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To pick up changes from:
b36d4b6aa88ef039 ("arch: hookup listns() system call")
This should be used to beautify the syscall arguments and it addresses
these tools/perf build warnings:
Warning: Kernel ABI header differences:
diff -u tools/include/uapi/asm-generic/unistd.h include/uapi/asm-generic/unistd.h
diff -u tools/scripts/syscall.tbl scripts/syscall.tbl
diff -u tools/perf/arch/x86/entry/syscalls/syscall_32.tbl arch/x86/entry/syscalls/syscall_32.tbl
diff -u tools/perf/arch/x86/entry/syscalls/syscall_64.tbl arch/x86/entry/syscalls/syscall_64.tbl
diff -u tools/perf/arch/powerpc/entry/syscalls/syscall.tbl arch/powerpc/kernel/syscalls/syscall.tbl
diff -u tools/perf/arch/s390/entry/syscalls/syscall.tbl arch/s390/kernel/syscalls/syscall.tbl
diff -u tools/perf/arch/mips/entry/syscalls/syscall_n64.tbl arch/mips/kernel/syscalls/syscall_n64.tbl
diff -u tools/perf/arch/arm/entry/syscalls/syscall.tbl arch/arm/tools/syscall.tbl
diff -u tools/perf/arch/sh/entry/syscalls/syscall.tbl arch/sh/kernel/syscalls/syscall.tbl
diff -u tools/perf/arch/sparc/entry/syscalls/syscall.tbl arch/sparc/kernel/syscalls/syscall.tbl
diff -u tools/perf/arch/xtensa/entry/syscalls/syscall.tbl arch/xtensa/kernel/syscalls/syscall.tbl
Please see tools/include/uapi/README.
Note that s390 syscall table is still out of sync as it switches to use the
generic table. But I'd like to minimize the change in this commit.
Cc: linux-arch@vger.kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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To pick up the changes in this cset:
be7efb2d20d67f33 fs: introduce file_getattr and file_setattr syscalls
This addresses these perf build warnings:
Warning: Kernel ABI header differences:
diff -u tools/include/uapi/asm-generic/unistd.h include/uapi/asm-generic/unistd.h
diff -u tools/scripts/syscall.tbl scripts/syscall.tbl
diff -u tools/perf/arch/x86/entry/syscalls/syscall_32.tbl arch/x86/entry/syscalls/syscall_32.tbl
diff -u tools/perf/arch/x86/entry/syscalls/syscall_64.tbl arch/x86/entry/syscalls/syscall_64.tbl
diff -u tools/perf/arch/powerpc/entry/syscalls/syscall.tbl arch/powerpc/kernel/syscalls/syscall.tbl
diff -u tools/perf/arch/s390/entry/syscalls/syscall.tbl arch/s390/kernel/syscalls/syscall.tbl
diff -u tools/perf/arch/mips/entry/syscalls/syscall_n64.tbl arch/mips/kernel/syscalls/syscall_n64.tbl
diff -u tools/perf/arch/arm/entry/syscalls/syscall.tbl arch/arm/tools/syscall.tbl
diff -u tools/perf/arch/sh/entry/syscalls/syscall.tbl arch/sh/kernel/syscalls/syscall.tbl
diff -u tools/perf/arch/sparc/entry/syscalls/syscall.tbl arch/sparc/kernel/syscalls/syscall.tbl
diff -u tools/perf/arch/xtensa/entry/syscalls/syscall.tbl arch/xtensa/kernel/syscalls/syscall.tbl
Please see tools/include/uapi/README for further details.
Cc: Arnd Bergmann <arnd@arndb.de>
CC: linux-api@vger.kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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As long as recvmsg() or recvmmsg() is used with cmsg, it is not
possible to avoid receiving file descriptors via SCM_RIGHTS.
This behaviour has occasionally been flagged as problematic, as
it can be (ab)used to trigger DoS during close(), for example, by
passing a FUSE-controlled fd or a hung NFS fd.
For instance, as noted on the uAPI Group page [0], an untrusted peer
could send a file descriptor pointing to a hung NFS mount and then
close it. Once the receiver calls recvmsg() with msg_control, the
descriptor is automatically installed, and then the responsibility
for the final close() now falls on the receiver, which may result
in blocking the process for a long time.
Regarding this, systemd calls cmsg_close_all() [1] after each
recvmsg() to close() unwanted file descriptors sent via SCM_RIGHTS.
However, this cannot work around the issue at all, because the final
fput() may still occur on the receiver's side once sendmsg() with
SCM_RIGHTS succeeds. Also, even filtering by LSM at recvmsg() does
not work for the same reason.
Thus, we need a better way to refuse SCM_RIGHTS at sendmsg().
Let's introduce SO_PASSRIGHTS to disable SCM_RIGHTS.
Note that this option is enabled by default for backward
compatibility.
Link: https://uapi-group.org/kernel-features/#disabling-reception-of-scm_rights-for-af_unix-sockets #[0]
Link: https://github.com/systemd/systemd/blob/v257.5/src/basic/fd-util.c#L612-L628 #[1]
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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kernel sources
To pick up the changes in:
6d61527d931ba07b mm/pkey: Add PKEY_UNRESTRICTED macro
Addressing this perf tools build warning:
Warning: Kernel ABI header differences:
diff -u tools/include/uapi/asm-generic/mman-common.h include/uapi/asm-generic/mman-common.h
Please see tools/include/uapi/README for further details.
Acked-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Cc: linux-arch@vger.kernel.org
Link: https://lore.kernel.org/r/20250410001125.391820-8-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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To pick up the changes in:
c4a16820d9019940 fs: add open_tree_attr()
2df1ad0d25803399 x86/arch_prctl: Simplify sys_arch_prctl()
e632bca07c8eef1d arm64: generate 64-bit syscall.tbl
This is basically to support the new open_tree_attr syscall. But it
also needs to update asm-generic unistd.h header to get the new syscall
number. And arm64 unistd.h header was converted to use the generic
64-bit header.
Addressing this perf tools build warning:
Warning: Kernel ABI header differences:
diff -u tools/scripts/syscall.tbl scripts/syscall.tbl
diff -u tools/perf/arch/x86/entry/syscalls/syscall_32.tbl arch/x86/entry/syscalls/syscall_32.tbl
diff -u tools/perf/arch/x86/entry/syscalls/syscall_64.tbl arch/x86/entry/syscalls/syscall_64.tbl
diff -u tools/perf/arch/powerpc/entry/syscalls/syscall.tbl arch/powerpc/kernel/syscalls/syscall.tbl
diff -u tools/perf/arch/s390/entry/syscalls/syscall.tbl arch/s390/kernel/syscalls/syscall.tbl
diff -u tools/perf/arch/mips/entry/syscalls/syscall_n64.tbl arch/mips/kernel/syscalls/syscall_n64.tbl
diff -u tools/perf/arch/arm/entry/syscalls/syscall.tbl arch/arm/tools/syscall.tbl
diff -u tools/perf/arch/sh/entry/syscalls/syscall.tbl arch/sh/kernel/syscalls/syscall.tbl
diff -u tools/perf/arch/sparc/entry/syscalls/syscall.tbl arch/sparc/kernel/syscalls/syscall.tbl
diff -u tools/perf/arch/xtensa/entry/syscalls/syscall.tbl arch/xtensa/kernel/syscalls/syscall.tbl
diff -u tools/arch/arm64/include/uapi/asm/unistd.h arch/arm64/include/uapi/asm/unistd.h
diff -u tools/include/uapi/asm-generic/unistd.h include/uapi/asm-generic/unistd.h
Please see tools/include/uapi/README for further details.
Acked-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Cc: linux-arch@vger.kernel.org
Link: https://lore.kernel.org/r/20250410001125.391820-6-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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This also fixes a wrong definitions for SCM_TS_OPT_ID & SO_RCVPRIORITY.
Accidentally found while working on another patchset.
Cc: linux-kernel@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Jason Xing <kerneljasonxing@gmail.com>
Cc: Anna Emese Nyiri <annaemesenyiri@gmail.com>
Cc: Kuniyuki Iwashima <kuniyu@amazon.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Fixes: a89568e9be75 ("selftests: txtimestamp: add SCM_TS_OPT_ID test")
Fixes: e45469e594b2 ("sock: Introduce SO_RCVPRIORITY socket option")
Link: https://lore.kernel.org/netdev/20250314195257.34854-1-kuniyu@amazon.com/
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Link: https://patch.msgid.link/20250314214155.16046-1-aleksandr.mikhalitsyn@canonical.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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Cross-merge networking fixes after downstream PR (net-6.13-rc4).
No conflicts.
Adjacent changes:
drivers/net/ethernet/renesas/rswitch.h
32fd46f5b69e ("net: renesas: rswitch: remove speed from gwca structure")
922b4b955a03 ("net: renesas: rswitch: rework ts tags management")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Add new socket option, SO_RCVPRIORITY, to include SO_PRIORITY in the
ancillary data returned by recvmsg().
This is analogous to the existing support for SO_RCVMARK,
as implemented in commit 6fd1d51cfa253 ("net: SO_RCVMARK socket option
for SO_MARK with recvmsg()").
Reviewed-by: Willem de Bruijn <willemb@google.com>
Suggested-by: Ferenc Fejes <fejes@inf.elte.hu>
Signed-off-by: Anna Emese Nyiri <annaemesenyiri@gmail.com>
Link: https://patch.msgid.link/20241213084457.45120-5-annaemesenyiri@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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To pick up the changes in this cset:
3630e82ab6bd2642 ("mman: Add map_shadow_stack() flags")
This addresses these perf build warnings:
Warning: Kernel ABI header differences:
diff -u tools/include/uapi/asm-generic/mman.h include/uapi/asm-generic/mman.h
Please see tools/include/uapi/README for further details.
Reviewed-by: James Clark <james.clark@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Mark Brown <broonie@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: linux-arch@vger.kernel.org
Link: https://lore.kernel.org/r/20241203035349.1901262-8-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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To pick up the changes in this cset:
6140be90ec70c39f ("fs/xattr: add *at family syscalls")
This addresses these perf build warnings:
Warning: Kernel ABI header differences:
diff -u tools/include/uapi/asm-generic/unistd.h include/uapi/asm-generic/unistd.h
diff -u tools/perf/arch/x86/entry/syscalls/syscall_32.tbl arch/x86/entry/syscalls/syscall_32.tbl
diff -u tools/perf/arch/x86/entry/syscalls/syscall_64.tbl arch/x86/entry/syscalls/syscall_64.tbl
diff -u tools/perf/arch/powerpc/entry/syscalls/syscall.tbl arch/powerpc/kernel/syscalls/syscall.tbl
diff -u tools/perf/arch/s390/entry/syscalls/syscall.tbl arch/s390/kernel/syscalls/syscall.tbl
diff -u tools/perf/arch/mips/entry/syscalls/syscall_n64.tbl arch/mips/kernel/syscalls/syscall_n64.tbl
The arm64 changes are not included as it requires more changes in the
tools. It'll be worked for the later cycle.
Please see tools/include/uapi/README for further details.
Reviewed-by: James Clark <james.clark@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christian Brauner <brauner@kernel.org>
CC: x86@kernel.org
CC: linux-mips@vger.kernel.org
CC: linuxppc-dev@lists.ozlabs.org
CC: linux-s390@vger.kernel.org
Link: https://lore.kernel.org/r/20241203035349.1901262-7-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- The series "zram: optimal post-processing target selection" from
Sergey Senozhatsky improves zram's post-processing selection
algorithm. This leads to improved memory savings.
- Wei Yang has gone to town on the mapletree code, contributing several
series which clean up the implementation:
- "refine mas_mab_cp()"
- "Reduce the space to be cleared for maple_big_node"
- "maple_tree: simplify mas_push_node()"
- "Following cleanup after introduce mas_wr_store_type()"
- "refine storing null"
- The series "selftests/mm: hugetlb_fault_after_madv improvements" from
David Hildenbrand fixes this selftest for s390.
- The series "introduce pte_offset_map_{ro|rw}_nolock()" from Qi Zheng
implements some rationaizations and cleanups in the page mapping
code.
- The series "mm: optimize shadow entries removal" from Shakeel Butt
optimizes the file truncation code by speeding up the handling of
shadow entries.
- The series "Remove PageKsm()" from Matthew Wilcox completes the
migration of this flag over to being a folio-based flag.
- The series "Unify hugetlb into arch_get_unmapped_area functions" from
Oscar Salvador implements a bunch of consolidations and cleanups in
the hugetlb code.
- The series "Do not shatter hugezeropage on wp-fault" from Dev Jain
takes away the wp-fault time practice of turning a huge zero page
into small pages. Instead we replace the whole thing with a THP. More
consistent cleaner and potentiall saves a large number of pagefaults.
- The series "percpu: Add a test case and fix for clang" from Andy
Shevchenko enhances and fixes the kernel's built in percpu test code.
- The series "mm/mremap: Remove extra vma tree walk" from Liam Howlett
optimizes mremap() by avoiding doing things which we didn't need to
do.
- The series "Improve the tmpfs large folio read performance" from
Baolin Wang teaches tmpfs to copy data into userspace at the folio
size rather than as individual pages. A 20% speedup was observed.
- The series "mm/damon/vaddr: Fix issue in
damon_va_evenly_split_region()" fro Zheng Yejian fixes DAMON
splitting.
- The series "memcg-v1: fully deprecate charge moving" from Shakeel
Butt removes the long-deprecated memcgv2 charge moving feature.
- The series "fix error handling in mmap_region() and refactor" from
Lorenzo Stoakes cleanup up some of the mmap() error handling and
addresses some potential performance issues.
- The series "x86/module: use large ROX pages for text allocations"
from Mike Rapoport teaches x86 to use large pages for
read-only-execute module text.
- The series "page allocation tag compression" from Suren Baghdasaryan
is followon maintenance work for the new page allocation profiling
feature.
- The series "page->index removals in mm" from Matthew Wilcox remove
most references to page->index in mm/. A slow march towards shrinking
struct page.
- The series "damon/{self,kunit}tests: minor fixups for DAMON debugfs
interface tests" from Andrew Paniakin performs maintenance work for
DAMON's self testing code.
- The series "mm: zswap swap-out of large folios" from Kanchana Sridhar
improves zswap's batching of compression and decompression. It is a
step along the way towards using Intel IAA hardware acceleration for
this zswap operation.
- The series "kasan: migrate the last module test to kunit" from
Sabyrzhan Tasbolatov completes the migration of the KASAN built-in
tests over to the KUnit framework.
- The series "implement lightweight guard pages" from Lorenzo Stoakes
permits userapace to place fault-generating guard pages within a
single VMA, rather than requiring that multiple VMAs be created for
this. Improved efficiencies for userspace memory allocators are
expected.
- The series "memcg: tracepoint for flushing stats" from JP Kobryn uses
tracepoints to provide increased visibility into memcg stats flushing
activity.
- The series "zram: IDLE flag handling fixes" from Sergey Senozhatsky
fixes a zram buglet which potentially affected performance.
- The series "mm: add more kernel parameters to control mTHP" from
Maíra Canal enhances our ability to control/configuremultisize THP
from the kernel boot command line.
- The series "kasan: few improvements on kunit tests" from Sabyrzhan
Tasbolatov has a couple of fixups for the KASAN KUnit tests.
- The series "mm/list_lru: Split list_lru lock into per-cgroup scope"
from Kairui Song optimizes list_lru memory utilization when lockdep
is enabled.
* tag 'mm-stable-2024-11-18-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (215 commits)
cma: enforce non-zero pageblock_order during cma_init_reserved_mem()
mm/kfence: add a new kunit test test_use_after_free_read_nofault()
zram: fix NULL pointer in comp_algorithm_show()
memcg/hugetlb: add hugeTLB counters to memcg
vmstat: call fold_vm_zone_numa_events() before show per zone NUMA event
mm: mmap_lock: check trace_mmap_lock_$type_enabled() instead of regcount
zram: ZRAM_DEF_COMP should depend on ZRAM
MAINTAINERS/MEMORY MANAGEMENT: add document files for mm
Docs/mm/damon: recommend academic papers to read and/or cite
mm: define general function pXd_init()
kmemleak: iommu/iova: fix transient kmemleak false positive
mm/list_lru: simplify the list_lru walk callback function
mm/list_lru: split the lock to per-cgroup scope
mm/list_lru: simplify reparenting and initial allocation
mm/list_lru: code clean up for reparenting
mm/list_lru: don't export list_lru_add
mm/list_lru: don't pass unnecessary key parameters
kasan: add kunit tests for kmalloc_track_caller, kmalloc_node_track_caller
kasan: change kasan_atomics kunit test as KUNIT_CASE_SLOW
kasan: use EXPORT_SYMBOL_IF_KUNIT to export symbols
...
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Import the new MADV_GUARD_INSTALL/REMOVE madvise flags.
Link: https://lkml.kernel.org/r/ada462fa73fa1defc114242e446ab625b8290b71.1730123433.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Suggested-by: Jann Horn <jannh@google.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Cc: Arnd Bergmann <arnd@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Chris Zankel <chris@zankel.net>
Cc: Helge Deller <deller@gmx.de>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Jeff Xu <jeffxu@chromium.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Vlastimil Babka <vbabkba@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Extend txtimestamp test to run with fixed tskey using
SCM_TS_OPT_ID control message for all types of sockets.
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Vadim Fedorenko <vadfed@meta.com>
Link: https://patch.msgid.link/20241001125716.2832769-4-vadfed@meta.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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And arch syscall tables to pick up changes from:
b1e31c134a8a powerpc: restore some missing spu syscalls
d3882564a77c syscalls: fix compat_sys_io_pgetevents_time64 usage
54233a425403 uretprobe: change syscall number, again
63ded110979b uprobe: Change uretprobe syscall scope and number
9142be9e6443 x86/syscall: Mark exit[_group] syscall handlers __noreturn
9aae1baa1c5d x86, arm: Add missing license tag to syscall tables files
5c28424e9a34 syscalls: Fix to add sys_uretprobe to syscall.tbl
190fec72df4a uprobe: Wire up uretprobe system call
This should be used to beautify syscall arguments and it addresses
these tools/perf build warnings:
Warning: Kernel ABI header differences:
diff -u tools/include/uapi/asm-generic/unistd.h include/uapi/asm-generic/unistd.h
diff -u tools/perf/arch/x86/entry/syscalls/syscall_64.tbl arch/x86/entry/syscalls/syscall_64.tbl
diff -u tools/perf/arch/powerpc/entry/syscalls/syscall.tbl arch/powerpc/kernel/syscalls/syscall.tbl
diff -u tools/perf/arch/s390/entry/syscalls/syscall.tbl arch/s390/kernel/syscalls/syscall.tbl
Please see tools/include/uapi/README for details (it's in the first patch
of this series).
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux-arch@vger.kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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When clone3() was introduced, it was not obvious how each architecture
deals with setting up the stack and keeping the register contents in
a fork()-like system call, so this was left for the architecture
maintainers to implement, with __ARCH_WANT_SYS_CLONE3 defined by those
that already implement it.
Five years later, we still have a few architectures left that are missing
clone3(), and the macro keeps getting in the way as it's fundamentally
different from all the other __ARCH_WANT_SYS_* macros that are meant
to provide backwards-compatibility with applications using older
syscalls that are no longer provided by default.
Address this by reversing the polarity of the macro, adding an
__ARCH_BROKEN_SYS_CLONE3 macro to all architectures that don't
already provide the syscall, and remove __ARCH_WANT_SYS_CLONE3
from all the other ones.
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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new 'mseal' syscall
But also to wire up shadow stacks on 32-bit x86, picking up those
changes from these csets:
ff388fe5c481d39c ("mseal: wire up mseal syscall")
2883f01ec37dd866 ("x86/shstk: Enable shadow stacks for x32")
This makes 'perf trace' support it, now its possible, for instance to
do:
# perf trace -e mseal --max-stack=16
Here is an example with the 'sendmmsg' syscall:
root@x1:~# perf trace -e sendmmsg --max-stack 16 --max-events=1
0.000 ( 0.062 ms): dbus-broker/1012 sendmmsg(fd: 150, mmsg: 0x7ffef57cca50, vlen: 1, flags: DONTWAIT|NOSIGNAL) = 1
syscall_exit_to_user_mode_prepare ([kernel.kallsyms])
syscall_exit_to_user_mode_prepare ([kernel.kallsyms])
syscall_exit_to_user_mode ([kernel.kallsyms])
do_syscall_64 ([kernel.kallsyms])
entry_SYSCALL_64 ([kernel.kallsyms])
[0x117ce7] (/usr/lib64/libc.so.6 (deleted))
root@x1:~#
To do a system wide tracing of the new 'mseal' syscall with a backtrace
of at most 16 entries.
This addresses these perf tools build warnings:
Warning: Kernel ABI header differences:
diff -u tools/include/uapi/asm-generic/unistd.h include/uapi/asm-generic/unistd.h
diff -u tools/perf/arch/x86/entry/syscalls/syscall_64.tbl arch/x86/entry/syscalls/syscall_64.tbl
diff -u tools/perf/arch/powerpc/entry/syscalls/syscall.tbl arch/powerpc/kernel/syscalls/syscall.tbl
diff -u tools/perf/arch/s390/entry/syscalls/syscall.tbl arch/s390/kernel/syscalls/syscall.tbl
diff -u tools/perf/arch/mips/entry/syscalls/syscall_n64.tbl arch/mips/kernel/syscalls/syscall_n64.tbl
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: H J Lu <hjl.tools@gmail.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jeff Xu <jeffxu@chromium.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/lkml/ZlXlo4TNcba4wnVZ@x1
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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To pick up the changes in this cset:
3c7a8e190bc58081 ("uapi: introduce uapi-friendly macros for GENMASK")
That just causes perf to rebuild. Its just some macros going to an uapi
header that we now have to grab a copy into tools/ as well.
This addresses this perf build warning:
Warning: Kernel ABI header differences:
diff -u tools/include/linux/bits.h include/linux/bits.h
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Link: https://lore.kernel.org/lkml/ZiwJsFOBez0MS4r9@x1
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
|
asm/fcntl.h
These were used to build perf to provide defines not available in older
distros, but this was back in 2017, nowadays all the distros that are
supported and I have build containers for work using just the system
headers, so ditch them.
Some of these older distros may not have things that are used in 'perf
trace', but then they also don't have libtraceevent packages, so don't
build 'perf trace'.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/lkml/20240315204835.748716-5-acme@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
|
lsm_{[gs]et_self_attr,list_modules} syscall numbers
To pick the changes in these csets:
d8b0f5465012538c ("wire up syscalls for statmount/listmount")
5f42375904b08890 ("LSM: wireup Linux Security Module syscalls")
Used in some architectures to create syscall tables.
This addresses this perf build warning:
Warning: Kernel ABI header differences:
diff -u tools/include/uapi/asm-generic/unistd.h include/uapi/asm-generic/unistd.h
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/lkml/ZbfMuAlUMRO9Hqa6@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
|
tldr; Just FYI, I'm carrying this on the perf tools tree.
Full explanation:
There used to be no copies, with tools/ code using kernel headers
directly. From time to time tools/perf/ broke due to legitimate kernel
hacking. At some point Linus complained about such direct usage. Then we
adopted the current model.
The way these headers are used in perf are not restricted to just
including them to compile something.
There are sometimes used in scripts that convert defines into string
tables, etc, so some change may break one of these scripts, or new MSRs
may use some different #define pattern, etc.
E.g.:
$ ls -1 tools/perf/trace/beauty/*.sh | head -5
tools/perf/trace/beauty/arch_errno_names.sh
tools/perf/trace/beauty/drm_ioctl.sh
tools/perf/trace/beauty/fadvise.sh
tools/perf/trace/beauty/fsconfig.sh
tools/perf/trace/beauty/fsmount.sh
$
$ tools/perf/trace/beauty/fadvise.sh
static const char *fadvise_advices[] = {
[0] = "NORMAL",
[1] = "RANDOM",
[2] = "SEQUENTIAL",
[3] = "WILLNEED",
[4] = "DONTNEED",
[5] = "NOREUSE",
};
$
The tools/perf/check-headers.sh script, part of the tools/ build
process, points out changes in the original files.
So its important not to touch the copies in tools/ when doing changes in
the original kernel headers, that will be done later, when
check-headers.sh inform about the change to the perf tools hackers.
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux-arch@vger.kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20231121225650.390246-6-namhyung@kernel.org
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic
Pull ia64 removal and asm-generic updates from Arnd Bergmann:
- The ia64 architecture gets its well-earned retirement as planned,
now that there is one last (mostly) working release that will be
maintained as an LTS kernel.
- The architecture specific system call tables are updated for the
added map_shadow_stack() syscall and to remove references to the
long-gone sys_lookup_dcookie() syscall.
* tag 'asm-generic-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
hexagon: Remove unusable symbols from the ptrace.h uapi
asm-generic: Fix spelling of architecture
arch: Reserve map_shadow_stack() syscall number for all architectures
syscalls: Cleanup references to sys_lookup_dcookie()
Documentation: Drop or replace remaining mentions of IA64
lib/raid6: Drop IA64 support
Documentation: Drop IA64 from feature descriptions
kernel: Drop IA64 support from sig_fault handlers
arch: Remove Itanium (IA-64) architecture
|
|
commit 'be65de6b03aa ("fs: Remove dcookies support")' removed the
syscall definition for lookup_dcookie. However, syscall tables still
point to the old sys_lookup_dcookie() definition. Update syscall tables
of all architectures to directly point to sys_ni_syscall() instead.
Signed-off-by: Sohil Mehta <sohil.mehta@intel.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Namhyung Kim <namhyung@kernel.org> # for perf
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
|
|
syscalls with the kernel sources
To pick the changes in these csets:
c35559f94ebc3e3b ("x86/shstk: Introduce map_shadow_stack syscall")
78252deb023cf087 ("arch: Register fchmodat2, usually as syscall 452")
That add support for this new syscall in tools such as 'perf trace'.
For instance, this is now possible:
# perf trace -v -e fchmodat*,map_shadow_stack --max-events=4
Using CPUID AuthenticAMD-25-21-0
Reusing "openat" BPF sys_enter augmenter for "fchmodat"
event qualifier tracepoint filter: (common_pid != 3499340 && common_pid != 11259) && (id == 268 || id == 452 || id == 453)
^C#
And it'll work as with other syscalls, for instance openat:
# perf trace -e openat* --max-events=4
0.000 ( 0.015 ms): systemd-oomd/1150 openat(dfd: CWD, filename: "/proc/meminfo", flags: RDONLY|CLOEXEC) = 11
0.068 ( 0.019 ms): systemd-oomd/1150 openat(dfd: CWD, filename: "/sys/fs/cgroup/user.slice/user-1001.slice/user@1001.service/memory.pressure", flags: RDONLY|CLOEXEC) = 11
0.119 ( 0.008 ms): systemd-oomd/1150 openat(dfd: CWD, filename: "/sys/fs/cgroup/user.slice/user-1001.slice/user@1001.service/memory.current", flags: RDONLY|CLOEXEC) = 11
0.138 ( 0.006 ms): systemd-oomd/1150 openat(dfd: CWD, filename: "/sys/fs/cgroup/user.slice/user-1001.slice/user@1001.service/memory.min", flags: RDONLY|CLOEXEC) = 11
#
That is the filter expression attached to the raw_syscalls:sys_{enter,exit}
tracepoints.
$ find tools/perf/arch/ -name "syscall*tbl" | xargs grep -E fchmodat\|sys_map_shadow_stack
tools/perf/arch/mips/entry/syscalls/syscall_n64.tbl:258 n64 fchmodat sys_fchmodat
tools/perf/arch/mips/entry/syscalls/syscall_n64.tbl:452 n64 fchmodat2 sys_fchmodat2
tools/perf/arch/powerpc/entry/syscalls/syscall.tbl:297 common fchmodat sys_fchmodat
tools/perf/arch/powerpc/entry/syscalls/syscall.tbl:452 common fchmodat2 sys_fchmodat2
tools/perf/arch/s390/entry/syscalls/syscall.tbl:299 common fchmodat sys_fchmodat sys_fchmodat
tools/perf/arch/s390/entry/syscalls/syscall.tbl:452 common fchmodat2 sys_fchmodat2 sys_fchmodat2
tools/perf/arch/x86/entry/syscalls/syscall_64.tbl:268 common fchmodat sys_fchmodat
tools/perf/arch/x86/entry/syscalls/syscall_64.tbl:452 common fchmodat2 sys_fchmodat2
tools/perf/arch/x86/entry/syscalls/syscall_64.tbl:453 64 map_shadow_stack sys_map_shadow_stack
$
$ grep -Ew map_shadow_stack\|fchmodat2 /tmp/build/perf-tools/arch/x86/include/generated/asm/syscalls_64.c
[452] = "fchmodat2",
[453] = "map_shadow_stack",
$
This addresses these perf build warnings:
Warning: Kernel ABI header differences:
diff -u tools/include/uapi/asm-generic/unistd.h include/uapi/asm-generic/unistd.h
diff -u tools/perf/arch/x86/entry/syscalls/syscall_64.tbl arch/x86/entry/syscalls/syscall_64.tbl
diff -u tools/perf/arch/powerpc/entry/syscalls/syscall.tbl arch/powerpc/kernel/syscalls/syscall.tbl
diff -u tools/perf/arch/s390/entry/syscalls/syscall.tbl arch/s390/kernel/syscalls/syscall.tbl
diff -u tools/perf/arch/mips/entry/syscalls/syscall_n64.tbl arch/mips/kernel/syscalls/syscall_n64.tbl
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Rick Edgecombe <rick.p.edgecombe@intel.com>
Link: https://lore.kernel.org/lkml/ZP8bE7aXDBu%2Fdrak@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
|
kernel sources
To pick the changes in these csets:
cf264e1329fb0307 ("cachestat: implement cachestat syscall")
That add support for this new syscall in tools such as 'perf trace'.
For instance, this is now possible:
# perf trace -e cachestat
^C[root@five ~]#
# perf trace -v -e cachestat
Using CPUID AuthenticAMD-25-21-0
event qualifier tracepoint filter: (common_pid != 3163687 && common_pid != 3147) && (id == 451)
mmap size 528384B
^C[root@five ~]
# perf trace -v -e *stat* --max-events=10
Using CPUID AuthenticAMD-25-21-0
event qualifier tracepoint filter: (common_pid != 3163713 && common_pid != 3147) && (id == 4 || id == 5 || id == 6 || id == 136 || id == 137 || id == 138 || id == 262 || id == 332 || id == 451)
mmap size 528384B
0.000 ( 0.009 ms): Cache2 I/O/4544 statfs(pathname: 0x45635288, buf: 0x7f8745725b60) = 0
0.012 ( 0.003 ms): Cache2 I/O/4544 newfstatat(dfd: CWD, filename: 0x45635288, statbuf: 0x7f874569d250) = 0
0.036 ( 0.002 ms): Cache2 I/O/4544 newfstatat(dfd: 138, filename: 0x541b7093, statbuf: 0x7f87457256f0, flag: 4096) = 0
0.372 ( 0.006 ms): Cache2 I/O/4544 statfs(pathname: 0x45635288, buf: 0x7f8745725b10) = 0
0.379 ( 0.003 ms): Cache2 I/O/4544 newfstatat(dfd: CWD, filename: 0x45635288, statbuf: 0x7f874569d250) = 0
0.390 ( 0.002 ms): Cache2 I/O/4544 newfstatat(dfd: 138, filename: 0x541b7093, statbuf: 0x7f87457256a0, flag: 4096) = 0
0.609 ( 0.005 ms): Cache2 I/O/4544 statfs(pathname: 0x45635288, buf: 0x7f8745725b60) = 0
0.615 ( 0.003 ms): Cache2 I/O/4544 newfstatat(dfd: CWD, filename: 0x45635288, statbuf: 0x7f874569d250) = 0
0.625 ( 0.002 ms): Cache2 I/O/4544 newfstatat(dfd: 138, filename: 0x541b7093, statbuf: 0x7f87457256f0, flag: 4096) = 0
0.826 ( 0.005 ms): Cache2 I/O/4544 statfs(pathname: 0x45635288, buf: 0x7f8745725b10) = 0
#
That is the filter expression attached to the raw_syscalls:sys_{enter,exit}
tracepoints.
$ find tools/perf/arch/ -name "syscall*tbl" | xargs grep -w sys_cachestat
tools/perf/arch/mips/entry/syscalls/syscall_n64.tbl:451 n64 cachestat sys_cachestat
tools/perf/arch/powerpc/entry/syscalls/syscall.tbl:451 common cachestat sys_cachestat
tools/perf/arch/s390/entry/syscalls/syscall.tbl:451 common cachestat sys_cachestat sys_cachestat
tools/perf/arch/x86/entry/syscalls/syscall_64.tbl:451 common cachestat sys_cachestat
$
$ grep -w cachestat /tmp/build/perf-tools/arch/x86/include/generated/asm/syscalls_64.c
[451] = "cachestat",
$
This addresses these perf build warnings:
Warning: Kernel ABI header differences:
diff -u tools/include/uapi/asm-generic/unistd.h include/uapi/asm-generic/unistd.h
diff -u tools/include/uapi/linux/mman.h include/uapi/linux/mman.h
diff -u tools/perf/arch/x86/entry/syscalls/syscall_64.tbl arch/x86/entry/syscalls/syscall_64.tbl
diff -u tools/perf/arch/powerpc/entry/syscalls/syscall.tbl arch/powerpc/kernel/syscalls/syscall.tbl
diff -u tools/perf/arch/s390/entry/syscalls/syscall.tbl arch/s390/kernel/syscalls/syscall.tbl
diff -u tools/perf/arch/mips/entry/syscalls/syscall_n64.tbl arch/mips/kernel/syscalls/syscall_n64.tbl
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Link: https://lore.kernel.org/lkml/ZK1pVBJpbjujJNJW@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic
Pull asm-generic updates from Arnd Bergmann:
"These are cleanups for architecture specific header files:
- the comments in include/linux/syscalls.h have gone out of sync and
are really pointless, so these get removed
- The asm/bitsperlong.h header no longer needs to be architecture
specific on modern compilers, so use a generic version for newer
architectures that use new enough userspace compilers
- A cleanup for virt_to_pfn/virt_to_bus to have proper type checking,
forcing the use of pointers"
* tag 'asm-generic-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
syscalls: Remove file path comments from headers
tools arch: Remove uapi bitsperlong.h of hexagon and microblaze
asm-generic: Unify uapi bitsperlong.h for arm64, riscv and loongarch
m68k/mm: Make pfn accessors static inlines
arm64: memory: Make virt_to_pfn() a static inline
ARM: mm: Make virt_to_pfn() a static inline
asm-generic/page.h: Make pfn accessors static inlines
xen/netback: Pass (void *) to virt_to_page()
netfs: Pass a pointer to virt_to_page()
cifs: Pass a pointer to virt_to_page() in cifsglob
cifs: Pass a pointer to virt_to_page()
riscv: mm: init: Pass a pointer to virt_to_page()
ARC: init: Pass a pointer to virt_to_pfn() in init
m68k: Pass a pointer to virt_to_pfn() virt_to_page()
fs/proc/kcore.c: Pass a pointer to virt_addr_valid()
|
|
Source file locations for syscall definitions can change over a period
of time. File paths in comments get stale and are hard to maintain long
term. Also, their usefulness is questionable since it would be easier to
locate a syscall definition using the SYSCALL_DEFINEx() macro.
Remove all source file path comments from the syscall headers. Also,
equalize the uneven line spacing (some of which is introduced due to the
deletions).
Signed-off-by: Sohil Mehta <sohil.mehta@intel.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
|
|
Now we specify the minimal version of GCC as 5.1 and Clang/LLVM as 11.0.0
in Documentation/process/changes.rst, __CHAR_BIT__ and __SIZEOF_LONG__ are
usable, it is probably fine to unify the definition of __BITS_PER_LONG as
(__CHAR_BIT__ * __SIZEOF_LONG__) in asm-generic uapi bitsperlong.h.
In order to keep safe and avoid regression, only unify uapi bitsperlong.h
for some archs such as arm64, riscv and loongarch which are using newer
toolchains that have the definitions of __CHAR_BIT__ and __SIZEOF_LONG__.
Suggested-by: Xi Ruoyao <xry111@xry111.site>
Link: https://lore.kernel.org/all/d3e255e4746de44c9903c4433616d44ffcf18d1b.camel@xry111.site/
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/linux-arch/a3a4f48a-07d4-4ed9-bc53-5d383428bdd2@app.fastmail.com/
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
|
|
Add SO_PEERPIDFD which allows to get pidfd of peer socket holder pidfd.
This thing is direct analog of SO_PEERCRED which allows to get plain PID.
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: David Ahern <dsahern@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Kuniyuki Iwashima <kuniyu@amazon.com>
Cc: Lennart Poettering <mzxreary@0pointer.de>
Cc: Luca Boccassi <bluca@debian.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Stanislav Fomichev <sdf@google.com>
Cc: bpf@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Reviewed-by: Christian Brauner <brauner@kernel.org>
Acked-by: Stanislav Fomichev <sdf@google.com>
Tested-by: Luca Boccassi <bluca@debian.org>
Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Implement SCM_PIDFD, a new type of CMSG type analogical to SCM_CREDENTIALS,
but it contains pidfd instead of plain pid, which allows programmers not
to care about PID reuse problem.
We mask SO_PASSPIDFD feature if CONFIG_UNIX is not builtin because
it depends on a pidfd_prepare() API which is not exported to the kernel
modules.
Idea comes from UAPI kernel group:
https://uapi-group.org/kernel-features/
Big thanks to Christian Brauner and Lennart Poettering for productive
discussions about this.
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: David Ahern <dsahern@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Kuniyuki Iwashima <kuniyu@amazon.com>
Cc: Lennart Poettering <mzxreary@0pointer.de>
Cc: Luca Boccassi <bluca@debian.org>
Cc: linux-kernel@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Tested-by: Luca Boccassi <bluca@debian.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
After a couple of years and multiple LTS releases we received a report
that the behavior of O_DIRECTORY | O_CREAT changed starting with v5.7.
On kernels prior to v5.7 combinations of O_DIRECTORY, O_CREAT, O_EXCL
had the following semantics:
(1) open("/tmp/d", O_DIRECTORY | O_CREAT)
* d doesn't exist: create regular file
* d exists and is a regular file: ENOTDIR
* d exists and is a directory: EISDIR
(2) open("/tmp/d", O_DIRECTORY | O_CREAT | O_EXCL)
* d doesn't exist: create regular file
* d exists and is a regular file: EEXIST
* d exists and is a directory: EEXIST
(3) open("/tmp/d", O_DIRECTORY | O_EXCL)
* d doesn't exist: ENOENT
* d exists and is a regular file: ENOTDIR
* d exists and is a directory: open directory
On kernels since to v5.7 combinations of O_DIRECTORY, O_CREAT, O_EXCL
have the following semantics:
(1) open("/tmp/d", O_DIRECTORY | O_CREAT)
* d doesn't exist: ENOTDIR (create regular file)
* d exists and is a regular file: ENOTDIR
* d exists and is a directory: EISDIR
(2) open("/tmp/d", O_DIRECTORY | O_CREAT | O_EXCL)
* d doesn't exist: ENOTDIR (create regular file)
* d exists and is a regular file: EEXIST
* d exists and is a directory: EEXIST
(3) open("/tmp/d", O_DIRECTORY | O_EXCL)
* d doesn't exist: ENOENT
* d exists and is a regular file: ENOTDIR
* d exists and is a directory: open directory
This is a fairly substantial semantic change that userspace didn't
notice until Pedro took the time to deliberately figure out corner
cases. Since no one noticed this breakage we can somewhat safely assume
that O_DIRECTORY | O_CREAT combinations are likely unused.
The v5.7 breakage is especially weird because while ENOTDIR is returned
indicating failure a regular file is actually created. This doesn't make
a lot of sense.
Time was spent finding potential users of this combination. Searching on
codesearch.debian.net showed that codebases often express semantical
expectations about O_DIRECTORY | O_CREAT which are completely contrary
to what our code has done and currently does.
The expectation often is that this particular combination would create
and open a directory. This suggests users who tried to use that
combination would stumble upon the counterintuitive behavior no matter
if pre-v5.7 or post v5.7 and quickly realize neither semantics give them
what they want. For some examples see the code examples in [1] to [3]
and the discussion in [4].
There are various ways to address this issue. The lazy/simple option
would be to restore the pre-v5.7 behavior and to just live with that bug
forever. But since there's a real chance that the O_DIRECTORY | O_CREAT
quirk isn't relied upon we should try to get away with murder(ing bad
semantics) first. If we need to Frankenstein pre-v5.7 behavior later so
be it.
So let's simply return EINVAL categorically for O_DIRECTORY | O_CREAT
combinations. In addition to cleaning up the old bug this also opens up
the possiblity to make that flag combination do something more intuitive
in the future.
Starting with this commit the following semantics apply:
(1) open("/tmp/d", O_DIRECTORY | O_CREAT)
* d doesn't exist: EINVAL
* d exists and is a regular file: EINVAL
* d exists and is a directory: EINVAL
(2) open("/tmp/d", O_DIRECTORY | O_CREAT | O_EXCL)
* d doesn't exist: EINVAL
* d exists and is a regular file: EINVAL
* d exists and is a directory: EINVAL
(3) open("/tmp/d", O_DIRECTORY | O_EXCL)
* d doesn't exist: ENOENT
* d exists and is a regular file: ENOTDIR
* d exists and is a directory: open directory
One additional note, O_TMPFILE is implemented as:
#define __O_TMPFILE 020000000
#define O_TMPFILE (__O_TMPFILE | O_DIRECTORY)
# |