Permalink
Browse files

taint: add explicit flag to show whether lock dep is still OK.

Fix up all callers as they were before, with make one change: an
unsigned module taints the kernel, but doesn't turn off lockdep.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
  • Loading branch information...
1 parent 64748a2 commit 373d4d099761cb1f637bed488ab3871945882273 @rustyrussell rustyrussell committed Jan 21, 2013
@@ -186,7 +186,7 @@ die_if_kernel(char * str, struct pt_regs *regs, long err, unsigned long *r9_15)
#endif
printk("%s(%d): %s %ld\n", current->comm, task_pid_nr(current), str, err);
dik_show_regs(regs, r9_15);
- add_taint(TAINT_DIE);
+ add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
dik_show_trace((unsigned long *)(regs+1));
dik_show_code((unsigned int *)regs->pc);
@@ -296,7 +296,7 @@ static void oops_end(unsigned long flags, struct pt_regs *regs, int signr)
bust_spinlocks(0);
die_owner = -1;
- add_taint(TAINT_DIE);
+ add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
die_nest_count--;
if (!die_nest_count)
/* Nest count reaches zero, release the lock. */
@@ -242,7 +242,7 @@ void die(const char *str, struct pt_regs *regs, int err)
crash_kexec(regs);
bust_spinlocks(0);
- add_taint(TAINT_DIE);
+ add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
raw_spin_unlock_irq(&die_lock);
oops_exit();
@@ -61,7 +61,7 @@ void die(const char *str, struct pt_regs *regs, long err)
show_regs_log_lvl(regs, KERN_EMERG);
show_stack_log_lvl(current, regs->sp, regs, KERN_EMERG);
bust_spinlocks(0);
- add_taint(TAINT_DIE);
+ add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
spin_unlock_irq(&die_lock);
if (in_interrupt())
@@ -225,7 +225,7 @@ int die(const char *str, struct pt_regs *regs, long err)
do_show_stack(current, &regs->r30, pt_elr(regs));
bust_spinlocks(0);
- add_taint(TAINT_DIE);
+ add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
spin_unlock_irq(&die.lock);
@@ -72,7 +72,7 @@ die (const char *str, struct pt_regs *regs, long err)
bust_spinlocks(0);
die.lock_owner = -1;
- add_taint(TAINT_DIE);
+ add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
spin_unlock_irq(&die.lock);
if (!regs)
@@ -1176,7 +1176,7 @@ void die_if_kernel (char *str, struct pt_regs *fp, int nr)
console_verbose();
printk("%s: %08x\n",str,nr);
show_registers(fp);
- add_taint(TAINT_DIE);
+ add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
do_exit(SIGSEGV);
}
@@ -396,7 +396,7 @@ void __noreturn die(const char *str, struct pt_regs *regs)
printk("%s[#%d]:\n", str, ++die_counter);
show_registers(regs);
- add_taint(TAINT_DIE);
+ add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
raw_spin_unlock_irq(&die_lock);
oops_exit();
@@ -282,7 +282,7 @@ void die_if_kernel(char *str, struct pt_regs *regs, long err)
show_regs(regs);
dump_stack();
- add_taint(TAINT_DIE);
+ add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
if (in_interrupt())
panic("Fatal exception in interrupt");
@@ -138,7 +138,7 @@ static void __kprobes oops_end(unsigned long flags, struct pt_regs *regs,
{
bust_spinlocks(0);
die_owner = -1;
- add_taint(TAINT_DIE);
+ add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
die_nest_count--;
oops_exit();
printk("\n");
@@ -271,7 +271,7 @@ void die(struct pt_regs *regs, const char *str)
print_modules();
show_regs(regs);
bust_spinlocks(0);
- add_taint(TAINT_DIE);
+ add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
spin_unlock_irq(&die_lock);
if (in_interrupt())
panic("Fatal exception in interrupt");
@@ -38,7 +38,7 @@ void die(const char *str, struct pt_regs *regs, long err)
notify_die(DIE_OOPS, str, regs, err, 255, SIGSEGV);
bust_spinlocks(0);
- add_taint(TAINT_DIE);
+ add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
spin_unlock_irq(&die_lock);
oops_exit();
@@ -115,7 +115,7 @@ static void __init process_switch(char c)
break;
}
cheetah_pcache_forced_on = 1;
- add_taint(TAINT_MACHINE_CHECK);
+ add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE);
cheetah_enable_pcache();
break;
@@ -58,7 +58,7 @@ void die_if_kernel(char *str, struct pt_regs *regs)
printk("%s(%d): %s [#%d]\n", current->comm, task_pid_nr(current), str, ++die_counter);
show_regs(regs);
- add_taint(TAINT_DIE);
+ add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
__SAVE; __SAVE; __SAVE; __SAVE;
__SAVE; __SAVE; __SAVE; __SAVE;
@@ -2383,7 +2383,7 @@ void die_if_kernel(char *str, struct pt_regs *regs)
notify_die(DIE_OOPS, str, regs, 0, 255, SIGSEGV);
__asm__ __volatile__("flushw");
show_regs(regs);
- add_taint(TAINT_DIE);
+ add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
if (regs->tstate & TSTATE_PRIV) {
struct thread_info *tp = current_thread_info();
struct reg_window *rw = (struct reg_window *)
@@ -231,7 +231,7 @@ void die(const char *str, struct pt_regs *regs, int err)
ret = __die(str, err, thread, regs);
bust_spinlocks(0);
- add_taint(TAINT_DIE);
+ add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
spin_unlock_irq(&die_lock);
oops_exit();
@@ -220,8 +220,7 @@ static void __cpuinit amd_k7_smp_check(struct cpuinfo_x86 *c)
*/
WARN_ONCE(1, "WARNING: This combination of AMD"
" processors is not suitable for SMP.\n");
- if (!test_taint(TAINT_UNSAFE_SMP))
- add_taint(TAINT_UNSAFE_SMP);
+ add_taint(TAINT_UNSAFE_SMP, LOCKDEP_NOW_UNRELIABLE);
valid_k7:
;
@@ -1085,7 +1085,7 @@ void do_machine_check(struct pt_regs *regs, long error_code)
/*
* Set taint even when machine check was not enabled.
*/
- add_taint(TAINT_MACHINE_CHECK);
+ add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE);
severity = mce_severity(&m, cfg->tolerant, NULL);
@@ -33,7 +33,7 @@ static void pentium_machine_check(struct pt_regs *regs, long error_code)
smp_processor_id());
}
- add_taint(TAINT_MACHINE_CHECK);
+ add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE);
}
/* Set up machine check reporting for processors with Intel style MCE: */
@@ -15,7 +15,7 @@
static void winchip_machine_check(struct pt_regs *regs, long error_code)
{
printk(KERN_EMERG "CPU0: Machine Check Exception.\n");
- add_taint(TAINT_MACHINE_CHECK);
+ add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE);
}
/* Set up machine check reporting on the Winchip C6 series */
@@ -542,7 +542,7 @@ static void generic_get_mtrr(unsigned int reg, unsigned long *base,
if (tmp != mask_lo) {
printk(KERN_WARNING "mtrr: your BIOS has configured an incorrect mask, fixing it.\n");
- add_taint(TAINT_FIRMWARE_WORKAROUND);
+ add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_STILL_OK);
mask_lo = tmp;
}
}
@@ -232,7 +232,7 @@ void __kprobes oops_end(unsigned long flags, struct pt_regs *regs, int signr)
bust_spinlocks(0);
die_owner = -1;
- add_taint(TAINT_DIE);
+ add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
die_nest_count--;
if (!die_nest_count)
/* Nest count reaches zero, release the lock. */
@@ -524,7 +524,7 @@ void die(const char * str, struct pt_regs * regs, long err)
if (!user_mode(regs))
show_stack(NULL, (unsigned long*)regs->areg[1]);
- add_taint(TAINT_DIE);
+ add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
spin_unlock_irq(&die_lock);
if (in_interrupt())
@@ -66,7 +66,7 @@ static ssize_t cm_write(struct file *file, const char __user * user_buf,
buf = NULL;
if (ACPI_FAILURE(status))
return -EINVAL;
- add_taint(TAINT_OVERRIDDEN_ACPI_TABLE);
+ add_taint(TAINT_OVERRIDDEN_ACPI_TABLE, LOCKDEP_NOW_UNRELIABLE);
}
return count;
View
@@ -661,7 +661,7 @@ static void acpi_table_taint(struct acpi_table_header *table)
pr_warn(PREFIX
"Override [%4.4s-%8.8s], this is unsafe: tainting kernel\n",
table->signature, table->oem_table_id);
- add_taint(TAINT_OVERRIDDEN_ACPI_TABLE);
+ add_taint(TAINT_OVERRIDDEN_ACPI_TABLE, LOCKDEP_NOW_UNRELIABLE);
}
@@ -267,7 +267,7 @@ static ssize_t regmap_map_write_file(struct file *file,
return -EINVAL;
/* Userspace has been fiddling around behind the kernel's back */
- add_taint(TAINT_USER);
+ add_taint(TAINT_USER, LOCKDEP_NOW_UNRELIABLE);
regmap_write(map, reg, value);
return buf_size;
@@ -398,7 +398,11 @@ extern int panic_on_unrecovered_nmi;
extern int panic_on_io_nmi;
extern int sysctl_panic_on_stackoverflow;
extern const char *print_tainted(void);
-extern void add_taint(unsigned flag);
+enum lockdep_ok {
+ LOCKDEP_STILL_OK,
+ LOCKDEP_NOW_UNRELIABLE
+};
+extern void add_taint(unsigned flag, enum lockdep_ok);
extern int test_taint(unsigned flag);
extern unsigned long get_taint(void);
extern int root_mountflags;
View
@@ -197,9 +197,10 @@ static inline int strong_try_module_get(struct module *mod)
return -ENOENT;
}
-static inline void add_taint_module(struct module *mod, unsigned flag)
+static inline void add_taint_module(struct module *mod, unsigned flag,
+ enum lockdep_ok lockdep_ok)
{
- add_taint(flag);
+ add_taint(flag, lockdep_ok);
mod->taints |= (1U << flag);
}
@@ -727,7 +728,7 @@ static inline int try_force_unload(unsigned int flags)
{
int ret = (flags & O_TRUNC);
if (ret)
- add_taint(TAINT_FORCED_RMMOD);
+ add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
return ret;
}
#else
@@ -1138,7 +1139,7 @@ static int try_to_force_load(struct module *mod, const char *reason)
if (!test_taint(TAINT_FORCED_MODULE))
printk(KERN_WARNING "%s: %s: kernel tainted.\n",
mod->name, reason);
- add_taint_module(mod, TAINT_FORCED_MODULE);
+ add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
return 0;
#else
return -ENOEXEC;
@@ -2147,7 +2148,8 @@ static void set_license(struct module *mod, const char *license)
if (!test_taint(TAINT_PROPRIETARY_MODULE))
printk(KERN_WARNING "%s: module license '%s' taints "
"kernel.\n", mod->name, license);
- add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
+ add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
+ LOCKDEP_NOW_UNRELIABLE);
}
}
@@ -2700,10 +2702,10 @@ static int check_modinfo(struct module *mod, struct load_info *info, int flags)
}
if (!get_modinfo(info, "intree"))
- add_taint_module(mod, TAINT_OOT_MODULE);
+ add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
if (get_modinfo(info, "staging")) {
- add_taint_module(mod, TAINT_CRAP);
+ add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
printk(KERN_WARNING "%s: module is from the staging directory,"
" the quality is unknown, you have been warned.\n",
mod->name);
@@ -2869,15 +2871,17 @@ static int check_module_license_and_versions(struct module *mod)
* using GPL-only symbols it needs.
*/
if (strcmp(mod->name, "ndiswrapper") == 0)
- add_taint(TAINT_PROPRIETARY_MODULE);
+ add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
/* driverloader was caught wrongly pretending to be under GPL */
if (strcmp(mod->name, "driverloader") == 0)
- add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
+ add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
+ LOCKDEP_NOW_UNRELIABLE);
/* lve claims to be GPL but upstream won't provide source */
if (strcmp(mod->name, "lve") == 0)
- add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
+ add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
+ LOCKDEP_NOW_UNRELIABLE);
#ifdef CONFIG_MODVERSIONS
if ((mod->num_syms && !mod->crcs)
@@ -3197,7 +3201,7 @@ static int load_module(struct load_info *info, const char __user *uargs,
"%s: module verification failed: signature and/or"
" required key missing - tainting kernel\n",
mod->name);
- add_taint_module(mod, TAINT_FORCED_MODULE);
+ add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_STILL_OK);
}
#endif
View
@@ -259,26 +259,19 @@ unsigned long get_taint(void)
return tainted_mask;
}
-void add_taint(unsigned flag)
+/**
+ * add_taint: add a taint flag if not already set.
+ * @flag: one of the TAINT_* constants.
+ * @lockdep_ok: whether lock debugging is still OK.
+ *
+ * If something bad has gone wrong, you'll want @lockdebug_ok = false, but for
+ * some notewortht-but-not-corrupting cases, it can be set to true.
+ */
+void add_taint(unsigned flag, enum lockdep_ok lockdep_ok)
{
- /*
- * Can't trust the integrity of the kernel anymore.
- * We don't call directly debug_locks_off() because the issue
- * is not necessarily serious enough to set oops_in_progress to 1
- * Also we want to keep up lockdep for staging/out-of-tree
- * development and post-warning case.
- */
- switch (flag) {
- case TAINT_CRAP:
- case TAINT_OOT_MODULE:
- case TAINT_WARN:
- case TAINT_FIRMWARE_WORKAROUND:
- break;
-
- default:
- if (__debug_locks_off())
- printk(KERN_WARNING "Disabling lock debugging due to kernel taint\n");
- }
+ if (lockdep_ok == LOCKDEP_NOW_UNRELIABLE && __debug_locks_off())
+ printk(KERN_WARNING
+ "Disabling lock debugging due to kernel taint\n");
set_bit(flag, &tainted_mask);
}
@@ -421,7 +414,8 @@ static void warn_slowpath_common(const char *file, int line, void *caller,
print_modules();
dump_stack();
print_oops_end_marker();
- add_taint(taint);
+ /* Just a warning, don't kill lockdep. */
+ add_taint(taint, LOCKDEP_STILL_OK);
}
void warn_slowpath_fmt(const char *file, int line, const char *fmt, ...)
View
@@ -2785,7 +2785,7 @@ static noinline void __schedule_bug(struct task_struct *prev)
if (irqs_disabled())
print_irqtrace_events(prev);
dump_stack();
- add_taint(TAINT_WARN);
+ add_taint(TAINT_WARN, LOCKDEP_STILL_OK);
}
/*
View
@@ -2006,7 +2006,7 @@ static int proc_taint(struct ctl_table *table, int write,
int i;
for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
if ((tmptaint >> i) & 1)
- add_taint(i);
+ add_taint(i, LOCKDEP_STILL_OK);
}
}
Oops, something went wrong.

0 comments on commit 373d4d0

Please sign in to comment.