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2019-05-21treewide: Add SPDX license identifier for missed filesThomas Gleixner
Add SPDX license identifiers to all files which: - Have no license information of any form - Have EXPORT_.*_SYMBOL_GPL inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-10vsprintf: Do not break early boot with probing addressesPetr Mladek
The commit 3e5903eb9cff70730 ("vsprintf: Prevent crash when dereferencing invalid pointers") broke boot on several architectures. The common pattern is that probe_kernel_read() is not working during early boot because userspace access framework is not ready. It is a generic problem. We have to avoid any complex external functions in vsprintf() code, especially in the common path. They might break printk() easily and are hard to debug. Replace probe_kernel_read() with some simple checks for obvious problems. Details: 1. Report on Power: Kernel crashes very early during boot with with CONFIG_PPC_KUAP and CONFIG_JUMP_LABEL_FEATURE_CHECK_DEBUG The problem is the combination of some new code called via printk(), check_pointer() which calls probe_kernel_read(). That then calls allow_user_access() (PPC_KUAP) and that uses mmu_has_feature() too early (before we've patched features). With the JUMP_LABEL debug enabled that causes us to call printk() & dump_stack() and we end up recursing and overflowing the stack. Because it happens so early you don't get any output, just an apparently dead system. The stack trace (which you don't see) is something like: ... dump_stack+0xdc probe_kernel_read+0x1a4 check_pointer+0x58 string+0x3c vsnprintf+0x1bc vscnprintf+0x20 printk_safe_log_store+0x7c printk+0x40 dump_stack_print_info+0xbc dump_stack+0x8 probe_kernel_read+0x1a4 probe_kernel_read+0x19c check_pointer+0x58 string+0x3c vsnprintf+0x1bc vscnprintf+0x20 vprintk_store+0x6c vprintk_emit+0xec vprintk_func+0xd4 printk+0x40 cpufeatures_process_feature+0xc8 scan_cpufeatures_subnodes+0x380 of_scan_flat_dt_subnodes+0xb4 dt_cpu_ftrs_scan_callback+0x158 of_scan_flat_dt+0xf0 dt_cpu_ftrs_scan+0x3c early_init_devtree+0x360 early_setup+0x9c 2. Report on s390: vsnprintf invocations, are broken on s390. For example, the early boot output now looks like this where the first (efault) should be the linux_banner: [ 0.099985] (efault) [ 0.099985] setup: Linux is running as a z/VM guest operating system in 64-bit mode [ 0.100066] setup: The maximum memory size is 8192MB [ 0.100070] cma: Reserved 4 MiB at (efault) [ 0.100100] numa: NUMA mode: (efault) The reason for this, is that the code assumes that probe_kernel_address() works very early. This however is not true on at least s390. Uaccess on KERNEL_DS works only after page tables have been setup on s390, which happens with setup_arch()->paging_init(). Any probe_kernel_address() invocation before that will return -EFAULT. Fixes: 3e5903eb9cff70730 ("vsprintf: Prevent crash when dereferencing invalid pointers") Link: http://lkml.kernel.org/r/20190510084213.22149-1-pmladek@suse.com Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: "Tobin C . Harding" <me@tobin.cc> Cc: Michal Hocko <mhocko@suse.cz> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: linux-kernel@vger.kernel.org Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: linuxppc-dev@lists.ozlabs.org Cc: Russell Currey <ruscur@russell.cc> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Stephen Rothwell <sfr@ozlabs.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux-arch@vger.kernel.org Cc: linux-s390@vger.kernel.org Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Petr Mladek <pmladek@suse.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-04-29lib/vsprintf: Make function pointer_string staticYueHaibing
Fix sparse warning: lib/vsprintf.c:673:6: warning: symbol 'pointer_string' was not declared. Should it be static? Link: http://lkml.kernel.org/r/20190426164630.22104-1-yuehaibing@huawei.com To: <sergey.senozhatsky@gmail.com> To: <andriy.shevchenko@linux.intel.com> To: <geert+renesas@glider.be> To: <rostedt@goodmis.org> Signed-off-by: YueHaibing <yuehaibing@huawei.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-04-26vsprintf: Limit the length of inlined error messagesPetr Mladek
The inlined error messages must be used carefully because they need to fit into the given buffer. Handle them using a custom wrapper that makes people aware of the problem. Also define a reasonable hard limit to avoid a completely insane usage. Suggested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Link: http://lkml.kernel.org/r/20190417115350.20479-11-pmladek@suse.com To: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: "Tobin C . Harding" <me@tobin.cc> Cc: Joe Perches <joe@perches.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: linux-kernel@vger.kernel.org Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-04-26vsprintf: Avoid confusion between invalid address and valuePetr Mladek
We are able to detect invalid values handled by %p[iI] printk specifier. The current error message is "invalid address". It might cause confusion against "(efault)" reported by the generic valid_pointer_address() check. Let's unify the style and use the more appropriate error code description "(einval)". Link: http://lkml.kernel.org/r/20190417115350.20479-10-pmladek@suse.com To: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: "Tobin C . Harding" <me@tobin.cc> Cc: Joe Perches <joe@perches.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: linux-kernel@vger.kernel.org Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-04-26vsprintf: Prevent crash when dereferencing invalid pointersPetr Mladek
We already prevent crash when dereferencing some obviously broken pointers. But the handling is not consistent. Sometimes we print "(null)" only for pure NULL pointer, sometimes for pointers in the first page and sometimes also for pointers in the last page (error codes). Note that printk() call this code under logbuf_lock. Any recursive printks are redirected to the printk_safe implementation and the messages are stored into per-CPU buffers. These buffers might be eventually flushed in printk_safe_flush_on_panic() but it is not guaranteed. This patch adds a check using probe_kernel_read(). It is not a full-proof test. But it should help to see the error message in 99% situations where the kernel would silently crash otherwise. Also it makes the error handling unified for "%s" and the many %p* specifiers that need to read the data from a given address. We print: + (null) when accessing data on pure pure NULL address + (efault) when accessing data on an invalid address It does not affect the %p* specifiers that just print the given address in some form, namely %pF, %pf, %pS, %ps, %pB, %pK, %px, and plain %p. Note that we print (efault) from security reasons. In fact, the real address can be seen only by %px or eventually %pK. Link: http://lkml.kernel.org/r/20190417115350.20479-9-pmladek@suse.com To: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: "Tobin C . Harding" <me@tobin.cc> Cc: Joe Perches <joe@perches.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: linux-kernel@vger.kernel.org Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-04-26vsprintf: Consolidate handling of unknown pointer specifiersPetr Mladek
There are few printk formats that make sense only with two or more specifiers. Also some specifiers make sense only when a kernel feature is enabled. The handling of unknown specifiers is inconsistent and not helpful. Using WARN() looks like an overkill for this type of error. pr_warn() is not good either. It would by handled via printk_safe buffer and it might be hard to match it with the problematic string. A reasonable compromise seems to be writing the unknown format specifier into the original string with a question mark, for example (%pC?). It should be self-explaining enough. Note that it is in brackets to follow the (null) style. Note that it introduces a warning about that test_hashed() function is unused. It is going to be used again by a later patch. Link: http://lkml.kernel.org/r/20190417115350.20479-8-pmladek@suse.com To: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: "Tobin C . Harding" <me@tobin.cc> Cc: Joe Perches <joe@perches.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: linux-kernel@vger.kernel.org Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-04-26vsprintf: Factor out %pO handler as kobject_string()Petr Mladek
Move code from the long pointer() function. We are going to improve error handling that will make it even more complicated. This patch does not change the existing behavior. Link: http://lkml.kernel.org/r/20190417115350.20479-7-pmladek@suse.com To: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: "Tobin C . Harding" <me@tobin.cc> Cc: Joe Perches <joe@perches.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: linux-kernel@vger.kernel.org Cc: Kees Cook <keescook@chromium.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-04-26vsprintf: Factor out %pV handler as va_format()Petr Mladek
Move the code from the long pointer() function. We are going to improve error handling that will make it more complicated. This patch does not change the existing behavior. Link: http://lkml.kernel.org/r/20190417115350.20479-6-pmladek@suse.com To: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: "Tobin C . Harding" <me@tobin.cc> Cc: Joe Perches <joe@perches.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: linux-kernel@vger.kernel.org Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-04-26vsprintf: Factor out %p[iI] handler as ip_addr_string()Petr Mladek
Move the non-trivial code from the long pointer() function. We are going to improve error handling that will make it even more complicated. This patch does not change the existing behavior. Link: http://lkml.kernel.org/r/20190417115350.20479-5-pmladek@suse.com To: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: "Tobin C . Harding" <me@tobin.cc> Cc: Joe Perches <joe@perches.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: linux-kernel@vger.kernel.org Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-04-26vsprintf: Do not check address of well-known stringsPetr Mladek
We are going to check the address using probe_kernel_address(). It will be more expensive and it does not make sense for well known address. This patch splits the string() function. The variant without the check is then used on locations that handle string constants or strings defined as local variables. This patch does not change the existing behavior. Link: http://lkml.kernel.org/r/20190417115350.20479-4-pmladek@suse.com To: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: "Tobin C . Harding" <me@tobin.cc> Cc: Joe Perches <joe@perches.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: linux-kernel@vger.kernel.org Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
2019-04-26vsprintf: Consistent %pK handling for kptr_restrict == 0Petr Mladek
restricted_pointer() pretends that it prints the address when kptr_restrict is set to zero. But it is never called in this situation. Instead, pointer() falls back to ptr_to_id() and hashes the pointer. This patch removes the potential confusion. klp_restrict is checked only in restricted_pointer(). It actually fixes a small race when the address might get printed unhashed: CPU0 CPU1 pointer() if (!kptr_restrict) /* for example set to 2 */ restricted_pointer() /* echo 0 >/proc/sys/kernel/kptr_restrict */ proc_dointvec_minmax_sysadmin() klpr_restrict = 0; switch(kptr_restrict) case 0: break: number() Fixes: ef0010a30935de4e0211 ("vsprintf: don't use 'restricted_pointer()' when not restricting") Link: http://lkml.kernel.org/r/20190417115350.20479-3-pmladek@suse.com To: Andy Shevchenko <andriy.shevchenko@linux.intel.com> To: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: "Tobin C . Harding" <me@tobin.cc> Cc: Joe Perches <joe@perches.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: linux-kernel@vger.kernel.org Cc: Kees Cook <keescook@chromium.org> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-04-26vsprintf: Shuffle restricted_pointer()Petr Mladek
This is just a preparation step for further changes. The patch does not change the code. Link: http://lkml.kernel.org/r/20190417115350.20479-2-pmladek@suse.com To: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: "Tobin C . Harding" <me@tobin.cc> Cc: Joe Perches <joe@perches.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: linux-kernel@vger.kernel.org Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-03-09Merge tag 'printk-for-5.1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk Pull printk updates from Petr Mladek: - Allow to sort mixed lines by an extra information about the caller - Remove no longer used LOG_PREFIX. - Some clean up and documentation update. * tag 'printk-for-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk: printk/docs: Add extra integer types to printk-formats printk: Remove no longer used LOG_PREFIX. lib/vsprintf: Remove %pCr remnant in comment printk: Pass caller information to log_store(). printk: Add caller information to printk() output.
2019-03-07lib/vsprintf.c: move sizeof(struct printf_spec) next to its definitionRasmus Villemoes
At the time of commit d048419311ff ("lib/vsprintf.c: expand field_width to 24 bits"), there was no compiletime_assert/BUILD_BUG/.... variant that could be used outside function scope. Now we have static_assert(), so move the assertion next to the definition instead of hiding it in some arbitrary function. Also add the appropriate #include to avoid relying on build_bug.h being pulled in via some arbitrary chain of includes. Link: http://lkml.kernel.org/r/20190208203015.29702-2-linux@rasmusvillemoes.dk Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Kees Cook <keescook@chromium.org> Cc: Luc Van Oostenryck <luc.vanoostenryck@gmail.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-02-28lib/vsprintf: Remove %pCr remnant in commentGeert Uytterhoeven
Support for "%pCr" was removed, but a reference in a comment was forgotten. Fixes: 666902e42fd8344b ("lib/vsprintf: Remove atomic-unsafe support for %pCr") Link: http://lkml.kernel.org/r/20190228105315.744-1-geert+renesas@glider.be To: Andy Shevchenko <andriy.shevchenko@linux.intel.com> To: Andrew Morton <akpm@linux-foundation.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-12-10lib/vsprintf: Print time and date in human readable format via %ptAndy Shevchenko
There are users which print time and date represented by content of struct rtc_time in human readable format. Instead of open coding that each time introduce %ptR[dt][r] specifier. Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Jonathan Hunter <jonathanh@nvidia.com> Cc: Krzysztof Kozlowski <krzk@kernel.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Petr Mladek <pmladek@suse.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-10-26Merge tag 'devicetree-for-4.20' of ↵Linus Torvalds
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 ...
2018-10-25Merge tag 'printk-for-4.20' of ↵Linus Torvalds
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 Torvalds
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 Uytterhoeven
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 Uytterhoeven
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 Uytterhoeven
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 Uytterhoeven
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 Uytterhoeven
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)
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 Herring
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>
2018-08-15Merge tag 'random_for_linus' of ↵Linus Torvalds
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 Assche
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>
2018-07-17vsprintf: Add command line option debug_boot_weak_hashTobin C. Harding
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>
2018-07-17vsprintf: Use hw RNG for ptr_keyTobin C. Harding
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>
2018-06-06Merge tag 'printk-for-4.18' of ↵Linus Torvalds
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 Mladek
2018-06-05lib/vsprintf: Remove atomic-unsafe support for %pCrGeert Uytterhoeven
"%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)
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 Senozhatsky
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 Vagin
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 Shevchenko
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 Yang
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 Shevchenko
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 Shevchenko
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 Shevchenko
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 Shevchenko
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 Shevchenko
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)
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 Borowski
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>
2018-02-01Merge branch 'for-linus' of ↵Linus Torvalds
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() ...
2018-02-01Merge tag 'trace-v4.16' of ↵Linus Torvalds
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)
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 Senozhatsky
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>