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2018-10-26Merge tag 'devicetree-for-4.20' of ↵Linus Torvalds1-1/+6
git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux Pull Devicetree updates from Rob Herring: "A bit bigger than normal as I've been busy this cycle. There's a few things with dependencies and a few things subsystem maintainers didn't pick up, so I'm taking them thru my tree. The fixes from Johan didn't get into linux-next, but they've been waiting for some time now and they are what's left of what subsystem maintainers didn't pick up. Summary: - Sync dtc with upstream version v1.4.7-14-gc86da84d30e4 - Work to get rid of direct accesses to struct device_node name and type pointers in preparation for removing them. New helpers for parsing DT cpu nodes and conversions to use the helpers. printk conversions to %pOFn for printing DT node names. Most went thru subystem trees, so this is the remainder. - Fixes to DT child node lookups to actually be restricted to child nodes instead of treewide. - Refactoring of dtb targets out of arch code. This makes the support more uniform and enables building all dtbs on c6x, microblaze, and powerpc. - Various DT binding updates for Renesas r8a7744 SoC - Vendor prefixes for Facebook, OLPC - Restructuring of some ARM binding docs moving some peripheral bindings out of board/SoC binding files - New "secure-chosen" binding for secure world settings on ARM - Dual licensing of 2 DT IRQ binding headers" * tag 'devicetree-for-4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (78 commits) ARM: dt: relicense two DT binding IRQ headers power: supply: twl4030-charger: fix OF sibling-node lookup NFC: nfcmrvl_uart: fix OF child-node lookup net: stmmac: dwmac-sun8i: fix OF child-node lookup net: bcmgenet: fix OF child-node lookup drm/msm: fix OF child-node lookup drm/mediatek: fix OF sibling-node lookup of: Add missing exports of node name compare functions dt-bindings: Add OLPC vendor prefix dt-bindings: misc: bk4: Add device tree binding for Liebherr's BK4 SPI bus dt-bindings: thermal: samsung: Add SPDX license identifier dt-bindings: clock: samsung: Add SPDX license identifiers dt-bindings: timer: ostm: Add R7S9210 support dt-bindings: phy: rcar-gen2: Add r8a7744 support dt-bindings: can: rcar_can: Add r8a7744 support dt-bindings: timer: renesas, cmt: Document r8a7744 CMT support dt-bindings: watchdog: renesas-wdt: Document r8a7744 support dt-bindings: thermal: rcar: Add device tree support for r8a7744 Documentation: dt: Add binding for /secure-chosen/stdout-path dt-bindings: arm: zte: Move sysctrl bindings to their own doc ...
2018-10-26Merge tag 'printk-for-4.20' of ↵Linus Torvalds1-108/+108
git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk Pull printk updates from Petr Mladek: - Fix two more locations where printf formatting leaked pointers - Better log_buf_len parameter handling - Add prefix to messages from printk code - Do not miss messages on other consoles when the log is replayed on a new one - Reduce race between console registration and panic() when the log might get replayed on all consoles - Some cont buffer code clean up - Call console only when there is something to do (log vs cont buffer) * tag 'printk-for-4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk: lib/vsprintf: Hash printed address for netdev bits fallback lib/vsprintf: Hash legacy clock addresses lib/vsprintf: Prepare for more general use of ptr_to_id() lib/vsprintf: Make ptr argument conts in ptr_to_id() printk: fix integer overflow in setup_log_buf() printk: do not preliminary split up cont buffer printk: lock/unlock console only for new logbuf entries printk: keep kernel cont support always enabled printk: Give error on attempt to set log buffer length to over 2G printk: Add KBUILD_MODNAME and remove a redundant print prefix printk: Correct wrong casting printk: Fix panic caused by passing log_buf_len to command line printk: CON_PRINTBUFFER console registration is a bit racy printk: Do not miss new messages when replaying the log
2018-10-24Merge tag 'docs-4.20' of git://git.lwn.net/linuxLinus Torvalds1-11/+9
Pull documentation updates from Jonathan Corbet: "This is a fairly typical cycle for documentation. There's some welcome readability improvements for the formatted output, some LICENSES updates including the addition of the ISC license, the removal of the unloved and unmaintained 00-INDEX files, the deprecated APIs document from Kees, more MM docs from Mike Rapoport, and the usual pile of typo fixes and corrections" * tag 'docs-4.20' of git://git.lwn.net/linux: (41 commits) docs: Fix typos in histogram.rst docs: Introduce deprecated APIs list kernel-doc: fix declaration type determination doc: fix a typo in adding-syscalls.rst docs/admin-guide: memory-hotplug: remove table of contents doc: printk-formats: Remove bogus kobject references for device nodes Documentation: preempt-locking: Use better example dm flakey: Document "error_writes" feature docs/completion.txt: Fix a couple of punctuation nits LICENSES: Add ISC license text LICENSES: Add note to CDDL-1.0 license that it should not be used docs/core-api: memory-hotplug: add some details about locking internals docs/core-api: rename memory-hotplug-notifier to memory-hotplug docs: improve readability for people with poorer eyesight yama: clarify ptrace_scope=2 in Yama documentation docs/vm: split memory hotplug notifier description to Documentation/core-api docs: move memory hotplug description into admin-guide/mm doc: Fix acronym "FEKEK" in ecryptfs docs: fix some broken documentation references iommu: Fix passthrough option documentation ...
2018-10-12doc: printk-formats: Remove bogus kobject references for device nodesGeert Uytterhoeven1-11/+9
When converting from text to rst, the kobjects section and its sole subsection about device tree nodes were coalesced into a single section, yielding an inconsistent result. Remove all references to kobjects, as 1. Device tree object pointers are not compatible to kobject pointers (the former may embed the latter, though), and 2. there are no printk formats defined for kobject types. Update the vsprintf() source code comments to match the above. Fixes: b3ed23213eab1e08 ("doc: convert printk-formats.txt to rst") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-10-12lib/vsprintf: Hash printed address for netdev bits fallbackGeert Uytterhoeven1-5/+4
The handler for "%pN" falls back to printing the raw pointer value when using a different format than the (sole supported) special format "%pNF", potentially leaking sensitive information regarding the kernel layout in memory. Avoid this leak by printing the hashed address instead. Note that there are no in-tree users of the fallback. Fixes: ad67b74d2469d9b8 ("printk: hash addresses printed with %p") Link: http://lkml.kernel.org/r/20181011084249.4520-4-geert+renesas@glider.be To: "Tobin C . Harding" <me@tobin.cc> To: Andrew Morton <akpm@linux-foundation.org> To: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-10-12lib/vsprintf: Hash legacy clock addressesGeert Uytterhoeven1-1/+1
On platforms using the Common Clock Framework, "%pC" prints the clock's name. On legacy platforms, it prints the unhashed clock's address, potentially leaking sensitive information regarding the kernel layout in memory. Avoid this leak by printing the hashed address instead. To distinguish between clocks, a 32-bit unique identifier is as good as an actual pointer value. Fixes: ad67b74d2469d9b8 ("printk: hash addresses printed with %p") Link: http://lkml.kernel.org/r/20181011084249.4520-3-geert+renesas@glider.be To: "Tobin C . Harding" <me@tobin.cc> To: Andrew Morton <akpm@linux-foundation.org> To: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-10-12lib/vsprintf: Prepare for more general use of ptr_to_id()Geert Uytterhoeven1-103/+103
Move the function and its dependencies up so it can be called from special pointer type formatting routines. Link: http://lkml.kernel.org/r/20181011084249.4520-2-geert+renesas@glider.be To: "Tobin C . Harding" <me@tobin.cc> To: Andrew Morton <akpm@linux-foundation.org> To: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> [pmladek@suse.com: Split into separate patch] Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-10-12lib/vsprintf: Make ptr argument conts in ptr_to_id()Geert Uytterhoeven1-1/+2
Make the ptr argument const to avoid adding casts in future callers. Link: http://lkml.kernel.org/r/20181011084249.4520-2-geert+renesas@glider.be To: "Tobin C . Harding" <me@tobin.cc> To: Andrew Morton <akpm@linux-foundation.org> To: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> [pmladek@suse.com: split into separate patch] Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-10-05vsprintf: Fix off-by-one bug in bstr_printf() processing dereferenced pointersSteven Rostedt (VMware)1-1/+1
The functions vbin_printf() and bstr_printf() are used by trace_printk() to try to keep the overhead down during printing. trace_printk() uses vbin_printf() at the time of execution, as it only scans the fmt string to record the printf values into the buffer, and then uses vbin_printf() to do the conversions to print the string based on the format and the saved values in the buffer. This is an issue for dereferenced pointers, as before commit 841a915d20c7b, the processing of the pointer could happen some time after the pointer value was recorded (reading the trace buffer). This means the processing of the value at a later time could show different results, or even crash the system, if the pointer no longer existed. Commit 841a915d20c7b addressed this by processing dereferenced pointers at the time of execution and save the result in the ring buffer as a string. The bstr_printf() would then treat these pointers as normal strings, and print the value. But there was an off-by-one bug here, where after processing the argument, it move the pointer only "strlen(arg)" which made the arg pointer not point to the next argument in the ring buffer, but instead point to the nul character of the last argument. This causes any values after a dereferenced pointer to be corrupted. Cc: stable@vger.kernel.org Fixes: 841a915d20c7b ("vsprintf: Do not have bprintf dereference pointers") Reported-by: Nikolay Borisov <nborisov@suse.com> Tested-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-09-07vsprintf: print OF node name using full_nameRob Herring1-1/+6
In preparation to remove the node name pointer from struct device_node, convert the node name print to get the node name from the full name. Reviewed-by: Frank Rowand <frank.rowand@sony.com> Signed-off-by: Rob Herring <robh@kernel.org>
2018-08-16Merge tag 'random_for_linus' of ↵Linus Torvalds1-1/+26
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random Pull random updates from Ted Ts'o: "Some changes to trust cpu-based hwrng (such as RDRAND) for initializing hashed pointers and (optionally, controlled by a config option) to initialize the CRNG to avoid boot hangs" * tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random: random: Make crng state queryable random: remove preempt disabled region random: add a config option to trust the CPU's hwrng vsprintf: Add command line option debug_boot_weak_hash vsprintf: Use hw RNG for ptr_key random: Return nbytes filled from hw RNG random: Fix whitespace pre random-bytes work
2018-08-07lib/vsprintf: Do not handle %pO[^F] as %pxBart Van Assche1-0/+1
This patch avoids that gcc reports the following when building with W=1: lib/vsprintf.c:1941:3: warning: this statement may fall through [-Wimplicit-fallthrough=] switch (fmt[1]) { ^~~~~~ Fixes: 7b1924a1d930eb2 ("vsprintf: add printk specifier %px") Link: http://lkml.kernel.org/r/20180806223421.11995-1-bart.vanassche@wdc.com Cc: linux-kernel@vger.kernel.org Cc: Bart Van Assche <bart.vanassche@wdc.com> Cc: Pantelis Antoniou <pantelis.antoniou@konsulko.com> Cc: Joe Perches <joe@perches.com> Cc: Rob Herring <robh@kernel.org> Cc: v4.15+ <stable@vger.kernel.org> Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-07-18vsprintf: Add command line option debug_boot_weak_hashTobin C. Harding1-0/+17
Currently printing [hashed] pointers requires enough entropy to be available. Early in the boot sequence this may not be the case resulting in a dummy string '(____ptrval____)' being printed. This makes debugging the early boot sequence difficult. We can relax the requirement to use cryptographically secure hashing during debugging. This enables debugging while keeping development/production kernel behaviour the same. If new command line option debug_boot_weak_hash is enabled use cryptographically insecure hashing and hash pointer value immediately. Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Tobin C. Harding <me@tobin.cc> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2018-07-18vsprintf: Use hw RNG for ptr_keyTobin C. Harding1-1/+9
Currently we must wait for enough entropy to become available before hashed pointers can be printed. We can remove this wait by using the hw RNG if available. Use hw RNG to get keying material. Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Suggested-by: Kees Cook <keescook@chromium.org> Signed-off-by: Tobin C. Harding <me@tobin.cc> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2018-06-07Merge tag 'printk-for-4.18' of ↵Linus Torvalds1-80/+53
git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk Pull printk updates from Petr Mladek: - Help userspace log daemons to catch up with a flood of messages. They will get woken after each message even if the console is far behind and handled by another process. - Flush printk safe buffers safely even when panic() happens in the normal context. - Fix possible va_list reuse when race happened in printk_safe(). - Remove %pCr printf format to prevent sleeping in the atomic context. - Misc vsprintf code cleanup. * tag 'printk-for-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk: printk: drop in_nmi check from printk_safe_flush_on_panic() lib/vsprintf: Remove atomic-unsafe support for %pCr serial: sh-sci: Stop using printk format %pCr thermal: bcm2835: Stop using printk format %pCr clk: renesas: cpg-mssr: Stop using printk format %pCr printk: fix possible reuse of va_list variable printk: wake up klogd in vprintk_emit vsprintf: Tweak pF/pf comment lib/vsprintf: Mark expected switch fall-through lib/vsprintf: Replace space with '_' before crng is ready lib/vsprintf: Deduplicate pointer_string() lib/vsprintf: Move pointer_string() upper lib/vsprintf: Make flag_spec global lib/vsprintf: Make strspec global lib/vsprintf: Make dec_spec global lib/test_printf: Mark big constant with UL
2018-06-05Merge branch 'for-4.18-vsprintf-pcr-removal' into for-4.18Petr Mladek1-3/+0
2018-06-05lib/vsprintf: Remove atomic-unsafe support for %pCrGeert Uytterhoeven1-3/+0
"%pCr" formats the current rate of a clock, and calls clk_get_rate(). The latter obtains a mutex, hence it must not be called from atomic context. Remove support for this rarely-used format, as vsprintf() (and e.g. printk()) must be callable from any context. Any remaining out-of-tree users will start seeing the clock's name printed instead of its rate. Reported-by: Jia-Ju Bai <baijiaju1990@gmail.com> Fixes: 900cca2944254edd ("lib/vsprintf: add %pC{,n,r} format specifiers for clocks") Link: http://lkml.kernel.org/r/1527845302-12159-5-git-send-email-geert+renesas@glider.be To: Jia-Ju Bai <baijiaju1990@gmail.com> To: Jonathan Corbet <corbet@lwn.net> To: Michael Turquette <mturquette@baylibre.com> To: Stephen Boyd <sboyd@kernel.org> To: Zhang Rui <rui.zhang@intel.com> To: Eduardo Valentin <edubezval@gmail.com> To: Eric Anholt <eric@anholt.net> To: Stefan Wahren <stefan.wahren@i2se.com> To: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: linux-doc@vger.kernel.org Cc: linux-clk@vger.kernel.org Cc: linux-pm@vger.kernel.org Cc: linux-serial@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-renesas-soc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: Geert Uytterhoeven <geert+renesas@glider.be> Cc: stable@vger.kernel.org # 4.1+ Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-05-16vsprintf: Replace memory barrier with static_key for random_ptr_key updateSteven Rostedt (VMware)1-11/+15
Reviewing Tobin's patches for getting pointers out early before entropy has been established, I noticed that there's a lone smp_mb() in the code. As with most lone memory barriers, this one appears to be incorrectly used. We currently basically have this: get_random_bytes(&ptr_key, sizeof(ptr_key)); /* * have_filled_random_ptr_key==true is dependent on get_random_bytes(). * ptr_to_id() needs to see have_filled_random_ptr_key==true * after get_random_bytes() returns. */ smp_mb(); WRITE_ONCE(have_filled_random_ptr_key, true); And later we have: if (unlikely(!have_filled_random_ptr_key)) return string(buf, end, "(ptrval)", spec); /* Missing memory barrier here. */ hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key); As the CPU can perform speculative loads, we could have a situation with the following: CPU0 CPU1 ---- ---- load ptr_key = 0 store ptr_key = random smp_mb() store have_filled_random_ptr_key load have_filled_random_ptr_key = true BAD BAD BAD! (you're so bad!) Because nothing prevents CPU1 from loading ptr_key before loading have_filled_random_ptr_key. But this race is very unlikely, but we can't keep an incorrect smp_mb() in place. Instead, replace the have_filled_random_ptr_key with a static_branch not_filled_random_ptr_key, that is initialized to true and changed to false when we get enough entropy. If the update happens in early boot, the static_key is updated immediately, otherwise it will have to wait till entropy is filled and this happens in an interrupt handler which can't enable a static_key, as that requires a preemptible context. In that case, a work_queue is used to enable it, as entropy already took too long to establish in the first place waiting a little more shouldn't hurt anything. The benefit of using the static key is that the unlikely branch in vsprintf() now becomes a nop. Link: http://lkml.kernel.org/r/20180515100558.21df515e@gandalf.local.home Cc: stable@vger.kernel.org Fixes: ad67b74d2469d ("printk: hash addresses printed with %p") Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-04-18vsprintf: Tweak pF/pf commentSergey Senozhatsky1-8/+4
Reflect changes that have happened to pf/pF (deprecation) specifiers in pointer() comment section. Link: http://lkml.kernel.org/r/20180414030005.25831-1-sergey.senozhatsky@gmail.com Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Joe Perches <joe@perches.com> Cc: linux-kernel@vger.kernel.org Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-04-11proc: add seq_put_decimal_ull_width to speed up /proc/pid/smapsAndrei Vagin1-4/+14
seq_put_decimal_ull_w(m, str, val, width) prints a decimal number with a specified minimal field width. It is equivalent of seq_printf(m, "%s%*d", str, width, val), but it works much faster. == test_smaps.py num = 0 with open("/proc/1/smaps") as f: for x in xrange(10000): data = f.read() f.seek(0, 0) == == Before patch == $ time python test_smaps.py real 0m4.593s user 0m0.398s sys 0m4.158s == After patch == $ time python test_smaps.py real 0m3.828s user 0m0.413s sys 0m3.408s $ perf -g record python test_smaps.py == Before patch == - 79.01% 3.36% python [kernel.kallsyms] [k] show_smap.isra.33 - 75.65% show_smap.isra.33 + 48.85% seq_printf + 15.75% __walk_page_range + 9.70% show_map_vma.isra.23 0.61% seq_puts == After patch == - 75.51% 4.62% python [kernel.kallsyms] [k] show_smap.isra.33 - 70.88% show_smap.isra.33 + 24.82% seq_put_decimal_ull_w + 19.78% __walk_page_range + 12.74% seq_printf + 11.08% show_map_vma.isra.23 + 1.68% seq_puts [akpm@linux-foundation.org: fix drivers/of/unittest.c build] Link: http://lkml.kernel.org/r/20180212074931.7227-1-avagin@openvz.org Signed-off-by: Andrei Vagin <avagin@openvz.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-11lib/vsprintf: Mark expected switch fall-throughAndy Shevchenko1-0/+3
In preparation to enabling -Wimplicit-fallthrough, mark switch cases where we are expecting to fall through. Link: http://lkml.kernel.org/r/20180216210711.79901-9-andriy.shevchenko@linux.intel.com To: "Tobin C . Harding" <me@tobin.cc> To: linux@rasmusvillemoes.dk To: Joe Perches <joe@perches.com> To: linux-kernel@vger.kernel.org To: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-04-11lib/vsprintf: Replace space with '_' before crng is readyShunyong Yang1-1/+2
Before crng is ready, output of "%p" composes of "(ptrval)" and left padding spaces for alignment as no random address can be generated. This seems a little strange when default string width is larger than strlen("(ptrval)"). For example, when irq domain names are built with "%p", the nodes under /sys/kernel/debug/irq/domains like this on AArch64 system, [root@y irq]# ls domains/ default irqchip@ (ptrval)-2 irqchip@ (ptrval)-4 \_SB_.TCS0.QIC1 \_SB_.TCS0.QIC3 irqchip@ (ptrval) irqchip@ (ptrval)-3 \_SB_.TCS0.QIC0 \_SB_.TCS0.QIC2 The name "irqchip@ (ptrval)-2" is not so readable in console output. This patch replaces space with readable "_" when output needs padding. Following is the output after applying the patch, [root@y domains]# ls default irqchip@(____ptrval____)-2 irqchip@(____ptrval____)-4 \_SB_.TCS0.QIC1 \_SB_.TCS0.QIC3 irqchip@(____ptrval____) irqchip@(____ptrval____)-3 \_SB_.TCS0.QIC0 \_SB_.TCS0.QIC2 There is same problem in some subsystem's dmesg output. Moreover, someone may call "%p" in a similar case. In addition, the timing of crng initialization done may vary on different system. So, the change is made in vsprintf.c. Suggested-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Link: http://lkml.kernel.org/r/20180216210711.79901-7-andriy.shevchenko@linux.intel.com To: "Tobin C . Harding" <me@tobin.cc> To: linux@rasmusvillemoes.dk To: Joe Perches <joe@perches.com> To: linux-kernel@vger.kernel.org To: Andrew Morton <akpm@linux-foundation.org> Cc: Joey Zheng <yu.zheng@hxt-semitech.com> Signed-off-by: Shunyong Yang <shunyong.yang@hxt-semitech.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-04-11lib/vsprintf: Deduplicate pointer_string()Andy Shevchenko1-20/+7
There is an exact code at the end of ptr_to_id(). Replace it by calling pointer_string() directly. This is followup to the commit ad67b74d2469 ("printk: hash addresses printed with %p"). Cc: Tobin C. Harding <me@tobin.cc> Link: http://lkml.kernel.org/r/20180216210711.79901-6-andriy.shevchenko@linux.intel.com To: "Tobin C . Harding" <me@tobin.cc> To: linux@rasmusvillemoes.dk To: Joe Perches <joe@perches.com> To: linux-kernel@vger.kernel.org To: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-04-11lib/vsprintf: Move pointer_string() upperAndy Shevchenko1-14/+14
As preparatory patch to further clean up. No functional change. Link: http://lkml.kernel.org/r/20180216210711.79901-5-andriy.shevchenko@linux.intel.com To: "Tobin C . Harding" <me@tobin.cc> To: linux@rasmusvillemoes.dk To: Joe Perches <joe@perches.com> To: linux-kernel@vger.kernel.org To: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-04-11lib/vsprintf: Make flag_spec globalAndy Shevchenko1-13/+8
There are places where default specification to print flags as number is in use. Make it global and convert existing users. Link: http://lkml.kernel.org/r/20180216210711.79901-4-andriy.shevchenko@linux.intel.com To: "Tobin C . Harding" <me@tobin.cc> To: linux@rasmusvillemoes.dk To: Joe Perches <joe@perches.com> To: linux-kernel@vger.kernel.org To: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-04-11lib/vsprintf: Make strspec globalAndy Shevchenko1-12/+9
There are places where default specification to print strings is in use. Make it global and convert existing users. Link: http://lkml.kernel.org/r/20180216210711.79901-3-andriy.shevchenko@linux.intel.com To: "Tobin C . Harding" <me@tobin.cc> To: linux@rasmusvillemoes.dk To: Joe Perches <joe@perches.com> To: linux-kernel@vger.kernel.org To: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-04-11lib/vsprintf: Make dec_spec globalAndy Shevchenko1-12/+9
There are places where default specification to print decimal numbers is in use. Make it global and convert existing users. Link: http://lkml.kernel.org/r/20180216210711.79901-2-andriy.shevchenko@linux.intel.com To: "Tobin C . Harding" <me@tobin.cc> To: linux@rasmusvillemoes.dk To: Joe Perches <joe@perches.com> To: linux-kernel@vger.kernel.org To: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-04-06vsprintf: Do not preprocess non-dereferenced pointers for bprintf (%px and %pK)Steven Rostedt (VMware)1-0/+4
Commit 841a915d20c7b2 ("printf: Do not have bprintf dereference pointers") would preprocess various pointers that are dereferenced in the bprintf() because the recording and printing are done at two different times. Some pointers stayed dereferenced in the ring buffer because user space could handle them (namely "%pS" and friends). Pointers that are not dereferenced should not be processed immediately but instead just saved directly. Cc: stable@vger.kernel.org Fixes: 841a915d20c7b2 ("printf: Do not have bprintf dereference pointers") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-02-08vsprintf: avoid misleading "(null)" for %pxAdam Borowski1-1/+1
Like %pK already does, print "00000000" instead. This confused people -- the convention is that "(null)" means you tried to dereference a null pointer as opposed to printing the address. Link: http://lkml.kernel.org/r/20180204174521.21383-1-kilobyte@angband.pl To: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> To: Steven Rostedt <rostedt@goodmis.org> To: linux-kernel@vger.kernel.org Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Joe Perches <joe@perches.com> Cc: Kees Cook <keescook@chromium.org> Cc: "Roberts, William C" <william.c.roberts@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: David Laight <David.Laight@ACULAB.COM> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Adam Borowski <kilobyte@angband.pl> Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-02-02Merge branch 'for-linus' of ↵Linus Torvalds1-3/+2
git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk Pull printk updates from Petr Mladek: - Add a console_msg_format command line option: The value "default" keeps the old "[time stamp] text\n" format. The value "syslog" allows to see the syslog-like "<log level>[timestamp] text" format. This feature was requested by people doing regression tests, for example, 0day robot. They want to have both filtered and full logs at hands. - Reduce the risk of softlockup: Pass the console owner in a busy loop. This is a new approach to the old problem. It was first proposed by Steven Rostedt on Kernel Summit 2017. It marks a context in which the console_lock owner calls console drivers and could not sleep. On the other side, printk() callers could detect this state and use a busy wait instead of a simple console_trylock(). Finally, the console_lock owner checks if there is a busy waiter at the end of the special context and eventually passes the console_lock to the waiter. The hand-off works surprisingly well and helps in many situations. Well, there is still a possibility of the softlockup, for example, when the flood of messages stops and the last owner still has too much to flush. There is increasing number of people having problems with printk-related softlockups. We might eventually need to get better solution. Anyway, this looks like a good start and promising direction. - Do not allow to schedule in console_unlock() called from printk(): This reverts an older controversial commit. The reschedule helped to avoid softlockups. But it also slowed down the console output. This patch is obsoleted by the new console waiter logic described above. In fact, the reschedule made the hand-off less effective. - Deprecate "%pf" and "%pF" format specifier: It was needed on ia64, ppc64 and parisc64 to dereference function descriptors and show the real function address. It is done transparently by "%ps" and "pS" format specifier now. Sergey Senozhatsky found that all the function descriptors were in a special elf section and could be easily detected. - Remove printk_symbol() API: It has been obsoleted by "%pS" format specifier, and this change helped to remove few continuous lines and a less intuitive old API. - Remove redundant memsets: Sergey removed unnecessary memset when processing printk.devkmsg command line option. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk: (27 commits) printk: drop redundant devkmsg_log_str memsets printk: Never set console_may_schedule in console_trylock() printk: Hide console waiter logic into helpers printk: Add console owner and waiter logic to load balance console writes kallsyms: remove print_symbol() function checkpatch: add pF/pf deprecation warning symbol lookup: introduce dereference_symbol_descriptor() parisc64: Add .opd based function descriptor dereference powerpc64: Add .opd based function descriptor dereference ia64: Add .opd based function descriptor dereference sections: split dereference_function_descriptor() openrisc: Fix conflicting types for _exext and _stext lib: do not use print_symbol() irq debug: do not use print_symbol() sysfs: do not use print_symbol() drivers: do not use print_symbol() x86: do not use print_symbol() unicore32: do not use print_symbol() sh: do not use print_symbol() mn10300: do not use print_symbol() ...
2018-02-02Merge tag 'trace-v4.16' of ↵Linus Torvalds1-13/+69
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: "There's not much changes for the tracing system this release. Mostly small clean ups and fixes. The biggest change is to how bprintf works. bprintf is used by trace_printk() to just save the format and args of a printf call, and the formatting is done when the trace buffer is read. This is done to keep the formatting out of the fast path (this was recommended by you). The issue is when arguments are de-referenced. If a pointer is saved, and the format has something like "%*pbl", when the buffer is read, it will de-reference the argument then. The problem is if the data no longer exists. This can cause the kernel to oops. The fix for this was to make these de-reference pointes do the formatting at the time it is called (the fast path), as this guarantees that the data exists (and doesn't change later)" * tag 'trace-v4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: vsprintf: Do not have bprintf dereference pointers ftrace: Mark function tracer test functions noinline/noclone trace_uprobe: Display correct offset in uprobe_events tracing: Make sure the parsed string always terminates with '\0' tracing: Clear parser->idx if only spaces are read tracing: Detect the string nul character when parsing user input string
2018-01-23vsprintf: Do not have bprintf dereference pointersSteven Rostedt (VMware)1-13/+69
When trace_printk() was introduced, it was discussed that making it be as low overhead as possible, that the processing of the format string should be delayed until it is read. That is, a "trace_printk()" should not convert the %d into numbers and so on, but instead, save the fmt string and all the args in the buffer at the time of recording. When the trace_printk() data is read, it would then parse the format string and do the conversions of the saved arguments in the tracing buffer. The code to perform this was added to vsprintf where vbin_printf() would save the arguments of a specified format string in a buffer, then bstr_printf() could be used to convert the buffer with the same format string into the final output, as if vsprintf() was called in one go. The issue arises when dereferenced pointers are used. The problem is that something like %*pbl which reads a bitmask, will save the pointer to the bitmask in the buffer. Then the reading of the buffer via bstr_printf() will then look at the pointer to process the final output. Obviously the value of that pointer could have changed since the time it was recorded to the time the buffer is read. Worse yet, the bitmask could be unmapped, and the reading of the trace buffer could actually cause a kernel oops. Another problem is that user space tools such as perf and trace-cmd do not have access to the contents of these pointers, and they become useless when the tracing buffer is extracted. Instead of having vbin_printf() simply save the pointer in the buffer for later processing, have it perform the formatting at the time bin_printf() is called. This will fix the issue of dereferencing pointers at a later time, and has the extra benefit of having user space tools understand these values. Since perf and trace-cmd already can handle %p[sSfF] via saving kallsyms, their pointers are saved and not processed during vbin_printf(). If they were converted, it would break perf and trace-cmd, as they would not know how to deal with the conversion. Link: http://lkml.kernel.org/r/20171228204025.14a71d8f@gandalf.local.home Reported-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-09symbol lookup: introduce dereference_symbol_descriptor()Sergey Senozhatsky1-3/+2
dereference_symbol_descriptor() invokes appropriate ARCH specific function descriptor dereference callbacks: - dereference_kernel_function_descriptor() if the pointer is a kernel symbol; - dereference_module_function_descriptor() if the pointer is a module symbol. This is the last step needed to make '%pS/%ps' smart enough to handle function descriptor dereference on affected ARCHs and to retire '%pF/%pf'. To refresh it: Some architectures (ia64, ppc64, parisc64) use an indirect pointer for C function pointers - the function pointer points to a function descriptor and we need to dereference it to get the actual function pointer. Function descriptors live in .opd elf section and all affected ARCHs (ia64, ppc64, parisc64) handle it properly for kernel and modules. So we, technically, can decide if the dereference is needed by simply looking at the pointer: if it belongs to .opd section then we need to dereference it. The kernel and modules have their own .opd sections, obviously, that's why we need to split dereference_function_descriptor() and use separate kernel and module dereference arch callbacks. Link: http://lkml.kernel.org/r/20171206043649.GB15885@jagdpanzerIV Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: James Bottomley <jejb@parisc-linux.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jessica Yu <jeyu@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: linux-ia64@vger.kernel.org Cc: linux-parisc@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Tested-by: Tony Luck <tony.luck@intel.com> #ia64 Tested-by: Santosh Sivaraj <santosh@fossix.org> #powerpc Tested-by: Helge Deller <deller@gmx.de> #parisc64 Signed-off-by: Petr Mladek <pmladek@suse.com>
2017-12-21vsprintf: Fix a dangling documentation referenceJonathan Corbet1-1/+1
A reference to printk-formats.txt didn't get updated when the file moved; fix that. Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-12-21doc: convert printk-formats.txt to rstTobin C. Harding1-1/+2
Documentation/printk-formats.txt is a candidate for conversion to ReStructuredText format. Some effort has already been made to do this conversion even thought the suffix is currently .txt Changes required to complete conversion - Move printk-formats.txt to core-api/printk-formats.rst - Add entry to Documentation/core-api/index.rst - Remove entry from Documentation/00-INDEX - Fix minor grammatical errors. - Order heading adornments as suggested by rst docs. - Use 'Passed by reference' uniformly. - Update pointer documentation around %px specifier. - Fix erroneous double backticks (to commas). - Remove extraneous double backticks (suggested by Jonathan Corbet). - Simplify documentation for kobject. Signed-off-by: Tobin C. Harding <me@tobin.cc> [jc: downcased "kernel"] Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-11-29vsprintf: don't use 'restricted_pointer()' when not restrictingLinus Torvalds1-0/+2
Instead, just fall back on the new '%p' behavior which hashes the pointer. Otherwise, '%pK' - that was intended to mark a pointer as restricted - just ends up leaking pointers that a normal '%p' wouldn't leak. Which just make the whole thing pointless. I suspect we should actually get rid of '%pK' entirely, and make it just work as '%p' regardless, but this is the minimal obvious fix. People who actually use 'kptr_restrict' should weigh in on which behavior they want. Cc: Tobin Harding <me@tobin.cc> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-29vsprintf: add printk specifier %pxTobin C. Harding1-0/+18
printk specifier %p now hashes all addresses before printing. Sometimes we need to see the actual unmodified address. This can be achieved using %lx but then we face the risk that if in future we want to change the way the Kernel handles printing of pointers we will have to grep through the already existent 50 000 %lx call sites. Let's add specifier %px as a clear, opt-in, way to print a pointer and maintain some level of isolation from all the other hex integer output within the Kernel. Add printk specifier %px to print the actual unmodified address. Signed-off-by: Tobin C. Harding <me@tobin.cc>
2017-11-29printk: hash addresses printed with %pTobin C. Harding1-7/+74
Currently there exist approximately 14 000 places in the kernel where addresses are being printed using an unadorned %p. This potentially leaks sensitive information regarding the Kernel layout in memory. Many of these calls are stale, instead of fixing every call lets hash the address by default before printing. This will of course break some users, forcing code printing needed addresses to be updated. Code that _really_ needs the address will soon be able to use the new printk specifier %px to print the address. For what it's worth, usage of unadorned %p can be broken down as follows (thanks to Joe Perches). $ git grep -E '%p[^A-Za-z0-9]' | cut -f1 -d"/" | sort | uniq -c 1084 arch 20 block 10 crypto 32 Documentation 8121 drivers 1221 fs 143 include 101 kernel 69 lib 100 mm 1510 net 40 samples 7 scripts 11 security 166 sound 152 tools 2 virt Add function ptr_to_id() to map an address to a 32 bit unique identifier. Hash any unadorned usage of specifier %p and any malformed specifiers. Signed-off-by: Tobin C. Harding <me@tobin.cc>
2017-11-29vsprintf: refactor %pK code out of pointer()Tobin C. Harding1-43/+54
Currently code to handle %pK is all within the switch statement in pointer(). This is the wrong level of abstraction. Each of the other switch clauses call a helper function, pK should do the same. Refactor code out of pointer() to new function restricted_pointer(). Signed-off-by: Tobin C. Harding <me@tobin.cc>
2017-10-25locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns ↵Mark Rutland1-2/+2
to READ_ONCE()/WRITE_ONCE() Please do not apply this to mainline directly, instead please re-run the coccinelle script shown below and apply its output. For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't harmful, and changing them results in churn. However, for some features, the read/write distinction is critical to correct operation. To distinguish these cases, separate read/write accessors must be used. This patch migrates (most) remaining ACCESS_ONCE() instances to {READ,WRITE}_ONCE(), using the following coccinelle script: ---- // Convert trivial ACCESS_ONCE() uses to equivalent READ_ONCE() and // WRITE_ONCE() // $ make coccicheck COCCI=/home/mark/once.cocci SPFLAGS="--include-headers" MODE=patch virtual patch @ depends on patch @ expression E1, E2; @@ - ACCESS_ONCE(E1) = E2 + WRITE_ONCE(E1, E2) @ depends on patch @ expression E; @@ - ACCESS_ONCE(E) + READ_ONCE(E) ---- Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: davem@davemloft.net Cc: linux-arch@vger.kernel.org Cc: mpe@ellerman.id.au Cc: shuah@kernel.org Cc: snitzer@redhat.com Cc: thor.thayer@linux.intel.com Cc: tj@kernel.org Cc: viro@zeniv.linux.org.uk Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1508792849-3115-19-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-07-07Merge tag 'devicetree-for-4.13' of ↵Linus Torvalds1-0/+136
git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux Pull DeviceTree updates from Rob Herring: - vsprintf format specifier %pOF for device_node's. This will enable us to stop storing the full node names. Conversion of users will happen next cycle. - Update documentation to point to DT specification instead of ePAPR. - Split out graph and property functions to a separate file. - New of-graph functions for ALSA - Add vendor prefixes for RISC-V, Linksys, iWave Systems, Roofull, Itead, and BananaPi. - Improve dtx_diff utility filename printing. * tag 'devicetree-for-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (32 commits) of: document /sys/firmware/fdt dt-bindings: Add RISC-V vendor prefix vsprintf: Add %p extension "%pOF" for device tree of: find_node_by_full_name rewrite to compare each level of: use kbasename instead of open coding dt-bindings: thermal: add file extension to brcm,ns-thermal of: update ePAPR references to point to Devicetree Specification scripts/dtc: dtx_diff - Show real file names in diff header of: detect invalid phandle in overlay of: be consistent in form of file mode of: make __of_attach_node() static of: address.c header comment typo of: fdt.c header comment typo of: make of_fdt_is_compatible() static dt-bindings: display-timing.txt convert non-ascii characters to ascii Documentation: remove overlay-notes reference to non-existent file dt-bindings: usb: exynos-usb: Add missing required VDD properties dt-bindings: Add vendor prefix for Linksys MAINTAINERS: add device tree ABI documentation file of: Add vendor prefix for iWave Systems Technologies Pvt. Ltd ...
2017-06-27vsprintf: Add %p extension "%pOF" for device treePantelis Antoniou1-0/+136
90% of the usage of device node's full_name is printing it out in a kernel message. However, storing the full path for every node is wasteful and redundant. With a custom format specifier, we can generate the full path at run-time and eventually remove the full path from every node. For instance typical use is: pr_info("Frobbing node %s\n", node->full_name); Which can be written now as: pr_info("Frobbing node %pOF\n", node); '%pO' is the base specifier to represent kobjects with '%pOF' representing struct device_node. Currently, struct device_node is the only supported type of kobject. More fine-grained control of formatting includes printing the name, flags, path-spec name and others, explained in the documentation entry. Originally written by Pantelis, but pretty much rewrote the core function using existing string/number functions. The 2 passes were unnecessary and have been removed. Also, updated the checkpatch.pl check. The unittest code was written by Grant Likely. Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com> Acked-by: Joe Perches <joe@perches.com> Signed-off-by: Rob Herring <robh@kernel.org>
2017-06-05uuid: rename uuid typesChristoph Hellwig1-2/+2
Our "little endian" UUID really is a Wintel GUID, so rename it and its helpers such (guid_t). The big endian UUID is the only true one, so give it the name uuid_t. The uuid_le and uuid_be names are retained for now, but will hopefully go away soon. The exception to that are the _cmp helpers that will be replaced by better primitives ASAP and thus don't get the new names. Also the _to_bin helpers are named to match the better named uuid_parse routine in userspace. Also remove the existing typedef in XFS that's now been superceeded by the generic type name. Signed-off-by: Christoph Hellwig <hch@lst.de> [andy: also update the UUID_LE/UUID_BE macros including fallout] Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-05-09checkpatch: add ability to find bad uses of vsprintf %p<foo> extensionsJoe Perches1-0/+3
%pK was at least once misused at %pk in an out-of-tree module. This lead to some security concerns. Add the ability to track single and multiple line statements for misuses of %p<foo>. [akpm@linux-foundation.org: add helpful comment into lib/vsprintf.c] [akpm@linux-foundation.org: text tweak] Link: http://lkml.kernel.org/r/163a690510e636a23187c0dc9caa09ddac6d4cde.1488228427.git.joe@perches.com Signed-off-by: Joe Perches <joe@perches.com> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: William Roberts <william.c.roberts@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-04-02kernel-api.rst: fix output of the vsnprintf() documentationmchehab@s-opensource.com1-3/+3
The vsnprintf() kernel-doc comment uses % character with a special meaning other than escaping a constant. As ReST already defines ``literal`` as an escape sequence, let's make kernel-doc handle it, and use it at lib/vsprintf.c. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-02-28lib/vsprintf.c: remove %Z supportAlexey Dobriyan1-4/+4
Now that %z is standartised in C99 there is no reason to support %Z. Unlike %L it doesn't even make format strings smaller. Use BUILD_BUG_ON in a couple ATM drivers. In case anyone didn't notice lib/vsprintf.o is about half of SLUB which is in my opinion is quite an achievement. Hopefully this patch inspires someone else to trim vsprintf.c more. Link: http://lkml.kernel.org/r/20170103230126.GA30170@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-21lib/uuid.c: introduce a few more generic helpersAndy Shevchenko1-5/+4
There are new helpers in this patch: uuid_is_valid checks if a UUID is valid uuid_be_to_bin converts from string to binary (big endian) uuid_le_to_bin converts from string to binary (little endian) They will be used in future, i.e. in the following patches in the series. This also moves the indices arrays to lib/uuid.c to be shared accross modules. [andriy.shevchenko@linux.intel.com: fix typo] Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com> Cc: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-21lib/vsprintf: simplify UUID printingAndy Shevchenko1-8/+4
There are few functions here and there along with type definitions that provide UUID API. This series consolidates everything under one hood and converts current users. This has been tested for a while internally, however it doesn't mean we covered all possible cases (especially accuracy of UUID constants after conversion). So, please test this as much as you can and provide your tag. We appreciate the effort. The ACPI conversion is postponed for now to sort more generic things out first. This patch (of 9): Since we have hex_byte_pack_upper() we may use it directly and avoid second loop. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com> Cc: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-18sscanf: implement basic character setsJessica Yu1-1/+58
Implement basic character sets for the '%[' conversion specifier. The '%[' conversion specifier matches a nonempty sequence of characters from the specified set of accepted (or with '^', rejected) characters between the brackets. The substring matched is to be made up of characters in (or not in) the set. This is useful for matching substrings that are delimited by something other than spaces. This implementation differs from its glibc counterpart in the following ways: (1) No support for character ranges (e.g., 'a-z' or '0-9') (2) The hyphen '-' is not a special character (3) The closing bracket ']' cannot be matched (4) No support (yet) for discarding matching input ('%*[') The bitmap code is largely based upon sample code which was provided by Rasmus. The motivation for adding character set support to sscanf originally stemmed from the kernel livepatching project. An ongoing patchset utilizes new livepatch Elf symbol and section names to store important metadata livepatch needs to properly apply its patches. Such metadata is stored in these section and symbol names as substrings delimited by periods '.' and commas ','. For example, a livepatch symbol name might look like this: .klp.sym.vmlinux.printk,0 However, sscanf currently can only extract "substrings" delimited by whitespace using the "%s" specifier. Thus for the above symbol name, one cannot not use sscanf() to extract substrings "vmlinux" or "printk", for example. A number of discussions on the livepatch mailing list dealing with string parsing code for extracting these '.' and ',' delimited substrings eventually led to the conclusion that such code would be completely unnecessary if the kernel sscanf() supported character sets. Thus only a single sscanf() call would be necessary to extract these substrings. In addition, such an addition to sscanf() could benefit other areas of the kernel that might have a similar need in the future. [akpm@linux-foundation.org: 80-col tweaks] Signed-off-by: Jessica Yu <jeyu@redhat.com> Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-16mm, printk: introduce new format string for flagsVlastimil Babka1-0/+75
In mm we use several kinds of flags bitfields that are sometimes printed for debugging purposes, or exported to userspace via sysfs. To make them easier to interpret independently on kernel version and config, we want to dump also the symbolic flag names. So far this has been done with repeated calls to pr_cont(), which is unreliable on SMP, and not usable for e.g. sysfs export. To get a more reliable and universal solution, this patch extends printk() format string for pointers to handle the page flags (%pGp), gfp_flags (%pGg) and vma flags (%pGv). Existing users of dump_flag_names() are converted and simplified. It would be possible to pass flags by value instead of pointer, but the %p format string for pointers already has extensions for various kernel structures, so it's a good fit, and the extra indirection in a non-critical path is negligible. [linux@rasmusvillemoes.dk: lots of good implementation suggestions] Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>