allow bug table entries to use relative pointers (and use it on x86-64)

Impact: reduce bug table size

This allows reducing the bug table size by half. Perhaps there are
other 64-bit architectures that could also make use of this.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Jan Beulich 2008-12-16 11:40:27 +00:00 committed by Ingo Molnar
parent 85072bd552
commit b93a531e31
4 changed files with 30 additions and 3 deletions

View file

@ -87,6 +87,10 @@ config GENERIC_IOMAP
config GENERIC_BUG
def_bool y
depends on BUG
select GENERIC_BUG_RELATIVE_POINTERS if X86_64
config GENERIC_BUG_RELATIVE_POINTERS
bool
config GENERIC_HWEIGHT
def_bool y

View file

@ -9,7 +9,7 @@
#ifdef CONFIG_X86_32
# define __BUG_C0 "2:\t.long 1b, %c0\n"
#else
# define __BUG_C0 "2:\t.quad 1b, %c0\n"
# define __BUG_C0 "2:\t.long 1b - 2b, %c0 - 2b\n"
#endif
#define BUG() \

View file

@ -8,9 +8,17 @@
#ifdef CONFIG_GENERIC_BUG
#ifndef __ASSEMBLY__
struct bug_entry {
#ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
unsigned long bug_addr;
#else
signed int bug_addr_disp;
#endif
#ifdef CONFIG_DEBUG_BUGVERBOSE
#ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
const char *file;
#else
signed int file_disp;
#endif
unsigned short line;
#endif
unsigned short flags;

View file

@ -5,6 +5,8 @@
CONFIG_BUG - emit BUG traps. Nothing happens without this.
CONFIG_GENERIC_BUG - enable this code.
CONFIG_GENERIC_BUG_RELATIVE_POINTERS - use 32-bit pointers relative to
the containing struct bug_entry for bug_addr and file.
CONFIG_DEBUG_BUGVERBOSE - emit full file+line information for each BUG
CONFIG_BUG and CONFIG_DEBUG_BUGVERBOSE are potentially user-settable
@ -43,6 +45,15 @@
extern const struct bug_entry __start___bug_table[], __stop___bug_table[];
static inline unsigned long bug_addr(const struct bug_entry *bug)
{
#ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
return bug->bug_addr;
#else
return (unsigned long)bug + bug->bug_addr_disp;
#endif
}
#ifdef CONFIG_MODULES
static LIST_HEAD(module_bug_list);
@ -55,7 +66,7 @@ static const struct bug_entry *module_find_bug(unsigned long bugaddr)
unsigned i;
for (i = 0; i < mod->num_bugs; ++i, ++bug)
if (bugaddr == bug->bug_addr)
if (bugaddr == bug_addr(bug))
return bug;
}
return NULL;
@ -108,7 +119,7 @@ const struct bug_entry *find_bug(unsigned long bugaddr)
const struct bug_entry *bug;
for (bug = __start___bug_table; bug < __stop___bug_table; ++bug)
if (bugaddr == bug->bug_addr)
if (bugaddr == bug_addr(bug))
return bug;
return module_find_bug(bugaddr);
@ -133,7 +144,11 @@ enum bug_trap_type report_bug(unsigned long bugaddr, struct pt_regs *regs)
if (bug) {
#ifdef CONFIG_DEBUG_BUGVERBOSE
#ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
file = bug->file;
#else
file = (const char *)bug + bug->file_disp;
#endif
line = bug->line;
#endif
warning = (bug->flags & BUGFLAG_WARNING) != 0;