ifndef __WARN
43 60 #ifndef __ASSEMBLY__
44 61 extern void warn_slowpath(const char *file, const int line,