Linus,
PowerPC has a conditional trap instruction that I would like to use
for BUG_ON. I would like to make BUG_ON for ppc look like this:
#define BUG_ON(x) do { \
__asm__ __volatile__( \
"1: twnei %0,0\n" \
".section __bug_table,\"a\"\n" \
" .long 1b,%1,%2\n" \
".previous" \
: : "r" (x), "i" (__LINE__), "i" (__FILE__)); \
} while (0)
This avoids a conditional branch and is nice and compact. (The twnei
instruction takes an exception if the register operand is not equal
to the immediate operand - trap word not equal immediate.)
However, at the moment BUG_ON is unconditionally defined in kernel.h.
The patch below is the simplest way I can see to make it possible for
architectures to supply their own BUG_ON. Please apply.
Thanks,
Paul.
diff -urN linux-2.5/include/linux/kernel.h pmac-2.5/include/linux/kernel.h
--- linux-2.5/include/linux/kernel.h 2003-05-21 08:27:25.000000000 +1000
+++ pmac-2.5/include/linux/kernel.h 2003-05-26 22:01:54.000000000 +1000
@@ -228,7 +228,9 @@
char _f[20-2*sizeof(long)-sizeof(int)]; /* Padding: libc5 uses this.. */
};
+#ifndef BUG_ON
#define BUG_ON(condition) do { if (unlikely((condition)!=0)) BUG(); } while(0)
+#endif
#define WARN_ON(condition) do { \
if (unlikely((condition)!=0)) { \
printk("Badness in %s at %s:%d\n", __FUNCTION__, __FILE__, __LINE__); \
On second thoughts, it would be cleaner to move BUG_ON() into each
architecture's bug.h alongside BUG() and PAGE_BUG(), rather than using
an ifdef in kernel.h as my previous patch did.
This patch moves the definition of BUG_ON from include/linux/kernel.h
into include/asm-*/bug.h so that I can use a conditional-trap
instruction to implement BUG_ON on PowerPC.
Architecture maintainers, this should be completely benign. An ack
would still be appreciated, though. If this will let you improve your
BUG_ON too, please let me know.
Thanks,
Paul.
diff -urN linux-2.5/include/asm-alpha/bug.h pmac-2.5/include/asm-alpha/bug.h
--- linux-2.5/include/asm-alpha/bug.h 2002-02-25 03:51:44.000000000 +1100
+++ pmac-2.5/include/asm-alpha/bug.h 2003-05-28 18:33:23.000000000 +1000
@@ -9,6 +9,8 @@
__asm__ __volatile__("call_pal %0 # bugchk\n\t"".long %1\n\t.8byte %2" \
: : "i" (PAL_bugchk), "i"(__LINE__), "i"(__FILE__))
+#define BUG_ON(condition) do { if (unlikely((condition)!=0)) BUG(); } while(0)
+
#define PAGE_BUG(page) BUG()
#endif
diff -urN linux-2.5/include/asm-arm/bug.h pmac-2.5/include/asm-arm/bug.h
--- linux-2.5/include/asm-arm/bug.h 2003-02-02 04:15:11.000000000 +1100
+++ pmac-2.5/include/asm-arm/bug.h 2003-05-28 18:33:35.000000000 +1000
@@ -18,4 +18,6 @@
#endif
+#define BUG_ON(condition) do { if (unlikely((condition)!=0)) BUG(); } while(0)
+
#endif
diff -urN linux-2.5/include/asm-cris/bug.h pmac-2.5/include/asm-cris/bug.h
--- linux-2.5/include/asm-cris/bug.h 2002-01-06 22:46:09.000000000 +1100
+++ pmac-2.5/include/asm-cris/bug.h 2003-05-28 18:33:44.000000000 +1000
@@ -9,4 +9,6 @@
BUG(); \
} while (0)
+#define BUG_ON(condition) do { if (unlikely((condition)!=0)) BUG(); } while(0)
+
#endif
diff -urN linux-2.5/include/asm-h8300/bug.h pmac-2.5/include/asm-h8300/bug.h
--- linux-2.5/include/asm-h8300/bug.h 2003-04-18 05:31:21.000000000 +1000
+++ pmac-2.5/include/asm-h8300/bug.h 2003-05-28 18:34:07.000000000 +1000
@@ -9,4 +9,6 @@
BUG(); \
} while (0)
+#define BUG_ON(condition) do { if (unlikely((condition)!=0)) BUG(); } while(0)
+
#endif
diff -urN linux-2.5/include/asm-i386/bug.h pmac-2.5/include/asm-i386/bug.h
--- linux-2.5/include/asm-i386/bug.h 2003-02-17 10:52:20.000000000 +1100
+++ pmac-2.5/include/asm-i386/bug.h 2003-05-28 18:34:35.000000000 +1000
@@ -19,6 +19,8 @@
#define BUG() __asm__ __volatile__("ud2\n")
#endif
+#define BUG_ON(condition) do { if (unlikely((condition)!=0)) BUG(); } while(0)
+
#define PAGE_BUG(page) do { \
BUG(); \
} while (0)
diff -urN linux-2.5/include/asm-ia64/bug.h pmac-2.5/include/asm-ia64/bug.h
--- linux-2.5/include/asm-ia64/bug.h 2002-01-06 22:57:28.000000000 +1100
+++ pmac-2.5/include/asm-ia64/bug.h 2003-05-28 18:34:51.000000000 +1000
@@ -7,6 +7,7 @@
# define ia64_abort() (*(volatile int *) 0 = 0)
#endif
#define BUG() do { printk("kernel BUG at %s:%d!\n", __FILE__, __LINE__); ia64_abort(); } while (0)
+#define BUG_ON(condition) do { if (unlikely((condition)!=0)) BUG(); } while(0)
#define PAGE_BUG(page) do { BUG(); } while (0)
#endif
diff -urN linux-2.5/include/asm-m68k/bug.h pmac-2.5/include/asm-m68k/bug.h
--- linux-2.5/include/asm-m68k/bug.h 2002-07-26 06:17:16.000000000 +1000
+++ pmac-2.5/include/asm-m68k/bug.h 2003-05-28 18:35:34.000000000 +1000
@@ -21,6 +21,11 @@
} while (0)
#endif
+#define BUG_ON(condition) do { \
+ if (unlikely((condition)!=0)) \
+ BUG(); \
+} while(0)
+
#define PAGE_BUG(page) do { \
BUG(); \
} while (0)
diff -urN linux-2.5/include/asm-m68knommu/bug.h pmac-2.5/include/asm-m68knommu/bug.h
--- linux-2.5/include/asm-m68knommu/bug.h 2003-01-15 22:04:34.000000000 +1100
+++ pmac-2.5/include/asm-m68knommu/bug.h 2003-05-28 18:35:54.000000000 +1000
@@ -5,6 +5,11 @@
printk("%s(%d): kernel BUG!\n", __FILE__, __LINE__); \
} while (0)
+#define BUG_ON(condition) do { \
+ if (unlikely((condition)!=0)) \
+ BUG(); \
+} while(0)
+
#define PAGE_BUG(page) do { \
BUG(); \
} while (0)
diff -urN linux-2.5/include/asm-mips/bug.h pmac-2.5/include/asm-mips/bug.h
--- linux-2.5/include/asm-mips/bug.h 2002-01-06 22:57:49.000000000 +1100
+++ pmac-2.5/include/asm-mips/bug.h 2003-05-28 18:36:16.000000000 +1000
@@ -3,6 +3,7 @@
#define __ASM_BUG_H
#define BUG() do { printk("kernel BUG at %s:%d!\n", __FILE__, __LINE__); *(int *)0=0; } while (0)
+#define BUG_ON(condition) do { if (unlikely((condition)!=0)) BUG(); } while(0)
#define PAGE_BUG(page) do { BUG(); } while (0)
#endif
diff -urN linux-2.5/include/asm-mips64/bug.h pmac-2.5/include/asm-mips64/bug.h
--- linux-2.5/include/asm-mips64/bug.h 2002-01-06 22:51:12.000000000 +1100
+++ pmac-2.5/include/asm-mips64/bug.h 2003-05-28 18:36:23.000000000 +1000
@@ -2,6 +2,7 @@
#define _ASM_BUG_H
#define BUG() do { printk("kernel BUG at %s:%d!\n", __FILE__, __LINE__); *(int *)0=0; } while (0)
+#define BUG_ON(condition) do { if (unlikely((condition)!=0)) BUG(); } while(0)
#define PAGE_BUG(page) do { BUG(); } while (0)
#endif
diff -urN linux-2.5/include/asm-parisc/bug.h pmac-2.5/include/asm-parisc/bug.h
--- linux-2.5/include/asm-parisc/bug.h 2003-03-18 04:58:50.000000000 +1100
+++ pmac-2.5/include/asm-parisc/bug.h 2003-05-28 18:36:42.000000000 +1000
@@ -10,6 +10,11 @@
dump_stack(); \
} while (0)
+#define BUG_ON(condition) do { \
+ if (unlikely((condition)!=0)) \
+ BUG(); \
+} while(0)
+
#define PAGE_BUG(page) do { \
BUG(); \
} while (0)
diff -urN linux-2.5/include/asm-ppc/bug.h pmac-2.5/include/asm-ppc/bug.h
--- linux-2.5/include/asm-ppc/bug.h 2003-05-26 22:18:59.000000000 +1000
+++ pmac-2.5/include/asm-ppc/bug.h 2003-05-27 11:24:03.000000000 +1000
@@ -1,9 +1,28 @@
#ifndef _PPC_BUG_H
#define _PPC_BUG_H
-#define BUG() do { \
- printk("kernel BUG at %s:%d!\n", __FILE__, __LINE__); \
- __asm__ __volatile__(".long 0x0"); \
+struct bug_entry {
+ unsigned long bug_addr;
+ int line;
+ const char *file;
+};
+
+#define BUG() do { \
+ __asm__ __volatile__( \
+ "1: twi 31,0,0\n" \
+ ".section __bug_table,\"a\"\n\t" \
+ " .long 1b,%0,%1\n" \
+ ".previous" \
+ : : "i" (__LINE__), "i" (__FILE__)); \
+} while (0)
+
+#define BUG_ON(x) do { \
+ __asm__ __volatile__( \
+ "1: twnei %0,0\n" \
+ ".section __bug_table,\"a\"\n\t" \
+ " .long 1b,%1,%2\n" \
+ ".previous" \
+ : : "r" (x), "i" (__LINE__), "i" (__FILE__)); \
} while (0)
#define PAGE_BUG(page) do { BUG(); } while (0)
diff -urN linux-2.5/include/asm-ppc64/bug.h pmac-2.5/include/asm-ppc64/bug.h
--- linux-2.5/include/asm-ppc64/bug.h 2003-01-15 20:38:42.000000000 +1100
+++ pmac-2.5/include/asm-ppc64/bug.h 2003-05-28 18:36:55.000000000 +1000
@@ -27,6 +27,8 @@
} while (0)
#endif
+#define BUG_ON(condition) do { if (unlikely((condition)!=0)) BUG(); } while(0)
+
#define PAGE_BUG(page) do { BUG(); } while (0)
#endif
diff -urN linux-2.5/include/asm-s390/bug.h pmac-2.5/include/asm-s390/bug.h
--- linux-2.5/include/asm-s390/bug.h 2002-01-06 22:53:36.000000000 +1100
+++ pmac-2.5/include/asm-s390/bug.h 2003-05-28 18:37:12.000000000 +1000
@@ -6,6 +6,11 @@
__asm__ __volatile__(".long 0"); \
} while (0)
+#define BUG_ON(condition) do { \
+ if (unlikely((condition)!=0)) \
+ BUG(); \
+} while(0)
+
#define PAGE_BUG(page) do { \
BUG(); \
} while (0)
diff -urN linux-2.5/include/asm-sh/bug.h pmac-2.5/include/asm-sh/bug.h
--- linux-2.5/include/asm-sh/bug.h 2002-01-06 22:54:51.000000000 +1100
+++ pmac-2.5/include/asm-sh/bug.h 2003-05-28 18:37:24.000000000 +1000
@@ -9,6 +9,11 @@
asm volatile("nop"); \
} while (0)
+#define BUG_ON(condition) do { \
+ if (unlikely((condition)!=0)) \
+ BUG(); \
+} while(0)
+
#define PAGE_BUG(page) do { \
BUG(); \
} while (0)
diff -urN linux-2.5/include/asm-sparc/bug.h pmac-2.5/include/asm-sparc/bug.h
--- linux-2.5/include/asm-sparc/bug.h 2003-05-21 08:27:25.000000000 +1000
+++ pmac-2.5/include/asm-sparc/bug.h 2003-05-28 18:37:37.000000000 +1000
@@ -12,6 +12,11 @@
#define BUG() __builtin_trap()
#endif
+#define BUG_ON(condition) do { \
+ if (unlikely((condition)!=0)) \
+ BUG(); \
+} while(0)
+
#define PAGE_BUG(page) do { \
BUG(); \
} while (0)
diff -urN linux-2.5/include/asm-sparc64/bug.h pmac-2.5/include/asm-sparc64/bug.h
--- linux-2.5/include/asm-sparc64/bug.h 2003-01-15 00:51:44.000000000 +1100
+++ pmac-2.5/include/asm-sparc64/bug.h 2003-05-28 18:37:44.000000000 +1000
@@ -13,6 +13,11 @@
#define BUG() __builtin_trap()
#endif
+#define BUG_ON(condition) do { \
+ if (unlikely((condition)!=0)) \
+ BUG(); \
+} while(0)
+
#define PAGE_BUG(page) do { \
BUG(); \
} while (0)
diff -urN linux-2.5/include/asm-um/bug.h pmac-2.5/include/asm-um/bug.h
--- linux-2.5/include/asm-um/bug.h 2003-01-17 02:42:26.000000000 +1100
+++ pmac-2.5/include/asm-um/bug.h 2003-05-28 18:37:56.000000000 +1000
@@ -7,6 +7,11 @@
panic("kernel BUG at %s:%d!\n", __FILE__, __LINE__); \
} while (0)
+#define BUG_ON(condition) do { \
+ if (unlikely((condition)!=0)) \
+ BUG(); \
+} while(0)
+
#define PAGE_BUG(page) do { \
BUG(); \
} while (0)
diff -urN linux-2.5/include/asm-v850/bug.h pmac-2.5/include/asm-v850/bug.h
--- linux-2.5/include/asm-v850/bug.h 2003-02-18 13:41:09.000000000 +1100
+++ pmac-2.5/include/asm-v850/bug.h 2003-05-28 18:38:18.000000000 +1000
@@ -18,4 +18,6 @@
#define BUG() __bug()
#define PAGE_BUG(page) __bug()
+#define BUG_ON(condition) do { if (unlikely((condition)!=0)) BUG(); } while(0)
+
#endif /* __V850_BUG_H__ */
diff -urN linux-2.5/include/asm-x86_64/bug.h pmac-2.5/include/asm-x86_64/bug.h
--- linux-2.5/include/asm-x86_64/bug.h 2003-01-17 06:36:26.000000000 +1100
+++ pmac-2.5/include/asm-x86_64/bug.h 2003-05-28 18:38:32.000000000 +1000
@@ -18,6 +18,7 @@
#define BUG() \
asm volatile("ud2 ; .quad %c1 ; .short %c0" :: \
"i"(__LINE__), "i" (__stringify(KBUILD_BASENAME)))
+#define BUG_ON(condition) do { if (unlikely((condition)!=0)) BUG(); } while(0)
#define PAGE_BUG(page) BUG()
void out_of_line_bug(void);
diff -urN linux-2.5/include/linux/kernel.h pmac-2.5/include/linux/kernel.h
--- linux-2.5/include/linux/kernel.h 2003-05-21 08:27:25.000000000 +1000
+++ pmac-2.5/include/linux/kernel.h 2003-05-28 18:32:37.000000000 +1000
@@ -228,7 +228,6 @@
char _f[20-2*sizeof(long)-sizeof(int)]; /* Padding: libc5 uses this.. */
};
-#define BUG_ON(condition) do { if (unlikely((condition)!=0)) BUG(); } while(0)
#define WARN_ON(condition) do { \
if (unlikely((condition)!=0)) { \
printk("Badness in %s at %s:%d\n", __FUNCTION__, __FILE__, __LINE__); \
On Thu, 29 May 2003, Paul Mackerras wrote:
>
> On second thoughts, it would be cleaner to move BUG_ON() into each
> architecture's bug.h alongside BUG() and PAGE_BUG(), rather than using
> an ifdef in kernel.h as my previous patch did.
Wouldn't it make sense to do the same thing to "WARN_ON()" then? It sounds
entirely appropriate to use the same kind of conditional trap instructions
for that too.. (The only difference being a bit somewhere that says that
the "WARN_ON()" kind of trap handler should resume after the fault).
Linus
Linus Torvalds writes:
> Wouldn't it make sense to do the same thing to "WARN_ON()" then? It sounds
> entirely appropriate to use the same kind of conditional trap instructions
> for that too.. (The only difference being a bit somewhere that says that
> the "WARN_ON()" kind of trap handler should resume after the fault).
Excellent idea. Here is a patch that does that.
I have included all the bits that handle the __bug_table section on
ppc so you all can see the complete implementation. The __bug_table
section has 4 words for each BUG/BUG_ON/WARN_ON, which are the address
of the trap instruction, the line number (with a high bit used to
indicate a WARN_ON as distinct from a BUG/BUG_ON), and pointers to the
filename and function name. I did it this way rather than putting the
information in line because putting it in line would mean an extra
branch and would pollute the icache unnecessarily.
At Rusty's suggestion, I added some fields to the mod_arch_specific
structure for ppc to hold a pointer to the __bug_table section for
each module, so I can use BUG et al. in modules. That gets set up in
module_finalize and added to a global list.
That meant that I needed to use find_sec(), which was static in
kernel/module.c (to find the __bug_table section), so I renamed it to
elf_find_sec() and made it externally accessible (once again at
Rusty's suggestion).
Tested OK on ppc, and compile-tested on x86 successfully.
How does this look?
Paul.
diff -urN linux-2.5/include/asm-alpha/bug.h pmac-2.5/include/asm-alpha/bug.h
--- linux-2.5/include/asm-alpha/bug.h 2002-02-25 03:51:44.000000000 +1100
+++ pmac-2.5/include/asm-alpha/bug.h 2003-05-29 19:51:06.000000000 +1000
@@ -9,6 +9,15 @@
__asm__ __volatile__("call_pal %0 # bugchk\n\t"".long %1\n\t.8byte %2" \
: : "i" (PAL_bugchk), "i"(__LINE__), "i"(__FILE__))
+#define BUG_ON(condition) do { if (unlikely((condition)!=0)) BUG(); } while(0)
+
#define PAGE_BUG(page) BUG()
+#define WARN_ON(condition) do { \
+ if (unlikely((condition)!=0)) { \
+ printk("Badness in %s at %s:%d\n", __FUNCTION__, __FILE__, __LINE__); \
+ dump_stack(); \
+ } \
+} while (0)
+
#endif
diff -urN linux-2.5/include/asm-arm/bug.h pmac-2.5/include/asm-arm/bug.h
--- linux-2.5/include/asm-arm/bug.h 2003-02-04 19:36:43.000000000 +1100
+++ pmac-2.5/include/asm-arm/bug.h 2003-05-29 19:49:38.000000000 +1000
@@ -18,4 +18,13 @@
#endif
+#define BUG_ON(condition) do { if (unlikely((condition)!=0)) BUG(); } while(0)
+
+#define WARN_ON(condition) do { \
+ if (unlikely((condition)!=0)) { \
+ printk("Badness in %s at %s:%d\n", __FUNCTION__, __FILE__, __LINE__); \
+ dump_stack(); \
+ } \
+} while (0)
+
#endif
diff -urN linux-2.5/include/asm-cris/bug.h pmac-2.5/include/asm-cris/bug.h
--- linux-2.5/include/asm-cris/bug.h 2002-01-06 22:46:09.000000000 +1100
+++ pmac-2.5/include/asm-cris/bug.h 2003-05-29 19:49:48.000000000 +1000
@@ -9,4 +9,13 @@
BUG(); \
} while (0)
+#define BUG_ON(condition) do { if (unlikely((condition)!=0)) BUG(); } while(0)
+
+#define WARN_ON(condition) do { \
+ if (unlikely((condition)!=0)) { \
+ printk("Badness in %s at %s:%d\n", __FUNCTION__, __FILE__, __LINE__); \
+ dump_stack(); \
+ } \
+} while (0)
+
#endif
diff -urN linux-2.5/include/asm-h8300/bug.h pmac-2.5/include/asm-h8300/bug.h
--- linux-2.5/include/asm-h8300/bug.h 2003-04-18 05:31:21.000000000 +1000
+++ pmac-2.5/include/asm-h8300/bug.h 2003-05-29 19:50:01.000000000 +1000
@@ -9,4 +9,13 @@
BUG(); \
} while (0)
+#define BUG_ON(condition) do { if (unlikely((condition)!=0)) BUG(); } while(0)
+
+#define WARN_ON(condition) do { \
+ if (unlikely((condition)!=0)) { \
+ printk("Badness in %s at %s:%d\n", __FUNCTION__, __FILE__, __LINE__); \
+ dump_stack(); \
+ } \
+} while (0)
+
#endif
diff -urN linux-2.5/include/asm-i386/bug.h pmac-2.5/include/asm-i386/bug.h
--- linux-2.5/include/asm-i386/bug.h 2003-03-08 14:12:53.000000000 +1100
+++ pmac-2.5/include/asm-i386/bug.h 2003-05-29 19:51:35.000000000 +1000
@@ -19,8 +19,17 @@
#define BUG() __asm__ __volatile__("ud2\n")
#endif
+#define BUG_ON(condition) do { if (unlikely((condition)!=0)) BUG(); } while(0)
+
#define PAGE_BUG(page) do { \
BUG(); \
} while (0)
+#define WARN_ON(condition) do { \
+ if (unlikely((condition)!=0)) { \
+ printk("Badness in %s at %s:%d\n", __FUNCTION__, __FILE__, __LINE__); \
+ dump_stack(); \
+ } \
+} while (0)
+
#endif
diff -urN linux-2.5/include/asm-ia64/bug.h pmac-2.5/include/asm-ia64/bug.h
--- linux-2.5/include/asm-ia64/bug.h 2002-01-06 22:57:28.000000000 +1100
+++ pmac-2.5/include/asm-ia64/bug.h 2003-05-29 19:51:50.000000000 +1000
@@ -7,6 +7,16 @@
# define ia64_abort() (*(volatile int *) 0 = 0)
#endif
#define BUG() do { printk("kernel BUG at %s:%d!\n", __FILE__, __LINE__); ia64_abort(); } while (0)
+
+#define BUG_ON(condition) do { if (unlikely((condition)!=0)) BUG(); } while(0)
+
#define PAGE_BUG(page) do { BUG(); } while (0)
+#define WARN_ON(condition) do { \
+ if (unlikely((condition)!=0)) { \
+ printk("Badness in %s at %s:%d\n", __FUNCTION__, __FILE__, __LINE__); \
+ dump_stack(); \
+ } \
+} while (0)
+
#endif
diff -urN linux-2.5/include/asm-m68k/bug.h pmac-2.5/include/asm-m68k/bug.h
--- linux-2.5/include/asm-m68k/bug.h 2002-07-26 06:17:16.000000000 +1000
+++ pmac-2.5/include/asm-m68k/bug.h 2003-05-29 19:50:57.000000000 +1000
@@ -21,8 +21,20 @@
} while (0)
#endif
+#define BUG_ON(condition) do { \
+ if (unlikely((condition)!=0)) \
+ BUG(); \
+} while(0)
+
#define PAGE_BUG(page) do { \
BUG(); \
} while (0)
+#define WARN_ON(condition) do { \
+ if (unlikely((condition)!=0)) { \
+ printk("Badness in %s at %s:%d\n", __FUNCTION__, __FILE__, __LINE__); \
+ dump_stack(); \
+ } \
+} while (0)
+
#endif
diff -urN linux-2.5/include/asm-m68knommu/bug.h pmac-2.5/include/asm-m68knommu/bug.h
--- linux-2.5/include/asm-m68knommu/bug.h 2003-01-15 22:04:34.000000000 +1100
+++ pmac-2.5/include/asm-m68knommu/bug.h 2003-05-29 19:52:13.000000000 +1000
@@ -5,8 +5,20 @@
printk("%s(%d): kernel BUG!\n", __FILE__, __LINE__); \
} while (0)
+#define BUG_ON(condition) do { \
+ if (unlikely((condition)!=0)) \
+ BUG(); \
+} while(0)
+
#define PAGE_BUG(page) do { \
BUG(); \
} while (0)
+#define WARN_ON(condition) do { \
+ if (unlikely((condition)!=0)) { \
+ printk("Badness in %s at %s:%d\n", __FUNCTION__, __FILE__, __LINE__); \
+ dump_stack(); \
+ } \
+} while (0)
+
#endif
diff -urN linux-2.5/include/asm-mips/bug.h pmac-2.5/include/asm-mips/bug.h
--- linux-2.5/include/asm-mips/bug.h 2002-01-06 22:57:49.000000000 +1100
+++ pmac-2.5/include/asm-mips/bug.h 2003-05-29 19:52:26.000000000 +1000
@@ -3,6 +3,14 @@
#define __ASM_BUG_H
#define BUG() do { printk("kernel BUG at %s:%d!\n", __FILE__, __LINE__); *(int *)0=0; } while (0)
+#define BUG_ON(condition) do { if (unlikely((condition)!=0)) BUG(); } while(0)
#define PAGE_BUG(page) do { BUG(); } while (0)
+#define WARN_ON(condition) do { \
+ if (unlikely((condition)!=0)) { \
+ printk("Badness in %s at %s:%d\n", __FUNCTION__, __FILE__, __LINE__); \
+ dump_stack(); \
+ } \
+} while (0)
+
#endif
diff -urN linux-2.5/include/asm-mips64/bug.h pmac-2.5/include/asm-mips64/bug.h
--- linux-2.5/include/asm-mips64/bug.h 2002-01-06 22:51:12.000000000 +1100
+++ pmac-2.5/include/asm-mips64/bug.h 2003-05-29 19:52:32.000000000 +1000
@@ -2,6 +2,14 @@
#define _ASM_BUG_H
#define BUG() do { printk("kernel BUG at %s:%d!\n", __FILE__, __LINE__); *(int *)0=0; } while (0)
+#define BUG_ON(condition) do { if (unlikely((condition)!=0)) BUG(); } while(0)
#define PAGE_BUG(page) do { BUG(); } while (0)
+#define WARN_ON(condition) do { \
+ if (unlikely((condition)!=0)) { \
+ printk("Badness in %s at %s:%d\n", __FUNCTION__, __FILE__, __LINE__); \
+ dump_stack(); \
+ } \
+} while (0)
+
#endif
diff -urN linux-2.5/include/asm-parisc/bug.h pmac-2.5/include/asm-parisc/bug.h
--- linux-2.5/include/asm-parisc/bug.h 2003-03-20 09:07:22.000000000 +1100
+++ pmac-2.5/include/asm-parisc/bug.h 2003-05-29 19:52:43.000000000 +1000
@@ -10,8 +10,20 @@
dump_stack(); \
} while (0)
+#define BUG_ON(condition) do { \
+ if (unlikely((condition)!=0)) \
+ BUG(); \
+} while(0)
+
#define PAGE_BUG(page) do { \
BUG(); \
} while (0)
+#define WARN_ON(condition) do { \
+ if (unlikely((condition)!=0)) { \
+ printk("Badness in %s at %s:%d\n", __FUNCTION__, __FILE__, __LINE__); \
+ dump_stack(); \
+ } \
+} while (0)
+
#endif
diff -urN linux-2.5/include/asm-ppc/bug.h pmac-2.5/include/asm-ppc/bug.h
--- linux-2.5/include/asm-ppc/bug.h 2003-05-29 13:45:33.000000000 +1000
+++ pmac-2.5/include/asm-ppc/bug.h 2003-05-29 21:23:54.000000000 +1000
@@ -1,11 +1,48 @@
#ifndef _PPC_BUG_H
#define _PPC_BUG_H
-#define BUG() do { \
- printk("kernel BUG at %s:%d!\n", __FILE__, __LINE__); \
- __asm__ __volatile__(".long 0x0"); \
+struct bug_entry {
+ unsigned long bug_addr;
+ int line;
+ const char *file;
+ const char *function;
+};
+
+/*
+ * If this bit is set in the line number it means that the trap
+ * is for WARN_ON rather than BUG or BUG_ON.
+ */
+#define BUG_WARNING_TRAP 0x1000000
+
+#define BUG() do { \
+ __asm__ __volatile__( \
+ "1: twi 31,0,0\n" \
+ ".section __bug_table,\"a\"\n\t" \
+ " .long 1b,%0,%1,%2\n" \
+ ".previous" \
+ : : "i" (__LINE__), "i" (__FILE__), "i" (__FUNCTION__)); \
+} while (0)
+
+#define BUG_ON(x) do { \
+ __asm__ __volatile__( \
+ "1: twnei %0,0\n" \
+ ".section __bug_table,\"a\"\n\t" \
+ " .long 1b,%1,%2,%3\n" \
+ ".previous" \
+ : : "r" (x), "i" (__LINE__), "i" (__FILE__), \
+ "i" (__FUNCTION__)); \
} while (0)
#define PAGE_BUG(page) do { BUG(); } while (0)
+#define WARN_ON(x) do { \
+ __asm__ __volatile__( \
+ "1: twnei %0,0\n" \
+ ".section __bug_table,\"a\"\n\t" \
+ " .long 1b,%1,%2,%3\n" \
+ ".previous" \
+ : : "r" (x), "i" (__LINE__ + BUG_WARNING_TRAP), \
+ "i" (__FILE__), "i" (__FUNCTION__)); \
+} while (0)
+
#endif
diff -urN linux-2.5/include/asm-ppc/module.h pmac-2.5/include/asm-ppc/module.h
--- linux-2.5/include/asm-ppc/module.h 2003-01-03 07:26:42.000000000 +1100
+++ pmac-2.5/include/asm-ppc/module.h 2003-05-27 12:15:39.000000000 +1000
@@ -2,6 +2,9 @@
#define _ASM_PPC_MODULE_H
/* Module stuff for PPC. (C) 2001 Rusty Russell */
+#include <linux/list.h>
+#include <asm/bug.h>
+
/* Thanks to Paul M for explaining this.
PPC can only do rel jumps += 32MB, and often the kernel and other
@@ -20,8 +23,15 @@
{
/* Indices of PLT sections within module. */
unsigned int core_plt_section, init_plt_section;
+
+ /* List of BUG addresses, source line numbers and filenames */
+ struct list_head bug_list;
+ struct bug_entry *bug_table;
+ unsigned int num_bugs;
};
+extern struct bug_entry *module_find_bug(unsigned long bugaddr);
+
#define Elf_Shdr Elf32_Shdr
#define Elf_Sym Elf32_Sym
#define Elf_Ehdr Elf32_Ehdr
diff -urN linux-2.5/include/asm-ppc64/bug.h pmac-2.5/include/asm-ppc64/bug.h
--- linux-2.5/include/asm-ppc64/bug.h 2003-01-15 20:38:42.000000000 +1100
+++ pmac-2.5/include/asm-ppc64/bug.h 2003-05-29 19:55:29.000000000 +1000
@@ -27,7 +27,16 @@
} while (0)
#endif
+#define BUG_ON(condition) do { if (unlikely((condition)!=0)) BUG(); } while(0)
+
#define PAGE_BUG(page) do { BUG(); } while (0)
+#define WARN_ON(condition) do { \
+ if (unlikely((condition)!=0)) { \
+ printk("Badness in %s at %s:%d\n", __FUNCTION__, __FILE__, __LINE__); \
+ dump_stack(); \
+ } \
+} while (0)
+
#endif
#endif
diff -urN linux-2.5/include/asm-s390/bug.h pmac-2.5/include/asm-s390/bug.h
--- linux-2.5/include/asm-s390/bug.h 2002-01-06 22:53:36.000000000 +1100
+++ pmac-2.5/include/asm-s390/bug.h 2003-05-29 19:55:38.000000000 +1000
@@ -6,8 +6,20 @@
__asm__ __volatile__(".long 0"); \
} while (0)
+#define BUG_ON(condition) do { \
+ if (unlikely((condition)!=0)) \
+ BUG(); \
+} while(0)
+
#define PAGE_BUG(page) do { \
BUG(); \
} while (0)
+#define WARN_ON(condition) do { \
+ if (unlikely((condition)!=0)) { \
+ printk("Badness in %s at %s:%d\n", __FUNCTION__, __FILE__, __LINE__); \
+ dump_stack(); \
+ } \
+} while (0)
+
#endif
diff -urN linux-2.5/include/asm-sh/bug.h pmac-2.5/include/asm-sh/bug.h
--- linux-2.5/include/asm-sh/bug.h 2002-01-06 22:54:51.000000000 +1100
+++ pmac-2.5/include/asm-sh/bug.h 2003-05-29 21:25:48.000000000 +1000
@@ -9,8 +9,20 @@
asm volatile("nop"); \
} while (0)
+#define BUG_ON(condition) do { \
+ if (unlikely((condition)!=0)) \
+ BUG(); \
+} while(0)
+
#define PAGE_BUG(page) do { \
BUG(); \
} while (0)
+#define WARN_ON(condition) do { \
+ if (unlikely((condition)!=0)) { \
+ printk("Badness in %s at %s:%d\n", __FUNCTION__, __FILE__, __LINE__); \
+ dump_stack(); \
+ } \
+} while (0)
+
#endif
diff -urN linux-2.5/include/asm-sparc/bug.h pmac-2.5/include/asm-sparc/bug.h
--- linux-2.5/include/asm-sparc/bug.h 2003-05-23 07:41:16.000000000 +1000
+++ pmac-2.5/include/asm-sparc/bug.h 2003-05-29 19:55:49.000000000 +1000
@@ -12,8 +12,20 @@
#define BUG() __builtin_trap()
#endif
+#define BUG_ON(condition) do { \
+ if (unlikely((condition)!=0)) \
+ BUG(); \
+} while(0)
+
#define PAGE_BUG(page) do { \
BUG(); \
} while (0)
+#define WARN_ON(condition) do { \
+ if (unlikely((condition)!=0)) { \
+ printk("Badness in %s at %s:%d\n", __FUNCTION__, __FILE__, __LINE__); \
+ dump_stack(); \
+ } \
+} while (0)
+
#endif
diff -urN linux-2.5/include/asm-sparc64/bug.h pmac-2.5/include/asm-sparc64/bug.h
--- linux-2.5/include/asm-sparc64/bug.h 2003-01-16 07:58:55.000000000 +1100
+++ pmac-2.5/include/asm-sparc64/bug.h 2003-05-29 19:55:55.000000000 +1000
@@ -13,8 +13,20 @@
#define BUG() __builtin_trap()
#endif
+#define BUG_ON(condition) do { \
+ if (unlikely((condition)!=0)) \
+ BUG(); \
+} while(0)
+
#define PAGE_BUG(page) do { \
BUG(); \
} while (0)
+#define WARN_ON(condition) do { \
+ if (unlikely((condition)!=0)) { \
+ printk("Badness in %s at %s:%d\n", __FUNCTION__, __FILE__, __LINE__); \
+ dump_stack(); \
+ } \
+} while (0)
+
#endif
diff -urN linux-2.5/include/asm-um/bug.h pmac-2.5/include/asm-um/bug.h
--- linux-2.5/include/asm-um/bug.h 2003-01-17 02:42:26.000000000 +1100
+++ pmac-2.5/include/asm-um/bug.h 2003-05-29 19:56:08.000000000 +1000
@@ -7,10 +7,22 @@
panic("kernel BUG at %s:%d!\n", __FILE__, __LINE__); \
} while (0)
+#define BUG_ON(condition) do { \
+ if (unlikely((condition)!=0)) \
+ BUG(); \
+} while(0)
+
#define PAGE_BUG(page) do { \
BUG(); \
} while (0)
+#define WARN_ON(condition) do { \
+ if (unlikely((condition)!=0)) { \
+ printk("Badness in %s at %s:%d\n", __FUNCTION__, __FILE__, __LINE__); \
+ dump_stack(); \
+ } \
+} while (0)
+
extern int foo;
#endif
diff -urN linux-2.5/include/asm-v850/bug.h pmac-2.5/include/asm-v850/bug.h
--- linux-2.5/include/asm-v850/bug.h 2003-02-18 13:41:09.000000000 +1100
+++ pmac-2.5/include/asm-v850/bug.h 2003-05-29 19:56:18.000000000 +1000
@@ -18,4 +18,13 @@
#define BUG() __bug()
#define PAGE_BUG(page) __bug()
+#define BUG_ON(condition) do { if (unlikely((condition)!=0)) BUG(); } while(0)
+
+#define WARN_ON(condition) do { \
+ if (unlikely((condition)!=0)) { \
+ printk("Badness in %s at %s:%d\n", __FUNCTION__, __FILE__, __LINE__); \
+ dump_stack(); \
+ } \
+} while (0)
+
#endif /* __V850_BUG_H__ */
diff -urN linux-2.5/include/asm-x86_64/bug.h pmac-2.5/include/asm-x86_64/bug.h
--- linux-2.5/include/asm-x86_64/bug.h 2003-01-17 06:36:26.000000000 +1100
+++ pmac-2.5/include/asm-x86_64/bug.h 2003-05-29 19:56:32.000000000 +1000
@@ -18,7 +18,15 @@
#define BUG() \
asm volatile("ud2 ; .quad %c1 ; .short %c0" :: \
"i"(__LINE__), "i" (__stringify(KBUILD_BASENAME)))
+#define BUG_ON(condition) do { if (unlikely((condition)!=0)) BUG(); } while(0)
#define PAGE_BUG(page) BUG()
void out_of_line_bug(void);
+#define WARN_ON(condition) do { \
+ if (unlikely((condition)!=0)) { \
+ printk("Badness in %s at %s:%d\n", __FUNCTION__, __FILE__, __LINE__); \
+ dump_stack(); \
+ } \
+} while (0)
+
#endif
diff -urN linux-2.5/include/linux/kernel.h pmac-2.5/include/linux/kernel.h
--- linux-2.5/include/linux/kernel.h 2003-05-23 07:41:16.000000000 +1000
+++ pmac-2.5/include/linux/kernel.h 2003-05-29 19:48:39.000000000 +1000
@@ -228,14 +228,6 @@
char _f[20-2*sizeof(long)-sizeof(int)]; /* Padding: libc5 uses this.. */
};
-#define BUG_ON(condition) do { if (unlikely((condition)!=0)) BUG(); } while(0)
-#define WARN_ON(condition) do { \
- if (unlikely((condition)!=0)) { \
- printk("Badness in %s at %s:%d\n", __FUNCTION__, __FILE__, __LINE__); \
- dump_stack(); \
- } \
-} while (0)
-
extern void BUILD_BUG(void);
#define BUILD_BUG_ON(condition) do { if (condition) BUILD_BUG(); } while(0)
diff -urN linux-2.5/include/linux/moduleloader.h pmac-2.5/include/linux/moduleloader.h
--- linux-2.5/include/linux/moduleloader.h 2003-05-14 08:22:46.000000000 +1000
+++ pmac-2.5/include/linux/moduleloader.h 2003-05-27 14:32:42.000000000 +1000
@@ -44,4 +44,10 @@
/* Any cleanup needed when module leaves. */
void module_arch_cleanup(struct module *mod);
+/* Find a module section: 0 means not found. */
+unsigned int elf_find_sec(const Elf_Ehdr *hdr,
+ const Elf_Shdr *sechdrs,
+ const char *secstrings,
+ const char *name);
+
#endif
diff -urN linux-2.5/kernel/module.c pmac-2.5/kernel/module.c
--- linux-2.5/kernel/module.c 2003-05-14 08:22:46.000000000 +1000
+++ pmac-2.5/kernel/module.c 2003-05-27 14:32:37.000000000 +1000
@@ -99,10 +99,10 @@
EXPORT_SYMBOL(init_module);
/* Find a module section: 0 means not found. */
-static unsigned int find_sec(Elf_Ehdr *hdr,
- Elf_Shdr *sechdrs,
- const char *secstrings,
- const char *name)
+unsigned int elf_find_sec(const Elf_Ehdr *hdr,
+ const Elf_Shdr *sechdrs,
+ const char *secstrings,
+ const char *name)
{
unsigned int i;
@@ -1175,7 +1175,7 @@
#endif
}
- modindex = find_sec(hdr, sechdrs, secstrings,
+ modindex = elf_find_sec(hdr, sechdrs, secstrings,
".gnu.linkonce.this_module");
if (!modindex) {
printk(KERN_WARNING "No module found in object\n");
@@ -1185,15 +1185,15 @@
mod = (void *)sechdrs[modindex].sh_addr;
/* Optional sections */
- exportindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab");
- gplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl");
- crcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab");
- gplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl");
- setupindex = find_sec(hdr, sechdrs, secstrings, "__param");
- exindex = find_sec(hdr, sechdrs, secstrings, "__ex_table");
- obsparmindex = find_sec(hdr, sechdrs, secstrings, "__obsparm");
- versindex = find_sec(hdr, sechdrs, secstrings, "__versions");
- infoindex = find_sec(hdr, sechdrs, secstrings, ".modinfo");
+ exportindex = elf_find_sec(hdr, sechdrs, secstrings, "__ksymtab");
+ gplindex = elf_find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl");
+ crcindex = elf_find_sec(hdr, sechdrs, secstrings, "__kcrctab");
+ gplcrcindex = elf_find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl");
+ setupindex = elf_find_sec(hdr, sechdrs, secstrings, "__param");
+ exindex = elf_find_sec(hdr, sechdrs, secstrings, "__ex_table");
+ obsparmindex = elf_find_sec(hdr, sechdrs, secstrings, "__obsparm");
+ versindex = elf_find_sec(hdr, sechdrs, secstrings, "__versions");
+ infoindex = elf_find_sec(hdr, sechdrs, secstrings, ".modinfo");
/* Don't keep modinfo section */
sechdrs[infoindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
diff -urN linux-2.5/arch/ppc/boot/ld.script pmac-2.5/arch/ppc/boot/ld.script
--- linux-2.5/arch/ppc/boot/ld.script 2003-05-29 13:45:33.000000000 +1000
+++ pmac-2.5/arch/ppc/boot/ld.script 2003-05-29 21:06:53.000000000 +1000
@@ -81,6 +81,7 @@
/DISCARD/ : {
*(__ksymtab)
*(__ksymtab_strings)
+ *(__bug_table)
}
}
diff -urN linux-2.5/arch/ppc/kernel/module.c pmac-2.5/arch/ppc/kernel/module.c
--- linux-2.5/arch/ppc/kernel/module.c 2003-05-14 08:22:45.000000000 +1000
+++ pmac-2.5/arch/ppc/kernel/module.c 2003-05-27 14:33:42.000000000 +1000
@@ -16,6 +16,7 @@
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/module.h>
+#include <linux/moduleloader.h>
#include <linux/elf.h>
#include <linux/vmalloc.h>
#include <linux/fs.h>
@@ -29,6 +30,8 @@
#define DEBUGP(fmt , ...)
#endif
+LIST_HEAD(module_bug_list);
+
void *module_alloc(unsigned long size)
{
if (size == 0)
@@ -267,9 +270,47 @@
const Elf_Shdr *sechdrs,
struct module *me)
{
+ char *secstrings;
+ unsigned int bugindex;
+
+ /* Find the __bug_table section, if present */
+ secstrings = (char *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
+ bugindex = elf_find_sec(hdr, sechdrs, secstrings, "__bug_table");
+
+ /*
+ * If there is no __bug_table, find_sec returns 0, and
+ * section 0 is conveniently always a 0-length section,
+ * according to Rusty.
+ */
+ me->arch.bug_table = (void *) sechdrs[bugindex].sh_addr;
+ me->arch.num_bugs = sechdrs[bugindex].sh_size / sizeof(struct bug_entry);
+
+ /*
+ * Strictly speaking this should have a spinlock to protect against
+ * traversals, but since we only traverse on BUG()s, a spinlock
+ * could potentially lead to deadlock and thus be counter-productive.
+ */
+ list_add(&me->arch.bug_list, &module_bug_list);
+
return 0;
}
void module_arch_cleanup(struct module *mod)
{
+ list_del(&mod->arch.bug_list);
+}
+
+struct bug_entry *module_find_bug(unsigned long bugaddr)
+{
+ struct mod_arch_specific *mod;
+ unsigned int i;
+ struct bug_entry *bug;
+
+ list_for_each_entry(mod, &module_bug_list, bug_list) {
+ bug = mod->bug_table;
+ for (i = 0; i < mod->num_bugs; ++i, ++bug)
+ if (bugaddr == bug->bug_addr)
+ return bug;
+ }
+ return NULL;
}
diff -urN linux-2.5/arch/ppc/kernel/traps.c pmac-2.5/arch/ppc/kernel/traps.c
--- linux-2.5/arch/ppc/kernel/traps.c 2003-05-29 13:45:33.000000000 +1000
+++ pmac-2.5/arch/ppc/kernel/traps.c 2003-05-29 21:21:35.000000000 +1000
@@ -296,6 +296,57 @@
return(retval);
}
+/*
+ * Look through the list of trap instructions that are used for BUG(),
+ * BUG_ON() and WARN_ON() and see if we hit one. At this point we know
+ * that the exception was caused by a trap instruction of some kind.
+ * Returns 1 if we should continue (i.e. it was a WARN_ON) or 0
+ * otherwise.
+ */
+extern struct bug_entry __start___bug_table[], __stop___bug_table[];
+
+#ifndef CONFIG_MODULES
+#define module_find_bug(x) NULL
+#endif
+
+static struct bug_entry *find_bug(unsigned long bugaddr)
+{
+ struct bug_entry *bug;
+
+ for (bug = __start___bug_table; bug < __stop___bug_table; ++bug)
+ if (bugaddr == bug->bug_addr)
+ return bug;
+ return module_find_bug(bugaddr);
+}
+
+int
+check_bug_trap(struct pt_regs *regs)
+{
+ struct bug_entry *bug;
+ unsigned long addr;
+ int line;
+
+ if (regs->msr & MSR_PR)
+ return 0; /* not in kernel */
+ addr = regs->nip; /* address of trap instruction */
+ if (addr < PAGE_OFFSET)
+ return 0;
+ bug = find_bug(regs->nip);
+ if (bug == NULL)
+ return 0;
+ if (bug->line & BUG_WARNING_TRAP) {
+ /* this is a WARN_ON rather than BUG/BUG_ON */
+ printk(KERN_ERR "Badness in %s at %s:%d\n",
+ bug->function, bug->file,
+ bug->line & ~BUG_WARNING_TRAP);
+ dump_stack();
+ return 1;
+ }
+ printk(KERN_CRIT "kernel BUG in %s at %s:%d!\n",
+ bug->function, bug->file, bug->line);
+ return 0;
+}
+
void
ProgramCheckException(struct pt_regs *regs)
{
@@ -325,6 +376,10 @@
/* trap exception */
if (debugger_bpt(regs))
return;
+ if (check_bug_trap(regs)) {
+ regs->nip += 4;
+ return;
+ }
_exception(SIGTRAP, regs);
return;
}
diff -urN linux-2.5/arch/ppc/vmlinux.lds.S pmac-2.5/arch/ppc/vmlinux.lds.S
--- linux-2.5/arch/ppc/vmlinux.lds.S 2003-04-14 09:28:41.000000000 +1000
+++ pmac-2.5/arch/ppc/vmlinux.lds.S 2003-05-26 21:58:49.000000000 +1000
@@ -54,6 +54,10 @@
__ex_table : { *(__ex_table) }
__stop___ex_table = .;
+ __start___bug_table = .;
+ __bug_table : { *(__bug_table) }
+ __stop___bug_table = .;
+
/* Read-write section, merged into data segment: */
. = ALIGN(4096);
.data :
In message <[email protected]> you write:
> That meant that I needed to use find_sec(), which was static in
> kernel/module.c (to find the __bug_table section), so I renamed it to
> elf_find_sec() and made it externally accessible (once again at
> Rusty's suggestion).
>
> Tested OK on ppc, and compile-tested on x86 successfully.
>
> How does this look?
Looks fine to me. If every arch goes this way in 2.7 (say) we can
fold it back into kernel/module.c like we do for exception tables.
Cheers,
Rusty.
--
Anyone who quotes me in their sig is an idiot. -- Rusty Russell.