linux-toradex.git/lib/string_helpers.c, branch v5.17-rc7

lib/string_helpers: Introduce managed variant of kasprintf_strarray()

2021-11-18T16:40:08+00:00

Some of the users want to have easy way to allocate array of strings
that will be automatically cleaned when associated device is gone.

Introduce managed variant of kasprintf_strarray() for such use cases.

Signed-off-by: Andy Shevchenko

lib/string_helpers: Introduce kasprintf_strarray()

2021-11-18T16:40:08+00:00

We have a few users already that basically want to have array of
sequential strings to be allocated and filled.

Provide a helper for them (basically adjusted version from gpio-mockup.c).

Signed-off-by: Andy Shevchenko 
Reviewed-by: Linus Walleij

string: uninline memcpy_and_pad

2021-11-03T18:41:25+00:00

When building m68k:allmodconfig, recent versions of gcc generate the
following error if the length of UTS_RELEASE is less than 8 bytes.

  In function 'memcpy_and_pad',
    inlined from 'nvmet_execute_disc_identify' at
      drivers/nvme/target/discovery.c:268:2: arch/m68k/include/asm/string.h:72:25: error:
	'__builtin_memcpy' reading 8 bytes from a region of size 7

Discussions around the problem suggest that this only happens if an
architecture does not provide strlen(), if -ffreestanding is provided as
compiler option, and if CONFIG_FORTIFY_SOURCE=n. All of this is the case
for m68k. The exact reasons are unknown, but seem to be related to the
ability of the compiler to evaluate the return value of strlen() and
the resulting execution flow in memcpy_and_pad(). It would be possible
to work around the problem by using sizeof(UTS_RELEASE) instead of
strlen(UTS_RELEASE), but that would only postpone the problem until the
function is called in a similar way. Uninline memcpy_and_pad() instead
to solve the problem for good.

Suggested-by: Linus Torvalds 
Reviewed-by: Geert Uytterhoeven 
Acked-by: Andy Shevchenko 
Signed-off-by: Guenter Roeck 
Signed-off-by: Linus Torvalds

fortify: Move remaining fortify helpers into fortify-string.h

2021-09-25T15:20:49+00:00

When commit a28a6e860c6c ("string.h: move fortified functions definitions
in a dedicated header.") moved the fortify-specific code, some helpers
were left behind. Move the remaining fortify-specific helpers into
fortify-string.h so they're together where they're used. This requires
that any FORTIFY helper function prototypes be conditionally built to
avoid "no prototype" warnings. Additionally removes unused helpers.

Cc: Andrew Morton 
Cc: Daniel Axtens 
Cc: Vincenzo Frascino 
Cc: Andrey Konovalov 
Cc: Dan Williams 
Acked-by: Francis Laniel 
Reviewed-by: Nick Desaulniers 
Signed-off-by: Kees Cook

lib/string: Move helper functions out of string.c

2021-09-25T15:20:49+00:00

The core functions of string.c are those that may be implemented by
per-architecture functions, or overloaded by FORTIFY_SOURCE. As a
result, it needs to be built with __NO_FORTIFY. Without this, macros
will collide with function declarations. This was accidentally working
due to -ffreestanding (on some architectures). Make this deterministic
by explicitly setting __NO_FORTIFY and move all the helper functions
into string_helpers.c so that they gain the fortification coverage they
had been missing.

Cc: Andrew Morton 
Cc: Nick Desaulniers 
Cc: Andy Lavr 
Cc: Nathan Chancellor 
Cc: Alexey Dobriyan 
Cc: Stephen Rothwell 
Cc: Bartosz Golaszewski 
Acked-by: Andy Shevchenko 
Signed-off-by: Kees Cook

string_helpers: Escape double quotes in escape_special

2021-07-19T09:39:28+00:00

From an abstract point of view, escape_special's counterpart,
unescape_special, already handles the unescaping of blackslashed double
quote sequences.

As a more practical example, printk indexing is an example case where
this is already practically useful. Compare an example with
`ESCAPE_SPECIAL | ESCAPE_SPACE`, with quotes not escaped:

    [root@ktst ~]# grep drivers/pci/pci-stub.c:69 /sys/kernel/debug/printk/index/vmlinux
    <4> drivers/pci/pci-stub.c:69 pci_stub_init "pci-stub: invalid ID string "%s"\n"

...and the same after this patch:

    [root@ktst ~]# grep drivers/pci/pci-stub.c:69 /sys/kernel/debug/printk/index/vmlinux
    <4> drivers/pci/pci-stub.c:69 pci_stub_init "pci-stub: invalid ID string \"%s\"\n"

One can of course, alternatively, use ESCAPE_APPEND with a quote in
@only, but without this patch quotes are coerced into hex or octal which
can hurt readability quite significantly.

I've checked uses of ESCAPE_SPECIAL and %pE across the codebase, and I'm
pretty confident that this shouldn't affect any stable interfaces.

Signed-off-by: Chris Down 
Reviewed-by: Andy Shevchenko 
Reviewed-by: Petr Mladek 
Cc: Rasmus Villemoes 
Acked-by: Andy Shevchenko 
Signed-off-by: Petr Mladek 
Link: https://lore.kernel.org/r/af144c5b75e41ce417386253ba2694456bc04118.1623775748.git.chris@chrisdown.name

seq_file: drop unused *_escape_mem_ascii()

2021-07-01T18:06:05+00:00

There are no more users of the seq_escape_mem_ascii() followed by
string_escape_mem_ascii().

Remove them for good.

Link: https://lkml.kernel.org/r/20210504180819.73127-16-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko 
Cc: Alexander Viro 
Cc: Chuck Lever 
Cc: "J. Bruce Fields" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

lib/string_helpers: allow to append additional characters to be escaped

2021-07-01T18:06:04+00:00

Introduce a new flag to append additional characters, passed in 'only'
parameter, to be escaped if they fall in the corresponding class.

Link: https://lkml.kernel.org/r/20210504180819.73127-7-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko 
Cc: Alexander Viro 
Cc: Chuck Lever 
Cc: "J. Bruce Fields" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

lib/string_helpers: introduce ESCAPE_NAP to escape non-ASCII and non-printable

2021-07-01T18:06:04+00:00

Some users may want to have an ASCII based filter for printable only
characters, provided by conjunction of isascii() and isprint() functions.

Here is the addition of a such.

Link: https://lkml.kernel.org/r/20210504180819.73127-6-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko 
Cc: Alexander Viro 
Cc: Chuck Lever 
Cc: "J. Bruce Fields" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

lib/string_helpers: introduce ESCAPE_NA for escaping non-ASCII

2021-07-01T18:06:04+00:00

Some users may want to have an ASCII based filter, provided by isascii()
function.  Here is the addition of a such.

Link: https://lkml.kernel.org/r/20210504180819.73127-5-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko 
Cc: Alexander Viro 
Cc: Chuck Lever 
Cc: "J. Bruce Fields" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds