kernel/linux.git/lib/vsprintf.c, branch v5.10.78

lib: vsprintf: Fix handling of number field widths in vsscanf

2021-07-14T14:55:57+00:00

[ Upstream commit 900fdc4573766dd43b847b4f54bd4a1ee2bc7360 ] The existing code attempted to handle numbers by doing a strto[u]l(), ignoring the field width, and then repeatedly dividing to extract the field out of the full converted value. If the string contains a run of valid digits longer than will fit in a long or long long, this would overflow and no amount of dividing can recover the correct value. This patch fixes vsscanf() to obey number field widths when parsing the number. A new _parse_integer_limit() is added that takes a limit for the number of characters to parse. The number field conversion in vsscanf is changed to use this new function. If a number starts with a radix prefix, the field width must be long enough for at last one digit after the prefix. If not, it will be handled like this: sscanf("0x4", "%1i", &i): i=0, scanning continues with the 'x' sscanf("0x4", "%2i", &i): i=0, scanning continues with the '4' This is consistent with the observed behaviour of userland sscanf. Note that this patch does NOT fix the problem of a single field value overflowing the target type. So for example: sscanf("123456789abcdef", "%x", &i); Will not produce the correct result because the value obviously overflows INT_MAX. But sscanf will report a successful conversion. Note that where a very large number is used to mean "unlimited", the value INT_MAX is used for consistency with the behaviour of vsnprintf(). Signed-off-by: Richard Fitzgerald Reviewed-by: Petr Mladek Signed-off-by: Petr Mladek Link: https://lore.kernel.org/r/20210514161206.30821-2-rf@opensource.cirrus.com Signed-off-by: Sasha Levin

lib/vsprintf.c: remove leftover 'f' and 'F' cases from bstr_printf()

2021-05-11T12:47:40+00:00

commit 84696cfaf4d90945eb2a8302edc6cf627db56b84 upstream. Commit 9af7706492f9 ("lib/vsprintf: Remove support for %pF and %pf in favour of %pS and %ps") removed support for %pF and %pf, and correctly removed the handling of those cases in vbin_printf(). However, the corresponding cases in bstr_printf() were left behind. In the same series, %pf was re-purposed for dealing with fwnodes (3bd32d6a2ee6, "lib/vsprintf: Add %pfw conversion specifier for printing fwnode names"). So should anyone use %pf with the binary printf routines, vbin_printf() would (correctly, as it involves dereferencing the pointer) do the string formatting to the u32 array, but bstr_printf() would not copy the string from the u32 array, but instead interpret the first sizeof(void*) bytes of the formatted string as a pointer - which generally won't end well (also, all subsequent get_args would be out of sync). Fixes: 9af7706492f9 ("lib/vsprintf: Remove support for %pF and %pf in favour of %pS and %ps") Cc: stable@vger.kernel.org Signed-off-by: Rasmus Villemoes Reviewed-by: Sakari Ailus Signed-off-by: Petr Mladek Link: https://lore.kernel.org/r/20210423094529.1862521-1-linux@rasmusvillemoes.dk Signed-off-by: Greg Kroah-Hartman

vsprintf: use bd_partno in bdev_name

2020-09-25T14:18:58+00:00

No need to go through the hd_struct to find the partition number. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

lib: Revert use of fallthrough pseudo-keyword in lib/

2020-08-24T21:17:44+00:00

The following build error for powerpc64 was reported by Nathan Chancellor: "$ scripts/config --file arch/powerpc/configs/powernv_defconfig -e KERNEL_XZ $ make -skj"$(nproc)" ARCH=powerpc CROSS_COMPILE=powerpc64le-linux- distclean powernv_defconfig zImage ... In file included from arch/powerpc/boot/../../../lib/decompress_unxz.c:234, from arch/powerpc/boot/decompress.c:38: arch/powerpc/boot/../../../lib/xz/xz_dec_stream.c: In function 'dec_main': arch/powerpc/boot/../../../lib/xz/xz_dec_stream.c:586:4: error: 'fallthrough' undeclared (first use in this function) 586 | fallthrough; | ^~~~~~~~~~~ This will end up affecting distribution configurations such as Debian and OpenSUSE according to my testing. I am not sure what the solution is, the PowerPC wrapper does not set -D__KERNEL__ so I am not sure that compiler_attributes.h can be safely included." In order to avoid these sort of problems, it seems that the best solution is to use /* fall through */ comments instead of the fallthrough pseudo-keyword macro in lib/, for now. Reported-by: Nathan Chancellor Fixes: df561f6688fe ("treewide: Use fallthrough pseudo-keyword") Signed-off-by: Gustavo A. R. Silva Reviewed-and-tested-by: Nathan Chancellor Signed-off-by: Linus Torvalds

treewide: Use fallthrough pseudo-keyword

2020-08-23T22:36:59+00:00

Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva

lib/vsprintf: Force type of flags value for gfp_t

2020-08-01T03:52:57+00:00

Sparse is not happy about restricted type being assigned: lib/vsprintf.c:1940:23: warning: incorrect type in assignment (different base types) lib/vsprintf.c:1940:23: expected unsigned long [assigned] flags lib/vsprintf.c:1940:23: got restricted gfp_t [usertype] Force type of flags value to make sparse happy. Signed-off-by: Andy Shevchenko Reviewed-by: Steven Rostedt (VMware) Link: https://lore.kernel.org/r/20200731180825.30575-3-andriy.shevchenko@linux.intel.com Signed-off-by: Sergey Senozhatsky

lib/vsprintf: Replace custom spec to print decimals with generic one

2020-08-01T03:52:36+00:00

When printing phandle via %pOFp the custom spec is used. First of all, it has a SMALL flag which makes no sense for decimal numbers. Second, we have already default spec for decimal numbers. Use the latter in the %pOFp case as well. Signed-off-by: Andy Shevchenko Reviewed-by: Steven Rostedt (VMware) Reviewed-by: Sergey Senozhatsky Cc: Pantelis Antoniou Cc: Rob Herring Cc: Joe Perches Cc: Grant Likely Link: https://lore.kernel.org/r/20200731180825.30575-2-andriy.shevchenko@linux.intel.com Signed-off-by: Sergey Senozhatsky

lib/vsprintf: Replace hidden BUILD_BUG_ON() with static_assert()

2020-08-01T03:52:32+00:00

First of all, there is no compile time check for the SMALL to be ' ' (0x20, i.e. space). Second, for ZEROPAD the check is hidden in the code. For better maintenance replace BUILD_BUG_ON() with static_assert() for ZEROPAD and move it closer to the definition. While at it, introduce check for SMALL. Signed-off-by: Andy Shevchenko Reviewed-by: Steven Rostedt (VMware) Reviewed-by: Sergey Senozhatsky Link: https://lore.kernel.org/r/20200731180825.30575-1-andriy.shevchenko@linux.intel.com Signed-off-by: Sergey Senozhatsky

Replace HTTP links with HTTPS ones: vsprintf

2020-07-03T12:07:00+00:00

Rationale: Reduces attack surface on kernel devs opening the links for MITM as HTTPS traffic is much harder to manipulate. Deterministic algorithm: For each file: If not .svg: For each line: If doesn't contain `\bxmlns\b`: For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`: If both the HTTP and HTTPS versions return 200 OK and serve the same content: Replace HTTP with HTTPS. Signed-off-by: Alexander A. Klimov Reviewed-by: Petr Mladek Reviewed-by: Sergey Senozhatsky Signed-off-by: Petr Mladek Link: https://lore.kernel.org/r/20200702200536.13389-1-grandmaster@al2klimov.de

Merge tag 'printk-for-5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux

2020-06-01T19:13:30+00:00

Pull printk updates from Petr Mladek: - Benjamin Herrenschmidt solved a problem with non-matched console aliases by first checking consoles defined on the command line. It is a more conservative approach than the previous attempts. - Benjamin also made sure that the console accessible via /dev/console always has CON_CONSDEV flag. - Andy Shevchenko added the %ptT modifier for printing struct time64_t. It extends the existing %ptR handling for struct rtc_time. - Bruno Meneguele fixed /dev/kmsg error value returned by unsupported SEEK_CUR. - Tetsuo Handa removed unused pr_cont_once(). ... and a few small fixes. * tag 'printk-for-5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: printk: Remove pr_cont_once() printk: handle blank console arguments passed in. kernel/printk: add kmsg SEEK_CUR handling printk: Fix a typo in comment "interator"->"iterator" usb: pulse8-cec: Switch to use %ptT ARM: bcm2835: Switch to use %ptT lib/vsprintf: Print time64_t in human readable format lib/vsprintf: update comment about simple_strto() functions printk: Correctly set CON_CONSDEV even when preferred console was not registered printk: Fix preferred console selection with multiple matches printk: Move console matching logic into a separate function printk: Convert a use of sprintf to snprintf in console_unlock