Re: [PATCH v3 06/10] lib/vsprintf: Remove support for %pF and %pf in favour of %pS and %ps

From: Andy Shevchenko
Date: Fri Aug 30 2019 - 08:48:23 EST


On Thu, Aug 29, 2019 at 01:10:39PM +0300, Sakari Ailus wrote:
> %pS and %ps are now the preferred conversion specifiers to print function
> %names. The functionality is equivalent; remove the old, deprecated %pF
> %and %pf support.
>

> Depends-on: ("treewide: Switch printk users from %pf and %pF to %ps and
> %pS, respectively")

Same comment for multi-line tags, besides that it misses hash, and since it's
in upstream, no need for it anymore?

FWIW,
Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>

> Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
> ---
> Documentation/core-api/printk-formats.rst | 10 ----------
> lib/vsprintf.c | 8 ++------
> scripts/checkpatch.pl | 1 -
> 3 files changed, 2 insertions(+), 17 deletions(-)
>
> diff --git a/Documentation/core-api/printk-formats.rst b/Documentation/core-api/printk-formats.rst
> index c6224d039bcbe..922a29eb70e6c 100644
> --- a/Documentation/core-api/printk-formats.rst
> +++ b/Documentation/core-api/printk-formats.rst
> @@ -86,8 +86,6 @@ Symbols/Function Pointers
>
> %pS versatile_init+0x0/0x110
> %ps versatile_init
> - %pF versatile_init+0x0/0x110
> - %pf versatile_init
> %pSR versatile_init+0x9/0x110
> (with __builtin_extract_return_addr() translation)
> %pB prev_fn_of_versatile_init+0x88/0x88
> @@ -97,14 +95,6 @@ The ``S`` and ``s`` specifiers are used for printing a pointer in symbolic
> format. They result in the symbol name with (S) or without (s)
> offsets. If KALLSYMS are disabled then the symbol address is printed instead.
>
> -Note, that the ``F`` and ``f`` specifiers are identical to ``S`` (``s``)
> -and thus deprecated. We have ``F`` and ``f`` because on ia64, ppc64 and
> -parisc64 function pointers are indirect and, in fact, are function
> -descriptors, which require additional dereferencing before we can lookup
> -the symbol. As of now, ``S`` and ``s`` perform dereferencing on those
> -platforms (when needed), so ``F`` and ``f`` exist for compatibility
> -reasons only.
> -
> The ``B`` specifier results in the symbol name with offsets and should be
> used when printing stack backtraces. The specifier takes into
> consideration the effect of compiler optimisations which may occur
> diff --git a/lib/vsprintf.c b/lib/vsprintf.c
> index b0967cf17137d..b00b57f9f911f 100644
> --- a/lib/vsprintf.c
> +++ b/lib/vsprintf.c
> @@ -909,7 +909,7 @@ char *symbol_string(char *buf, char *end, void *ptr,
> #ifdef CONFIG_KALLSYMS
> if (*fmt == 'B')
> sprint_backtrace(sym, value);
> - else if (*fmt != 'f' && *fmt != 's')
> + else if (*fmt != 's')
> sprint_symbol(sym, value);
> else
> sprint_symbol_no_offset(sym, value);
> @@ -2007,9 +2007,7 @@ static char *kobject_string(char *buf, char *end, void *ptr,
> *
> * - 'S' For symbolic direct pointers (or function descriptors) with offset
> * - 's' For symbolic direct pointers (or function descriptors) without offset
> - * - 'F' Same as 'S'
> - * - 'f' Same as 's'
> - * - '[FfSs]R' as above with __builtin_extract_return_addr() translation
> + * - '[Ss]R' as above with __builtin_extract_return_addr() translation
> * - 'B' For backtraced symbolic direct pointers with offset
> * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
> * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
> @@ -2112,8 +2110,6 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr,
> struct printf_spec spec)
> {
> switch (*fmt) {
> - case 'F':
> - case 'f':
> case 'S':
> case 's':
> ptr = dereference_symbol_descriptor(ptr);
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> index 93a7edfe0f059..a60c241112cd4 100755
> --- a/scripts/checkpatch.pl
> +++ b/scripts/checkpatch.pl
> @@ -6012,7 +6012,6 @@ sub process {
> my $ext_type = "Invalid";
> my $use = "";
> if ($bad_specifier =~ /p[Ff]/) {
> - $ext_type = "Deprecated";
> $use = " - use %pS instead";
> $use =~ s/pS/ps/ if ($bad_specifier =~ /pf/);
> }
> --
> 2.20.1
>

--
With Best Regards,
Andy Shevchenko