<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/tools/include, branch v6.9-rc4</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge tag 'fixes-2024-04-08' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock</title>
<updated>2024-04-08T17:11:37+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-04-08T17:11:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=4f0a8fe3215c432234baed20eb8210efe1c32b10'/>
<id>4f0a8fe3215c432234baed20eb8210efe1c32b10</id>
<content type='text'>
Pull memblock fixes from Mike Rapoport:
 "Fix build errors in memblock tests:

   - add stubs to functions that calls to them were recently added to
     memblock but they were missing in tests

   - update gfp_types.h to include bits.h so that BIT() definitions
     won't depend on other includes"

* tag 'fixes-2024-04-08' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock:
  memblock tests: fix undefined reference to `BIT'
  memblock tests: fix undefined reference to `panic'
  memblock tests: fix undefined reference to `early_pfn_to_nid'
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull memblock fixes from Mike Rapoport:
 "Fix build errors in memblock tests:

   - add stubs to functions that calls to them were recently added to
     memblock but they were missing in tests

   - update gfp_types.h to include bits.h so that BIT() definitions
     won't depend on other includes"

* tag 'fixes-2024-04-08' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock:
  memblock tests: fix undefined reference to `BIT'
  memblock tests: fix undefined reference to `panic'
  memblock tests: fix undefined reference to `early_pfn_to_nid'
</pre>
</div>
</content>
</entry>
<entry>
<title>memblock tests: fix undefined reference to `panic'</title>
<updated>2024-04-04T08:08:33+00:00</updated>
<author>
<name>Wei Yang</name>
<email>richard.weiyang@gmail.com</email>
</author>
<published>2024-04-02T13:27:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=e0f5a8e74be88f2476e58b25d3b49a9521bdc4ec'/>
<id>e0f5a8e74be88f2476e58b25d3b49a9521bdc4ec</id>
<content type='text'>
commit e96c6b8f212a ("memblock: report failures when memblock_can_resize
is not set") introduced the usage of panic, which is not defined in
memblock test.

Let's define it directly in panic.h to fix it.

Signed-off-by: Wei Yang &lt;richard.weiyang@gmail.com&gt;
CC: Song Shuai &lt;songshuaishuai@tinylab.org&gt;
CC: Mike Rapoport &lt;rppt@kernel.org&gt;
Link: https://lore.kernel.org/r/20240402132701.29744-3-richard.weiyang@gmail.com
Signed-off-by: Mike Rapoport (IBM) &lt;rppt@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit e96c6b8f212a ("memblock: report failures when memblock_can_resize
is not set") introduced the usage of panic, which is not defined in
memblock test.

Let's define it directly in panic.h to fix it.

Signed-off-by: Wei Yang &lt;richard.weiyang@gmail.com&gt;
CC: Song Shuai &lt;songshuaishuai@tinylab.org&gt;
CC: Mike Rapoport &lt;rppt@kernel.org&gt;
Link: https://lore.kernel.org/r/20240402132701.29744-3-richard.weiyang@gmail.com
Signed-off-by: Mike Rapoport (IBM) &lt;rppt@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>memblock tests: fix undefined reference to `early_pfn_to_nid'</title>
<updated>2024-04-04T08:08:32+00:00</updated>
<author>
<name>Wei Yang</name>
<email>richard.weiyang@gmail.com</email>
</author>
<published>2024-04-02T13:26:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=7d8ed162e6a92268d4b2b84d364a931216102c8e'/>
<id>7d8ed162e6a92268d4b2b84d364a931216102c8e</id>
<content type='text'>
commit 6a9531c3a880 ("memblock: fix crash when reserved memory is not
added to memory") introduce the usage of early_pfn_to_nid, which is not
defined in memblock tests.

The original definition of early_pfn_to_nid is defined in mm.h, so let
add this in the corresponding mm.h.

Signed-off-by: Wei Yang &lt;richard.weiyang@gmail.com&gt;
CC: Yajun Deng &lt;yajun.deng@linux.dev&gt;
CC: Mike Rapoport &lt;rppt@kernel.org&gt;
Link: https://lore.kernel.org/r/20240402132701.29744-2-richard.weiyang@gmail.com
Signed-off-by: Mike Rapoport (IBM) &lt;rppt@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 6a9531c3a880 ("memblock: fix crash when reserved memory is not
added to memory") introduce the usage of early_pfn_to_nid, which is not
defined in memblock tests.

The original definition of early_pfn_to_nid is defined in mm.h, so let
add this in the corresponding mm.h.

Signed-off-by: Wei Yang &lt;richard.weiyang@gmail.com&gt;
CC: Yajun Deng &lt;yajun.deng@linux.dev&gt;
CC: Mike Rapoport &lt;rppt@kernel.org&gt;
Link: https://lore.kernel.org/r/20240402132701.29744-2-richard.weiyang@gmail.com
Signed-off-by: Mike Rapoport (IBM) &lt;rppt@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tools/resolve_btfids: fix build with musl libc</title>
<updated>2024-03-29T01:58:29+00:00</updated>
<author>
<name>Natanael Copa</name>
<email>ncopa@alpinelinux.org</email>
</author>
<published>2024-03-28T10:59:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=62248b22d01e96a4d669cde0d7005bd51ebf9e76'/>
<id>62248b22d01e96a4d669cde0d7005bd51ebf9e76</id>
<content type='text'>
Include the header that defines u32.
This fixes build of 6.6.23 and 6.1.83 kernels for Alpine Linux, which
uses musl libc. I assume that GNU libc indirecly pulls in linux/types.h.

Fixes: 9707ac4fe2f5 ("tools/resolve_btfids: Refactor set sorting with types from btf_ids.h")
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218647
Cc: stable@vger.kernel.org
Signed-off-by: Natanael Copa &lt;ncopa@alpinelinux.org&gt;
Tested-by: Greg Thelen &lt;gthelen@google.com&gt;
Link: https://lore.kernel.org/r/20240328110103.28734-1-ncopa@alpinelinux.org
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Include the header that defines u32.
This fixes build of 6.6.23 and 6.1.83 kernels for Alpine Linux, which
uses musl libc. I assume that GNU libc indirecly pulls in linux/types.h.

Fixes: 9707ac4fe2f5 ("tools/resolve_btfids: Refactor set sorting with types from btf_ids.h")
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218647
Cc: stable@vger.kernel.org
Signed-off-by: Natanael Copa &lt;ncopa@alpinelinux.org&gt;
Tested-by: Greg Thelen &lt;gthelen@google.com&gt;
Link: https://lore.kernel.org/r/20240328110103.28734-1-ncopa@alpinelinux.org
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'loongarch-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson</title>
<updated>2024-03-22T17:22:45+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-03-22T17:22:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=1e3cd03c54b76b4cbc8b31256dc3f18c417a6876'/>
<id>1e3cd03c54b76b4cbc8b31256dc3f18c417a6876</id>
<content type='text'>
Pull LoongArch updates from Huacai Chen:

 - Add objtool support for LoongArch

 - Add ORC stack unwinder support for LoongArch

 - Add kernel livepatching support for LoongArch

 - Select ARCH_HAS_CURRENT_STACK_POINTER in Kconfig

 - Select HAVE_ARCH_USERFAULTFD_MINOR in Kconfig

 - Some bug fixes and other small changes

* tag 'loongarch-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson:
  LoongArch/crypto: Clean up useless assignment operations
  LoongArch: Define the __io_aw() hook as mmiowb()
  LoongArch: Remove superfluous flush_dcache_page() definition
  LoongArch: Move {dmw,tlb}_virt_to_page() definition to page.h
  LoongArch: Change __my_cpu_offset definition to avoid mis-optimization
  LoongArch: Select HAVE_ARCH_USERFAULTFD_MINOR in Kconfig
  LoongArch: Select ARCH_HAS_CURRENT_STACK_POINTER in Kconfig
  LoongArch: Add kernel livepatching support
  LoongArch: Add ORC stack unwinder support
  objtool: Check local label in read_unwind_hints()
  objtool: Check local label in add_dead_ends()
  objtool/LoongArch: Enable orc to be built
  objtool/x86: Separate arch-specific and generic parts
  objtool/LoongArch: Implement instruction decoder
  objtool/LoongArch: Enable objtool to be built
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull LoongArch updates from Huacai Chen:

 - Add objtool support for LoongArch

 - Add ORC stack unwinder support for LoongArch

 - Add kernel livepatching support for LoongArch

 - Select ARCH_HAS_CURRENT_STACK_POINTER in Kconfig

 - Select HAVE_ARCH_USERFAULTFD_MINOR in Kconfig

 - Some bug fixes and other small changes

* tag 'loongarch-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson:
  LoongArch/crypto: Clean up useless assignment operations
  LoongArch: Define the __io_aw() hook as mmiowb()
  LoongArch: Remove superfluous flush_dcache_page() definition
  LoongArch: Move {dmw,tlb}_virt_to_page() definition to page.h
  LoongArch: Change __my_cpu_offset definition to avoid mis-optimization
  LoongArch: Select HAVE_ARCH_USERFAULTFD_MINOR in Kconfig
  LoongArch: Select ARCH_HAS_CURRENT_STACK_POINTER in Kconfig
  LoongArch: Add kernel livepatching support
  LoongArch: Add ORC stack unwinder support
  objtool: Check local label in read_unwind_hints()
  objtool: Check local label in add_dead_ends()
  objtool/LoongArch: Enable orc to be built
  objtool/x86: Separate arch-specific and generic parts
  objtool/LoongArch: Implement instruction decoder
  objtool/LoongArch: Enable objtool to be built
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'slab-for-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab</title>
<updated>2024-03-13T03:14:54+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-03-13T03:14:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=0ea680eda6c9f59a9512f8b0dd4abf229bb9f6cf'/>
<id>0ea680eda6c9f59a9512f8b0dd4abf229bb9f6cf</id>
<content type='text'>
Pull slab updates from Vlastimil Babka:

 - Freelist loading optimization (Chengming Zhou)

   When the per-cpu slab is depleted and a new one loaded from the cpu
   partial list, optimize the loading to avoid an irq enable/disable
   cycle. This results in a 3.5% performance improvement on the "perf
   bench sched messaging" test.

 - Kernel boot parameters cleanup after SLAB removal (Xiongwei Song)

   Due to two different main slab implementations we've had boot
   parameters prefixed either slab_ and slub_ with some later becoming
   an alias as both implementations gained the same functionality (i.e.
   slab_nomerge vs slub_nomerge). In order to eventually get rid of the
   implementation-specific names, the canonical and documented
   parameters are now all prefixed slab_ and the slub_ variants become
   deprecated but still working aliases.

 - SLAB_ kmem_cache creation flags cleanup (Vlastimil Babka)

   The flags had hardcoded #define values which became tedious and
   error-prone when adding new ones. Assign the values via an enum that
   takes care of providing unique bit numbers. Also deprecate
   SLAB_MEM_SPREAD which was only used by SLAB, so it's a no-op since
   SLAB removal. Assign it an explicit zero value. The removals of the
   flag usage are handled independently in the respective subsystems,
   with a final removal of any leftover usage planned for the next
   release.

 - Misc cleanups and fixes (Chengming Zhou, Xiaolei Wang, Zheng Yejian)

   Includes removal of unused code or function parameters and a fix of a
   memleak.

* tag 'slab-for-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab:
  slab: remove PARTIAL_NODE slab_state
  mm, slab: remove memcg_from_slab_obj()
  mm, slab: remove the corner case of inc_slabs_node()
  mm/slab: Fix a kmemleak in kmem_cache_destroy()
  mm, slab, kasan: replace kasan_never_merge() with SLAB_NO_MERGE
  mm, slab: use an enum to define SLAB_ cache creation flags
  mm, slab: deprecate SLAB_MEM_SPREAD flag
  mm, slab: fix the comment of cpu partial list
  mm, slab: remove unused object_size parameter in kmem_cache_flags()
  mm/slub: remove parameter 'flags' in create_kmalloc_caches()
  mm/slub: remove unused parameter in next_freelist_entry()
  mm/slub: remove full list manipulation for non-debug slab
  mm/slub: directly load freelist from cpu partial slab in the likely case
  mm/slub: make the description of slab_min_objects helpful in doc
  mm/slub: replace slub_$params with slab_$params in slub.rst
  mm/slub: unify all sl[au]b parameters with "slab_$param"
  Documentation: kernel-parameters: remove noaliencache
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull slab updates from Vlastimil Babka:

 - Freelist loading optimization (Chengming Zhou)

   When the per-cpu slab is depleted and a new one loaded from the cpu
   partial list, optimize the loading to avoid an irq enable/disable
   cycle. This results in a 3.5% performance improvement on the "perf
   bench sched messaging" test.

 - Kernel boot parameters cleanup after SLAB removal (Xiongwei Song)

   Due to two different main slab implementations we've had boot
   parameters prefixed either slab_ and slub_ with some later becoming
   an alias as both implementations gained the same functionality (i.e.
   slab_nomerge vs slub_nomerge). In order to eventually get rid of the
   implementation-specific names, the canonical and documented
   parameters are now all prefixed slab_ and the slub_ variants become
   deprecated but still working aliases.

 - SLAB_ kmem_cache creation flags cleanup (Vlastimil Babka)

   The flags had hardcoded #define values which became tedious and
   error-prone when adding new ones. Assign the values via an enum that
   takes care of providing unique bit numbers. Also deprecate
   SLAB_MEM_SPREAD which was only used by SLAB, so it's a no-op since
   SLAB removal. Assign it an explicit zero value. The removals of the
   flag usage are handled independently in the respective subsystems,
   with a final removal of any leftover usage planned for the next
   release.

 - Misc cleanups and fixes (Chengming Zhou, Xiaolei Wang, Zheng Yejian)

   Includes removal of unused code or function parameters and a fix of a
   memleak.

* tag 'slab-for-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab:
  slab: remove PARTIAL_NODE slab_state
  mm, slab: remove memcg_from_slab_obj()
  mm, slab: remove the corner case of inc_slabs_node()
  mm/slab: Fix a kmemleak in kmem_cache_destroy()
  mm, slab, kasan: replace kasan_never_merge() with SLAB_NO_MERGE
  mm, slab: use an enum to define SLAB_ cache creation flags
  mm, slab: deprecate SLAB_MEM_SPREAD flag
  mm, slab: fix the comment of cpu partial list
  mm, slab: remove unused object_size parameter in kmem_cache_flags()
  mm/slub: remove parameter 'flags' in create_kmalloc_caches()
  mm/slub: remove unused parameter in next_freelist_entry()
  mm/slub: remove full list manipulation for non-debug slab
  mm/slub: directly load freelist from cpu partial slab in the likely case
  mm/slub: make the description of slab_min_objects helpful in doc
  mm/slub: replace slub_$params with slab_$params in slub.rst
  mm/slub: unify all sl[au]b parameters with "slab_$param"
  Documentation: kernel-parameters: remove noaliencache
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next</title>
<updated>2024-03-12T01:06:04+00:00</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2024-03-12T01:06:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=5f20e6ab1f65aaaaae248e6946d5cb6d039e7de8'/>
<id>5f20e6ab1f65aaaaae248e6946d5cb6d039e7de8</id>
<content type='text'>
Alexei Starovoitov says:

====================
pull-request: bpf-next 2024-03-11

We've added 59 non-merge commits during the last 9 day(s) which contain
a total of 88 files changed, 4181 insertions(+), 590 deletions(-).

The main changes are:

1) Enforce VM_IOREMAP flag and range in ioremap_page_range and introduce
   VM_SPARSE kind and vm_area_[un]map_pages to be used in bpf_arena,
   from Alexei.

2) Introduce bpf_arena which is sparse shared memory region between bpf
   program and user space where structures inside the arena can have
   pointers to other areas of the arena, and pointers work seamlessly for
   both user-space programs and bpf programs, from Alexei and Andrii.

3) Introduce may_goto instruction that is a contract between the verifier
   and the program. The verifier allows the program to loop assuming it's
   behaving well, but reserves the right to terminate it, from Alexei.

4) Use IETF format for field definitions in the BPF standard
   document, from Dave.

5) Extend struct_ops libbpf APIs to allow specify version suffixes for
   stuct_ops map types, share the same BPF program between several map
   definitions, and other improvements, from Eduard.

6) Enable struct_ops support for more than one page in trampolines,
   from Kui-Feng.

7) Support kCFI + BPF on riscv64, from Puranjay.

8) Use bpf_prog_pack for arm64 bpf trampoline, from Puranjay.

9) Fix roundup_pow_of_two undefined behavior on 32-bit archs, from Toke.
====================

Link: https://lore.kernel.org/r/20240312003646.8692-1-alexei.starovoitov@gmail.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Alexei Starovoitov says:

====================
pull-request: bpf-next 2024-03-11

We've added 59 non-merge commits during the last 9 day(s) which contain
a total of 88 files changed, 4181 insertions(+), 590 deletions(-).

The main changes are:

1) Enforce VM_IOREMAP flag and range in ioremap_page_range and introduce
   VM_SPARSE kind and vm_area_[un]map_pages to be used in bpf_arena,
   from Alexei.

2) Introduce bpf_arena which is sparse shared memory region between bpf
   program and user space where structures inside the arena can have
   pointers to other areas of the arena, and pointers work seamlessly for
   both user-space programs and bpf programs, from Alexei and Andrii.

3) Introduce may_goto instruction that is a contract between the verifier
   and the program. The verifier allows the program to loop assuming it's
   behaving well, but reserves the right to terminate it, from Alexei.

4) Use IETF format for field definitions in the BPF standard
   document, from Dave.

5) Extend struct_ops libbpf APIs to allow specify version suffixes for
   stuct_ops map types, share the same BPF program between several map
   definitions, and other improvements, from Eduard.

6) Enable struct_ops support for more than one page in trampolines,
   from Kui-Feng.

7) Support kCFI + BPF on riscv64, from Puranjay.

8) Use bpf_prog_pack for arm64 bpf trampoline, from Puranjay.

9) Fix roundup_pow_of_two undefined behavior on 32-bit archs, from Toke.
====================

Link: https://lore.kernel.org/r/20240312003646.8692-1-alexei.starovoitov@gmail.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: Disasm support for addr_space_cast instruction.</title>
<updated>2024-03-11T22:37:24+00:00</updated>
<author>
<name>Alexei Starovoitov</name>
<email>ast@kernel.org</email>
</author>
<published>2024-03-08T01:08:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=667a86ad9b71d934c444eec193cf3508016f35c5'/>
<id>667a86ad9b71d934c444eec193cf3508016f35c5</id>
<content type='text'>
LLVM generates rX = addr_space_cast(rY, dst_addr_space, src_addr_space)
instruction when pointers in non-zero address space are used by the bpf
program. Recognize this insn in uapi and in bpf disassembler.

Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Acked-by: Kumar Kartikeya Dwivedi &lt;memxor@gmail.com&gt;
Link: https://lore.kernel.org/bpf/20240308010812.89848-3-alexei.starovoitov@gmail.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
LLVM generates rX = addr_space_cast(rY, dst_addr_space, src_addr_space)
instruction when pointers in non-zero address space are used by the bpf
program. Recognize this insn in uapi and in bpf disassembler.

Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Acked-by: Kumar Kartikeya Dwivedi &lt;memxor@gmail.com&gt;
Link: https://lore.kernel.org/bpf/20240308010812.89848-3-alexei.starovoitov@gmail.com
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: Introduce bpf_arena.</title>
<updated>2024-03-11T22:37:23+00:00</updated>
<author>
<name>Alexei Starovoitov</name>
<email>ast@kernel.org</email>
</author>
<published>2024-03-08T01:07:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=317460317a02a1af512697e6e964298dedd8a163'/>
<id>317460317a02a1af512697e6e964298dedd8a163</id>
<content type='text'>
Introduce bpf_arena, which is a sparse shared memory region between the bpf
program and user space.

Use cases:
1. User space mmap-s bpf_arena and uses it as a traditional mmap-ed
   anonymous region, like memcached or any key/value storage. The bpf
   program implements an in-kernel accelerator. XDP prog can search for
   a key in bpf_arena and return a value without going to user space.
2. The bpf program builds arbitrary data structures in bpf_arena (hash
   tables, rb-trees, sparse arrays), while user space consumes it.
3. bpf_arena is a "heap" of memory from the bpf program's point of view.
   The user space may mmap it, but bpf program will not convert pointers
   to user base at run-time to improve bpf program speed.

Initially, the kernel vm_area and user vma are not populated. User space
can fault in pages within the range. While servicing a page fault,
bpf_arena logic will insert a new page into the kernel and user vmas. The
bpf program can allocate pages from that region via
bpf_arena_alloc_pages(). This kernel function will insert pages into the
kernel vm_area. The subsequent fault-in from user space will populate that
page into the user vma. The BPF_F_SEGV_ON_FAULT flag at arena creation time
can be used to prevent fault-in from user space. In such a case, if a page
is not allocated by the bpf program and not present in the kernel vm_area,
the user process will segfault. This is useful for use cases 2 and 3 above.

bpf_arena_alloc_pages() is similar to user space mmap(). It allocates pages
either at a specific address within the arena or allocates a range with the
maple tree. bpf_arena_free_pages() is analogous to munmap(), which frees
pages and removes the range from the kernel vm_area and from user process
vmas.

bpf_arena can be used as a bpf program "heap" of up to 4GB. The speed of
bpf program is more important than ease of sharing with user space. This is
use case 3. In such a case, the BPF_F_NO_USER_CONV flag is recommended.
It will tell the verifier to treat the rX = bpf_arena_cast_user(rY)
instruction as a 32-bit move wX = wY, which will improve bpf prog
performance. Otherwise, bpf_arena_cast_user is translated by JIT to
conditionally add the upper 32 bits of user vm_start (if the pointer is not
NULL) to arena pointers before they are stored into memory. This way, user
space sees them as valid 64-bit pointers.

Diff https://github.com/llvm/llvm-project/pull/84410 enables LLVM BPF
backend generate the bpf_addr_space_cast() instruction to cast pointers
between address_space(1) which is reserved for bpf_arena pointers and
default address space zero. All arena pointers in a bpf program written in
C language are tagged as __attribute__((address_space(1))). Hence, clang
provides helpful diagnostics when pointers cross address space. Libbpf and
the kernel support only address_space == 1. All other address space
identifiers are reserved.

rX = bpf_addr_space_cast(rY, /* dst_as */ 1, /* src_as */ 0) tells the
verifier that rX-&gt;type = PTR_TO_ARENA. Any further operations on
PTR_TO_ARENA register have to be in the 32-bit domain. The verifier will
mark load/store through PTR_TO_ARENA with PROBE_MEM32. JIT will generate
them as kern_vm_start + 32bit_addr memory accesses. The behavior is similar
to copy_from_kernel_nofault() except that no address checks are necessary.
The address is guaranteed to be in the 4GB range. If the page is not
present, the destination register is zeroed on read, and the operation is
ignored on write.

rX = bpf_addr_space_cast(rY, 0, 1) tells the verifier that rX-&gt;type =
unknown scalar. If arena-&gt;map_flags has BPF_F_NO_USER_CONV set, then the
verifier converts such cast instructions to mov32. Otherwise, JIT will emit
native code equivalent to:
rX = (u32)rY;
if (rY)
  rX |= clear_lo32_bits(arena-&gt;user_vm_start); /* replace hi32 bits in rX */

After such conversion, the pointer becomes a valid user pointer within
bpf_arena range. The user process can access data structures created in
bpf_arena without any additional computations. For example, a linked list
built by a bpf program can be walked natively by user space.

Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Reviewed-by: Barret Rhoden &lt;brho@google.com&gt;
Link: https://lore.kernel.org/bpf/20240308010812.89848-2-alexei.starovoitov@gmail.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Introduce bpf_arena, which is a sparse shared memory region between the bpf
program and user space.

Use cases:
1. User space mmap-s bpf_arena and uses it as a traditional mmap-ed
   anonymous region, like memcached or any key/value storage. The bpf
   program implements an in-kernel accelerator. XDP prog can search for
   a key in bpf_arena and return a value without going to user space.
2. The bpf program builds arbitrary data structures in bpf_arena (hash
   tables, rb-trees, sparse arrays), while user space consumes it.
3. bpf_arena is a "heap" of memory from the bpf program's point of view.
   The user space may mmap it, but bpf program will not convert pointers
   to user base at run-time to improve bpf program speed.

Initially, the kernel vm_area and user vma are not populated. User space
can fault in pages within the range. While servicing a page fault,
bpf_arena logic will insert a new page into the kernel and user vmas. The
bpf program can allocate pages from that region via
bpf_arena_alloc_pages(). This kernel function will insert pages into the
kernel vm_area. The subsequent fault-in from user space will populate that
page into the user vma. The BPF_F_SEGV_ON_FAULT flag at arena creation time
can be used to prevent fault-in from user space. In such a case, if a page
is not allocated by the bpf program and not present in the kernel vm_area,
the user process will segfault. This is useful for use cases 2 and 3 above.

bpf_arena_alloc_pages() is similar to user space mmap(). It allocates pages
either at a specific address within the arena or allocates a range with the
maple tree. bpf_arena_free_pages() is analogous to munmap(), which frees
pages and removes the range from the kernel vm_area and from user process
vmas.

bpf_arena can be used as a bpf program "heap" of up to 4GB. The speed of
bpf program is more important than ease of sharing with user space. This is
use case 3. In such a case, the BPF_F_NO_USER_CONV flag is recommended.
It will tell the verifier to treat the rX = bpf_arena_cast_user(rY)
instruction as a 32-bit move wX = wY, which will improve bpf prog
performance. Otherwise, bpf_arena_cast_user is translated by JIT to
conditionally add the upper 32 bits of user vm_start (if the pointer is not
NULL) to arena pointers before they are stored into memory. This way, user
space sees them as valid 64-bit pointers.

Diff https://github.com/llvm/llvm-project/pull/84410 enables LLVM BPF
backend generate the bpf_addr_space_cast() instruction to cast pointers
between address_space(1) which is reserved for bpf_arena pointers and
default address space zero. All arena pointers in a bpf program written in
C language are tagged as __attribute__((address_space(1))). Hence, clang
provides helpful diagnostics when pointers cross address space. Libbpf and
the kernel support only address_space == 1. All other address space
identifiers are reserved.

rX = bpf_addr_space_cast(rY, /* dst_as */ 1, /* src_as */ 0) tells the
verifier that rX-&gt;type = PTR_TO_ARENA. Any further operations on
PTR_TO_ARENA register have to be in the 32-bit domain. The verifier will
mark load/store through PTR_TO_ARENA with PROBE_MEM32. JIT will generate
them as kern_vm_start + 32bit_addr memory accesses. The behavior is similar
to copy_from_kernel_nofault() except that no address checks are necessary.
The address is guaranteed to be in the 4GB range. If the page is not
present, the destination register is zeroed on read, and the operation is
ignored on write.

rX = bpf_addr_space_cast(rY, 0, 1) tells the verifier that rX-&gt;type =
unknown scalar. If arena-&gt;map_flags has BPF_F_NO_USER_CONV set, then the
verifier converts such cast instructions to mov32. Otherwise, JIT will emit
native code equivalent to:
rX = (u32)rY;
if (rY)
  rX |= clear_lo32_bits(arena-&gt;user_vm_start); /* replace hi32 bits in rX */

After such conversion, the pointer becomes a valid user pointer within
bpf_arena range. The user process can access data structures created in
bpf_arena without any additional computations. For example, a linked list
built by a bpf program can be walked natively by user space.

Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Reviewed-by: Barret Rhoden &lt;brho@google.com&gt;
Link: https://lore.kernel.org/bpf/20240308010812.89848-2-alexei.starovoitov@gmail.com
</pre>
</div>
</content>
</entry>
<entry>
<title>objtool/LoongArch: Implement instruction decoder</title>
<updated>2024-03-11T14:23:47+00:00</updated>
<author>
<name>Tiezhu Yang</name>
<email>yangtiezhu@loongson.cn</email>
</author>
<published>2024-03-11T14:23:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=b2d23158e6c881326321c2351b92568be4e57030'/>
<id>b2d23158e6c881326321c2351b92568be4e57030</id>
<content type='text'>
Only copy the minimal definitions of instruction opcodes and formats
in inst.h from arch/loongarch to tools/arch/loongarch, and also copy
the definition of sign_extend64() to tools/include/linux/bitops.h to
decode the following kinds of instructions:

(1) stack pointer related instructions
addi.d, ld.d, st.d, ldptr.d and stptr.d

(2) branch and jump related instructions
beq, bne, blt, bge, bltu, bgeu, beqz, bnez, bceqz, bcnez, b, bl and jirl

(3) other instructions
break, nop and ertn

See more info about instructions in LoongArch Reference Manual:
https://loongson.github.io/LoongArch-Documentation/LoongArch-Vol1-EN.html

Co-developed-by: Jinyang He &lt;hejinyang@loongson.cn&gt;
Signed-off-by: Jinyang He &lt;hejinyang@loongson.cn&gt;
Co-developed-by: Youling Tang &lt;tangyouling@loongson.cn&gt;
Signed-off-by: Youling Tang &lt;tangyouling@loongson.cn&gt;
Signed-off-by: Tiezhu Yang &lt;yangtiezhu@loongson.cn&gt;
Signed-off-by: Huacai Chen &lt;chenhuacai@loongson.cn&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Only copy the minimal definitions of instruction opcodes and formats
in inst.h from arch/loongarch to tools/arch/loongarch, and also copy
the definition of sign_extend64() to tools/include/linux/bitops.h to
decode the following kinds of instructions:

(1) stack pointer related instructions
addi.d, ld.d, st.d, ldptr.d and stptr.d

(2) branch and jump related instructions
beq, bne, blt, bge, bltu, bgeu, beqz, bnez, bceqz, bcnez, b, bl and jirl

(3) other instructions
break, nop and ertn

See more info about instructions in LoongArch Reference Manual:
https://loongson.github.io/LoongArch-Documentation/LoongArch-Vol1-EN.html

Co-developed-by: Jinyang He &lt;hejinyang@loongson.cn&gt;
Signed-off-by: Jinyang He &lt;hejinyang@loongson.cn&gt;
Co-developed-by: Youling Tang &lt;tangyouling@loongson.cn&gt;
Signed-off-by: Youling Tang &lt;tangyouling@loongson.cn&gt;
Signed-off-by: Tiezhu Yang &lt;yangtiezhu@loongson.cn&gt;
Signed-off-by: Huacai Chen &lt;chenhuacai@loongson.cn&gt;
</pre>
</div>
</content>
</entry>
</feed>
