Sealing read-only of elf mapping so it can't be changed by mprotect.

[jeffxu@chromium.org: style change]
  Link: https://lkml.kernel.org/r/20240416220944.2481203-2-jeffxu@chromium.org
[amer.shanawany@gmail.com: fix linker error for inline function]
  Link: https://lkml.kernel.org/r/20240420202346.546444-1-amer.shanawany@gmail.com
[jeffxu@chromium.org: fix compile warning]
  Link: https://lkml.kernel.org/r/20240420003515.345982-2-jeffxu@chromium.org
[jeffxu@chromium.org: fix arm build]
  Link: https://lkml.kernel.org/r/20240502225331.3806279-2-jeffxu@chromium.org
Link: https://lkml.kernel.org/r/20240415163527.626541-6-jeffxu@chromium.orgSigned-off-by: Jeff Xu <jeffxu@chromium.org>
Signed-off-by: Amer Al Shanawany <amer.shanawany@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Jann Horn <jannh@google.com>
Cc: Jeff Xu <jeffxu@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Jorge Lucangeli Obes <jorgelo@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Pedro Falcato <pedro.falcato@gmail.com>
Cc: Stephen Röttger <sroettger@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Amer Al Shanawany <amer.shanawany@gmail.com>
Cc: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Add documentation for mseal().

Link: https://lkml.kernel.org/r/20240415163527.626541-5-jeffxu@chromium.orgSigned-off-by: Jeff Xu <jeffxu@chromium.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Jann Horn <jannh@google.com>
Cc: Jeff Xu <jeffxu@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Jorge Lucangeli Obes <jorgelo@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Pedro Falcato <pedro.falcato@gmail.com>
Cc: Stephen Röttger <sroettger@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Amer Al Shanawany <amer.shanawany@gmail.com>
Cc: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

selftest for memory sealing change in mmap() and mseal().

Link: https://lkml.kernel.org/r/20240415163527.626541-4-jeffxu@chromium.orgSigned-off-by: Jeff Xu <jeffxu@chromium.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Jann Horn <jannh@google.com>
Cc: Jeff Xu <jeffxu@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Jorge Lucangeli Obes <jorgelo@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Pedro Falcato <pedro.falcato@gmail.com>
Cc: Stephen Röttger <sroettger@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Amer Al Shanawany <amer.shanawany@gmail.com>
Cc: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

The new mseal() is an syscall on 64 bit CPU, and with following signature:

int mseal(void addr, size_t len, unsigned long flags)
addr/len: memory range.
flags: reserved.

mseal() blocks following operations for the given memory range.

1> Unmapping, moving to another location, and shrinking the size,
   via munmap() and mremap(), can leave an empty space, therefore can
   be replaced with a VMA with a new set of attributes.

2> Moving or expanding a different VMA into the current location,
   via mremap().

3> Modifying a VMA via mmap(MAP_FIXED).

4> Size expansion, via mremap(), does not appear to pose any specific
   risks to sealed VMAs. It is included anyway because the use case is
   unclear. In any case, users can rely on merging to expand a sealed VMA.

5> mprotect() and pkey_mprotect().

6> Some destructive madvice() behaviors (e.g. MADV_DONTNEED) for anonymous
   memory, when users don't have write permission to the memory. Those
   behaviors can alter region contents by discarding pages, effectively a
   memset(0) for anonymous memory.

Following input during RFC are incooperated into this patch:

Jann Horn: raising awareness and providing valuable insights on the
destructive madvise operations.
Linus Torvalds: assisting in defining system call signature and scope.
Liam R. Howlett: perf optimization.
Theo de Raadt: sharing the experiences and insight gained from
  implementing mimmutable() in OpenBSD.

Finally, the idea that inspired this patch comes from Stephen Röttger's
work in Chrome V8 CFI.

[jeffxu@chromium.org: add branch prediction hint, per Pedro]
  Link: https://lkml.kernel.org/r/20240423192825.1273679-2-jeffxu@chromium.org
Link: https://lkml.kernel.org/r/20240415163527.626541-3-jeffxu@chromium.orgSigned-off-by: Jeff Xu <jeffxu@chromium.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Pedro Falcato <pedro.falcato@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Jann Horn <jannh@google.com>
Cc: Jeff Xu <jeffxu@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Jorge Lucangeli Obes <jorgelo@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Pedro Falcato <pedro.falcato@gmail.com>
Cc: Stephen Röttger <sroettger@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Amer Al Shanawany <amer.shanawany@gmail.com>
Cc: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Patch series "Introduce mseal", v10.

This patchset proposes a new mseal() syscall for the Linux kernel.

In a nutshell, mseal() protects the VMAs of a given virtual memory range
against modifications, such as changes to their permission bits.

Modern CPUs support memory permissions, such as the read/write (RW) and
no-execute (NX) bits.  Linux has supported NX since the release of kernel
version 2.6.8 in August 2004 [1].  The memory permission feature improves
the security stance on memory corruption bugs, as an attacker cannot
simply write to arbitrary memory and point the code to it.  The memory
must be marked with the X bit, or else an exception will occur. 
Internally, the kernel maintains the memory permissions in a data
structure called VMA (vm_area_struct).  mseal() additionally protects the
VMA itself against modifications of the selected seal type.

Memory sealing is useful to mitigate memory corruption issues where a
corrupted pointer is passed to a memory management system.  For example,
such an attacker primitive can break control-flow integrity guarantees
since read-only memory that is supposed to be trusted can become writable
or .text pages can get remapped.  Memory sealing can automatically be
applied by the runtime loader to seal .text and .rodata pages and
applications can additionally seal security critical data at runtime.  A
similar feature already exists in the XNU kernel with the
VM_FLAGS_PERMANENT [3] flag and on OpenBSD with the mimmutable syscall
[4].  Also, Chrome wants to adopt this feature for their CFI work [2] and
this patchset has been designed to be compatible with the Chrome use case.

Two system calls are involved in sealing the map:  mmap() and mseal().

The new mseal() is an syscall on 64 bit CPU, and with following signature:

int mseal(void addr, size_t len, unsigned long flags)
addr/len: memory range.
flags: reserved.

mseal() blocks following operations for the given memory range.

1> Unmapping, moving to another location, and shrinking the size,
   via munmap() and mremap(), can leave an empty space, therefore can
   be replaced with a VMA with a new set of attributes.

2> Moving or expanding a different VMA into the current location,
   via mremap().

3> Modifying a VMA via mmap(MAP_FIXED).

4> Size expansion, via mremap(), does not appear to pose any specific
   risks to sealed VMAs. It is included anyway because the use case is
   unclear. In any case, users can rely on merging to expand a sealed VMA.

5> mprotect() and pkey_mprotect().

6> Some destructive madvice() behaviors (e.g. MADV_DONTNEED) for anonymous
   memory, when users don't have write permission to the memory. Those
   behaviors can alter region contents by discarding pages, effectively a
   memset(0) for anonymous memory.

The idea that inspired this patch comes from Stephen Röttger’s work in
V8 CFI [5].  Chrome browser in ChromeOS will be the first user of this
API.

Indeed, the Chrome browser has very specific requirements for sealing,
which are distinct from those of most applications.  For example, in the
case of libc, sealing is only applied to read-only (RO) or read-execute
(RX) memory segments (such as .text and .RELRO) to prevent them from
becoming writable, the lifetime of those mappings are tied to the lifetime
of the process.

Chrome wants to seal two large address space reservations that are managed
by different allocators.  The memory is mapped RW- and RWX respectively
but write access to it is restricted using pkeys (or in the future ARM
permission overlay extensions).  The lifetime of those mappings are not
tied to the lifetime of the process, therefore, while the memory is
sealed, the allocators still need to free or discard the unused memory. 
For example, with madvise(DONTNEED).

However, always allowing madvise(DONTNEED) on this range poses a security
risk.  For example if a jump instruction crosses a page boundary and the
second page gets discarded, it will overwrite the target bytes with zeros
and change the control flow.  Checking write-permission before the discard
operation allows us to control when the operation is valid.  In this case,
the madvise will only succeed if the executing thread has PKEY write
permissions and PKRU changes are protected in software by control-flow
integrity.

Although the initial version of this patch series is targeting the Chrome
browser as its first user, it became evident during upstream discussions
that we would also want to ensure that the patch set eventually is a
complete solution for memory sealing and compatible with other use cases. 
The specific scenario currently in mind is glibc's use case of loading and
sealing ELF executables.  To this end, Stephen is working on a change to
glibc to add sealing support to the dynamic linker, which will seal all
non-writable segments at startup.  Once this work is completed, all
applications will be able to automatically benefit from these new
protections.

In closing, I would like to formally acknowledge the valuable
contributions received during the RFC process, which were instrumental in
shaping this patch:

Jann Horn: raising awareness and providing valuable insights on the
  destructive madvise operations.
Liam R. Howlett: perf optimization.
Linus Torvalds: assisting in defining system call signature and scope.
Theo de Raadt: sharing the experiences and insight gained from
  implementing mimmutable() in OpenBSD.

MM perf benchmarks
==================
This patch adds a loop in the mprotect/munmap/madvise(DONTNEED) to
check the VMAs’ sealing flag, so that no partial update can be made,
when any segment within the given memory range is sealed.

To measure the performance impact of this loop, two tests are developed.
[8]

The first is measuring the time taken for a particular system call,
by using clock_gettime(CLOCK_MONOTONIC). The second is using
PERF_COUNT_HW_REF_CPU_CYCLES (exclude user space). Both tests have
similar results.

The tests have roughly below sequence:
for (i = 0; i < 1000, i++)
    create 1000 mappings (1 page per VMA)
    start the sampling
    for (j = 0; j < 1000, j++)
        mprotect one mapping
    stop and save the sample
    delete 1000 mappings
calculates all samples.

Below tests are performed on Intel(R) Pentium(R) Gold 7505 @ 2.00GHz,
4G memory, Chromebook.

Based on the latest upstream code:
The first test (measuring time)
syscall__	vmas	t	t_mseal	delta_ns	per_vma	%
munmap__  	1	909	944	35	35	104%
munmap__  	2	1398	1502	104	52	107%
munmap__  	4	2444	2594	149	37	106%
munmap__  	8	4029	4323	293	37	107%
munmap__  	16	6647	6935	288	18	104%
munmap__  	32	11811	12398	587	18	105%
mprotect	1	439	465	26	26	106%
mprotect	2	1659	1745	86	43	105%
mprotect	4	3747	3889	142	36	104%
mprotect	8	6755	6969	215	27	103%
mprotect	16	13748	14144	396	25	103%
mprotect	32	27827	28969	1142	36	104%
madvise_	1	240	262	22	22	109%
madvise_	2	366	442	76	38	121%
madvise_	4	623	751	128	32	121%
madvise_	8	1110	1324	215	27	119%
madvise_	16	2127	2451	324	20	115%
madvise_	32	4109	4642	534	17	113%

The second test (measuring cpu cycle)
syscall__	vmas	cpu	cmseal	delta_cpu	per_vma	%
munmap__	1	1790	1890	100	100	106%
munmap__	2	2819	3033	214	107	108%
munmap__	4	4959	5271	312	78	106%
munmap__	8	8262	8745	483	60	106%
munmap__	16	13099	14116	1017	64	108%
munmap__	32	23221	24785	1565	49	107%
mprotect	1	906	967	62	62	107%
mprotect	2	3019	3203	184	92	106%
mprotect	4	6149	6569	420	105	107%
mprotect	8	9978	10524	545	68	105%
mprotect	16	20448	21427	979	61	105%
mprotect	32	40972	42935	1963	61	105%
madvise_	1	434	497	63	63	115%
madvise_	2	752	899	147	74	120%
madvise_	4	1313	1513	200	50	115%
madvise_	8	2271	2627	356	44	116%
madvise_	16	4312	4883	571	36	113%
madvise_	32	8376	9319	943	29	111%

Based on the result, for 6.8 kernel, sealing check adds
20-40 nano seconds, or around 50-100 CPU cycles, per VMA.

In addition, I applied the sealing to 5.10 kernel:
The first test (measuring time)
syscall__	vmas	t	tmseal	delta_ns	per_vma	%
munmap__	1	357	390	33	33	109%
munmap__	2	442	463	21	11	105%
munmap__	4	614	634	20	5	103%
munmap__	8	1017	1137	120	15	112%
munmap__	16	1889	2153	263	16	114%
munmap__	32	4109	4088	-21	-1	99%
mprotect	1	235	227	-7	-7	97%
mprotect	2	495	464	-30	-15	94%
mprotect	4	741	764	24	6	103%
mprotect	8	1434	1437	2	0	100%
mprotect	16	2958	2991	33	2	101%
mprotect	32	6431	6608	177	6	103%
madvise_	1	191	208	16	16	109%
madvise_	2	300	324	24	12	108%
madvise_	4	450	473	23	6	105%
madvise_	8	753	806	53	7	107%
madvise_	16	1467	1592	125	8	108%
madvise_	32	2795	3405	610	19	122%
					
The second test (measuring cpu cycle)
syscall__	nbr_vma	cpu	cmseal	delta_cpu	per_vma	%
munmap__	1	684	715	31	31	105%
munmap__	2	861	898	38	19	104%
munmap__	4	1183	1235	51	13	104%
munmap__	8	1999	2045	46	6	102%
munmap__	16	3839	3816	-23	-1	99%
munmap__	32	7672	7887	216	7	103%
mprotect	1	397	443	46	46	112%
mprotect	2	738	788	50	25	107%
mprotect	4	1221	1256	35	9	103%
mprotect	8	2356	2429	72	9	103%
mprotect	16	4961	4935	-26	-2	99%
mprotect	32	9882	10172	291	9	103%
madvise_	1	351	380	29	29	108%
madvise_	2	565	615	49	25	109%
madvise_	4	872	933	61	15	107%
madvise_	8	1508	1640	132	16	109%
madvise_	16	3078	3323	245	15	108%
madvise_	32	5893	6704	811	25	114%

For 5.10 kernel, sealing check adds 0-15 ns in time, or 10-30
CPU cycles, there is even decrease in some cases.

It might be interesting to compare 5.10 and 6.8 kernel
The first test (measuring time)
syscall__	vmas	t_5_10	t_6_8	delta_ns	per_vma	%
munmap__	1	357	909	552	552	254%
munmap__	2	442	1398	956	478	316%
munmap__	4	614	2444	1830	458	398%
munmap__	8	1017	4029	3012	377	396%
munmap__	16	1889	6647	4758	297	352%
munmap__	32	4109	11811	7702	241	287%
mprotect	1	235	439	204	204	187%
mprotect	2	495	1659	1164	582	335%
mprotect	4	741	3747	3006	752	506%
mprotect	8	1434	6755	5320	665	471%
mprotect	16	2958	13748	10790	674	465%
mprotect	32	6431	27827	21397	669	433%
madvise_	1	191	240	49	49	125%
madvise_	2	300	366	67	33	122%
madvise_	4	450	623	173	43	138%
madvise_	8	753	1110	357	45	147%
madvise_	16	1467	2127	660	41	145%
madvise_	32	2795	4109	1314	41	147%

The second test (measuring cpu cycle)
syscall__	vmas	cpu_5_10	c_6_8	delta_cpu	per_vma	%
munmap__	1	684	1790	1106	1106	262%
munmap__	2	861	2819	1958	979	327%
munmap__	4	1183	4959	3776	944	419%
munmap__	8	1999	8262	6263	783	413%
munmap__	16	3839	13099	9260	579	341%
munmap__	32	7672	23221	15549	486	303%
mprotect	1	397	906	509	509	228%
mprotect	2	738	3019	2281	1140	409%
mprotect	4	1221	6149	4929	1232	504%
mprotect	8	2356	9978	7622	953	423%
mprotect	16	4961	20448	15487	968	412%
mprotect	32	9882	40972	31091	972	415%
madvise_	1	351	434	82	82	123%
madvise_	2	565	752	186	93	133%
madvise_	4	872	1313	442	110	151%
madvise_	8	1508	2271	763	95	151%
madvise_	16	3078	4312	1234	77	140%
madvise_	32	5893	8376	2483	78	142%

From 5.10 to 6.8
munmap: added 250-550 ns in time, or 500-1100 in cpu cycle, per vma.
mprotect: added 200-750 ns in time, or 500-1200 in cpu cycle, per vma.
madvise: added 33-50 ns in time, or 70-110 in cpu cycle, per vma.

In comparison to mseal, which adds 20-40 ns or 50-100 CPU cycles, the
increase from 5.10 to 6.8 is significantly larger, approximately ten times
greater for munmap and mprotect.

When I discuss the mm performance with Brian Makin, an engineer who worked
on performance, it was brought to my attention that such performance
benchmarks, which measuring millions of mm syscall in a tight loop, may
not accurately reflect real-world scenarios, such as that of a database
service.  Also this is tested using a single HW and ChromeOS, the data
from another HW or distribution might be different.  It might be best to
take this data with a grain of salt.


This patch (of 5):

Wire up mseal syscall for all architectures.

Link: https://lkml.kernel.org/r/20240415163527.626541-1-jeffxu@chromium.org
Link: https://lkml.kernel.org/r/20240415163527.626541-2-jeffxu@chromium.orgSigned-off-by: Jeff Xu <jeffxu@chromium.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Jann Horn <jannh@google.com> [Bug #2]
Cc: Jeff Xu <jeffxu@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Jorge Lucangeli Obes <jorgelo@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Pedro Falcato <pedro.falcato@gmail.com>
Cc: Stephen Röttger <sroettger@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Amer Al Shanawany <amer.shanawany@gmail.com>
Cc: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Merge tag 'mm-nonmm-stable-2024-05-22-17-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull more non-mm updates from Andrew Morton:

 - A series ("kbuild: enable more warnings by default") from Arnd
   Bergmann which enables a number of additional build-time warnings. We
   fixed all the fallout which we could find, there may still be a few
   stragglers.

 - Samuel Holland has developed the series "Unified cross-architecture
   kernel-mode FPU API". This does a lot of consolidation of
   per-architecture kernel-mode FPU usage and enables the use of newer
   AMD GPUs on RISC-V.

 - Tao Su has fixed some selftests build warnings in the series
   "Selftests: Fix compilation warnings due to missing _GNU_SOURCE
   definition".

 - This pull also includes a nilfs2 fixup from Ryusuke Konishi.

* tag 'mm-nonmm-stable-2024-05-22-17-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (23 commits)
  nilfs2: make block erasure safe in nilfs_finish_roll_forward()
  selftests/harness: use 1024 in place of LINE_MAX
  Revert "selftests/harness: remove use of LINE_MAX"
  selftests/fpu: allow building on other architectures
  selftests/fpu: move FP code to a separate translation unit
  drm/amd/display: use ARCH_HAS_KERNEL_FPU_SUPPORT
  drm/amd/display: only use hard-float, not altivec on powerpc
  riscv: add support for kernel-mode FPU
  x86: implement ARCH_HAS_KERNEL_FPU_SUPPORT
  powerpc: implement ARCH_HAS_KERNEL_FPU_SUPPORT
  LoongArch: implement ARCH_HAS_KERNEL_FPU_SUPPORT
  lib/raid6: use CC_FLAGS_FPU for NEON CFLAGS
  arm64: crypto: use CC_FLAGS_FPU for NEON CFLAGS
  arm64: implement ARCH_HAS_KERNEL_FPU_SUPPORT
  ARM: crypto: use CC_FLAGS_FPU for NEON CFLAGS
  ARM: implement ARCH_HAS_KERNEL_FPU_SUPPORT
  arch: add ARCH_HAS_KERNEL_FPU_SUPPORT
  x86/fpu: fix asm/fpu/types.h include guard
  kbuild: enable -Wcast-function-type-strict unconditionally
  kbuild: enable -Wformat-truncation on clang
  ...

Pull more mm updates from Andrew Morton:
 "A series from Dave Chinner which cleans up and fixes the handling of
  nested allocations within stackdepot and page-owner"

* tag 'mm-stable-2024-05-22-17-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  mm/page-owner: use gfp_nested_mask() instead of open coded masking
  stackdepot: use gfp_nested_mask() instead of open coded masking
  mm: lift gfp_kmemleak_mask() to gfp.h

Use '%pD' to print out the filename, and print out the actual offset
within the file too, rather than just what the virtual address of the
mapping is (which doesn't tell you anything about any mapping offsets).

Also, use the exact vma_lookup() instead of find_vma() - the latter
looks up any vma _after_ the address, which is of questionable value
(yes, maybe you fell off the beginning, but you'd be more likely to fall
off the end).
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge trivial x86 code generation annoyances

 - Introduce helper macros for clang asm input problems

 - use said macros to improve trivially stupid code generation issues in
   bitops and array_index_mask_nospec

 - also improve codegen with 32-bit array index comparisons

None of these really matter, but I look at code generation and profiles
fairly regularly, and these misfeatures caused the generated code to
look really odd and distract from the real issues.

* branch 'x86-codegen' of local tree:
  x86: improve bitop code generation with clang
  x86: improve array_index_mask_nospec() code generation
  clang: work around asm input constraint problems

This uses the new ASM_INPUT_RM macro to avoid the bad code generation
issue that clang has with more generic asm inputs.

This ends up avoiding generating code like this:

 	mov    %r10,(%rsp)
 	tzcnt  (%rsp),%rcx

which now becomes just

 	tzcnt  %r10,%rcx

and in the process ends up also removing a few unnecessary stack frames
when the only use was that pointless "asm uses memory location off stack".
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Don't force the inputs to be 'unsigned long', when the comparison can
easily be done in 32-bit if that's more appropriate.

Note that while we can look at the inputs to choose an appropriate size
for the compare instruction, the output is fixed at 'unsigned long'.
That's not technically optimal either, since a 32-bit 'sbbl' would often
be sufficient.

But for the outgoing mask we don't know how the mask ends up being used
(ie we have uses that have an incoming 32-bit array index, but end up
using the mask for other things).  That said, it only costs the extra
REX prefix to always generate the 64-bit mask.

[ A 'sbbl' also always technically generates a 64-bit mask, but with the
  upper 32 bits clear: that's fine for when the incoming index that will
  be masked is already 32-bit, but not if you use the mask to mask a
  pointer afterwards, like the file table lookup does ]

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Work around clang problems with asm constraints that have multiple
possibilities, particularly "g" and "rm".

Clang seems to turn inputs like that into the most generic form, which
is the memory input - but to make matters worse, clang won't even use a
possible original memory location, but will spill the value to stack,
and use the stack for the asm input.

See

  https://github.com/llvm/llvm-project/issues/20571#issuecomment-980933442

for some explanation of why clang has this strange behavior, but the end
result is that "g" and "rm" really end up generating horrid code.

Link: https://github.com/llvm/llvm-project/issues/20571
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull char/misc and other driver subsystem updates from Greg KH:
 "Here is the big set of char/misc and other driver subsystem updates
  for 6.10-rc1. Nothing major here, just lots of new drivers and updates
  for apis and new hardware types. Included in here are:

   - big IIO driver updates with more devices and drivers added

   - fpga driver updates

   - hyper-v driver updates

   - uio_pruss driver removal, no one uses it, other drivers control the
     same hardware now

   - binder minor updates

   - mhi driver updates

   - excon driver updates

   - counter driver updates

   - accessability driver updates

   - coresight driver updates

   - other hwtracing driver updates

   - nvmem driver updates

   - slimbus driver updates

   - spmi driver updates

   - other smaller misc and char driver updates

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'char-misc-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (319 commits)
  misc: ntsync: mark driver as "broken" to prevent from building
  spmi: pmic-arb: Add multi bus support
  spmi: pmic-arb: Register controller for bus instead of arbiter
  spmi: pmic-arb: Make core resources acquiring a version operation
  spmi: pmic-arb: Make the APID init a version operation
  spmi: pmic-arb: Fix some compile warnings about members not being described
  dt-bindings: spmi: Deprecate qcom,bus-id
  dt-bindings: spmi: Add X1E80100 SPMI PMIC ARB schema
  spmi: pmic-arb: Replace three IS_ERR() calls by null pointer checks in spmi_pmic_arb_probe()
  spmi: hisi-spmi-controller: Do not override device identifier
  dt-bindings: spmi: hisilicon,hisi-spmi-controller: clean up example
  dt-bindings: spmi: hisilicon,hisi-spmi-controller: fix binding references
  spmi: make spmi_bus_type const
  extcon: adc-jack: Document missing struct members
  extcon: realtek: Remove unused of_gpio.h
  extcon: usbc-cros-ec: Convert to platform remove callback returning void
  extcon: usb-gpio: Convert to platform remove callback returning void
  extcon: max77843: Convert to platform remove callback returning void
  extcon: max3355: Convert to platform remove callback returning void
  extcon: intel-mrfld: Convert to platform remove callback returning void
  ...

Merge tag 'driver-core-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here is the small set of driver core and kernfs changes for 6.10-rc1.

  Nothing major here at all, just a small set of changes for some driver
  core apis, and minor fixups. Included in here are:

   - sysfs_bin_attr_simple_read() helper added and used

   - device_show_string() helper added and used

  All usages of these were acked by the various maintainers. Also in
  here are:

   - kernfs minor cleanup

   - removed unused functions

   - typo fix in documentation

   - pay attention to sysfs_create_link() failures in module.c finally

  All of these have been in linux-next for a very long time with no
  reported problems"

* tag 'driver-core-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  device property: Fix a typo in the description of device_get_child_node_count()
  kernfs: mount: Remove unnecessary ‘NULL’ values from knparent
  scsi: Use device_show_string() helper for sysfs attributes
  platform/x86: Use device_show_string() helper for sysfs attributes
  perf: Use device_show_string() helper for sysfs attributes
  IB/qib: Use device_show_string() helper for sysfs attributes
  hwmon: Use device_show_string() helper for sysfs attributes
  driver core: Add device_show_string() helper for sysfs attributes
  treewide: Use sysfs_bin_attr_simple_read() helper
  sysfs: Add sysfs_bin_attr_simple_read() helper
  module: don't ignore sysfs_create_link() failures
  driver core: Remove unused platform_notify, platform_notify_remove

Pull staging driver updates from Greg KH:
 "Here is the big set of staging driver changes for 6.10-rc1. Not a lot
  of cleanups happening this kernel release, intern applications must be
  out of sync at the moment. But we did delete two drivers, wlan-ng and
  pi433, as they are no longer in use and the developers involved wanted
  them just gone entirely, allowing us to drop 19k lines from the tree.

  Other than the normal coding style cleanups here, there has been a lot
  of work on the vc04_services code, with the intent to finally get that
  out of staging hopefully soon. It's getting closer, which is nice to
  see.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'staging-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (98 commits)
  staging: pi433: Remove unused driver
  staging: vchiq_core: Add missing blank lines
  staging: vchiq_core: Drop unnecessary blank lines
  staging: vchiq_core: Add parentheses to VCHIQ_MSG_SRCPORT
  staging: vchiq_core: Use printk messages for devices
  staging: vchiq_arm: Drop unnecessary NULL check
  staging: vc04_services: Delete unnecessary NULL check
  staging: vc04_services: vchiq_arm: Fix NULL ptr dereferences
  Staging: rtl8192e: Rename variable DssCCk
  Staging: rtl8192e: Rename variable ExtHTCapInfo
  Staging: rtl8192e: Rename variable MPDUDensity
  Staging: rtl8192e: Rename variable MaxRxAMPDUFactor
  Staging: rtl8192e: Rename variable MaxAMSDUSize
  Staging: rtl8192e: Rename variable DelayBA
  Staging: rtl8192e: Rename variable RxSTBC
  Staging: rtl8192e: Rename variable TxSTBC
  Staging: rtl8192e: Rename variable GreenField
  Staging: rtl8192e: Rename variable ShortGI20Mhz
  Staging: rtl8192e: Rename variable ShortGI40Mhz
  Staging: rtl8192e: Rename variable MimoPwrSave
  ...

Pull tty / serial updates from Greg KH:
 "Here is the big set of tty/serial driver changes for 6.10-rc1.
  Included in here are:

   - Usual good set of api cleanups and evolution by Jiri Slaby to make
     the serial interfaces move out of the 1990's by using kfifos
     instead of hand-rolling their own logic.

   - 8250_exar driver updates

   - max3100 driver updates

   - sc16is7xx driver updates

   - exar driver updates

   - sh-sci driver updates

   - tty ldisc api addition to help refuse bindings

   - other smaller serial driver updates

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'tty-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (113 commits)
  serial: Clear UPF_DEAD before calling tty_port_register_device_attr_serdev()
  serial: imx: Raise TX trigger level to 8
  serial: 8250_pnp: Simplify "line" related code
  serial: sh-sci: simplify locking when re-issuing RXDMA fails
  serial: sh-sci: let timeout timer only run when DMA is scheduled
  serial: sh-sci: describe locking requirements for invalidating RXDMA
  serial: sh-sci: protect invalidating RXDMA on shutdown
  tty: add the option to have a tty reject a new ldisc
  serial: core: Call device_set_awake_path() for console port
  dt-bindings: serial: brcm,bcm2835-aux-uart: convert to dtschema
  tty: serial: uartps: Add support for uartps controller reset
  arm64: zynqmp: Add resets property for UART nodes
  dt-bindings: serial: cdns,uart: Add optional reset property
  serial: 8250_pnp: Switch to DEFINE_SIMPLE_DEV_PM_OPS()
  serial: 8250_exar: Keep the includes sorted
  serial: 8250_exar: Make type of bit the same in exar_ee_*_bit()
  serial: 8250_exar: Use BIT() in exar_ee_read()
  serial: 8250_exar: Switch to use dev_err_probe()
  serial: 8250_exar: Return directly from switch-cases
  serial: 8250_exar: Decrease indentation level
  ...

Pull USB / Thunderbolt updates from Greg KH:
 "Here is the big set of USB and Thunderbolt changes for 6.10-rc1.
  Nothing hugely earth-shattering, just constant forward progress for
  hardware support of new devices and cleanups over the drivers.

  Included in here are:

   - Thunderbolt / USB 4 driver updates

   - typec driver updates

   - dwc3 driver updates

   - gadget driver updates

   - uss720 driver id additions and fixes (people use USB->arallel port
     devices still!)

   - onboard-hub driver rename and additions for new hardware

   - xhci driver updates

   - other small USB driver updates and additions for quirks and api
     changes

  All of these have been in linux-next for a while with no reported
  problems"

* tag 'usb-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (154 commits)
  drm/bridge: aux-hpd-bridge: correct devm_drm_dp_hpd_bridge_add() stub
  usb: fotg210: Add missing kernel doc description
  usb: dwc3: core: Fix unused variable warning in core driver
  usb: typec: tipd: rely on i2c_get_match_data()
  usb: typec: tipd: fix event checking for tps6598x
  usb: typec: tipd: fix event checking for tps25750
  dt-bindings: usb: qcom,dwc3: fix interrupt max items
  usb: fotg210: Use *-y instead of *-objs in Makefile
  usb: phy: tegra: Replace of_gpio.h by proper one
  usb: typec: ucsi: displayport: Fix potential deadlock
  usb: typec: qcom-pmic-typec: split HPD bridge alloc and registration
  usb: musc: Remove unused list 'buffers'
  usb: dwc3: Wait unconditionally after issuing EndXfer command
  usb: gadget: u_audio: Clear uac pointer when freed.
  usb: gadget: u_audio: Fix race condition use of controls after free during gadget unbind.
  dt-bindings: usb: dwc3: Add QDU1000 compatible
  usb: core: Remove the useless struct usb_devmap which is just a bitmap
  MAINTAINERS: Remove {ehci,uhci}-platform.c from ARM/VT8500 entry
  USB: usb_parse_endpoint: ignore reserved bits
  usb: xhci: compact 'trb_in_td()' arguments
  ...

Pull LED updates from Lee Jones:
 "Core Frameworks:
   - Ensure seldom updated triggers have a brightness value before first
     update

  New Device Support:
   - Add support for Simatic IPC Device BX_59A to IPC LEDs Core
   - Add support for Qualcomm PMI8950 PWM to LPG Core

  New Functionality:
   - Add a bunch of new LED function identifiers
   - Add support for High Resolution Timers in LED Trigger Patten

  Fix-ups:
   - Shift out Audio Trigger to the Sound subsystem
   - Convert suitable calls to devm_* managed resources
   - Device Tree binding adaptions/conversions/creation
   - Remove superfluous code/variables/attributes and simplify overall
   - Use/convert to new/better APIs/helpers/MACROs instead of
     hand-rolling implementations

  Bug Fixes:
   - Repair enabling Torch Mode from V4L2 on the second LED
   - Ensure PWM is disabled when suspending"

* tag 'leds-next-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/leds: (28 commits)
  leds: mt6370: Remove unused field 'reg_cfgs' from 'struct mt6370_priv'
  leds: lp50xx: Remove unused field 'num_of_banked_leds' from 'struct lp50xx'
  leds: lp50xx: Remove unused field 'bank_modules' from 'struct lp50xx_led'
  leds: aat1290: Remove unused field 'torch_brightness' from 'struct aat1290_led'
  leds: sun50i-a100: Use match_string() helper to simplify the code
  leds: pwm: Disable PWM when going to suspend
  leds: trigger: pattern: Add support for hrtimer
  leds: mt6360: Fix the second LED can not enable torch mode by V4L2
  dt-bindings: leds: leds-qcom-lpg: Add support for PMI8950 PWM
  leds: qcom-lpg: Add support for PMI8950 PWM
  leds: apu: Remove duplicate DMI lookup data
  leds: trigger: netdev: Remove not needed call to led_set_brightness in deactivate
  dt-bindings: leds: Add LED_FUNCTION_SPEED_* for link speed on LAN/WAN
  dt-bindings: leds: Add LED_FUNCTION_MOBILE for mobile network
  leds: simatic-ipc-leds-gpio: Add support for module BX-59A
  dt-bindings: leds: qcom-lpg: Document PM6150L compatible
  dt-bindings: leds: pca963x: Convert text bindings to YAML
  leds: an30259a: Use devm_mutex_init() for mutex initialization
  leds: mlxreg: Use devm_mutex_init() for mutex initialization
  leds: nic78bx: Use devm API to cleanup module's resources
  ...

Pull backlight updates from Lee Jones:
 "Fix-ups:
   - FB Backlight interaction overhaul
   - Remove superfluous code and simplify overall
   - Constify various structs and struct attributes

  Bug Fixes:
   - Repair LED flickering
   - Fix signedness bugs"

* tag 'backlight-next-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight: (42 commits)
  backlight: sky81452-backlight: Remove unnecessary call to of_node_get()
  backlight: mp3309c: Fix LEDs flickering in PWM mode
  backlight: otm3225a: Drop driver owner assignment
  backlight: lp8788: Drop support for platform data
  backlight: lcd: Make lcd_class constant
  backlight: Make backlight_class constant
  backlight: mp3309c: Fix signedness bug in mp3309c_parse_fwnode()
  const_structs.checkpatch: add lcd_ops
  fbdev: omap: lcd_ams_delta: Constify lcd_ops
  fbdev: imx: Constify lcd_ops
  fbdev: clps711x: Constify lcd_ops
  HID: picoLCD: Constify lcd_ops
  backlight: tdo24m: Constify lcd_ops
  backlight: platform_lcd: Constify lcd_ops
  backlight: otm3225a: Constify lcd_ops
  backlight: ltv350qv: Constify lcd_ops
  backlight: lms501kf03: Constify lcd_ops
  backlight: lms283gf05: Constify lcd_ops
  backlight: l4f00242t03: Constify lcd_ops
  backlight: jornada720_lcd: Constify lcd_ops
  ...

Pull MFD updates from Lee Jones:
 "New Device Support:
   - Add support for X-Powers AXP717 PMIC to AXP22X
   - Add support for Rockchip RK816 PMIC to RK8XX
   - Add support for TI TPS65224 PMIC to TPS6594

  New Functionality:
   - Add Power Off functionality to Rohm BD71828
   - Allow I2C SMBus access in Renesas RSMU

  Fix-ups:
   - Device Tree binding adaptions/conversions/creation
   - Shift Intel support over to MSI interrupts
   - Generify adding platform data away from being ACPI specific
   - Use device core supplied attribute to register sysfs entries
   - Replace hand-rolled functionality with generic APIs
   - Utilise centrally provided helpers and macros
   - Clean-up error handling
   - Remove superfluous/duplicated/unused sections
   - Trivial; spelling, whitespace, coding-style adaptions
   - More Maple Tree conversions"

* tag 'mfd-next-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd: (44 commits)
  dt-bindings: mfd: Use full path to other schemas
  mfd: rsmu: support I2C SMBus access
  dt-bindings: mfd: Convert lp873x.txt to json-schema
  dt-bindings: mfd: aspeed: Drop 'oneOf' for pinctrl node
  dt-bindings: mfd: allwinner,sun6i-a31-prcm: Use hyphens in node names
  mfd: ssbi: Remove unused field 'slave' from 'struct ssbi'
  mfd: kempld: Remove custom DMI matching code
  mfd: cs42l43: Update patching revision check
  dt-bindings: mfd: qcom: pm8xxx: Add pm8901 compatible
  mfd: timberdale: Remove redundant assignment to variable err
  dt-bindings: mfd: qcom,spmi-pmic: Add pbs to SPMI device types
  dt-bindings: mfd: syscon: Add ti,am62p-cpsw-mac-efuse compatible
  dt-bindings: mfd: qcom,tcsr: Add compatible for SDX75
  mfd: axp20x: Convert to use Maple Tree register cache
  mfd: bd71828: Remove commented code lines
  mfd: intel-m10-bmc: Change staging size to a variable
  dt-bindings: mfd: Add ROHM BD71879
  mfd: Tidy Kconfig dependency's parentheses
  mfd: ocelot-spi: Use spi_sync_transfer()
  dt-bindings: mfd: syscon: Add missing simple syscon compatibles
  ...

Pull RISC-V updates from Palmer Dabbelt:

 - Add byte/half-word compare-and-exchange, emulated via LR/SC loops

 - Support for Rust

 - Support for Zihintpause in hwprobe

 - Add PR_RISCV_SET_ICACHE_FLUSH_CTX prctl()

 - Support lockless lockrefs

* tag 'riscv-for-linus-6.10-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (42 commits)
  riscv: defconfig: Enable CONFIG_CLK_SOPHGO_CV1800
  riscv: select ARCH_HAS_FAST_MULTIPLIER
  riscv: mm: still create swiotlb buffer for kmalloc() bouncing if required
  riscv: Annotate pgtable_l{4,5}_enabled with __ro_after_init
  riscv: Remove redundant CONFIG_64BIT from pgtable_l{4,5}_enabled
  riscv: mm: Always use an ASID to flush mm contexts
  riscv: mm: Preserve global TLB entries when switching contexts
  riscv: mm: Make asid_bits a local variable
  riscv: mm: Use a fixed layout for the MM context ID
  riscv: mm: Introduce cntx2asid/cntx2version helper macros
  riscv: Avoid TLB flush loops when affected by SiFive CIP-1200
  riscv: Apply SiFive CIP-1200 workaround to single-ASID sfence.vma
  riscv: mm: Combine the SMP and UP TLB flush code
  riscv: Only send remote fences when some other CPU is online
  riscv: mm: Broadcast kernel TLB flushes only when needed
  riscv: Use IPIs for remote cache/TLB flushes by default
  riscv: Factor out page table TLB synchronization
  riscv: Flush the instruction cache during SMP bringup
  riscv: hwprobe: export Zihintpause ISA extension
  riscv: misaligned: remove CONFIG_RISCV_M_MODE specific code
  ...

Merge tag 'loongarch-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson

Pull LoongArch updates from Huacai Chen:

 - Select some options in Kconfig

 - Give a chance to build with !CONFIG_SMP

 - Switch to use built-in rustc target

 - Add new supported device nodes to dts

 - Some bug fixes and other small changes

 - Update the default config file

* tag 'loongarch-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson:
  LoongArch: Update Loongson-3 default config file
  LoongArch: dts: Add new supported device nodes to Loongson-2K2000
  LoongArch: dts: Add new supported device nodes to Loongson-2K0500
  LoongArch: dts: Remove "disabled" state of clock controller node
  LoongArch: rust: Switch to use built-in rustc target
  LoongArch: Fix callchain parse error with kernel tracepoint events again
  LoongArch: Give a chance to build with !CONFIG_SMP
  LoongArch: Select THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE
  LoongArch: Select ARCH_WANT_DEFAULT_BPF_JIT
  LoongArch: Select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
  LoongArch: Select ARCH_HAS_FAST_MULTIPLIER

Pull microblaze updates from Michal Simek:

 - Cleanup code around removed early_printk

* tag 'microblaze-v6.10' of git://git.monstr.eu/linux-2.6-microblaze:
  microblaze: Remove early printk call from cpuinfo-static.c
  microblaze: Remove gcc flag for non existing early_printk.c file

Pull overlayfs updates from Miklos Szeredi:

 - Add tmpfile support

 - Clean up include

* tag 'ovl-update-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/overlayfs/vfs:
  ovl: remove duplicate included header
  ovl: remove upper umask handling from ovl_create_upper()
  ovl: implement tmpfile

Pull fuse updates from Miklos Szeredi:

 - Add fs-verity support (Richard Fung)

 - Add multi-queue support to virtio-fs (Peter-Jan Gootzen)

 - Fix a bug in NOTIFY_RESEND handling (Hou Tao)

 - page -> folio cleanup (Matthew Wilcox)

* tag 'fuse-update-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  virtio-fs: add multi-queue support
  virtio-fs: limit number of request queues
  fuse: clear FR_SENT when re-adding requests into pending list
  fuse: set FR_PENDING atomically in fuse_resend()
  fuse: Add initial support for fs-verity
  fuse: Convert fuse_readpages_end() to use folio_end_read()

Our applications, built on Elasticsearch[0], frequently create and
delete files.  These applications operate within containers, some with a
memory limit exceeding 100GB.  Over prolonged periods, the accumulation
of negative dentries within these containers can amount to tens of
gigabytes.

Upon container exit, directories are deleted.  However, due to the
numerous associated dentries, this process can be time-consuming.  Our
users have expressed frustration with this prolonged exit duration,
which constitutes our first issue.

Simultaneously, other processes may attempt to access the parent
directory of the Elasticsearch directories.  Since the task responsible
for deleting the dentries holds the inode lock, processes attempting
directory lookup experience significant delays.  This issue, our second
problem, is easily demonstrated:

  - Task 1 generates negative dentries:
  $ pwd
  ~/test
  $ mkdir es && cd es/ && ./create_and_delete_files.sh

  [ After generating tens of GB dentries ]

  $ cd ~/test && rm -rf es

  [ It will take a long duration to finish ]

  - Task 2 attempts to lookup the 'test/' directory
  $ pwd
  ~/test
  $ ls

  The 'ls' command in Task 2 experiences prolonged execution as Task 1
  is deleting the dentries.

We've devised a solution to address both issues by deleting associated
dentry when removing a file.  Interestingly, we've noted that a similar
patch was proposed years ago[1], although it was rejected citing the
absence of tangible issues caused by negative dentries.  Given our
current challenges, we're resubmitting the proposal.  All relevant
stakeholders from previous discussions have been included for reference.

Some alternative solutions are also under discussion[2][3], such as
shrinking child dentries outside of the parent inode lock or even
asynchronously shrinking child dentries.  However, given the
straightforward nature of the current solution, I believe this approach
is still necessary.

[ NOTE! This is a pretty fundamental change in how we deal with
  unlinking dentries, and it doesn't change the fact that you can have
  lots of negative dentries from just doing negative lookups.

  But the kernel test robot is at least initially happy with this from a
  performance angle, so I'm applying this ASAP just to get more testing
  and as a "known fix for an issue people hit in real life".

  Put another way: we should still look at the alternatives, and this
  patch may get reverted if somebody finds a performance regression on
  some other load.       - Linus ]
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://github.com/elastic/elasticsearch [0]
Link: https://patchwork.kernel.org/project/linux-fsdevel/patch/1502099673-31620-1-git-send-email-wangkai86@huawei.com [1]
Link: https://lore.kernel.org/linux-fsdevel/20240511200240.6354-2-torvalds@linux-foundation.org/ [2]
Link: https://lore.kernel.org/linux-fsdevel/CAHk-=wjEMf8Du4UFzxuToGDnF3yLaMcrYeyNAaH1NJWa6fwcNQ@mail.gmail.com/ [3]
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Waiman Long <longman@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Wangkai <wangkai86@huawei.com>
Cc: Colin Walters <walters@verbum.org>
Tested-by: kernel test robot <oliver.sang@intel.com>
Link: https://lore.kernel.org/all/202405221518.ecea2810-oliver.sang@intel.com/Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'perf-tools-for-v6.10-1-2024-05-21' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools

Pull perf tools updates from Arnaldo Carvalho de Melo:
 "General:

   - Integrate the shellcheck utility with the build of perf to allow
     catching shell problems early in areas such as 'perf test', 'perf
     trace' scrape scripts, etc

   - Add 'uretprobe' variant in the 'perf bench uprobe' tool

   - Add script to run instances of 'perf script' in parallel

   - Allow parsing tracepoint names that start with digits, such as
     9p/9p_client_req, etc. Make sure 'perf test' tests it even on
     systems where those tracepoints aren't available

   - Add Kan Liang to MAINTAINERS as a perf tools reviewer

   - Add support for using the 'capstone' disassembler library in
     various tools, such as 'perf script' and 'perf annotate'. This is
     an alternative for the use of the 'xed' and 'objdump' disassemblers

  Data-type profiling improvements:

   - Resolve types for a->b->c by backtracking the assignments until it
     finds DWARF info for one of those members

   - Support for global variables, keeping a cache to speed up lookups

   - Handle the 'call' instruction, dealing with effects on registers
     and handling its return when tracking register data types

   - Handle x86's segment based addressing like %gs:0x28, to support
     things like per CPU variables, the stack canary, etc

   - Data-type profiling got big speedups when using capstone for
     disassembling. The objdump outoput parsing method is left as a
     fallback when capstone fails or isn't available. There are patches
     posted for 6.11 that to use a LLVM disassembler

   - Support event group display in the TUI when annotating types with
     --data-type, for instance to show memory load and store events for
     the data type fields

   - Optimize the 'perf annotate' data structures, reducing memory usage

   - Add a initial 'perf test' for 'perf annotate', checking that a
     target symbol appears on the output, specifying objdump via the
     command line, etc

  Vendor Events:

   - Update Intel JSON files for Cascade Lake X, Emerald Rapids, Grand
     Ridge, Ice Lake X, Lunar Lake, Meteor Lake, Sapphire Rapids, Sierra
     Forest, Sky Lake X, Sky Lake and Snow Ridge X. Remove info metrics
     erroneously in TopdownL1

   - Add AMD's Zen 5 core and uncore events and metrics. Those come from
     the "Performance Monitor Counters for AMD Family 1Ah Model 00h- 0Fh
     Processors" document, with events that capture information on op
     dispatch, execution and retirement, branch prediction, L1 and L2
     cache activity, TLB activity, etc

   - Mark L1D_CACHE_INVAL impacted by errata for ARM64's AmpereOne/
     AmpereOneX

  Miscellaneous:

   - Sync header copies with the kernel sources

   - Move some header copies used only for generating translation string
     tables for ioctl cmds and other syscall integer arguments to a new
     directory under tools/perf/beauty/, to separate from copies in
     tools/include/ that are used to build the tools

   - Introduce scrape script for several syscall 'flags'/'mask'
     arguments

   - Improve cpumap utilization, fixing up pairing of refcounts, using
     the right iterators (perf_cpu_map__for_each_cpu), etc

   - Give more details about raw event encodings in 'perf list', show
     tracepoint encoding in the detailed output

   - Refactor the DSOs handling code, reducing memory usage

   - Document the BPF event modifier and add a 'perf test' for it

   - Improve the event parser, better error messages and add further
     'perf test's for it

   - Add reference count checking to 'struct comm_str' and 'struct
     mem_info'

   - Make ARM64's 'perf test' entries for the Neoverse N1 more robust

   - Tweak the ARM64's Coresight 'perf test's

   - Improve ARM64's CoreSight ETM version detection and error reporting

   - Fix handling of symbols when using kcore

   - Fix PAI (Processor Activity Instrumentation) counter names for s390
     virtual machines in 'perf report'

   - Fix -g/--call-graph option failure in 'perf sched timehist'

   - Add LIBTRACEEVENT_DIR build option to allow building with
     libtraceevent installed in non-standard directories, such as when
     doing cross builds

   - Various 'perf test' and 'perf bench' fixes

   - Improve 'perf probe' error message for long C++ probe names"

* tag 'perf-tools-for-v6.10-1-2024-05-21' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools: (260 commits)
  tools lib subcmd: Show parent options in help
  perf pmu: Count sys and cpuid JSON events separately
  perf stat: Don't display metric header for non-leader uncore events
  perf annotate-data: Ensure the number of type histograms
  perf annotate: Fix segfault on sample histogram
  perf daemon: Fix file leak in daemon_session__control
  libsubcmd: Fix parse-options memory leak
  perf lock: Avoid memory leaks from strdup()
  perf sched: Rename 'switches' column header to 'count' and add usage description, options for latency
  perf tools: Ignore deleted cgroups
  perf parse: Allow tracepoint names to start with digits
  perf parse-events: Add new 'fake_tp' parameter for tests
  perf parse-events: pass parse_state to add_tracepoint
  perf symbols: Fix ownership of string in dso__load_vmlinux()
  perf symbols: Update kcore map before merging in remaining symbols
  perf maps: Re-use __maps__free_maps_by_name()
  perf symbols: Remove map from list before updating addresses
  perf tracepoint: Don't scan all tracepoints to test if one exists
  perf dwarf-aux: Fix build with HAVE_DWARF_CFI_SUPPORT
  perf thread: Fixes to thread__new() related to initializing comm
  ...

Pull bitmap updates from Yury Norov:

 - topology_span_sane() optimization from Kyle Meyer

 - fns() rework from Kuan-Wei Chiu (used in cpumask_local_spread() and
   other places)

 - headers cleanup from Andy

 - add a MAINTAINERS record for bitops API

* tag 'bitmap-for-6.10v2' of https://github.com/norov/linux:
  usercopy: Don't use "proxy" headers
  bitops: Move aligned_byte_mask() to wordpart.h
  MAINTAINERS: add BITOPS API record
  bitmap: relax find_nth_bit() limitation on return value
  lib: make test_bitops compilable into the kernel image
  bitops: Optimize fns() for improved performance
  lib/test_bitops: Add benchmark test for fns()
  Compiler Attributes: Add __always_used macro
  sched/topology: Optimize topology_span_sane()
  cpumask: Add for_each_cpu_from()

Pull misc vfs updates from Al Viro:
 "Assorted commits that had missed the last merge window..."

* tag 'pull-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  remove call_{read,write}_iter() functions
  do_dentry_open(): kill inode argument
  kernel_file_open(): get rid of inode argument
  get_file_rcu(): no need to check for NULL separately
  fd_is_open(): move to fs/file.c
  close_on_exec(): pass files_struct instead of fdtable

Pull bdev flags update from Al Viro:
 "Compactifying bdev flags.

  We can easily have up to 24 flags with sane atomicity, _without_
  pushing anything out of the first cacheline of struct block_device"

* tag 'pull-bd_flags-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  bdev: move ->bd_make_it_fail to ->__bd_flags
  bdev: move ->bd_ro_warned to ->__bd_flags
  bdev: move ->bd_has_subit_bio to ->__bd_flags
  bdev: move ->bd_write_holder into ->__bd_flags
  bdev: move ->bd_read_only to ->__bd_flags
  bdev: infrastructure for flags
  wrapper for access to ->bd_partno
  Use bdev_is_paritition() instead of open-coding it

Pull more s390 updates from Alexander Gordeev:

 - Switch read and write software bits for PUDs

 - Add missing hardware bits for PUDs and PMDs

 - Generate unwind information for C modules to fix GDB unwind error for
   vDSO functions

 - Create .build-id links for unstripped vDSO files to enable vDSO
   debugging with symbols

 - Use standard stack frame layout for vDSO generated stack frames to
   manually walk stack frames without DWARF information

 - Rework perf_callchain_user() and arch_stack_walk_user() functions to
   reduce code duplication

 - Skip first stack frame when walking user stack

 - Add basic checks to identify invalid instruction pointers when
   walking stack frames

 - Introduce and use struct stack_frame_vdso_wrapper within vDSO user
   wrapper code to automatically generate an asm-offset define. Also use
   STACK_FRAME_USER_OVERHEAD instead of STACK_FRAME_OVERHEAD to document
   that the code works with user space stack

 - Clear the backchain of the extra stack frame added by the vDSO user
   wrapper code. This allows the user stack walker to detect and skip
   the non-standard stack frame. Without this an incorrect instruction
   pointer would be added to stack traces.

 - Rewrite psw_idle() function in C to ease maintenance and further
   enhancements

 - Remove get_vtimer() function and use get_cpu_timer() instead

 - Mark psw variable in __load_psw_mask() as __unitialized to avoid
   superfluous clearing of PSW

 - Remove obsolete and superfluous comment about removed TIF_FPU flag

 - Replace memzero_explicit() and kfree() with kfree_sensitive() to fix
   warnings reported by Coccinelle

 - Wipe sensitive data and all copies of protected- or secure-keys from
   stack when an IOCTL fails

 - Both do_airq_interrupt() and do_io_interrupt() functions set
   CIF_NOHZ_DELAY flag. Move it in do_io_irq() to simplify the code

 - Provide iucv_alloc_device() and iucv_release_device() helpers, which
   can be used to deduplicate more or less identical IUCV device
   allocation and release code in four different drivers

 - Make use of iucv_alloc_device() and iucv_release_device() helpers to
   get rid of quite some code and also remove a cast to an incompatible
   function (clang W=1)

 - There is no user of iucv_root outside of the core IUCV code left.
   Therefore remove the EXPORT_SYMBOL

 - __apply_alternatives() contains a runtime check which verifies that
   the size of the to be patched code area is even. Convert this to a
   compile time check

 - Increase size of buffers for sending z/VM CP DIAGNOSE X'008' commands
   from 128 to 240

 - Do not accept z/VM CP DIAGNOSE X'008' commands longer than maximally
   allowed

 - Use correct defines IPL_BP_NVME_LEN and IPL_BP0_NVME_LEN instead of
   IPL_BP_FCP_LEN and IPL_BP0_FCP_LEN ones to initialize NVMe reIPL
   block on 'scp_data' sysfs attribute update

 - Initialize the correct fields of the NVMe dump block, which were
   confused with FCP fields

 - Refactor macros for 'scp_data' (re-)IPL sysfs attribute to reduce
   code duplication

 - Introduce 'scp_data' sysfs attribute for dump IPL to allow tools such
   as dumpconf passing additional kernel command line parameters to a
   stand-alone dumper

 - Rework the CPACF query functions to use the correct RRE or RRF
   instruction formats and set instruction register fields correctly

 - Instead of calling BUG() at runtime force a link error during compile
   when a unsupported opcode is used with __cpacf_query() or
   __cpacf_check_opcode() functions

 - Fix a crash in ap_parse_bitmap_str() function on /sys/bus/ap/apmask
   or /sys/bus/ap/aqmask sysfs file update with a relative mask value

 - Fix "bindings complete" udev event which should be sent once all AP
   devices have been bound to device drivers and again when unbind/bind
   actions take place and all AP devices are bound again

 - Facility list alt_stfle_fac_list is nowhere used in the decompressor,
   therefore remove it there

 - Remove custom kprobes insn slot allocator in favour of the standard
   module_alloc() one, since kernel image and module areas are located
   within 4GB

 - Use kvcalloc() instead of kvmalloc_array() in zcrypt driver to avoid
   calling memset() with a large byte count and get rid of the sparse
   warning as result

* tag 's390-6.10-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (39 commits)
  s390/zcrypt: Use kvcalloc() instead of kvmalloc_array()
  s390/kprobes: Remove custom insn slot allocator
  s390/boot: Remove alt_stfle_fac_list from decompressor
  s390/ap: Fix bind complete udev event sent after each AP bus scan
  s390/ap: Fix crash in AP internal function modify_bitmap()
  s390/cpacf: Make use of invalid opcode produce a link error
  s390/cpacf: Split and rework cpacf query functions
  s390/ipl: Introduce sysfs attribute 'scp_data' for dump ipl
  s390/ipl: Introduce macros for (re)ipl sysfs attribute 'scp_data'
  s390/ipl: Fix incorrect initialization of nvme dump block
  s390/ipl: Fix incorrect initialization of len fields in nvme reipl block
  s390/ipl: Do not accept z/VM CP diag X'008' cmds longer than max length
  s390/ipl: Fix size of vmcmd buffers for sending z/VM CP diag X'008' cmds
  s390/alternatives: Convert runtime sanity check into compile time check
  s390/iucv: Unexport iucv_root
  tty: hvc-iucv: Make use of iucv_alloc_device()
  s390/smsgiucv_app: Make use of iucv_alloc_device()
  s390/netiucv: Make use of iucv_alloc_device()
  s390/vmlogrdr: Make use of iucv_alloc_device()
  s390/iucv: Provide iucv_alloc_device() / iucv_release_device()
  ...

Pull m68knommu update from Greg Ungerer:

 . remove use of kernel config option from uapi header

* tag 'm68knommu-for-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu:
  m68k: Avoid CONFIG_COLDFIRE switch in uapi header

Pull EFI fix from Ard Biesheuvel:

 - Followup fix for the EFI boot sequence refactor, which may result in
   physical KASLR putting the kernel in a region which is being used for
   a special purpose via a command line argument.

* tag 'efi-fixes-for-v6.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
  x86/efistub: Omit physical KASLR when memory reservations exist

Merge tag 'for-6.10/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper fixes from Mike Snitzer:

 - Fix DM discard regressions due to DM core switching over to using
   queue_limits_set() without DM core and targets first being updated to
   set (and stack) discard limits in terms of max_hw_discard_sectors and
   not max_discard_sectors

 - Fix stable@ DM integrity discard support to set device's
   discard_granularity limit to the device's logical block size

* tag 'for-6.10/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm: always manage discard support in terms of max_hw_discard_sectors
  dm-integrity: set discard_granularity to logical block size

Pull power management fixes from Rafael Wysocki:
 "These fix the amd-pstate driver and the operating performance point
  (OPP) handling related to generic PM domains.

  Specifics:

   - Fix a memory leak in the exit path of amd-pstate (Peng Ma)

   - Fix required_opp_tables handling in the cases when multiple generic
     PM domains share one OPP table (Viresh Kumar)"

* tag 'pm-6.10-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  OPP: Fix required_opp_tables for multiple genpds using same table
  cpufreq: amd-pstate: fix memory leak on CPU EPP exit

Pull ACPI fixes from Rafael Wysocki:
 "These make the ACPI EC driver always install the EC address space
  handler at the root of the ACPI namespace which causes it to take care
  of all EC operation regions everywhere.

  This means that the custom EC address space handler in the WMI driver
  is not needed any more and accordingly it gets removed altogether"

* tag 'acpi-6.10-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  platform/x86: wmi: Remove custom EC address space handler
  ACPI: EC: Install address space handler at the namespace root

Pull thermal control fixes from Rafael Wysocki:
 "These fix the MediaTek lvts_thermal driver and the handling of trip
  points that start as invalid and are adjusted later by user space via
  sysfs.

  Specifics:

   - Fix and clean up the MediaTek lvts_thermal driver (Julien Panis)

   - Prevent invalid trip point handling from triggering spurious trip
     point crossing events and allow passive polling to stop when a
     passive trip point involved in it becomes invalid (Rafael Wysocki)"

* tag 'thermal-6.10-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  thermal: core: Fix the handling of invalid trip points
  thermal/drivers/mediatek/lvts_thermal: Fix wrong lvts_ctrl index
  thermal/drivers/mediatek/lvts_thermal: Remove unused members from struct lvts_ctrl_data
  thermal/drivers/mediatek/lvts_thermal: Check NULL ptr on lvts_data

Merge tag 'intel-gpio-v6.10-2' of git://git.kernel.org/pub/scm/linux/kernel/git/andy/linux-gpio-intel

Pull intel-gpio fixes from Andy Shevchenko:

 - NULL pointer dereference fix in GPIO APCI library

 - Restore ACPI handle matching for GPIO devices represented in banks

* tag 'intel-gpio-v6.10-2' of git://git.kernel.org/pub/scm/linux/kernel/git/andy/linux-gpio-intel:
  gpiolib: acpi: Fix failed in acpi_gpiochip_find() by adding parent node match
  gpiolib: acpi: Move ACPI device NULL check to acpi_can_fallback_to_crs()

Pull soundwire updates from Vinod Koul:

 - cleanup and conversion for soundwire sysfs groups

 - intel support for ace2x bits, auxdevice pm improvements

 - qcom multi link device support

* tag 'soundwire-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/soundwire: (33 commits)
  soundwire: intel_ace2.x: add support for DOAISE property
  soundwire: intel_ace2.x: add support for DODSE property
  soundwire: intel_ace2x: use DOAIS and DODS settings from firmware
  soundwire: intel_ace2x: cleanup DOAIS/DODS settings
  soundwire: intel_ace2x: simplify check_wake()
  soundwire: intel_ace2x: fix wakeup handling
  soundwire: intel_init: resume all devices on exit.
  soundwire: intel: export intel_resume_child_device
  soundwire: intel_auxdevice: use pm_runtime_resume() instead of pm_request_resume()
  ASoC: SOF: Intel: hda: disable SoundWire interrupt later
  soundwire: qcom: allow multi-link on newer devices
  soundwire: intel_ace2x: use legacy formula for intel_alh_id
  soundwire: reconcile dp0_prop and dpn_prop
  soundwire: intel_ace2x: set the clock source
  soundwire: intel_ace2.x: power-up first before setting SYNCPRD
  soundwire: intel_ace2x: move and extend clock selection
  soundwire: intel: add support for MeteorLake additional clocks
  soundwire: intel: add more values for SYNCPRD
  soundwire: bus: extend base clock checks to 96 MHz
  soundwire: cadence: show the bus frequency and frame shape
  ...

Pull generic phy updates from Vinod Koul:
 "New HW Support:
   - Support for Embedded DisplayPort and DisplayPort submodes and
     driver support on Qualcomm X1E80100 edp driver
   - Qualcomm QMP UFS PHY for SM8475, QMP USB phy for QDU1000/QRU1000
     and eusb2-repeater for SMB2360
   - Samsung HDMI PHY for i.MX8MP, gs101 UFS phy
   - Mediatek XFI T-PHY support for mt7988
   - Rockchip usbdp combo phy driver

  Updates:
   - Qualcomm x4 lane EP support for sa8775p, v4 ad v6 support for
     X1E80100, SM8650 tables for UFS Gear 4 & 5 and correct voltage
     swing tables
   - Freescale imx8m-pci pcie link-up updates
   - Rockchip rx-common-refclk-mode support
   - More platform remove callback returning void conversions"

* tag 'phy-for-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/phy/linux-phy: (43 commits)
  dt-bindings: phy: qcom,usb-snps-femto-v2: use correct fallback for sc8180x
  dt-bindings: phy: qcom,sc8280xp-qmp-ufs-phy: fix msm899[68] power-domains
  dt-bindings: phy: qcom,sc8280xp-qmp-pcie-phy: fix x1e80100-gen3x2 schema
  phy: qcpm-qmp-usb: Add support for QDU1000/QRU1000
  dt-bindings: phy: qcom,qmp-usb: Add QDU1000 USB3 PHY
  dt-bindings: phy: qcom,usb-snps-femto-v2: Add bindings for QDU1000
  phy: qcom-qmp-pcie: add x4 lane EP support for sa8775p
  phy: samsung-ufs: ufs: exit on first reported error
  phy: samsung-ufs: ufs: remove superfluous mfd/syscon.h header
  phy: rockchip: fix CONFIG_TYPEC dependency
  phy: rockchip: usbdp: fix uninitialized variable
  phy: rockchip-snps-pcie3: add support for rockchip,rx-common-refclk-mode
  dt-bindings: phy: rockchip,pcie3-phy: add rockchip,rx-common-refclk-mode
  phy: rockchip: add usbdp combo phy driver
  dt-bindings: phy: add rockchip usbdp combo phy document
  phy: add driver for MediaTek XFI T-PHY
  dt-bindings: phy: mediatek,mt7988-xfi-tphy: add new bindings
  phy: freescale: fsl-samsung-hdmi: Convert to platform remove callback returning void
  phy: qcom: qmp-ufs: update SM8650 tables for Gear 4 & 5
  MAINTAINERS: Add phy-gs101-ufs file to Tensor GS101.
  ...