From: Miguel Ojeda <ojeda@kernel.org>
To: Linus Torvalds <torvalds@linux-foundation.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org,
Miguel Ojeda <ojeda@kernel.org>, Gary Guo <gary@garyguo.net>,
Alex Gaynor <alex.gaynor@gmail.com>,
Wedson Almeida Filho <wedsonaf@google.com>,
Petr Mladek <pmladek@suse.com>,
Steven Rostedt <rostedt@goodmis.org>,
Sergey Senozhatsky <senozhatsky@chromium.org>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Rasmus Villemoes <linux@rasmusvillemoes.dk>
Subject: [PATCH v4 12/20] vsprintf: add new `%pA` format specifier
Date: Sat, 12 Feb 2022 14:03:38 +0100 [thread overview]
Message-ID: <20220212130410.6901-13-ojeda@kernel.org> (raw)
In-Reply-To: <20220212130410.6901-1-ojeda@kernel.org>
From: Gary Guo <gary@garyguo.net>
This patch adds a format specifier `%pA` to `vsprintf` which formats
a pointer as `core::fmt::Arguments`. Doing so allows us to directly
format to the internal buffer of `printf`, so we do not have to use
a temporary buffer on the stack to pre-assemble the message on
the Rust side.
This specifier is intended only to be used from Rust and not for C, so
`checkpatch.pl` is intentionally unchanged to catch any misuse.
Co-developed-by: Alex Gaynor <alex.gaynor@gmail.com>
Signed-off-by: Alex Gaynor <alex.gaynor@gmail.com>
Co-developed-by: Wedson Almeida Filho <wedsonaf@google.com>
Signed-off-by: Wedson Almeida Filho <wedsonaf@google.com>
Signed-off-by: Gary Guo <gary@garyguo.net>
Co-developed-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
lib/rust.h | 14 ++++++++++++++
lib/vsprintf.c | 7 +++++++
2 files changed, 21 insertions(+)
create mode 100644 lib/rust.h
diff --git a/lib/rust.h b/lib/rust.h
new file mode 100644
index 000000000000..9cf0b102b496
--- /dev/null
+++ b/lib/rust.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LIB_RUST_H
+#define _LIB_RUST_H
+
+#ifdef CONFIG_RUST
+char *rust_fmt_argument(char* buf, char* end, void *ptr);
+#else
+static inline char *rust_fmt_argument(char* buf, char* end, void *ptr)
+{
+ return NULL;
+}
+#endif
+
+#endif /* _LIB_RUST_H */
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 3b8129dd374c..61528094ec87 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -52,6 +52,7 @@
#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)
{
@@ -2378,6 +2379,10 @@ early_param("no_hash_pointers", no_hash_pointers_enable);
*
* Note: The default behaviour (unadorned %p) is to hash the address,
* rendering it useful as a unique identifier.
+ *
+ * There is also a '%pA' format specifier, but it is only intended to be used
+ * from Rust code to format core::fmt::Arguments. Do *not* use it from C.
+ * See rust/kernel/print.rs for details.
*/
static noinline_for_stack
char *pointer(const char *fmt, char *buf, char *end, void *ptr,
@@ -2450,6 +2455,8 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr,
return device_node_string(buf, end, ptr, spec, fmt + 1);
case 'f':
return fwnode_string(buf, end, ptr, spec, fmt + 1);
+ case 'A':
+ return rust_fmt_argument(buf, end, ptr);
case 'x':
return pointer_string(buf, end, ptr, spec);
case 'e':
--
2.35.1
next prev parent reply other threads:[~2022-02-12 13:06 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-12 13:03 [PATCH v4 00/20] Rust support Miguel Ojeda
2022-02-12 13:03 ` [PATCH v4 01/20] kallsyms: support "big" kernel symbols Miguel Ojeda
2022-02-12 13:03 ` [PATCH v4 02/20] kallsyms: increase maximum kernel symbol length to 512 Miguel Ojeda
2022-02-22 8:19 ` Petr Mladek
2022-02-22 12:45 ` Miguel Ojeda
2022-02-12 13:03 ` [PATCH v4 03/20] kallsyms: use the correct buffer size for symbols Miguel Ojeda
2022-02-12 13:03 ` [PATCH v4 04/20] rust: add C helpers Miguel Ojeda
2022-02-12 13:03 ` [PATCH v4 05/20] rust: add `compiler_builtins` crate Miguel Ojeda
2022-02-12 13:03 ` [PATCH v4 07/20] rust: add `build_error` crate Miguel Ojeda
2022-02-12 13:03 ` [PATCH v4 08/20] rust: add `macros` crate Miguel Ojeda
2022-02-12 13:03 ` [PATCH v4 09/20] rust: add `kernel` crate's `sync` module Miguel Ojeda
2022-02-12 13:03 ` [PATCH v4 11/20] rust: export generated symbols Miguel Ojeda
2022-02-12 13:03 ` Miguel Ojeda [this message]
2022-02-14 10:18 ` [PATCH v4 12/20] vsprintf: add new `%pA` format specifier Andy Shevchenko
2022-02-14 10:52 ` Rasmus Villemoes
2022-02-14 11:36 ` David Laight
2022-02-14 14:04 ` Miguel Ojeda
2022-02-14 12:12 ` Miguel Ojeda
2022-02-22 9:29 ` Petr Mladek
2022-02-22 10:35 ` Rasmus Villemoes
2022-02-24 9:55 ` Petr Mladek
2022-02-14 12:27 ` Miguel Ojeda
2022-02-14 13:54 ` Andy Shevchenko
2022-02-14 14:56 ` Miguel Ojeda
2022-02-12 13:03 ` [PATCH v4 13/20] scripts: add `generate_rust_analyzer.py` Miguel Ojeda
2022-02-12 13:03 ` [PATCH v4 14/20] scripts: decode_stacktrace: demangle Rust symbols Miguel Ojeda
2022-02-12 13:03 ` [PATCH v4 16/20] Kbuild: add Rust support Miguel Ojeda
2022-02-12 14:16 ` Russell King (Oracle)
2022-02-12 15:47 ` Miguel Ojeda
2022-02-12 16:18 ` Russell King (Oracle)
2022-02-12 18:32 ` Miguel Ojeda
2022-02-12 18:27 ` John Paul Adrian Glaubitz
2022-02-12 18:57 ` Miguel Ojeda
2022-02-12 13:03 ` [PATCH v4 17/20] samples: add Rust examples Miguel Ojeda
2022-02-12 13:03 ` [PATCH v4 18/20] MAINTAINERS: Rust Miguel Ojeda
2022-02-12 13:03 ` [PATCH v4 19/20] [RFC] drivers: gpio: PrimeCell PL061 in Rust Miguel Ojeda
2022-02-13 9:31 ` [PATCH v4 00/20] Rust support, nn/nn Geert Stappers
2022-02-13 9:55 ` Greg KH
2022-02-13 10:52 ` Geert Stappers
2022-02-14 14:16 ` Miguel Ojeda
2022-02-14 14:48 ` Geert Stappers
[not found] ` <20220212130410.6901-11-ojeda@kernel.org>
2022-02-14 5:27 ` [PATCH v4 10/20] rust: add `kernel` crate Sergey Senozhatsky
2022-02-14 13:36 ` Miguel Ojeda
2022-02-22 9:06 ` Petr Mladek
2022-02-22 12:48 ` Miguel Ojeda
2022-02-24 12:39 ` Petr Mladek
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