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-kbuild@vger.kernel.org,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
Gary Guo <gary@garyguo.net>, Alex Gaynor <alex.gaynor@gmail.com>,
Wedson Almeida Filho <wedsonaf@google.com>,
Miguel Ojeda <ojeda@kernel.org>
Subject: [PATCH 11/19] vsprintf: add new `%pA` format specifier
Date: Mon, 6 Dec 2021 15:03:05 +0100 [thread overview]
Message-ID: <20211206140313.5653-12-ojeda@kernel.org> (raw)
In-Reply-To: <20211206140313.5653-1-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/vsprintf.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 58d5e567f836..bc9c05427d9a 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -2233,6 +2233,10 @@ char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode,
return widen_string(buf, buf - buf_start, end, spec);
}
+#ifdef CONFIG_RUST
+char *rust_fmt_argument(char* buf, char* end, void *ptr);
+#endif
+
/* Disable pointer hashing if requested */
bool no_hash_pointers __ro_after_init;
EXPORT_SYMBOL_GPL(no_hash_pointers);
@@ -2388,6 +2392,10 @@ 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,
@@ -2460,6 +2468,10 @@ 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);
+#ifdef CONFIG_RUST
+ case 'A':
+ return rust_fmt_argument(buf, end, ptr);
+#endif
case 'x':
return pointer_string(buf, end, ptr, spec);
case 'e':
--
2.34.0
next prev parent reply other threads:[~2021-12-06 14:06 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-06 14:02 [PATCH 00/19] Rust support Miguel Ojeda
2021-12-06 14:02 ` [PATCH 01/19] kallsyms: support "big" kernel symbols Miguel Ojeda
2021-12-06 14:18 ` Matthew Wilcox
2021-12-06 17:00 ` Miguel Ojeda
2021-12-06 14:02 ` [PATCH 02/19] kallsyms: increase maximum kernel symbol length to 512 Miguel Ojeda
2021-12-06 14:02 ` [PATCH 03/19] kallsyms: use the correct buffer size for symbols Miguel Ojeda
2021-12-06 14:02 ` [PATCH 04/19] rust: add C helpers Miguel Ojeda
2021-12-06 14:02 ` [PATCH 05/19] rust: add `compiler_builtins` crate Miguel Ojeda
2021-12-07 23:01 ` Nick Desaulniers
2021-12-09 19:34 ` Miguel Ojeda
2021-12-06 14:03 ` [PATCH 06/19] rust: add `alloc` crate Miguel Ojeda
2021-12-06 14:03 ` [PATCH 07/19] rust: add `build_error` crate Miguel Ojeda
2021-12-06 14:03 ` [PATCH 08/19] rust: add `macros` crate Miguel Ojeda
2021-12-06 14:03 ` [PATCH 09/19] rust: add `kernel` crate Miguel Ojeda
2021-12-06 14:03 ` [PATCH 10/19] rust: export generated symbols Miguel Ojeda
2021-12-06 14:03 ` Miguel Ojeda [this message]
2021-12-06 15:02 ` [PATCH 11/19] vsprintf: add new `%pA` format specifier Greg Kroah-Hartman
2021-12-06 15:56 ` Miguel Ojeda
2021-12-06 16:02 ` Greg Kroah-Hartman
2021-12-06 19:52 ` Nick Desaulniers
2021-12-06 19:55 ` Matthew Wilcox
2021-12-06 20:02 ` Nick Desaulniers
2021-12-06 14:03 ` [PATCH 12/19] scripts: add `generate_rust_analyzer.py` Miguel Ojeda
2021-12-06 14:03 ` [PATCH 13/19] scripts: decode_stacktrace: demangle Rust symbols Miguel Ojeda
2021-12-06 14:03 ` [PATCH 14/19] docs: add Rust documentation Miguel Ojeda
2021-12-08 1:29 ` Nick Desaulniers
2021-12-08 23:07 ` Miguel Ojeda
2021-12-06 14:03 ` [PATCH 15/19] Kbuild: add Rust support Miguel Ojeda
2021-12-07 22:45 ` Nick Desaulniers
2021-12-07 23:21 ` Nick Desaulniers
2021-12-07 23:25 ` Wedson Almeida Filho
2021-12-08 0:05 ` Nick Desaulniers
2021-12-08 22:52 ` Miguel Ojeda
2021-12-11 15:53 ` Masahiro Yamada
2022-01-17 4:45 ` Miguel Ojeda
2021-12-06 14:03 ` [PATCH 16/19] samples: add Rust examples Miguel Ojeda
2021-12-06 14:03 ` [PATCH 17/19] MAINTAINERS: Rust Miguel Ojeda
2021-12-06 14:03 ` [RFC PATCH 18/19] drivers: gpio: PrimeCell PL061 in Rust Miguel Ojeda
2021-12-06 14:03 ` [RFC PATCH 19/19] drivers: android: Binder IPC " Miguel Ojeda
2021-12-06 15:01 ` Greg Kroah-Hartman
2021-12-06 15:59 ` Wedson Almeida Filho
2021-12-06 16:02 ` Greg Kroah-Hartman
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