mirror of
https://github.com/torvalds/linux.git
synced 2024-11-16 17:12:06 +00:00
8d4fbcfbe0
Alexey Dobriyan noticed that the new WARN_ON() semantics that were
introduced by commit 684f978347 (to also
return the value to be warned on) didn't compile when given a bitfield,
because the typeof doesn't work for bitfields.
So instead of the typeof trick, use an "int" variable together with a
"!!(x)" expression, as suggested by Al Viro.
To make matters more interesting, Paul Mackerras points out that that is
sub-optimal on Power, but the old asm-coded comparison seems to be buggy
anyway on 32-bit Power if the conditional was 64-bit, so I think there
are more problems there.
Regardless, the new WARN_ON() semantics may have been a bad idea. But
this at least avoids the more serious complications.
Cc: Alexey Dobriyan <adobriyan@sw.ru>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
122 lines
3.0 KiB
C
122 lines
3.0 KiB
C
#ifndef _ASM_POWERPC_BUG_H
|
|
#define _ASM_POWERPC_BUG_H
|
|
#ifdef __KERNEL__
|
|
|
|
#include <asm/asm-compat.h>
|
|
/*
|
|
* Define an illegal instr to trap on the bug.
|
|
* We don't use 0 because that marks the end of a function
|
|
* in the ELF ABI. That's "Boo Boo" in case you wonder...
|
|
*/
|
|
#define BUG_OPCODE .long 0x00b00b00 /* For asm */
|
|
#define BUG_ILLEGAL_INSTR "0x00b00b00" /* For BUG macro */
|
|
|
|
#ifdef CONFIG_BUG
|
|
|
|
#ifdef __ASSEMBLY__
|
|
#ifdef CONFIG_DEBUG_BUGVERBOSE
|
|
.macro EMIT_BUG_ENTRY addr,file,line,flags
|
|
.section __bug_table,"a"
|
|
5001: PPC_LONG \addr, 5002f
|
|
.short \line, \flags
|
|
.org 5001b+BUG_ENTRY_SIZE
|
|
.previous
|
|
.section .rodata,"a"
|
|
5002: .asciz "\file"
|
|
.previous
|
|
.endm
|
|
#else
|
|
.macro EMIT_BUG_ENTRY addr,file,line,flags
|
|
.section __bug_table,"a"
|
|
5001: PPC_LONG \addr
|
|
.short \flags
|
|
.org 5001b+BUG_ENTRY_SIZE
|
|
.previous
|
|
.endm
|
|
#endif /* verbose */
|
|
|
|
#else /* !__ASSEMBLY__ */
|
|
/* _EMIT_BUG_ENTRY expects args %0,%1,%2,%3 to be FILE, LINE, flags and
|
|
sizeof(struct bug_entry), respectively */
|
|
#ifdef CONFIG_DEBUG_BUGVERBOSE
|
|
#define _EMIT_BUG_ENTRY \
|
|
".section __bug_table,\"a\"\n" \
|
|
"2:\t" PPC_LONG "1b, %0\n" \
|
|
"\t.short %1, %2\n" \
|
|
".org 2b+%3\n" \
|
|
".previous\n"
|
|
#else
|
|
#define _EMIT_BUG_ENTRY \
|
|
".section __bug_table,\"a\"\n" \
|
|
"2:\t" PPC_LONG "1b\n" \
|
|
"\t.short %2\n" \
|
|
".org 2b+%3\n" \
|
|
".previous\n"
|
|
#endif
|
|
|
|
/*
|
|
* BUG_ON() and WARN_ON() do their best to cooperate with compile-time
|
|
* optimisations. However depending on the complexity of the condition
|
|
* some compiler versions may not produce optimal results.
|
|
*/
|
|
|
|
#define BUG() do { \
|
|
__asm__ __volatile__( \
|
|
"1: twi 31,0,0\n" \
|
|
_EMIT_BUG_ENTRY \
|
|
: : "i" (__FILE__), "i" (__LINE__), \
|
|
"i" (0), "i" (sizeof(struct bug_entry))); \
|
|
for(;;) ; \
|
|
} while (0)
|
|
|
|
#define BUG_ON(x) do { \
|
|
if (__builtin_constant_p(x)) { \
|
|
if (x) \
|
|
BUG(); \
|
|
} else { \
|
|
__asm__ __volatile__( \
|
|
"1: "PPC_TLNEI" %4,0\n" \
|
|
_EMIT_BUG_ENTRY \
|
|
: : "i" (__FILE__), "i" (__LINE__), "i" (0), \
|
|
"i" (sizeof(struct bug_entry)), \
|
|
"r" ((__force long)(x))); \
|
|
} \
|
|
} while (0)
|
|
|
|
#define __WARN() do { \
|
|
__asm__ __volatile__( \
|
|
"1: twi 31,0,0\n" \
|
|
_EMIT_BUG_ENTRY \
|
|
: : "i" (__FILE__), "i" (__LINE__), \
|
|
"i" (BUGFLAG_WARNING), \
|
|
"i" (sizeof(struct bug_entry))); \
|
|
} while (0)
|
|
|
|
#define WARN_ON(x) ({ \
|
|
int __ret_warn_on = !!(x); \
|
|
if (__builtin_constant_p(__ret_warn_on)) { \
|
|
if (__ret_warn_on) \
|
|
__WARN(); \
|
|
} else { \
|
|
__asm__ __volatile__( \
|
|
"1: "PPC_TLNEI" %4,0\n" \
|
|
_EMIT_BUG_ENTRY \
|
|
: : "i" (__FILE__), "i" (__LINE__), \
|
|
"i" (BUGFLAG_WARNING), \
|
|
"i" (sizeof(struct bug_entry)), \
|
|
"r" (__ret_warn_on)); \
|
|
} \
|
|
unlikely(__ret_warn_on); \
|
|
})
|
|
|
|
#define HAVE_ARCH_BUG
|
|
#define HAVE_ARCH_BUG_ON
|
|
#define HAVE_ARCH_WARN_ON
|
|
#endif /* __ASSEMBLY __ */
|
|
#endif /* CONFIG_BUG */
|
|
|
|
#include <asm-generic/bug.h>
|
|
|
|
#endif /* __KERNEL__ */
|
|
#endif /* _ASM_POWERPC_BUG_H */
|