panic: Allow warnings to set different taint flags

WARN() is used in some places to report firmware or hardware bugs that
are then worked-around.  These bugs do not affect the stability of the
kernel and should not set the flag for TAINT_WARN.  To allow for this,
add WARN_TAINT() and WARN_TAINT_ONCE() macros that take a taint number
as argument.

Architectures that implement warnings using trap instructions instead
of calls to warn_slowpath_*() now implement __WARN_TAINT(taint)
instead of __WARN().

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Acked-by: Helge Deller <deller@gmx.de>
Tested-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 20 insertions, 4 deletions

diff --git a/kernel/panic.c b/kernel/panic.c
index 13d966b4c14a..8b821bce66e6 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -365,7 +365,8 @@ struct slowpath_args {
         va_list args;
 };
 
-static void warn_slowpath_common(const char *file, int line, void *caller, struct slowpath_args *args)
+static void warn_slowpath_common(const char *file, int line, void *caller,
+                                 unsigned taint, struct slowpath_args *args)
 {
         const char *board;
 
@@ -381,7 +382,7 @@ static void warn_slowpath_common(const char *file, int line, void *caller, struc
         print_modules();
         dump_stack();
         print_oops_end_marker();
-        add_taint(TAINT_WARN);
+        add_taint(taint);
 }
 
 void warn_slowpath_fmt(const char *file, int line, const char *fmt, ...)
@@ -390,14 +391,29 @@ void warn_slowpath_fmt(const char *file, int line, const char *fmt, ...)
 
         args.fmt = fmt;
         va_start(args.args, fmt);
-        warn_slowpath_common(file, line, __builtin_return_address(0), &args);
+        warn_slowpath_common(file, line, __builtin_return_address(0),
+                             TAINT_WARN, &args);
         va_end(args.args);
 }
 EXPORT_SYMBOL(warn_slowpath_fmt);
 
+void warn_slowpath_fmt_taint(const char *file, int line,
+                             unsigned taint, const char *fmt, ...)
+{
+        struct slowpath_args args;
+
+        args.fmt = fmt;
+        va_start(args.args, fmt);
+        warn_slowpath_common(file, line, __builtin_return_address(0),
+                             taint, &args);
+        va_end(args.args);
+}
+EXPORT_SYMBOL(warn_slowpath_fmt_taint);
+
 void warn_slowpath_null(const char *file, int line)
 {
-        warn_slowpath_common(file, line, __builtin_return_address(0), NULL);
+        warn_slowpath_common(file, line, __builtin_return_address(0),
+                             TAINT_WARN, NULL);
 }
 EXPORT_SYMBOL(warn_slowpath_null);
 #endif