- 07 May, 2021 40 commits
-
-
Drew Fustini authored
Add typo "overlfow" for "overflow". This typo was found and fixed in net/sctp/tsnmap.c. Link: https://lore.kernel.org/netdev/20210304055548.56829-1-drew@beagleboard.org/ Link: https://lkml.kernel.org/r/20210304072657.64577-1-drew@beagleboard.orgSigned-off-by:
Drew Fustini <drew@beagleboard.org> Suggested-by:
Kees Cook <keescook@chromium.org> Reviewed-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
-
Maninder Singh authored
In case of a use after free kernel oops, the freeing path of the object is required to debug futher. In most of cases the object address is present in one of the registers. Thus check the register's address and if it belongs to slab, print its alloc and free path. e.g. in the below issue register r6 belongs to slab, and a use after free issue occurred on one of its dereferenced values: Unable to handle kernel paging request at virtual address 6b6b6b6f .... pc : [<c0538afc>] lr : [<c0465674>] psr: 60000013 sp : c8927d40 ip : ffffefff fp : c8aa8020 r10: c8927e10 r9 : 00000001 r8 : 00400cc0 r7 : 00000000 r6 : c8ab0180 r5 : c1804a80 r4 : c8aa8008 r3 : c1a5661c r2 : 00000000 r1 : 6b6b6b6b r0 : c139bf48 ..... Register r6 information: slab kmalloc-64 start c8ab0140 data offset 64 pointer offset 0 size 64 allocated at meminfo_proc_show+0x40/0x4fc meminfo_proc_show+0x40/0x4fc seq_read_iter+0x18c/0x4c4 proc_reg_read_iter+0x84/0xac generic_file_splice_read+0xe8/0x17c splice_direct_to_actor+0xb8/0x290 do_splice_direct+0xa0/0xe0 do_sendfile+0x2d0/0x438 sys_sendfile64+0x12c/0x140 ret_fast_syscall+0x0/0x58 0xbeeacde4 Free path: meminfo_proc_show+0x5c/0x4fc seq_read_iter+0x18c/0x4c4 proc_reg_read_iter+0x84/0xac generic_file_splice_read+0xe8/0x17c splice_direct_to_actor+0xb8/0x290 do_splice_direct+0xa0/0xe0 do_sendfile+0x2d0/0x438 sys_sendfile64+0x12c/0x140 ret_fast_syscall+0x0/0x58 0xbeeacde4 Link: https://lkml.kernel.org/r/1615891032-29160-3-git-send-email-maninder1.s@samsung.comCo-developed-by:Vaneet Narang <v.narang@samsung.com> Signed-off-by:
Maninder Singh <maninder1.s@samsung.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Dmitry Safonov <0x7f454c46@gmail.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by:
-
David Hildenbrand authored
The last user (/dev/kmem) is gone. Let's drop it. Link: https://lkml.kernel.org/r/20210324102351.6932-4-david@redhat.comSigned-off-by:
David Hildenbrand <david@redhat.com> Acked-by:
Michal Hocko <mhocko@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hillf Danton <hdanton@sina.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Minchan Kim <minchan@kernel.org> Cc: huang ying <huang.ying.caritas@gmail.com> Signed-off-by:
-
David Hildenbrand authored
Since /dev/kmem has been removed, let's remove the xlate_dev_kmem_ptr() leftovers. Link: https://lkml.kernel.org/r/20210324102351.6932-3-david@redhat.comSigned-off-by:
Geert Uytterhoeven <geert@linux-m68k.org> Acked-by:
-
David Hildenbrand authored
Patch series "drivers/char: remove /dev/kmem for good". Exploring /dev/kmem and /dev/mem in the context of memory hot(un)plug and memory ballooning, I started questioning the existence of /dev/kmem. Comparing it with the /proc/kcore implementation, it does not seem to be able to deal with things like a) Pages unmapped from the direct mapping (e.g., to be used by secretmem) -> kern_addr_valid(). virt_addr_valid() is not sufficient. b) Special cases like gart aperture memory that is not to be touched -> mem_pfn_is_ram() Unless I am missing something, it's at least broken in some cases and might fault/crash the machine. Looks like its existence has been questioned before in 2005 and 2010 [1], after ~11 additional years, it might make sense to revive the discussion. CONFIG_DEVKMEM is only enabled in a single defconfig (on purpose or by mistake?). All distributions disable it: in Ubuntu it has been disabled for more than 10 years, in Debian since 2.6.31, in Fedora at least starting with FC3, in RHEL starting with RHEL4, in SUSE starting from 15sp2, and OpenSUSE has it disabled as well. 1) /dev/kmem was popular for rootkits [2] before it got disabled basically everywhere. Ubuntu documents [3] "There is no modern user of /dev/kmem any more beyond attackers using it to load kernel rootkits.". RHEL documents in a BZ [5] "it served no practical purpose other than to serve as a potential security problem or to enable binary module drivers to access structures/functions they shouldn't be touching" 2) /proc/kcore is a decent interface to have a controlled way to read kernel memory for debugging puposes. (will need some extensions to deal with memory offlining/unplug, memory ballooning, and poisoned pages, though) 3) It might be useful for corner case debugging [1]. KDB/KGDB might be a better fit, especially, to write random memory; harder to shoot yourself into the foot. 4) "Kernel Memory Editor" [4] hasn't seen any updates since 2000 and seems to be incompatible with 64bit [1]. For educational purposes, /proc/kcore might be used to monitor value updates -- or older kernels can be used. 5) It's broken on arm64, and therefore, completely disabled there. Looks like it's essentially unused and has been replaced by better suited interfaces for individual tasks (/proc/kcore, KDB/KGDB). Let's just remove it. [1] https://lwn.net/Articles/147901/ [2] https://www.linuxjournal.com/article/10505 [3] https://wiki.ubuntu.com/Security/Features#A.2Fdev.2Fkmem_disabled [4] https://sourceforge.net/projects/kme/ [5] https://bugzilla.redhat.com/show_bug.cgi?id=154796 Link: https://lkml.kernel.org/r/20210324102351.6932-1-david@redhat.com Link: https://lkml.kernel.org/r/20210324102351.6932-2-david@redhat.comSigned-off-by:
-
Shijie Luo authored
fix some typos and code style problems in mm. gfp.h: s/MAXNODES/MAX_NUMNODES mmzone.h: s/then/than rmap.c: s/__vma_split()/__vma_adjust() swap.c: s/__mod_zone_page_stat/__mod_zone_page_state, s/is is/is swap_state.c: s/whoes/whose z3fold.c: code style problem fix in z3fold_unregister_migration zsmalloc.c: s/of/or, s/give/given Link: https://lkml.kernel.org/r/20210419083057.64820-1-luoshijie1@huawei.comSigned-off-by:
Shijie Luo <luoshijie1@huawei.com> Signed-off-by:
Miaohe Lin <linmiaohe@huawei.com> Signed-off-by:
-
Bhaskar Chowdhury authored
s/runtine/runtime/ s/AQUIRE/ACQUIRE/ s/seperately/separately/ s/wont/won\'t/ s/succesfull/successful/ Link: https://lkml.kernel.org/r/20210326022240.26375-1-unixbhaskar@gmail.comSigned-off-by:
Bhaskar Chowdhury <unixbhaskar@gmail.com> Acked-by:
Randy Dunlap <rdunlap@infradead.org> Signed-off-by:
-
Rasmus Villemoes authored
Allow the developer to specifiy the initial value of the modprobe_path[] string. This can be used to set it to the empty string initially, thus effectively disabling request_module() during early boot until userspace writes a new value via the /proc/sys/kernel/modprobe interface. [1] When building a custom kernel (often for an embedded target), it's normal to build everything into the kernel that is needed for booting, and indeed the initramfs often contains no modules at all, so every such request_module() done before userspace init has mounted the real rootfs is a waste of time. This is particularly useful when combined with the previous patch, which made the initramfs unpacking asynchronous - for that to work, it had to make any usermodehelper call wait for the unpacking to finish before attempting to invoke the userspace helper. By eliminating all such (known-to-be-futile) calls of usermodehelper, the initramfs unpacking and the {device,late}_initcalls can proceed in parallel for much longer. For a relatively slow ppc board I'm working on, the two patches combined lead to 0.2s faster boot - but more importantly, the fact that the initramfs unpacking proceeds completely in the background while devices get probed means I get to handle the gpio watchdog in time without getting reset. [1] __request_module() already has an early -ENOENT return when modprobe_path is the empty string. Link: https://lkml.kernel.org/r/20210313212528.2956377-3-linux@rasmusvillemoes.dkSigned-off-by:Rasmus Villemoes <linux@rasmusvillemoes.dk> Reviewed-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by:
Jessica Yu <jeyu@kernel.org> Acked-by:
Luis Chamberlain <mcgrof@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Takashi Iwai <tiwai@suse.de> Signed-off-by:
-
Rasmus Villemoes authored
Patch series "background initramfs unpacking, and CONFIG_MODPROBE_PATH", v3. These two patches are independent, but better-together. The second is a rather trivial patch that simply allows the developer to change "/sbin/modprobe" to something else - e.g. the empty string, so that all request_module() during early boot return -ENOENT early, without even spawning a usermode helper, needlessly synchronizing with the initramfs unpacking. The first patch delegates decompressing the initramfs to a worker thread, allowing do_initcalls() in main.c to proceed to the device_ and late_ initcalls without waiting for that decompression (and populating of rootfs) to finish. Obviously, some of those later calls may rely on the initramfs being available, so I've added synchronization points in the firmware loader and usermodehelper paths - there might be other places that would need this, but so far no one has been able to think of any places I have missed. There's not much to win if most of the functionality needed during boot is only available as modules. But systems with a custom-made .config and initramfs can boot faster, partly due to utilizing more than one cpu earlier, partly by avoiding known-futile modprobe calls (which would still trigger synchronization with the initramfs unpacking, thus eliminating most of the first benefit). This patch (of 2): Most of the boot process doesn't actually need anything from the initramfs, until of course PID1 is to be executed. So instead of doing the decompressing and populating of the initramfs synchronously in populate_rootfs() itself, push that off to a worker thread. This is primarily motivated by an embedded ppc target, where unpacking even the rather modest sized initramfs takes 0.6 seconds, which is long enough that the external watchdog becomes unhappy that it doesn't get attention soon enough. By doing the initramfs decompression in a worker thread, we get to do the device_initcalls and hence start petting the watchdog much sooner. Normal desktops might benefit as well. On my mostly stock Ubuntu kernel, my initramfs is a 26M xz-compressed blob, decompressing to around 126M. That takes almost two seconds: [ 0.201454] Trying to unpack rootfs image as initramfs... [ 1.976633] Freeing initrd memory: 29416K Before this patch, these lines occur consecutively in dmesg. With this patch, the timestamps on these two lines is roughly the same as above, but with 172 lines inbetween - so more than one cpu has been kept busy doing work that would otherwise only happen after the populate_rootfs() finished. Should one of the initcalls done after rootfs_initcall time (i.e., device_ and late_ initcalls) need something from the initramfs (say, a kernel module or a firmware blob), it will simply wait for the initramfs unpacking to be done before proceeding, which should in theory make this completely safe. But if some driver pokes around in the filesystem directly and not via one of the official kernel interfaces (i.e. request_firmware*(), call_usermodehelper*) that theory may not hold - also, I certainly might have missed a spot when sprinkling wait_for_initramfs(). So there is an escape hatch in the form of an initramfs_async= command line parameter. Link: https://lkml.kernel.org/r/20210313212528.2956377-1-linux@rasmusvillemoes.dk Link: https://lkml.kernel.org/r/20210313212528.2956377-2-linux@rasmusvillemoes.dkSigned-off-by:
-
Rasmus Villemoes authored
No callers in the tree. Link: https://lkml.kernel.org/r/20210309151723.1907838-2-linux@rasmusvillemoes.dkSigned-off-by:
-
Rasmus Villemoes authored
It's currently nigh impossible to get these pr_debug()s to print something. Being guarded by initcall_debug means one has to enable tons of other debug output during boot, and the system_state condition further means it's impossible to get them when loading modules later. Also, the compiler can't know that these global conditions do not change, so there are W=2 warnings kernel/async.c:125:9: warning: `calltime' may be used uninitialized in this function [-Wmaybe-uninitialized] kernel/async.c:300:9: warning: `starttime' may be used uninitialized in this function [-Wmaybe-uninitialized] Make it possible, for a DYNAMIC_DEBUG kernel, to get these to print their messages by booting with appropriate 'dyndbg="file async.c +p"' command line argument. For a non-DYNAMIC_DEBUG kernel, pr_debug() compiles to nothing. This does cost doing an unconditional ktime_get() for the starttime value, but the corresponding ktime_get for the end time can be elided by factoring it into a function which only gets called if the printk() arguments end up being evaluated. Link: https://lkml.kernel.org/r/20210309151723.1907838-1-linux@rasmusvillemoes.dkSigned-off-by:
-
Zhang Yunkai authored
'assert.h' included in 'sparsebit.c' is duplicated. It is also included in the 161th line. 'string.h' included in 'mincore_selftest.c' is duplicated. It is also included in the 15th line. 'sched.h' included in 'tlbie_test.c' is duplicated. It is also included in the 33th line. Link: https://lkml.kernel.org/r/20210316073336.426255-1-zhang.yunkai@zte.com.cnSigned-off-by:
Zhang Yunkai <zhang.yunkai@zte.com.cn> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by:
-
Alistair Popple authored
request_free_mem_region() is used to find an empty range of physical addresses for hotplugging ZONE_DEVICE memory. It does this by iterating over the range of possible addresses using region_intersects() to see if the range is free before calling request_mem_region() to allocate the region. However the resource_lock is dropped between these two calls meaning by the time request_mem_region() is called in request_free_mem_region() another thread may have already reserved the requested region. This results in unexpected failures and a message in the kernel log from hitting this condition: /* * mm/hmm.c reserves physical addresses which then * become unavailable to other users. Conflicts are * not expected. Warn to aid debugging if encountered. */ if (conflict->desc == IORES_DESC_DEVICE_PRIVATE_MEMORY) { pr_warn("Unaddressable device %s %pR conflicts with %pR", conflict->name, conflict, res); These unexpected failures can be corrected by holding resource_lock across the two calls. This also requires memory allocation to be performed prior to taking the lock. Link: https://lkml.kernel.org/r/20210419070109.4780-3-apopple@nvidia.comSigned-off-by:Alistair Popple <apopple@nvidia.com> Reviewed-by:
-
Alistair Popple authored
Refactor the portion of __request_region() done whilst holding the resource_lock into a separate function to allow callers to hold the lock. Link: https://lkml.kernel.org/r/20210419070109.4780-2-apopple@nvidia.comSigned-off-by:
-
Alistair Popple authored
Introduce a version of region_intersects() that can be called with the resource_lock already held. This will be used in a future fix to __request_free_mem_region(). [akpm@linux-foundation.org: make __region_intersects static] Link: https://lkml.kernel.org/r/20210419070109.4780-1-apopple@nvidia.comSigned-off-by:
-
David Hildenbrand authored
All functions that search for IORESOURCE_SYSTEM_RAM or IORESOURCE_MEM resources now properly consider the whole resource tree, not just the first level. Let's drop the unused first_lvl / siblings_only logic. Remove documentation that indicates that some functions behave differently, all consider the full resource tree now. Link: https://lkml.kernel.org/r/20210325115326.7826-4-david@redhat.comSigned-off-by:
Dan Williams <dan.j.williams@intel.com> Reviewed-by:
Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Cc: Dave Young <dyoung@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Keith Busch <keith.busch@intel.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Qian Cai <cai@lca.pw> Cc: Oscar Salvador <osalvador@suse.de> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by:
-
David Hildenbrand authored
It used to be true that we can have system RAM (IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY) only on the first level in the resource tree. However, this is no longer holds for driver-managed system RAM (i.e., added via dax/kmem and virtio-mem), which gets added on lower levels, for example, inside device containers. IORESOURCE_SYSTEM_RAM is defined as IORESOURCE_MEM | IORESOURCE_SYSRAM and just a special type of IORESOURCE_MEM. The function walk_mem_res() only considers the first level and is used in arch/x86/mm/ioremap.c:__ioremap_check_mem() only. We currently fail to identify System RAM added by dax/kmem and virtio-mem as "IORES_MAP_SYSTEM_RAM", for example, allowing for remapping of such "normal RAM" in __ioremap_caller(). Let's find all IORESOURCE_MEM | IORESOURCE_BUSY resources, making the function behave similar to walk_system_ram_res(). Link: https://lkml.kernel.org/r/20210325115326.7826-3-david@redhat.com Fixes: ebf71552 ("virtio-mem: Add parent resource for all added "System RAM"") Fixes: c221c0b0 ("device-dax: "Hotplug" persistent memory for use like normal RAM") Signed-off-by:
-
David Hildenbrand authored
Patch series "kernel/resource: make walk_system_ram_res() and walk_mem_res() search the whole tree", v2. Playing with kdump+virtio-mem I noticed that kexec_file_load() does not consider System RAM added via dax/kmem and virtio-mem when preparing the elf header for kdump. Looking into the details, the logic used in walk_system_ram_res() and walk_mem_res() seems to be outdated. walk_system_ram_range() already does the right thing, let's change walk_system_ram_res() and walk_mem_res(), and clean up. Loading a kdump kernel via "kexec -p -s" ... will result in the kdump kernel to also dump dax/kmem and virtio-mem added System RAM now. Note: kexec-tools on x86-64 also have to be updated to consider this memory in the kexec_load() case when processing /proc/iomem. This patch (of 3): It used to be true that we can have system RAM (IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY) only on the first level in the resource tree. However, this is no longer holds for driver-managed system RAM (i.e., added via dax/kmem and virtio-mem), which gets added on lower levels, for example, inside device containers. We have two users of walk_system_ram_res(), which currently only consideres the first level: a) kernel/kexec_file.c:kexec_walk_resources() -- We properly skip IORESOURCE_SYSRAM_DRIVER_MANAGED resources via locate_mem_hole_callback(), so even after this change, we won't be placing kexec images onto dax/kmem and virtio-mem added memory. No change. b) arch/x86/kernel/crash.c:fill_up_crash_elf_data() -- we're currently not adding relevant ranges to the crash elf header, resulting in them not getting dumped via kdump. This change fixes loading a crashkernel via kexec_file_load() and including dax/kmem and virtio-mem added System RAM in the crashdump on x86-64. Note that e.g,, arm64 relies on memblock data and, therefore, always considers all added System RAM already. Let's find all IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY resources, making the function behave like walk_system_ram_range(). Link: https://lkml.kernel.org/r/20210325115326.7826-1-david@redhat.com Link: https://lkml.kernel.org/r/20210325115326.7826-2-david@redhat.com Fixes: ebf71552 ("virtio-mem: Add parent resource for all added "System RAM"") Fixes: c221c0b0 ("device-dax: "Hotplug" persistent memory for use like normal RAM") Signed-off-by:
Baoquan He <bhe@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Cc: Dave Young <dyoung@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Keith Busch <keith.busch@intel.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Qian Cai <cai@lca.pw> Cc: Oscar Salvador <osalvador@suse.de> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Brijesh Singh <brijesh.singh@amd.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by:
-
Barry Song authored
arm64 uses SP_EL0 to save the current task_struct address. While running in EL0, SP_EL0 is clobbered by userspace. So if the upper bit is not 1 (not TTBR1), the current address is invalid. This patch checks the upper bit of SP_EL0, if the upper bit is 1, lx_current() of arm64 will return the derefrence of current task. Otherwise, lx_current() will tell users they are running in userspace(EL0). While arm64 is running in EL0, it is actually pointless to print current task as the memory of kernel space is not accessible in EL0. Link: https://lkml.kernel.org/r/20210314203444.15188-3-song.bao.hua@hisilicon.comSigned-off-by:
Barry Song <song.bao.hua@hisilicon.com> Cc: Jan Kiszka <jan.kiszka@siemens.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kieran Bingham <kbingham@kernel.org> Signed-off-by:
-
Barry Song authored
Patch series "scripts/gdb: clarify the platforms supporting lx_current and add arm64 support", v2. lx_current depends on per_cpu current_task variable which exists on x86 only. so it actually works on x86 only. the 1st patch documents this clearly; the 2nd patch adds support for arm64. This patch (of 2): x86 is the only architecture which has per_cpu current_task: arch$ git grep current_task | grep -i per_cpu x86/include/asm/current.h:DECLARE_PER_CPU(struct task_struct *, current_task); x86/kernel/cpu/common.c:DEFINE_PER_CPU(struct task_struct *, current_task) ____cacheline_aligned = x86/kernel/cpu/common.c:EXPORT_PER_CPU_SYMBOL(current_task); x86/kernel/cpu/common.c:DEFINE_PER_CPU(struct task_struct *, current_task) = &init_task; x86/kernel/cpu/common.c:EXPORT_PER_CPU_SYMBOL(current_task); x86/kernel/smpboot.c: per_cpu(current_task, cpu) = idle; On other architectures, lx_current() will lead to a python exception: (gdb) p $lx_current().pid Python Exception <class 'gdb.error'> No symbol "current_task" in current context.: Error occurred in Python: No symbol "current_task" in current context. To avoid more people struggling and wasting time in other architectures, document it. Link: https://lkml.kernel.org/r/20210314203444.15188-1-song.bao.hua@hisilicon.com Link: https://lkml.kernel.org/r/20210314203444.15188-2-song.bao.hua@hisilicon.comSigned-off-by:
-
Johannes Berg authored
If we store the relative path, the user might later cd to a different directory, and that would break the automatic symbol resolving that happens when a module is loaded into the target kernel. Fix this by storing the abspath() of each path given, just like we already do for the cwd (os.getcwd() is absolute.) Link: https://lkml.kernel.org/r/20201217091747.bf4332cf2b35.I10ebbdb7e9b80ab1a5cddebf53d073be8232d656@changeidSigned-off-by:
Johannes Berg <johannes.berg@intel.com> Reviewed-by:
Jan Kiszka <jan.kiszka@siemens.com> Cc: Kieran Bingham <kbingham@kernel.org> Signed-off-by:
-
Yafang Shao authored
When I was implementing a latency analyzer tool by using task->delays and other things, I found an issue in delayacct. The issue is it should clear the target's flag instead of current's in delayacct_blkio_end(). When I git blame delayacct, I found there're some similar issues we have fixed in delayacct_blkio_end(). - Commit c96f5471 ("delayacct: Account blkio completion on the correct task") fixed the issue that it should account blkio completion on the target task instead of current. - Commit b512719f ("delayacct: fix crash in delayacct_blkio_end() after delayacct init failure") fixed the issue that it should check target task's delays instead of current task'. It seems that delayacct_blkio_{begin, end} are error prone. So I introduce a new paratmeter - the target task 'p' - to these helpers. After that change, the callsite will specifilly set the right task, which should make it less error prone. Link: https://lkml.kernel.org/r/20210414083720.24083-1-laoar.shao@gmail.comSigned-off-by:
Yafang Shao <laoar.shao@gmail.com> Cc: Tejun Heo <tj@kernel.org> Cc: Josh Snyder <joshs@netflix.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by:
-
He Ying authored
We found these warnings in kernel/panic.c by using sparse tool: warning: symbol 'panic_smp_self_stop' was not declared. warning: symbol 'nmi_panic_self_stop' was not declared. warning: symbol 'crash_smp_send_stop' was not declared. To avoid them, add declarations for these three functions in include/linux/smp.h. Link: https://lkml.kernel.org/r/20210316084150.75201-1-heying24@huawei.comSigned-off-by:
He Ying <heying24@huawei.com> Reported-by:
Hulk Robot <hulkci@huawei.com> Signed-off-by:
-
Nick Desaulniers authored
LLVM changed the expected function signatures for llvm_gcda_start_file() and llvm_gcda_emit_function() in the clang-11 release. Drop the older implementations and require folks to upgrade their compiler if they're interested in GCOV support. Link: https://reviews.llvm.org/rGcdd683b516d147925212724b09ec6fb792a40041 Link: https://reviews.llvm.org/rG13a633b438b6500ecad9e4f936ebadf3411d0f44 Link: https://lkml.kernel.org/r/20210312224132.3413602-3-ndesaulniers@google.com Link: https://lkml.kernel.org/r/20210413183113.2977432-1-ndesaulniers@google.comSigned-off-by:
Nick Desaulniers <ndesaulniers@google.com> Suggested-by:
Nathan Chancellor <nathan@kernel.org> Acked-by:
Peter Oberparleiter <oberpar@linux.ibm.com> Reviewed-by:
Fangrui Song <maskray@google.com> Cc: Prasad Sodagudi <psodagud@quicinc.com> Cc: Johannes Berg <johannes.berg@intel.com> Signed-off-by:
-
Johannes Berg authored
Using vmalloc() in gcov is really quite wasteful, many of the objects allocated are really small (e.g. I've seen 24 bytes.) Use kvmalloc() to automatically pick the better of kmalloc() or vmalloc() depending on the size. [johannes.berg@intel.com: fix clang-11+ build] Link: https://lkml.kernel.org/r/20210412214210.6e1ecca9cdc5.I24459763acf0591d5e6b31c7e3a59890d802f79c@changeid Link: https://lkml.kernel.org/r/20210315235453.799e7a9d627d.I741d0db096c6f312910f7f1bcdfde0fda20801a4@changeidSigned-off-by:
-
Johannes Berg authored
Use just a single vmalloc() with struct_size() instead of a separate kmalloc() for the iter struct. Link: https://lkml.kernel.org/r/20210315235453.b6de4a92096e.Iac40a5166589cefbff8449e466bd1b38ea7a17af@changeidSigned-off-by:
-
Johannes Berg authored
There's a lot of duplicated code between gcc and clang implementations, move it over to fs.c to simplify the code, there's no reason to believe that for small data like this one would not just implement the simple convert_to_gcda() function. Link: https://lkml.kernel.org/r/20210315235453.e3fbb86e99a0.I08a3ee6dbe47ea3e8024956083f162884a958e40@changeidSigned-off-by:
-
Pavel Tatashin authored
kmsg_dump(KMSG_DUMP_SHUTDOWN) is called before machine_restart(), machine_halt(), and machine_power_off(). The only one that is missing is machine_kexec(). The dmesg output that it contains can be used to study the shutdown performance of both kernel and systemd during kexec reboot. Here is example of dmesg data collected after kexec: root@dplat-cp22:~# cat /sys/fs/pstore/dmesg-ramoops-0 | tail ... [ 70.914592] psci: CPU3 killed (polled 0 ms) [ 70.915705] CPU4: shutdown [ 70.916643] psci: CPU4 killed (polled 4 ms) [ 70.917715] CPU5: shutdown [ 70.918725] psci: CPU5 killed (polled 0 ms) [ 70.919704] CPU6: shutdown [ 70.920726] psci: CPU6 killed (polled 4 ms) [ 70.921642] CPU7: shutdown [ 70.922650] psci: CPU7 killed (polled 0 ms) Link: https://lkml.kernel.org/r/20210319192326.146000-2-pasha.tatashin@soleen.comSigned-off-by:
Pavel Tatashin <pasha.tatashin@soleen.com> Reviewed-by:
Petr Mladek <pmladek@suse.com> Reviewed-by:
Bhupesh Sharma <bhsharma@redhat.com> Acked-by:
Tyler Hicks <tyhicks@linux.microsoft.com> Cc: James Morris <jmorris@namei.org> Cc: Sasha Levin <sashal@kernel.org> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Anton Vorontsov <anton@enomsg.org> Cc: Colin Cross <ccross@android.com> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by:
-
Jia-Ju Bai authored
When vzalloc() returns NULL to sha_regions, no error return code of kexec_calculate_store_digests() is assigned. To fix this bug, ret is assigned with -ENOMEM in this case. Link: https://lkml.kernel.org/r/20210309083904.24321-1-baijiaju1990@gmail.com Fixes: a43cac0d ("kexec: split kexec_file syscall code to kexec_file.c") Signed-off-by:
Jia-Ju Bai <baijiaju1990@gmail.com> Reported-by:
TOTE Robot <oslab@tsinghua.edu.cn> Acked-by:
-
Joe LeVeque authored
The purpose is to notify the kernel module for fast reboot. Upstream a patch from the SONiC network operating system [1]. [1]: https://github.com/Azure/sonic-linux-kernel/pull/46 Link: https://lkml.kernel.org/r/20210304124626.13927-1-pmenzel@molgen.mpg.deSigned-off-by:
Joe LeVeque <jolevequ@microsoft.com> Signed-off-by:
Paul Menzel <pmenzel@molgen.mpg.de> Acked-by:
-
Xiaofeng Cao authored
change 'ancestoral' to 'ancestral' change 'reuseable' to 'reusable' delete 'do' grammatically Link: https://lkml.kernel.org/r/20210317082031.11692-1-caoxiaofeng@yulong.comSigned-off-by:
Xiaofeng Cao <caoxiaofeng@yulong.com> Reviewed-by:
Christian Brauner <christian.brauner@ubuntu.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by:
-
Rolf Eike Beer authored
All this can happen without a single goto. Link: https://lkml.kernel.org/r/2072685.XptgVkyDqn@devpool47Signed-off-by:
Rolf Eike Beer <eb@emlix.com> Reviewed-by:
-
Jim Newsome authored
Add a special-case when waiting on a pid (via waitpid, waitid, wait4, etc) to avoid doing an O(n) scan of children and tracees, and instead do an O(1) lookup. This improves performance when waiting on a pid from a thread group with many children and/or tracees. Time to fork and then call waitpid on the child, from a task that already has N children [1]: N | Before | After -----|---------|------ 1 | 74 us | 74 us 20 | 72 us | 75 us 100 | 83 us | 77 us 500 | 99 us | 74 us 1000 | 179 us | 75 us 5000 | 804 us | 79 us 8000 | 1268 us | 78 us [1]: https://lkml.org/lkml/2021/3/12/1567 This can make a substantial performance improvement for applications with a thread that has many children or tracees and frequently needs to wait on them. Tools that use ptrace to intercept syscalls for a large number of processes are likely to fall into this category. In particular this patch was developed while building a ptrace-based second generation of the Shadow emulator [2], for which it allows us to avoid quadratic scaling (without having to use a workaround that introduces a ~40% performance penalty) [3]. Other examples of tools that fall into this category which this patch may help include User Mode Linux [4] and DetTrace [5]. [2]: https://shadow.github.io/ [3]: https://github.com/shadow/shadow/issues/1134#issuecomment-798992292 [4]: https://en.wikipedia.org/wiki/User-mode_Linux [5]: https://github.com/dettrace/dettrace Link: https://lkml.kernel.org/r/20210314231544.9379-1-jnewsome@torproject.orgSigned-off-by:
James Newsome <jnewsome@torproject.org> Reviewed-by:
Oleg Nesterov <oleg@redhat.com> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: Christian Brauner <christian@brauner.io> Signed-off-by:
-
Gustavo A. R. Silva authored
There is a regular need in the kernel to provide a way to declare having a dynamically sized set of trailing elements in a structure. Kernel code should always use “flexible array members”[1] for these cases. The older style of one-element or zero-length arrays should no longer be used[2]. Also, this helps with the ongoing efforts to enable -Warray-bounds by fixing the following warning: CC [M] fs/hpfs/dir.o fs/hpfs/dir.c: In function `hpfs_readdir': fs/hpfs/dir.c:163:41: warning: array subscript 1 is above array bounds of `u8[1]' {aka `unsigned char[1]'} [-Warray-bounds] 163 | || de ->name[0] != 1 || de->name[1] != 1)) | ~~~~~~~~^~~ [1] https://en.wikipedia.org/wiki/Flexible_array_member [2] https://www.kernel.org/doc/html/v5.10/process/deprecated.html#zero-length-and-one-element-arrays Link: https://github.com/KSPP/linux/issues/79 Link: https://github.com/KSPP/linux/issues/109 Link: https://lkml.kernel.org/r/20210326173510.GA81212@embeddedorSigned-off-by:Gustavo A. R. Silva <gustavoars@kernel.org> Cc: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz> Signed-off-by:
-
Lu Jialin authored
numer -> number in fs/nilfs2/cpfile.c Decription -> Description in fs/nilfs2/ioctl.c isntance -> instance in fs/nilfs2/the_nilfs.c Link: https://lkml.kernel.org/r/1617942951-14631-1-git-send-email-konishi.ryusuke@gmail.com Link: https://lore.kernel.org/r/20210409022519.176988-1-lujialin4@huawei.comSigned-off-by:
Lu Jialin <lujialin4@huawei.com> Signed-off-by:
Ryusuke Konishi <konishi.ryusuke@gmail.com> Signed-off-by:
-
Liu xuzhi authored
Two typos are found out by codespell tool \ in 2217th and 2254th lines of segment.c: $ codespell ./fs/nilfs2/ ./segment.c:2217 :retured ==> returned ./segment.c:2254: retured ==> returned Fix two typos found by codespell. Link: https://lkml.kernel.org/r/1617864087-8198-1-git-send-email-konishi.ryusuke@gmail.comSigned-off-by:
Liu xuzhi <liu.xuzhi@zte.com.cn> Signed-off-by:
-
Gustavo A. R. Silva authored
In preparation to enable -Wimplicit-fallthrough for Clang, fix a warning by explicitly adding a break statement instead of just letting the code fall through to the next case. Link: https://github.com/KSPP/linux/issues/115 Link: https://lkml.kernel.org/r/5b7caa73958588065fabc59032c340179b409ef5.1605896059.git.gustavoars@kernel.orgSigned-off-by:
-
Davidlohr Bueso authored
Commit 339ddb53 ("fs/epoll: remove unnecessary wakeups of nested epoll") changed the userspace visible behavior of exclusive waiters blocked on a common epoll descriptor upon a single event becoming ready. Previously, all tasks doing epoll_wait would awake, and now only one is awoken, potentially causing missed wakeups on applications that rely on this behavior, such as Apache Qpid. While the aforementioned commit aims at having only a wakeup single path in ep_poll_callback (with the exceptions of epoll_ctl cases), we need to restore the wakeup in what was the old ep_scan_ready_list() such that the next thread can be awoken, in a cascading style, after the waker's corresponding ep_send_events(). Link: https://lkml.kernel.org/r/20210405231025.33829-3-dave@stgolabs.net Fixes: 339ddb53 ("fs/epoll: remove unnecessary wakeups of nested epoll") Signed-off-by:
Davidlohr Bueso <dbueso@suse.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Jason Baron <jbaron@akamai.com> Cc: Roman Penyaev <rpenyaev@suse.de> Cc: <stable@vger.kernel.org> Signed-off-by:
-
Davidlohr Bueso authored
Patch series "fs/epoll: restore user-visible behavior upon event ready". This series tries to address a change in user visible behavior, reported in https://bugzilla.kernel.org/show_bug.cgi?id=208943. Epoll does not report an event to all the threads running epoll_wait() on the same epoll descriptor. Unsurprisingly, this was bisected back to 339ddb53 (fs/epoll: remove unnecessary wakeups of nested epoll), which has had various problems in the past, beyond only nested epoll usage. This patch (of 2): This incorporates the testcase originally reported in: https://bugzilla.kernel.org/show_bug.cgi?id=208943 Which ensures an event is reported to all threads blocked on the same epoll descriptor, otherwise only a single thread will receive the wakeup once the event become ready. Link: https://lkml.kernel.org/r/20210405231025.33829-1-dave@stgolabs.net Link: https://lkml.kernel.org/r/20210405231025.33829-2-dave@stgolabs.netSigned-off-by:
-
Christophe JAILLET authored
The devm_ variant of 'kcalloc()' and 'kmalloc_array()' are not tested Add the corresponding check. Link: https://lkml.kernel.org/r/205fc4847972fb6779abcc8818f39c14d1b45af1.1618595794.git.christophe.jaillet@wanadoo.frSigned-off-by:
Christophe JAILLET <christophe.jaillet@wanadoo.fr> Acked-by:
Joe Perches <joe@perches.com> Signed-off-by:
-
