Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.
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The latest UV platforms include the new ApachePass NVDIMMs into the
UV address space. This has introduced address ranges in the Global
Address Map Table that are less than the previous lowest range, which
was 2GB. Fix the address calculation so it accommodates address ranges
from bytes to exabytes.
Signed-off-by: Mike Travis <mike.travis@hpe.com>
Reviewed-by: Andrew Banman <andrew.banman@hpe.com>
Reviewed-by: Dimitri Sivanich <dimitri.sivanich@hpe.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russ Anderson <russ.anderson@hpe.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180205221503.190219903@stormcage.americas.sgi.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The file was generated by make command and should not be in the source tree.
Signed-off-by: Progyan Bhattacharya <progyanb@acm.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When a physical CPU is hot-removed, the following warning messages
are shown while the uncore device is removed in uncore_pci_remove():
WARNING: CPU: 120 PID: 5 at arch/x86/events/intel/uncore.c:988
uncore_pci_remove+0xf1/0x110
...
CPU: 120 PID: 5 Comm: kworker/u1024:0 Not tainted 4.15.0-rc8 #1
Workqueue: kacpi_hotplug acpi_hotplug_work_fn
...
Call Trace:
pci_device_remove+0x36/0xb0
device_release_driver_internal+0x145/0x210
pci_stop_bus_device+0x76/0xa0
pci_stop_root_bus+0x44/0x60
acpi_pci_root_remove+0x1f/0x80
acpi_bus_trim+0x54/0x90
acpi_bus_trim+0x2e/0x90
acpi_device_hotplug+0x2bc/0x4b0
acpi_hotplug_work_fn+0x1a/0x30
process_one_work+0x141/0x340
worker_thread+0x47/0x3e0
kthread+0xf5/0x130
When uncore_pci_remove() runs, it tries to get the package ID to
clear the value of uncore_extra_pci_dev[].dev[] by using
topology_phys_to_logical_pkg(). The warning messesages are
shown because topology_phys_to_logical_pkg() returns -1.
arch/x86/events/intel/uncore.c:
static void uncore_pci_remove(struct pci_dev *pdev)
{
...
phys_id = uncore_pcibus_to_physid(pdev->bus);
...
pkg = topology_phys_to_logical_pkg(phys_id); // returns -1
for (i = 0; i < UNCORE_EXTRA_PCI_DEV_MAX; i++) {
if (uncore_extra_pci_dev[pkg].dev[i] == pdev) {
uncore_extra_pci_dev[pkg].dev[i] = NULL;
break;
}
}
WARN_ON_ONCE(i >= UNCORE_EXTRA_PCI_DEV_MAX); // <=========== HERE!!
topology_phys_to_logical_pkg() tries to find
cpuinfo_x86->phys_proc_id that matches the phys_pkg argument.
arch/x86/kernel/smpboot.c:
int topology_phys_to_logical_pkg(unsigned int phys_pkg)
{
int cpu;
for_each_possible_cpu(cpu) {
struct cpuinfo_x86 *c = &cpu_data(cpu);
if (c->initialized && c->phys_proc_id == phys_pkg)
return c->logical_proc_id;
}
return -1;
}
However, the phys_proc_id was already set to 0 by remove_siblinginfo()
when the CPU was offlined.
So, topology_phys_to_logical_pkg() cannot find the correct
logical_proc_id and always returns -1.
As the result, uncore_pci_remove() calls WARN_ON_ONCE() and the warning
messages are shown.
What is worse is that the bogus 'pkg' index results in two bugs:
- We dereference uncore_extra_pci_dev[] with a negative index
- We fail to clean up a stale pointer in uncore_extra_pci_dev[][]
To fix these bugs, remove the clearing of ->phys_proc_id from remove_siblinginfo().
This should not cause any problems, because ->phys_proc_id is not
used after it is hot-removed and it is re-set while hot-adding.
Signed-off-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: yasu.isimatu@gmail.com
Cc: <stable@vger.kernel.org>
Fixes: 30bb9811856f ("x86/topology: Avoid wasting 128k for package id array")
Link: http://lkml.kernel.org/r/ed738d54-0f01-b38b-b794-c31dc118c207@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The vsyscall page should be visible only if vsyscall=emulate/native when dumping /proc/kcore.
Signed-off-by: Jia Zhang <zhang.jia@linux.alibaba.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: jolsa@redhat.com
Link: http://lkml.kernel.org/r/1518446694-21124-3-git-send-email-zhang.jia@linux.alibaba.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Commit:
df04abfd181a ("fs/proc/kcore.c: Add bounce buffer for ktext data")
... introduced a bounce buffer to work around CONFIG_HARDENED_USERCOPY=y.
However, accessing the vsyscall user page will cause an SMAP fault.
Replace memcpy() with copy_from_user() to fix this bug works, but adding
a common way to handle this sort of user page may be useful for future.
Currently, only vsyscall page requires KCORE_USER.
Signed-off-by: Jia Zhang <zhang.jia@linux.alibaba.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: jolsa@redhat.com
Link: http://lkml.kernel.org/r/1518446694-21124-2-git-send-email-zhang.jia@linux.alibaba.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Clean up various aspects of the x86 CONFIG_NR_CPUS configuration switches:
- Rename the three CONFIG_NR_CPUS related variables to create a common
namespace for them:
RANGE_BEGIN_CPUS => NR_CPUS_RANGE_BEGIN
RANGE_END_CPUS => NR_CPUS_RANGE_END
DEF_CONFIG_CPUS => NR_CPUS_DEFAULT
- Align them vertically, such as:
config NR_CPUS_RANGE_END
int
depends on X86_64
default 8192 if SMP && ( MAXSMP || CPUMASK_OFFSTACK)
default 512 if SMP && (!MAXSMP && !CPUMASK_OFFSTACK)
default 1 if !SMP
- Update help text, add more comments.
Test results:
# i386 allnoconfig:
CONFIG_NR_CPUS_RANGE_BEGIN=1
CONFIG_NR_CPUS_RANGE_END=1
CONFIG_NR_CPUS_DEFAULT=1
CONFIG_NR_CPUS=1
# i386 defconfig:
CONFIG_NR_CPUS_RANGE_BEGIN=2
CONFIG_NR_CPUS_RANGE_END=8
CONFIG_NR_CPUS_DEFAULT=8
CONFIG_NR_CPUS=8
# i386 allyesconfig:
CONFIG_NR_CPUS_RANGE_BEGIN=2
CONFIG_NR_CPUS_RANGE_END=64
CONFIG_NR_CPUS_DEFAULT=32
CONFIG_NR_CPUS=32
# x86_64 allnoconfig:
CONFIG_NR_CPUS_RANGE_BEGIN=1
CONFIG_NR_CPUS_RANGE_END=1
CONFIG_NR_CPUS_DEFAULT=1
CONFIG_NR_CPUS=1
# x86_64 defconfig:
CONFIG_NR_CPUS_RANGE_BEGIN=2
CONFIG_NR_CPUS_RANGE_END=512
CONFIG_NR_CPUS_DEFAULT=64
CONFIG_NR_CPUS=64
# x86_64 allyesconfig:
CONFIG_NR_CPUS_RANGE_BEGIN=8192
CONFIG_NR_CPUS_RANGE_END=8192
CONFIG_NR_CPUS_DEFAULT=8192
CONFIG_NR_CPUS=8192
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180210113629.jcv6su3r4suuno63@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Clean up and simplify the X86 NR_CPUS Kconfig symbol/option by
introducing RANGE_BEGIN_CPUS, RANGE_END_CPUS, and DEF_CONFIG_CPUS.
Then combine some default values when their conditionals can be
reduced.
Also move the X86_BIGSMP kconfig option inside an "if X86_32"/"endif"
config block and drop its explicit "depends on X86_32".
Combine the max. 8192 cases of RANGE_END_CPUS (X86_64 only).
Split RANGE_END_CPUS and DEF_CONFIG_CPUS into separate cases for
X86_32 and X86_64.
Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/0b833246-ed4b-e451-c426-c4464725be92@infradead.org
Link: lkml.kernel.org/r/CA+55aFzOd3j6ZUSkEwTdk85qtt1JywOtm3ZAb-qAvt8_hJ6D4A@mail.gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The following commit:
7b6061627eb8 ("x86: do not use print_symbol()")
... introduced a new build warning on 32-bit x86:
arch/x86/kernel/cpu/mcheck/mce.c:237:21: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
pr_cont("{%pS}", (void *)m->ip);
^
Fix the type mismatch between the 'void *' expected by %pS and the mce->ip
field which is u64 by casting to long.
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-kernel@vger.kernel.org
Fixes: 7b6061627eb8 ("x86: do not use print_symbol()")
Link: http://lkml.kernel.org/r/20180210145314.22174-1-bp@alien8.de
[ Cleaned up the changelog. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Because more readable..
Requested-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull nfsd update from Bruce Fields:
"A fairly small update this time around. Some cleanup, RDMA fixes,
overlayfs fixes, and a fix for an NFSv4 state bug.
The bigger deal for nfsd this time around was Jeff Layton's
already-merged i_version patches"
* tag 'nfsd-4.16' of git://linux-nfs.org/~bfields/linux:
svcrdma: Fix Read chunk round-up
NFSD: hide unused svcxdr_dupstr()
nfsd: store stat times in fill_pre_wcc() instead of inode times
nfsd: encode stat->mtime for getattr instead of inode->i_mtime
nfsd: return RESOURCE not GARBAGE_ARGS on too many ops
nfsd4: don't set lock stateid's sc_type to CLOSED
nfsd: Detect unhashed stids in nfsd4_verify_open_stid()
sunrpc: remove dead code in svc_sock_setbufsize
svcrdma: Post Receives in the Receive completion handler
nfsd4: permit layoutget of executable-only files
lockd: convert nlm_rqst.a_count from atomic_t to refcount_t
lockd: convert nlm_lockowner.count from atomic_t to refcount_t
lockd: convert nsm_handle.sm_count from atomic_t to refcount_t
Because its daft..
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull idr updates from Matthew Wilcox:
- test-suite improvements
- replace the extended API by improving the normal API
- performance improvement for IDRs which are 1-based rather than
0-based
- add documentation
* 'idr-2018-02-06' of git://git.infradead.org/users/willy/linux-dax:
idr: Add documentation
idr: Make 1-based IDRs more efficient
idr: Warn if old iterators see large IDs
idr: Rename idr_for_each_entry_ext
idr: Remove idr_alloc_ext
cls_u32: Convert to idr_alloc_u32
cls_u32: Reinstate cyclic allocation
cls_flower: Convert to idr_alloc_u32
cls_bpf: Convert to use idr_alloc_u32
cls_basic: Convert to use idr_alloc_u32
cls_api: Convert to idr_alloc_u32
net sched actions: Convert to use idr_alloc_u32
idr: Add idr_alloc_u32 helper
idr: Delete idr_find_ext function
idr: Delete idr_replace_ext function
idr: Delete idr_remove_ext function
IDR test suite: Check handling negative end correctly
idr test suite: Fix ida_test_random()
radix tree test suite: Remove ARRAY_SIZE