Merge pull request #715 from ojeda/petr

printk/vsprintf: C side printing rework

Author: ojeda

MAINTAINERS

@@ -16821,7 +16821,6 @@ T:	git https://github.com/Rust-for-Linux/linux.git rust-next
 F:	rust/
 F:	samples/rust/
 F:	Documentation/rust/
-F:	lib/rust.h
 F:	scripts/*rust*
 K:	\b(?i:rust)\b
 

kernel/printk/printk.c

@@ -392,10 +392,7 @@ static struct latched_seq clear_seq = {
 /* the maximum size of a formatted record (i.e. with prefix added per line) */
 #define CONSOLE_LOG_MAX		1024
 
-/*
- * The maximum size allowed to be reserved for a record.
- * Keep in sync with rust/kernel/print.rs.
- */
+/* the maximum size allowed to be reserved for a record */
 #define LOG_LINE_MAX		(CONSOLE_LOG_MAX - PREFIX_MAX)
 
 #define LOG_LEVEL(v)		((v) & 0x07)

lib/rust.h

@@ -52,7 +52,6 @@
 
 #include <linux/string_helpers.h>
 #include "kstrtox.h"
-#include "rust.h"
 
 static noinline unsigned long long simple_strntoull(const char *startp, size_t max_chars, char **endp, unsigned int base)
 {
@@ -2253,6 +2252,9 @@ int __init no_hash_pointers_enable(char *str)
 }
 early_param("no_hash_pointers", no_hash_pointers_enable);
 
+/* Used for Rust formatting ('%pA'). */
+char *rust_fmt_argument(char* buf, char* end, void *ptr);
+
 /*
  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
  * by an extra set of alphanumeric characters that are extended format
@@ -2456,6 +2458,10 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr,
 	case 'f':
 		return fwnode_string(buf, end, ptr, spec, fmt + 1);
 	case 'A':
+		if (!IS_ENABLED(CONFIG_RUST)) {
+			WARN_ONCE(1, "Please remove %%pA from non-Rust code\n");
+			return error_string(buf, end, "(%pA?)", spec);
+		}
 		return rust_fmt_argument(buf, end, ptr);
 	case 'x':
 		return pointer_string(buf, end, ptr, spec);