user/sven/linux.git/include/linux/kernel.h, branch v5.9.8

kernel.h: Silence sparse warning in lower_32_bits

2020-08-28T18:21:20Z

I keep getting sparse warnings in crypto such as: CHECK drivers/crypto/ccree/cc_hash.c drivers/crypto/ccree/cc_hash.c:49:9: warning: cast truncates bits from constant value (47b5481dbefa4fa4 becomes befa4fa4) drivers/crypto/ccree/cc_hash.c:49:26: warning: cast truncates bits from constant value (db0c2e0d64f98fa7 becomes 64f98fa7) [.. many more ..] This patch removes the warning by adding a mask to keep sparse happy. Signed-off-by: Herbert Xu Signed-off-by: Linus Torvalds

panic: make print_oops_end_marker() static

2020-08-12T17:58:02Z

Since print_oops_end_marker() is not used externally, also remove it in kernel.h at the same time. Signed-off-by: Yue Hu Signed-off-by: Andrew Morton Cc: Kees Cook Link: http://lkml.kernel.org/r/20200724011516.12756-1-zbestahu@gmail.com Signed-off-by: Linus Torvalds

kernel/panic.c: make oops_may_print() return bool

2020-08-12T17:58:01Z

The return value of oops_may_print() is true or false, so change its type to reflect that. Signed-off-by: Tiezhu Yang Signed-off-by: Andrew Morton Reviewed-by: Kees Cook Cc: Xuefeng Li Link: http://lkml.kernel.org/r/1591103358-32087-1-git-send-email-yangtiezhu@loongson.cn Signed-off-by: Linus Torvalds

kstrto: do not describe simple_strto() as obsolete/replaced

2020-08-12T17:58:00Z

The documentation of the kstrto*() functions describes kstrto*() as "replacements" of the "obsolete" simple_strto*() functions. Both of these terms are inaccurate: they're not replacements because they have different behaviour, and the simple_strto*() are not obsolete because there are cases where they have benefits over kstrto*(). Remove usage of the terms "replacement" and "obsolete" in reference to simple_strto*(), and instead use the term "preferred over". Fixes: 4c925d6031f71 ("kstrto*: add documentation") Fixes: 885e68e8b7b13 ("kernel.h: update comment about simple_strto() functions") Signed-off-by: Kars Mulder Signed-off-by: Andrew Morton Reviewed-by: Andy Shevchenko Cc: Eldad Zack Cc: Miguel Ojeda Cc: Geert Uytterhoeven Cc: Mans Rullgard Cc: Petr Mladek Link: http://lkml.kernel.org/r/29b9-5f234c80-13-4e3aa200@244003027 Signed-off-by: Linus Torvalds

kstrto: correct documentation references to simple_strto()

2020-08-12T17:58:00Z

The documentation of the kstrto*() functions reference the simple_strtoull function by "used as a replacement for [the obsolete] simple_strtoull". All these functions describes themselves as replacements for the function simple_strtoull, even though a function like kstrtol() would be more aptly described as a replacement of simple_strtol(). Fix these references by making the documentation of kstrto*() reference the closest simple_strto*() equivalent available. The functions kstrto[u]int() do not have direct simple_strto[u]int() equivalences, so these are made to refer to simple_strto[u]l() instead. Furthermore, add parentheses after function names, as is standard in kernel documentation. Fixes: 4c925d6031f71 ("kstrto*: add documentation") Signed-off-by: Kars Mulder Signed-off-by: Andrew Morton Reviewed-by: Andy Shevchenko Cc: Eldad Zack Cc: Miguel Ojeda Cc: Geert Uytterhoeven Cc: Mans Rullgard Cc: Petr Mladek Link: http://lkml.kernel.org/r/1ee1-5f234c00-f3-165a6440@234394593 Signed-off-by: Linus Torvalds

kernel.h: remove duplicate include of asm/div64.h

2020-08-12T17:57:59Z

This seems to have been added inadvertently in commit 72deb455b5ec ("block: remove CONFIG_LBDAF") Fixes: 72deb455b5ec ("block: remove CONFIG_LBDAF") Signed-off-by: Arvind Sankar Signed-off-by: Andrew Morton Reviewed-by: Christoph Hellwig Link: http://lkml.kernel.org/r/20200727034852.2813453-1-nivedita@alum.mit.edu Signed-off-by: Linus Torvalds

linux/kernel.h: Add PTR_ALIGN_DOWN macro

2020-07-27T14:46:16Z

Add a macro for aligning down a pointer. This is useful to get an aligned register address when a device allows only word access and doesn't allow half word or byte access. Link: https://lore.kernel.org/r/20200722110317.4744-4-kishon@ti.com Signed-off-by: Kishon Vijay Abraham I Signed-off-by: Lorenzo Pieralisi Acked-by: Rob Herring

panic: add sysctl to dump all CPUs backtraces on oops event

2020-06-08T18:05:56Z

Usually when the kernel reaches an oops condition, it's a point of no return; in case not enough debug information is available in the kernel splat, one of the last resorts would be to collect a kernel crash dump and analyze it. The problem with this approach is that in order to collect the dump, a panic is required (to kexec-load the crash kernel). When in an environment of multiple virtual machines, users may prefer to try living with the oops, at least until being able to properly shutdown their VMs / finish their important tasks. This patch implements a way to collect a bit more debug details when an oops event is reached, by printing all the CPUs backtraces through the usage of NMIs (on architectures that support that). The sysctl added (and documented) here was called "oops_all_cpu_backtrace", and when set will (as the name suggests) dump all CPUs backtraces. Far from ideal, this may be the last option though for users that for some reason cannot panic on oops. Most of times oopses are clear enough to indicate the kernel portion that must be investigated, but in virtual environments it's possible to observe hypervisor/KVM issues that could lead to oopses shown in other guests CPUs (like virtual APIC crashes). This patch hence aims to help debug such complex issues without resorting to kdump. Signed-off-by: Guilherme G. Piccoli Signed-off-by: Andrew Morton Reviewed-by: Kees Cook Cc: Luis Chamberlain Cc: Iurii Zaikin Cc: Thomas Gleixner Cc: Vlastimil Babka Cc: Randy Dunlap Cc: Matthew Wilcox Link: http://lkml.kernel.org/r/20200327224116.21030-1-gpiccoli@canonical.com Signed-off-by: Linus Torvalds

kernel: add panic_on_taint

2020-06-08T18:05:56Z

Analogously to the introduction of panic_on_warn, this patch introduces a kernel option named panic_on_taint in order to provide a simple and generic way to stop execution and catch a coredump when the kernel gets tainted by any given flag. This is useful for debugging sessions as it avoids having to rebuild the kernel to explicitly add calls to panic() into the code sites that introduce the taint flags of interest. For instance, if one is interested in proceeding with a post-mortem analysis at the point a given code path is hitting a bad page (i.e. unaccount_page_cache_page(), or slab_bug()), a coredump can be collected by rebooting the kernel with 'panic_on_taint=0x20' amended to the command line. Another, perhaps less frequent, use for this option would be as a means for assuring a security policy case where only a subset of taints, or no single taint (in paranoid mode), is allowed for the running system. The optional switch 'nousertaint' is handy in this particular scenario, as it will avoid userspace induced crashes by writes to sysctl interface /proc/sys/kernel/tainted causing false positive hits for such policies. [akpm@linux-foundation.org: tweak kernel-parameters.txt wording] Suggested-by: Qian Cai Signed-off-by: Rafael Aquini Signed-off-by: Andrew Morton Reviewed-by: Luis Chamberlain Cc: Dave Young Cc: Baoquan He Cc: Jonathan Corbet Cc: Kees Cook Cc: Randy Dunlap Cc: "Theodore Ts'o" Cc: Adrian Bunk Cc: Greg Kroah-Hartman Cc: Laura Abbott Cc: Jeff Mahoney Cc: Jiri Kosina Cc: Takashi Iwai Link: http://lkml.kernel.org/r/20200515175502.146720-1-aquini@redhat.com Signed-off-by: Linus Torvalds

sched: Provide cant_migrate()

2020-02-20T20:17:24Z

Some code pathes rely on preempt_disable() to prevent migration on a non RT enabled kernel. These preempt_disable/enable() pairs are substituted by migrate_disable/enable() pairs or other forms of RT specific protection. On RT these protections prevent migration but not preemption. Obviously a cant_sleep() check in such a section will trigger on RT because preemption is not disabled. Provide a cant_migrate() macro which maps to cant_sleep() on a non RT kernel and an empty placeholder for RT for now. The placeholder will be changed to a proper debug check along with the RT specific migration protection mechanism. Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/20200214161503.070487511@linutronix.de

user/sven/linux.git/include/linux/kernel.h, branch v5.9.8

kernel.h: Silence sparse warning in lower_32_bits

panic: make print_oops_end_marker() static

kernel/panic.c: make oops_may_print() return bool

kstrto*: do not describe simple_strto*() as obsolete/replaced

kstrto*: correct documentation references to simple_strto*()

kernel.h: remove duplicate include of asm/div64.h

linux/kernel.h: Add PTR_ALIGN_DOWN macro

panic: add sysctl to dump all CPUs backtraces on oops event

kernel: add panic_on_taint

sched: Provide cant_migrate()

kstrto: do not describe simple_strto() as obsolete/replaced

kstrto: correct documentation references to simple_strto()