Revision a01cc6570326c01e70619bf6540fb32139947c33 authored by David Brownell on 04 July 2008, 16:59:26 UTC, committed by Linus Torvalds on 04 July 2008, 17:40:04 UTC
While 0e36a9a4a788e4e92407774df76c545910810d35 ("rtc: fix readback from /sys/class/rtc/rtc?/wakealarm") made sure that active alarms were never returned with invalid "wildcard" fields (negative), it can still report (wrongly) that the alarm triggers in the past. Example, if it's now 10am, an alarm firing at 5am will be triggered TOMORROW not today. (Which may also be next month or next year...) This updates that alarm handling in three ways: * Handle alarm rollover in the common cases of RTCs that don't support matching on all date fields. * Skip the invalid-field logic when it's not needed. * Minor bugfix ... tm_isdst should be ignored, it's one of the fields Linux doesn't maintain. A warning is emitted for some of the unhandled rollover cases, but the possible combinations are a bit too numerous to handle every bit of potential hardware and firmware braindamage. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: Mark Lord <lkml@rtr.ca> Acked-by: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 251b97f
bug.c
/*
Generic support for BUG()
This respects the following config options:
CONFIG_BUG - emit BUG traps. Nothing happens without this.
CONFIG_GENERIC_BUG - enable this code.
CONFIG_DEBUG_BUGVERBOSE - emit full file+line information for each BUG
CONFIG_BUG and CONFIG_DEBUG_BUGVERBOSE are potentially user-settable
(though they're generally always on).
CONFIG_GENERIC_BUG is set by each architecture using this code.
To use this, your architecture must:
1. Set up the config options:
- Enable CONFIG_GENERIC_BUG if CONFIG_BUG
2. Implement BUG (and optionally BUG_ON, WARN, WARN_ON)
- Define HAVE_ARCH_BUG
- Implement BUG() to generate a faulting instruction
- NOTE: struct bug_entry does not have "file" or "line" entries
when CONFIG_DEBUG_BUGVERBOSE is not enabled, so you must generate
the values accordingly.
3. Implement the trap
- In the illegal instruction trap handler (typically), verify
that the fault was in kernel mode, and call report_bug()
- report_bug() will return whether it was a false alarm, a warning,
or an actual bug.
- You must implement the is_valid_bugaddr(bugaddr) callback which
returns true if the eip is a real kernel address, and it points
to the expected BUG trap instruction.
Jeremy Fitzhardinge <jeremy@goop.org> 2006
*/
#include <linux/list.h>
#include <linux/module.h>
#include <linux/bug.h>
#include <linux/sched.h>
extern const struct bug_entry __start___bug_table[], __stop___bug_table[];
#ifdef CONFIG_MODULES
static LIST_HEAD(module_bug_list);
static const struct bug_entry *module_find_bug(unsigned long bugaddr)
{
struct module *mod;
list_for_each_entry(mod, &module_bug_list, bug_list) {
const struct bug_entry *bug = mod->bug_table;
unsigned i;
for (i = 0; i < mod->num_bugs; ++i, ++bug)
if (bugaddr == bug->bug_addr)
return bug;
}
return NULL;
}
int module_bug_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs,
struct module *mod)
{
char *secstrings;
unsigned int i;
mod->bug_table = NULL;
mod->num_bugs = 0;
/* Find the __bug_table section, if present */
secstrings = (char *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
for (i = 1; i < hdr->e_shnum; i++) {
if (strcmp(secstrings+sechdrs[i].sh_name, "__bug_table"))
continue;
mod->bug_table = (void *) sechdrs[i].sh_addr;
mod->num_bugs = sechdrs[i].sh_size / sizeof(struct bug_entry);
break;
}
/*
* 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(&mod->bug_list, &module_bug_list);
return 0;
}
void module_bug_cleanup(struct module *mod)
{
list_del(&mod->bug_list);
}
#else
static inline const struct bug_entry *module_find_bug(unsigned long bugaddr)
{
return NULL;
}
#endif
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)
return bug;
return module_find_bug(bugaddr);
}
enum bug_trap_type report_bug(unsigned long bugaddr, struct pt_regs *regs)
{
const struct bug_entry *bug;
const char *file;
unsigned line, warning;
if (!is_valid_bugaddr(bugaddr))
return BUG_TRAP_TYPE_NONE;
bug = find_bug(bugaddr);
printk(KERN_EMERG "------------[ cut here ]------------\n");
file = NULL;
line = 0;
warning = 0;
if (bug) {
#ifdef CONFIG_DEBUG_BUGVERBOSE
file = bug->file;
line = bug->line;
#endif
warning = (bug->flags & BUGFLAG_WARNING) != 0;
}
if (warning) {
/* this is a WARN_ON rather than BUG/BUG_ON */
if (file)
printk(KERN_ERR "Badness at %s:%u\n",
file, line);
else
printk(KERN_ERR "Badness at %p "
"[verbose debug info unavailable]\n",
(void *)bugaddr);
show_regs(regs);
return BUG_TRAP_TYPE_WARN;
}
if (file)
printk(KERN_CRIT "kernel BUG at %s:%u!\n",
file, line);
else
printk(KERN_CRIT "Kernel BUG at %p "
"[verbose debug info unavailable]\n",
(void *)bugaddr);
return BUG_TRAP_TYPE_BUG;
}
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