[PATCH v3 2/7] Split up struct warn_args

[Emese Revfy]

to enable dataflow verification by the initify plugin. This allows marking
warn_slowpath* parameters as nocapture and compile time verification of
the related dataflows.

Signed-off-by: Emese Revfy <re.em...@gmail.com>
---
 include/asm-generic/bug.h |  5 +----
 kernel/panic.c            | 32 ++++++++++++--------------------
 lib/bug.c                 |  2 +-
 3 files changed, 14 insertions(+), 25 deletions(-)

diff --git a/include/asm-generic/bug.h b/include/asm-generic/bug.h
index 6f96247..3048d10 100644
--- a/include/asm-generic/bug.h
+++ b/include/asm-generic/bug.h
@@ -81,11 +81,8 @@ extern void warn_slowpath_null(const char *file, const int 
line);
        do { printk(arg); __WARN_TAINT(taint); } while (0)
 #endif
 
-/* used internally by panic.c */
-struct warn_args;
-
 void __warn(const char *file, int line, void *caller, unsigned taint,
-           struct pt_regs *regs, struct warn_args *args);
+           struct pt_regs *regs, const char *fmt, va_list args);
 
 #ifndef WARN_ON
 #define WARN_ON(condition) ({                                          \
diff --git a/kernel/panic.c b/kernel/panic.c
index ca8cea1..993ad20 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -475,13 +475,8 @@ void oops_exit(void)
        kmsg_dump(KMSG_DUMP_OOPS);
 }
 
-struct warn_args {
-       const char *fmt;
-       va_list args;
-};
-
 void __warn(const char *file, int line, void *caller, unsigned taint,
-           struct pt_regs *regs, struct warn_args *args)
+           struct pt_regs *regs, const char *fmt, va_list args)
 {
        disable_trace_on_warning();
 
@@ -495,8 +490,8 @@ void __warn(const char *file, int line, void *caller, 
unsigned taint,
                pr_warn("WARNING: CPU: %d PID: %d at %pS\n",
                        raw_smp_processor_id(), current->pid, caller);
 
-       if (args)
-               vprintk(args->fmt, args->args);
+       if (fmt)
+               vprintk(fmt, args);
 
        if (panic_on_warn) {
                /*
@@ -525,31 +520,28 @@ void __warn(const char *file, int line, void *caller, 
unsigned taint,
 #ifdef WANT_WARN_ON_SLOWPATH
 void warn_slowpath_fmt(const char *file, int line, const char *fmt, ...)
 {
-       struct warn_args args;
+       va_list args;
 
-       args.fmt = fmt;
-       va_start(args.args, fmt);
-       __warn(file, line, __builtin_return_address(0), TAINT_WARN, NULL,
-              &args);
-       va_end(args.args);
+       va_start(args, fmt);
+       __warn(file, line, __builtin_return_address(0), TAINT_WARN, NULL, fmt, 
args);
+       va_end(args);
 }
 EXPORT_SYMBOL(warn_slowpath_fmt);
 
 void warn_slowpath_fmt_taint(const char *file, int line,
                             unsigned taint, const char *fmt, ...)
 {
-       struct warn_args args;
+       va_list args;
 
-       args.fmt = fmt;
-       va_start(args.args, fmt);
-       __warn(file, line, __builtin_return_address(0), taint, NULL, &args);
-       va_end(args.args);
+       va_start(args, fmt);
+       __warn(file, line, __builtin_return_address(0), taint, NULL, fmt, args);
+       va_end(args);
 }
 EXPORT_SYMBOL(warn_slowpath_fmt_taint);
 
 void warn_slowpath_null(const char *file, int line)
 {
-       __warn(file, line, __builtin_return_address(0), TAINT_WARN, NULL, NULL);
+       __warn(file, line, __builtin_return_address(0), TAINT_WARN, NULL, NULL, 
NULL);
 }
 EXPORT_SYMBOL(warn_slowpath_null);
 #endif
diff --git a/lib/bug.c b/lib/bug.c
index bc3656e..c8bdebb 100644
--- a/lib/bug.c
+++ b/lib/bug.c
@@ -168,7 +168,7 @@ enum bug_trap_type report_bug(unsigned long bugaddr, struct 
pt_regs *regs)
        if (warning) {
                /* this is a WARN_ON rather than BUG/BUG_ON */
                __warn(file, line, (void *)bugaddr, BUG_GET_TAINT(bug), regs,
-                      NULL);
+                      NULL, NULL);
                return BUG_TRAP_TYPE_WARN;
        }
 
-- 
2.8.1