Messages in this thread Patch in this message | | | From | ojeda@kernel ... | Subject | [PATCH 04/17] vsprintf: add new `%pA` format specifier | Date | Sun, 4 Jul 2021 22:27:43 +0200 |
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From: Miguel Ojeda <ojeda@kernel.org>
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: Geoffrey Thomas <geofft@ldpreload.com> Signed-off-by: Geoffrey Thomas <geofft@ldpreload.com> Co-developed-by: Finn Behrens <me@kloenk.de> Signed-off-by: Finn Behrens <me@kloenk.de> Co-developed-by: Adam Bratschi-Kaye <ark.email@gmail.com> Signed-off-by: Adam Bratschi-Kaye <ark.email@gmail.com> Co-developed-by: Wedson Almeida Filho <wedsonaf@google.com> Signed-off-by: Wedson Almeida Filho <wedsonaf@google.com> Co-developed-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Co-developed-by: Sumera Priyadarsini <sylphrenadin@gmail.com> Signed-off-by: Sumera Priyadarsini <sylphrenadin@gmail.com> Co-developed-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Co-developed-by: Sven Van Asbroeck <thesven73@gmail.com> Signed-off-by: Sven Van Asbroeck <thesven73@gmail.com> Co-developed-by: Gary Guo <gary@garyguo.net> Signed-off-by: Gary Guo <gary@garyguo.net> Co-developed-by: Boris-Chengbiao Zhou <bobo1239@web.de> Signed-off-by: Boris-Chengbiao Zhou <bobo1239@web.de> Co-developed-by: Fox Chen <foxhlchen@gmail.com> Signed-off-by: Fox Chen <foxhlchen@gmail.com> Co-developed-by: Ayaan Zaidi <zaidi.ayaan@gmail.com> Signed-off-by: Ayaan Zaidi <zaidi.ayaan@gmail.com> Co-developed-by: Douglas Su <d0u9.su@outlook.com> Signed-off-by: Douglas Su <d0u9.su@outlook.com> Co-developed-by: Yuki Okushi <jtitor@2k36.org> Signed-off-by: Yuki Okushi <jtitor@2k36.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 f0c35d9b65b..e7afe954004 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -2182,6 +2182,10 @@ 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); @@ -2335,6 +2339,10 @@ 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, @@ -2407,6 +2415,10 @@ 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': -- 2.32.0
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