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Commit 007d88d0 authored by David Woodhouse's avatar David Woodhouse Committed by Paul Mackerras
Browse files

[POWERPC] Fix manual assembly WARN_ON() in enter_rtas(). 



When we switched over to the generic BUG mechanism we forgot to change
the assembly code which open-codes a WARN_ON() in enter_rtas(), so the
bug table got corrupted.

This patch provides an EMIT_BUG_ENTRY macro for use in assembly code,
and uses it in entry_64.S. Tested with CONFIG_DEBUG_BUGVERBOSE on ppc64
but not without -- I tried to turn it off but it wouldn't go away; I
suspect Aunt Tillie probably needed it.

This version gets __FILE__ and __LINE__ right in the assembly version --
rather than saying include/asm-powerpc/bug.h line 21 every time which is
a little suboptimal.

Signed-off-by: default avatarDavid Woodhouse <dwmw2@infradead.org>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent 673aeb76

arch/powerpc/kernel/asm-offsets.c

+3 −0
Original line number Diff line number Diff line
@@ -303,5 +303,8 @@ int main(void) 
	DEFINE(NSEC_PER_SEC, NSEC_PER_SEC);

	DEFINE(CLOCK_REALTIME_RES, TICK_NSEC);



#ifdef CONFIG_BUG

	DEFINE(BUG_ENTRY_SIZE, sizeof(struct bug_entry));

#endif

	return 0;

}

arch/powerpc/kernel/entry_64.S

+5 −8
Original line number Diff line number Diff line
@@ -28,6 +28,7 @@ 
#include <asm/asm-offsets.h>

#include <asm/cputable.h>

#include <asm/firmware.h>

#include <asm/bug.h>



/*

 * System calls.
@@ -634,18 +635,14 @@ _GLOBAL(enter_rtas) 
	li	r0,0

	mtcr	r0



#ifdef CONFIG_BUG	

	/* There is no way it is acceptable to get here with interrupts enabled,

	 * check it with the asm equivalent of WARN_ON

	 */

	lbz	r0,PACASOFTIRQEN(r13)

1:	tdnei	r0,0

.section __bug_table,"a"

	.llong	1b,__LINE__ + 0x1000000, 1f, 2f

.previous

.section .rodata,"a"

1:	.asciz	__FILE__

2:	.asciz "enter_rtas"

.previous

	EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,BUGFLAG_WARNING

#endif

	

	/* Hard-disable interrupts */

	mfmsr	r6

include/asm-powerpc/bug.h

+24 −3
Original line number Diff line number Diff line
@@ -11,10 +11,31 @@ 
#define BUG_OPCODE .long 0x00b00b00  /* For asm */

#define BUG_ILLEGAL_INSTR "0x00b00b00" /* For BUG macro */



#ifndef __ASSEMBLY__



#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
@@ -91,8 +112,8 @@ 
#define HAVE_ARCH_BUG

#define HAVE_ARCH_BUG_ON

#define HAVE_ARCH_WARN_ON

#endif /* CONFIG_BUG */

#endif /* __ASSEMBLY __ */

#endif /* CONFIG_BUG */



#include <asm-generic/bug.h>