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  1. 27 Jul, 2022 7 commits
    • Leo Yan's avatar
      perf symbol: Skip symbols if SHF_ALLOC flag is not set · 882528d2
      Leo Yan authored 
      Some symbols are observed with the 'st_value' field zeroed.  E.g.
libc.so.6 in Ubuntu contains a symbol '__evoke_link_warning_getwd' which
resides in the '.gnu.warning.getwd' section.

Unlike normal sections, such kind of sections are used for linker
warning when a file calls deprecated functions, but they are not part of
memory images, the symbols in these sections should be dropped.

This patch checks the section attribute SHF_ALLOC bit, if the bit is not
set, it skips symbols to avoid spurious ones.
Suggested-by: default avatarFangrui Song <maskray@google.com>
Signed-off-by: default avatarLeo Yan <leo.yan@linaro.org>
Acked-by: default avatarNamhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Chang Rui <changruinj@gmail.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220724060013.171050-3-leo.yan@linaro.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      882528d2
    • Leo Yan's avatar
      perf symbol: Correct address for bss symbols · 2d86612a
      Leo Yan authored 
      When using 'perf mem' and 'perf c2c', an issue is observed that tool
reports the wrong offset for global data symbols.  This is a common
issue on both x86 and Arm64 platforms.

Let's see an example, for a test program, below is the disassembly for
its .bss section which is dumped with objdump:

  ...

  Disassembly of section .bss:

  0000000000004040 <completed.0>:
  	...

  0000000000004080 <buf1>:
  	...

  00000000000040c0 <buf2>:
  	...

  0000000000004100 <thread>:
  	...

First we used 'perf mem record' to run the test program and then used
'perf --debug verbose=4 mem report' to observe what's the symbol info
for 'buf1' and 'buf2' structures.

  # ./perf mem record -e ldlat-loads,ldlat-stores -- false_sharing.exe 8
  # ./perf --debug verbose=4 mem report
    ...
    dso__load_sym_internal: adjusting symbol: st_value: 0x40c0 sh_addr: 0x4040 sh_offset: 0x3028
    symbol__new: buf2 0x30a8-0x30e8
    ...
    dso__load_sym_internal: adjusting symbol: st_value: 0x4080 sh_addr: 0x4040 sh_offset: 0x3028
    symbol__new: buf1 0x3068-0x30a8
    ...

The perf tool relies on libelf to parse symbols, in executable and
shared object files, 'st_value' holds a virtual address; 'sh_addr' is
the address at which section's first byte should reside in memory, and
'sh_offset' is the byte offset from the beginning of the file to the
first byte in the section.  The perf tool uses below formula to convert
a symbol's memory address to a file address:

  file_address = st_value - sh_addr + sh_offset
                    ^
                    ` Memory address

We can see the final adjusted address ranges for buf1 and buf2 are
[0x30a8-0x30e8) and [0x3068-0x30a8) respectively, apparently this is
incorrect, in the code, the structure for 'buf1' and 'buf2' specifies
compiler attribute with 64-byte alignment.

The problem happens for 'sh_offset', libelf returns it as 0x3028 which
is not 64-byte aligned, combining with disassembly, it's likely libelf
doesn't respect the alignment for .bss section, therefore, it doesn't
return the aligned value for 'sh_offset'.

Suggested by Fangrui Song, ELF file contains program header which
contains PT_LOAD segments, the fields p_vaddr and p_offset in PT_LOAD
segments contain the execution info.  A better choice for converting
memory address to file address is using the formula:

  file_address = st_value - p_vaddr + p_offset

This patch introduces elf_read_program_header() which returns the
program header based on the passed 'st_value', then it uses the formula
above to calculate the symbol file address; and the debugging log is
updated respectively.

After applying the change:

  # ./perf --debug verbose=4 mem report
    ...
    dso__load_sym_internal: adjusting symbol: st_value: 0x40c0 p_vaddr: 0x3d28 p_offset: 0x2d28
    symbol__new: buf2 0x30c0-0x3100
    ...
    dso__load_sym_internal: adjusting symbol: st_value: 0x4080 p_vaddr: 0x3d28 p_offset: 0x2d28
    symbol__new: buf1 0x3080-0x30c0
    ...

Fixes: f17e04af ("perf report: Fix ELF symbol parsing")
Reported-by: default avatarChang Rui <changruinj@gmail.com>
Suggested-by: default avatarFangrui Song <maskray@google.com>
Signed-off-by: default avatarLeo Yan <leo.yan@linaro.org>
Acked-by: default avatarNamhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220724060013.171050-2-leo.yan@linaro.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      2d86612a
    • Leo Yan's avatar
      perf scripts python: Let script to be python2 compliant · b2265219
      Leo Yan authored 
      The mainline kernel can be used for relative old distros, e.g. RHEL 7.
The distro doesn't upgrade from python2 to python3, this causes the
building error that the python script is not python2 compliant.

To fix the building failure, this patch changes from the python f-string
format to traditional string format.

Fixes: 12fdd6c0 ("perf scripts python: Support Arm CoreSight trace data disassembly")
Reported-by: default avatarAkemi Yagi <toracat@elrepo.org>
Signed-off-by: default avatarLeo Yan <leo.yan@linaro.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: ElRepo <contact@elrepo.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220725104220.1106663-1-leo.yan@linaro.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      b2265219
    • Arnaldo Carvalho de Melo's avatar
      tools headers cpufeatures: Sync with the kernel sources · 553de6e1
      Arnaldo Carvalho de Melo authored 
      To pick the changes from:

  28a99e95 ("x86/amd: Use IBPB for firmware calls")

This only causes these perf files to be rebuilt:

  CC       /tmp/build/perf/bench/mem-memcpy-x86-64-asm.o
  CC       /tmp/build/perf/bench/mem-memset-x86-64-asm.o

And addresses this perf build warning:

  Warning: Kernel ABI header at 'tools/arch/x86/include/asm/cpufeatures.h' differs from latest version at 'arch/x86/include/asm/cpufeatures.h'
  diff -u tools/arch/x86/include/asm/cpufeatures.h arch/x86/include/asm/cpufeatures.h

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org
Link: https://lore.kernel.org/lkml/Yt6oWce9UDAmBAtX@kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      553de6e1
    • Linus Torvalds's avatar
      Merge tag 'mm-hotfixes-stable-2022-07-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm · 39c3c396
      Linus Torvalds authored 
      Pull misc fixes from Andrew Morton:
 "Thirteen hotfixes.

  Eight are cc:stable and the remainder are for post-5.18 issues or are
  too minor to warrant backporting"

* tag 'mm-hotfixes-stable-2022-07-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  mailmap: update Gao Xiang's email addresses
  userfaultfd: provide properly masked address for huge-pages
  Revert "ocfs2: mount shared volume without ha stack"
  hugetlb: fix memoryleak in hugetlb_mcopy_atomic_pte
  fs: sendfile handles O_NONBLOCK of out_fd
  ntfs: fix use-after-free in ntfs_ucsncmp()
  secretmem: fix unhandled fault in truncate
  mm/hugetlb: separate path for hwpoison entry in copy_hugetlb_page_range()
  mm: fix missing wake-up event for FSDAX pages
  mm: fix page leak with multiple threads mapping the same page
  mailmap: update Seth Forshee's email address
  tmpfs: fix the issue that the mount and remount results are inconsistent.
  mm: kfence: apply kmemleak_ignore_phys on early allocated pool
      39c3c396
    • Gao Xiang's avatar
      mailmap: update Gao Xiang's email addresses · 1f7ea547
      Gao Xiang authored 
      I've been in Alibaba Cloud for more than one year, mainly to address
cloud-native challenges (such as high-performance container images) for
open source communities.

Update my email addresses on behalf of my current employer (Alibaba Cloud)
to support all my (team) work in this area.  Also add an outdated
@redhat.com address of me.

Link: https://lkml.kernel.org/r/20220719154246.62970-1-xiang@kernel.orgSigned-off-by: default avatarGao Xiang <xiang@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      1f7ea547
    • Nadav Amit's avatar
      userfaultfd: provide properly masked address for huge-pages · d172b1a3
      Nadav Amit authored 
      Commit 824ddc60 ("userfaultfd: provide unmasked address on
page-fault") was introduced to fix an old bug, in which the offset in the
address of a page-fault was masked.  Concerns were raised - although were
never backed by actual code - that some userspace code might break because
the bug has been around for quite a while.  To address these concerns a
new flag was introduced, and only when this flag is set by the user,
userfaultfd provides the exact address of the page-fault.

The commit however had a bug, and if the flag is unset, the offset was
always masked based on a base-page granularity.  Yet, for huge-pages, the
behavior prior to the commit was that the address is masked to the
huge-page granulrity.

While there are no reports on real breakage, fix this issue.  If the flag
is unset, use the address with the masking that was done before.

Link: https://lkml.kernel.org/r/20220711165906.2682-1-namit@vmware.com
Fixes: 824ddc60 ("userfaultfd: provide unmasked address on page-fault")
Signed-off-by: default avatarNadav Amit <namit@vmware.com>
Reported-by: default avatarJames Houghton <jthoughton@google.com>
Reviewed-by: default avatarMike Rapoport <rppt@linux.ibm.com>
Reviewed-by: default avatarPeter Xu <peterx@redhat.com>
Reviewed-by: default avatarJames Houghton <jthoughton@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      d172b1a3
  3. 26 Jul, 2022 2 commits
  5. 24 Jul, 2022 6 commits
  7. 23 Jul, 2022 2 commits
  9. 22 Jul, 2022 15 commits
  11. 21 Jul, 2022 8 commits
    • Ben Dooks's avatar
      riscv: add as-options for modules with assembly compontents · c1f6eff3
      Ben Dooks authored 
      When trying to load modules built for RISC-V which include assembly files
the kernel loader errors with "unexpected relocation type 'R_RISCV_ALIGN'"
due to R_RISCV_ALIGN relocations being generated by the assembler.

The R_RISCV_ALIGN relocations can be removed at the expense of code space
by adding -mno-relax to gcc and as.  In commit 7a8e7da4
("RISC-V: Fixes to module loading") -mno-relax is added to the build
variable KBUILD_CFLAGS_MODULE. See [1] for more info.

The issue is that when kbuild builds a .S file, it invokes gcc with
the -mno-relax flag, but this is not being passed through to the
assembler. Adding -Wa,-mno-relax to KBUILD_AFLAGS_MODULE ensures that
the assembler is invoked correctly. This may have now been fixed in
gcc[2] and this addition should not stop newer gcc and as from working.

[1] https://github.com/riscv/riscv-elf-psabi-doc/issues/183
[2] https://github.com/gcc-mirror/gcc/commit/3b0a7d624e64eeb81e4d5e8c62c46d86ef521857Signed-off-by: default avatarBen Dooks <ben.dooks@codethink.co.uk>
Reviewed-by: default avatarBin Meng <bmeng.cn@gmail.com>
Link: https://lore.kernel.org/r/20220529152200.609809-1-ben.dooks@codethink.co.uk
Fixes: ab1ef68e ("RISC-V: Add sections of PLT and GOT for kernel module")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarPalmer Dabbelt <palmer@rivosinc.com>
      c1f6eff3
    • Linus Torvalds's avatar
      Merge tag 'mtd/fixes-for-5.19-final' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux · 68e77ffb
      Linus Torvalds authored 
      Pull MTD fix from Richard Weinberger:
 "A aingle NAND controller fix:

   - gpmi: Fix busy timeout setting (wrong calculation, yes again)"

* tag 'mtd/fixes-for-5.19-final' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux:
  mtd: rawnand: gpmi: Set WAIT_FOR_READY timeout based on program/erase times
      68e77ffb
    • Linus Torvalds's avatar
      Merge tag 'net-5.19-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net · 7ca433dc
      Linus Torvalds authored 
      Pull networking fixes from Paolo Abeni:
 "Including fixes from can.

  Still no major regressions, most of the changes are still due to data
  races fixes, plus the usual bunch of drivers fixes.

  Previous releases - regressions:

   - tcp/udp: make early_demux back namespacified.

   - dsa: fix issues with vlan_filtering_is_global

  Previous releases - always broken:

   - ip: fix data-races around ipv4_net_table (round 2, 3 & 4)

   - amt: fix validation and synchronization bugs

   - can: fix detection of mcp251863

   - eth: iavf: fix handling of dummy receive descriptors

   - eth: lan966x: fix issues with MAC table

   - eth: stmmac: dwmac-mediatek: fix clock issue

  Misc:

   - dsa: update documentation"

* tag 'net-5.19-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (107 commits)
  mlxsw: spectrum_router: Fix IPv4 nexthop gateway indication
  net/sched: cls_api: Fix flow action initialization
  tcp: Fix data-races around sysctl_tcp_max_reordering.
  tcp: Fix a data-race around sysctl_tcp_abort_on_overflow.
  tcp: Fix a data-race around sysctl_tcp_rfc1337.
  tcp: Fix a data-race around sysctl_tcp_stdurg.
  tcp: Fix a data-race around sysctl_tcp_retrans_collapse.
  tcp: Fix data-races around sysctl_tcp_slow_start_after_idle.
  tcp: Fix a data-race around sysctl_tcp_thin_linear_timeouts.
  tcp: Fix data-races around sysctl_tcp_recovery.
  tcp: Fix a data-race around sysctl_tcp_early_retrans.
  tcp: Fix data-races around sysctl knobs related to SYN option.
  udp: Fix a data-race around sysctl_udp_l3mdev_accept.
  ip: Fix data-races around sysctl_ip_prot_sock.
  ipv4: Fix data-races around sysctl_fib_multipath_hash_fields.
  ipv4: Fix data-races around sysctl_fib_multipath_hash_policy.
  ipv4: Fix a data-race around sysctl_fib_multipath_use_neigh.
  can: rcar_canfd: Add missing of_node_put() in rcar_canfd_probe()
  can: mcp251xfd: fix detection of mcp251863
  Documentation: fix udp_wmem_min in ip-sysctl.rst
  ...
      7ca433dc
    • Harald Freudenberger's avatar
      s390/archrandom: prevent CPACF trng invocations in interrupt context · 918e75f7
      Harald Freudenberger authored 
      This patch slightly reworks the s390 arch_get_random_seed_{int,long}
implementation: Make sure the CPACF trng instruction is never
called in any interrupt context. This is done by adding an
additional condition in_task().

Justification:

There are some constrains to satisfy for the invocation of the
arch_get_random_seed_{int,long}() functions:
- They should provide good random data during kernel initialization.
- They should not be called in interrupt context as the TRNG
  instruction is relatively heavy weight and may for example
  make some network loads cause to timeout and buck.

However, it was not clear what kind of interrupt context is exactly
encountered during kernel init or network traffic eventually calling
arch_get_random_seed_long().

After some days of investigations it is clear that the s390
start_kernel function is not running in any interrupt context and
so the trng is called:

Jul 11 18:33:39 t35lp54 kernel:  [<00000001064e90ca>] arch_get_random_seed_long.part.0+0x32/0x70
Jul 11 18:33:39 t35lp54 kernel:  [<000000010715f246>] random_init+0xf6/0x238
Jul 11 18:33:39 t35lp54 kernel:  [<000000010712545c>] start_kernel+0x4a4/0x628
Jul 11 18:33:39 t35lp54 kernel:  [<000000010590402a>] startup_continue+0x2a/0x40

The condition in_task() is true and the CPACF trng provides random data
during kernel startup.

The network traffic however, is more difficult. A typical call stack
looks like this:

Jul 06 17:37:07 t35lp54 kernel:  [<000000008b5600fc>] extract_entropy.constprop.0+0x23c/0x240
Jul 06 17:37:07 t35lp54 kernel:  [<000000008b560136>] crng_reseed+0x36/0xd8
Jul 06 17:37:07 t35lp54 kernel:  [<000000008b5604b8>] crng_make_state+0x78/0x340
Jul 06 17:37:07 t35lp54 kernel:  [<000000008b5607e0>] _get_random_bytes+0x60/0xf8
Jul 06 17:37:07 t35lp54 kernel:  [<000000008b56108a>] get_random_u32+0xda/0x248
Jul 06 17:37:07 t35lp54 kernel:  [<000000008aefe7a8>] kfence_guarded_alloc+0x48/0x4b8
Jul 06 17:37:07 t35lp54 kernel:  [<000000008aeff35e>] __kfence_alloc+0x18e/0x1b8
Jul 06 17:37:07 t35lp54 kernel:  [<000000008aef7f10>] __kmalloc_node_track_caller+0x368/0x4d8
Jul 06 17:37:07 t35lp54 kernel:  [<000000008b611eac>] kmalloc_reserve+0x44/0xa0
Jul 06 17:37:07 t35lp54 kernel:  [<000000008b611f98>] __alloc_skb+0x90/0x178
Jul 06 17:37:07 t35lp54 kernel:  [<000000008b6120dc>] __napi_alloc_skb+0x5c/0x118
Jul 06 17:37:07 t35lp54 kernel:  [<000000008b8f06b4>] qeth_extract_skb+0x13c/0x680
Jul 06 17:37:07 t35lp54 kernel:  [<000000008b8f6526>] qeth_poll+0x256/0x3f8
Jul 06 17:37:07 t35lp54 kernel:  [<000000008b63d76e>] __napi_poll.constprop.0+0x46/0x2f8
Jul 06 17:37:07 t35lp54 kernel:  [<000000008b63dbec>] net_rx_action+0x1cc/0x408
Jul 06 17:37:07 t35lp54 kernel:  [<000000008b937302>] __do_softirq+0x132/0x6b0
Jul 06 17:37:07 t35lp54 kernel:  [<000000008abf46ce>] __irq_exit_rcu+0x13e/0x170
Jul 06 17:37:07 t35lp54 kernel:  [<000000008abf531a>] irq_exit_rcu+0x22/0x50
Jul 06 17:37:07 t35lp54 kernel:  [<000000008b922506>] do_io_irq+0xe6/0x198
Jul 06 17:37:07 t35lp54 kernel:  [<000000008b935826>] io_int_handler+0xd6/0x110
Jul 06 17:37:07 t35lp54 kernel:  [<000000008b9358a6>] psw_idle_exit+0x0/0xa
Jul 06 17:37:07 t35lp54 kernel: ([<000000008ab9c59a>] arch_cpu_idle+0x52/0xe0)
Jul 06 17:37:07 t35lp54 kernel:  [<000000008b933cfe>] default_idle_call+0x6e/0xd0
Jul 06 17:37:07 t35lp54 kernel:  [<000000008ac59f4e>] do_idle+0xf6/0x1b0
Jul 06 17:37:07 t35lp54 kernel:  [<000000008ac5a28e>] cpu_startup_entry+0x36/0x40
Jul 06 17:37:07 t35lp54 kernel:  [<000000008abb0d90>] smp_start_secondary+0x148/0x158
Jul 06 17:37:07 t35lp54 kernel:  [<000000008b935b9e>] restart_int_handler+0x6e/0x90

which confirms that the call is in softirq context. So in_task() covers exactly
the cases where we want to have CPACF trng called: not in nmi, not in hard irq,
not in soft irq but in normal task context and during kernel init.
Signed-off-by: default avatarHarald Freudenberger <freude@linux.ibm.com>
Acked-by: default avatarJason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: default avatarJuergen Christ <jchrist@linux.ibm.com>
Link: https://lore.kernel.org/r/20220713131721.257907-1-freude@linux.ibm.com
Fixes: e4f74400 ("s390/archrandom: simplify back to earlier design and initialize earlier")
[agordeev@linux.ibm.com changed desc, added Fixes and Link, removed -stable]
Signed-off-by: default avatarAlexander Gordeev <agordeev@linux.ibm.com>
      918e75f7
    • Peter Zijlstra's avatar
      mmu_gather: Force tlb-flush VM_PFNMAP vmas · b67fbebd
      Peter Zijlstra authored 
      Jann reported a race between munmap() and unmap_mapping_range(), where
unmap_mapping_range() will no-op once unmap_vmas() has unlinked the
VMA; however munmap() will not yet have invalidated the TLBs.

Therefore unmap_mapping_range() will complete while there are still
(stale) TLB entries for the specified range.

Mitigate this by force flushing TLBs for VM_PFNMAP ranges.
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: default avatarWill Deacon <will@kernel.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      b67fbebd
    • Peter Zijlstra's avatar
      mmu_gather: Let there be one tlb_{start,end}_vma() implementation · 18ba064e
      Peter Zijlstra authored 
      Now that architectures are no longer allowed to override
tlb_{start,end}_vma() re-arrange code so that there is only one
implementation for each of these functions.

This much simplifies trying to figure out what they actually do.
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: default avatarWill Deacon <will@kernel.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      18ba064e
    • Peter Zijlstra's avatar
      csky/tlb: Remove tlb_flush() define · 1d7708e7
      Peter Zijlstra authored 
      The previous patch removed the tlb_flush_end() implementation which
used tlb_flush_range(). This means:

 - csky did double invalidates, a range invalidate per vma and a full
   invalidate at the end

 - csky actually has range invalidates and as such the generic
   tlb_flush implementation is more efficient for it.
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: default avatarWill Deacon <will@kernel.org>
Tested-by: default avatarGuo Ren <guoren@kernel.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      1d7708e7
    • Peter Zijlstra's avatar
      mmu_gather: Remove per arch tlb_{start,end}_vma() · 1e9fdf21
      Peter Zijlstra authored 
      Scattered across the archs are 3 basic forms of tlb_{start,end}_vma().
Provide two new MMU_GATHER_knobs to enumerate them and remove the per
arch tlb_{start,end}_vma() implementations.

 - MMU_GATHER_NO_FLUSH_CACHE indicates the arch has flush_cache_range()
   but does *NOT* want to call it for each VMA.

 - MMU_GATHER_MERGE_VMAS indicates the arch wants to merge the
   invalidate across multiple VMAs if possible.

With these it is possible to capture the three forms:

  1) empty stubs;
     select MMU_GATHER_NO_FLUSH_CACHE and MMU_GATHER_MERGE_VMAS

  2) start: flush_cache_range(), end: empty;
     select MMU_GATHER_MERGE_VMAS

  3) start: flush_cache_range(), end: flush_tlb_range();
     default

Obviously, if the architecture does not have flush_cache_range() then
it also doesn't need to select MMU_GATHER_NO_FLUSH_CACHE.
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: default avatarWill Deacon <will@kernel.org>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      1e9fdf21
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