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| author | Jan Beulich <jbeulich@novell.com> | 2008-12-16 11:40:27 +0000 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-12-16 18:40:32 +0100 |
| commit | b93a531e315e97ef00367099e6b5f19651936e20 (patch) | |
| tree | 231e6d626fbf85dd80d7cbac49a9c9a14282f898 /lib | |
| parent | 85072bd55219231b8ca5d9d3fa3492eb4fa6635f (diff) | |
| download | lwn-b93a531e315e97ef00367099e6b5f19651936e20.tar.gz lwn-b93a531e315e97ef00367099e6b5f19651936e20.zip | |
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>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/bug.c | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/lib/bug.c b/lib/bug.c index bfeafd60ee9f..300e41afbf97 100644 --- a/lib/bug.c +++ b/lib/bug.c @@ -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; |