<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/tools/testing/selftests/bpf, branch v6.3</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>selftests/bpf: Adjust bpf_xdp_metadata_rx_hash for new arg</title>
<updated>2023-04-13T18:15:11+00:00</updated>
<author>
<name>Jesper Dangaard Brouer</name>
<email>brouer@redhat.com</email>
</author>
<published>2023-04-12T19:49:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0f26b74e7d071b0dc18e2c43d79d496c2b144035'/>
<id>0f26b74e7d071b0dc18e2c43d79d496c2b144035</id>
<content type='text'>
Update BPF selftests to use the new RSS type argument for kfunc
bpf_xdp_metadata_rx_hash.

Signed-off-by: Jesper Dangaard Brouer &lt;brouer@redhat.com&gt;
Acked-by: Toke Høiland-Jørgensen &lt;toke@redhat.com&gt;
Acked-by: Stanislav Fomichev &lt;sdf@google.com&gt;
Link: https://lore.kernel.org/r/168132894068.340624.8914711185697163690.stgit@firesoul
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Update BPF selftests to use the new RSS type argument for kfunc
bpf_xdp_metadata_rx_hash.

Signed-off-by: Jesper Dangaard Brouer &lt;brouer@redhat.com&gt;
Acked-by: Toke Høiland-Jørgensen &lt;toke@redhat.com&gt;
Acked-by: Stanislav Fomichev &lt;sdf@google.com&gt;
Link: https://lore.kernel.org/r/168132894068.340624.8914711185697163690.stgit@firesoul
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>selftests/bpf: xdp_hw_metadata remove bpf_printk and add counters</title>
<updated>2023-04-13T18:15:10+00:00</updated>
<author>
<name>Jesper Dangaard Brouer</name>
<email>brouer@redhat.com</email>
</author>
<published>2023-04-12T19:48:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e8163b98d96c4d87c870689f560c53be7ccd55c8'/>
<id>e8163b98d96c4d87c870689f560c53be7ccd55c8</id>
<content type='text'>
The tool xdp_hw_metadata can be used by driver developers
implementing XDP-hints metadata kfuncs.

Remove all bpf_printk calls, as the tool already transfers all the
XDP-hints related information via metadata area to AF_XDP
userspace process.

Add counters for providing remaining information about failure and
skipped packet events.

Signed-off-by: Jesper Dangaard Brouer &lt;brouer@redhat.com&gt;
Acked-by: Stanislav Fomichev &lt;sdf@google.com&gt;
Link: https://lore.kernel.org/r/168132891533.340624.7313781245316405141.stgit@firesoul
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The tool xdp_hw_metadata can be used by driver developers
implementing XDP-hints metadata kfuncs.

Remove all bpf_printk calls, as the tool already transfers all the
XDP-hints related information via metadata area to AF_XDP
userspace process.

Add counters for providing remaining information about failure and
skipped packet events.

Signed-off-by: Jesper Dangaard Brouer &lt;brouer@redhat.com&gt;
Acked-by: Stanislav Fomichev &lt;sdf@google.com&gt;
Link: https://lore.kernel.org/r/168132891533.340624.7313781245316405141.stgit@firesoul
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>selftests/bpf: fix xdp_redirect xdp-features selftest for veth driver</title>
<updated>2023-04-06T16:35:09+00:00</updated>
<author>
<name>Lorenzo Bianconi</name>
<email>lorenzo@kernel.org</email>
</author>
<published>2023-04-06T10:40:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=919e659ed12568b5b8ba6c2ffdd82d8d31fc28af'/>
<id>919e659ed12568b5b8ba6c2ffdd82d8d31fc28af</id>
<content type='text'>
xdp-features supported by veth driver are no more static, but they
depends on veth configuration (e.g. if GRO is enabled/disabled or
TX/RX queue configuration). Take it into account in xdp_redirect
xdp-features selftest for veth driver.

Fixes: fccca038f300 ("veth: take into account device reconfiguration for xdp_features flag")
Signed-off-by: Lorenzo Bianconi &lt;lorenzo@kernel.org&gt;
Link: https://lore.kernel.org/r/bc35455cfbb1d4f7f52536955ded81ad47d8dc54.1680777371.git.lorenzo@kernel.org
Signed-off-by: Martin KaFai Lau &lt;martin.lau@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
xdp-features supported by veth driver are no more static, but they
depends on veth configuration (e.g. if GRO is enabled/disabled or
TX/RX queue configuration). Take it into account in xdp_redirect
xdp-features selftest for veth driver.

Fixes: fccca038f300 ("veth: take into account device reconfiguration for xdp_features flag")
Signed-off-by: Lorenzo Bianconi &lt;lorenzo@kernel.org&gt;
Link: https://lore.kernel.org/r/bc35455cfbb1d4f7f52536955ded81ad47d8dc54.1680777371.git.lorenzo@kernel.org
Signed-off-by: Martin KaFai Lau &lt;martin.lau@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'bpf: Allow reads from uninit stack'</title>
<updated>2023-03-13T20:21:22+00:00</updated>
<author>
<name>Alexei Starovoitov</name>
<email>ast@kernel.org</email>
</author>
<published>2023-03-13T20:20:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a33a6eaa19d3af261e8708bfc8ba62020703117f'/>
<id>a33a6eaa19d3af261e8708bfc8ba62020703117f</id>
<content type='text'>
Merge commit bf9bec4cb3a4 ("Merge branch 'bpf: Allow reads from uninit stack'")
from bpf-next to bpf tree to address verification issues in some programs
due to stack usage.

Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Merge commit bf9bec4cb3a4 ("Merge branch 'bpf: Allow reads from uninit stack'")
from bpf-next to bpf tree to address verification issues in some programs
due to stack usage.

Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>selftests/bpf: Fix progs/test_deny_namespace.c issues.</title>
<updated>2023-03-10T20:54:12+00:00</updated>
<author>
<name>Alexei Starovoitov</name>
<email>ast@kernel.org</email>
</author>
<published>2023-03-10T20:47:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e8c8361cfdbf450f760e8a2bdbd4222d1947366b'/>
<id>e8c8361cfdbf450f760e8a2bdbd4222d1947366b</id>
<content type='text'>
The following build error can be seen:
progs/test_deny_namespace.c:22:19: error: call to undeclared function 'BIT_LL'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
        __u64 cap_mask = BIT_LL(CAP_SYS_ADMIN);

The struct kernel_cap_struct no longer exists in the kernel as well.
Adjust bpf prog to fix both issues.

Fixes: f122a08b197d ("capability: just use a 'u64' instead of a 'u32[2]' array")
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The following build error can be seen:
progs/test_deny_namespace.c:22:19: error: call to undeclared function 'BIT_LL'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
        __u64 cap_mask = BIT_LL(CAP_SYS_ADMIN);

The struct kernel_cap_struct no longer exists in the kernel as well.
Adjust bpf prog to fix both issues.

Fixes: f122a08b197d ("capability: just use a 'u64' instead of a 'u32[2]' array")
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>selftests/bpf: Fix progs/find_vma_fail1.c build error.</title>
<updated>2023-03-10T20:41:18+00:00</updated>
<author>
<name>Alexei Starovoitov</name>
<email>ast@kernel.org</email>
</author>
<published>2023-03-10T20:41:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=32513d40d908b267508d37994753d9bd1600914b'/>
<id>32513d40d908b267508d37994753d9bd1600914b</id>
<content type='text'>
The commit 11e456cae91e ("selftests/bpf: Fix compilation errors: Assign a value to a constant")
fixed the issue cleanly in bpf-next.
This is an alternative fix in bpf tree to avoid merge conflict between bpf and bpf-next.

Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The commit 11e456cae91e ("selftests/bpf: Fix compilation errors: Assign a value to a constant")
fixed the issue cleanly in bpf-next.
This is an alternative fix in bpf tree to avoid merge conflict between bpf and bpf-next.

Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'net-6.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net</title>
<updated>2023-03-09T18:56:58+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-03-09T18:56:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=44889ba56cbb3d51154660ccd15818bc77276696'/>
<id>44889ba56cbb3d51154660ccd15818bc77276696</id>
<content type='text'>
Pull networking fixes from Paolo Abeni:
 "Including fixes from netfilter and bpf.

  Current release - regressions:

   - core: avoid skb end_offset change in __skb_unclone_keeptruesize()

   - sched:
      - act_connmark: handle errno on tcf_idr_check_alloc
      - flower: fix fl_change() error recovery path

   - ieee802154: prevent user from crashing the host

  Current release - new code bugs:

   - eth: bnxt_en: fix the double free during device removal

   - tools: ynl:
      - fix enum-as-flags in the generic CLI
      - fully inherit attrs in subsets
      - re-license uniformly under GPL-2.0 or BSD-3-clause

  Previous releases - regressions:

   - core: use indirect calls helpers for sk_exit_memory_pressure()

   - tls:
      - fix return value for async crypto
      - avoid hanging tasks on the tx_lock

   - eth: ice: copy last block omitted in ice_get_module_eeprom()

  Previous releases - always broken:

   - core: avoid double iput when sock_alloc_file fails

   - af_unix: fix struct pid leaks in OOB support

   - tls:
      - fix possible race condition
      - fix device-offloaded sendpage straddling records

   - bpf:
      - sockmap: fix an infinite loop error
      - test_run: fix &amp;xdp_frame misplacement for LIVE_FRAMES
      - fix resolving BTF_KIND_VAR after ARRAY, STRUCT, UNION, PTR

   - netfilter: tproxy: fix deadlock due to missing BH disable

   - phylib: get rid of unnecessary locking

   - eth: bgmac: fix *initial* chip reset to support BCM5358

   - eth: nfp: fix csum for ipsec offload

   - eth: mtk_eth_soc: fix RX data corruption issue

  Misc:

   - usb: qmi_wwan: add telit 0x1080 composition"

* tag 'net-6.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (64 commits)
  tools: ynl: fix enum-as-flags in the generic CLI
  tools: ynl: move the enum classes to shared code
  net: avoid double iput when sock_alloc_file fails
  af_unix: fix struct pid leaks in OOB support
  eth: fealnx: bring back this old driver
  net: dsa: mt7530: permit port 5 to work without port 6 on MT7621 SoC
  net: microchip: sparx5: fix deletion of existing DSCP mappings
  octeontx2-af: Unlock contexts in the queue context cache in case of fault detection
  net/smc: fix fallback failed while sendmsg with fastopen
  ynl: re-license uniformly under GPL-2.0 OR BSD-3-Clause
  mailmap: update entries for Stephen Hemminger
  mailmap: add entry for Maxim Mikityanskiy
  nfc: change order inside nfc_se_io error path
  ethernet: ice: avoid gcc-9 integer overflow warning
  ice: don't ignore return codes in VSI related code
  ice: Fix DSCP PFC TLV creation
  net: usb: qmi_wwan: add Telit 0x1080 composition
  net: usb: cdc_mbim: avoid altsetting toggling for Telit FE990
  netfilter: conntrack: adopt safer max chain length
  net: tls: fix device-offloaded sendpage straddling records
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull networking fixes from Paolo Abeni:
 "Including fixes from netfilter and bpf.

  Current release - regressions:

   - core: avoid skb end_offset change in __skb_unclone_keeptruesize()

   - sched:
      - act_connmark: handle errno on tcf_idr_check_alloc
      - flower: fix fl_change() error recovery path

   - ieee802154: prevent user from crashing the host

  Current release - new code bugs:

   - eth: bnxt_en: fix the double free during device removal

   - tools: ynl:
      - fix enum-as-flags in the generic CLI
      - fully inherit attrs in subsets
      - re-license uniformly under GPL-2.0 or BSD-3-clause

  Previous releases - regressions:

   - core: use indirect calls helpers for sk_exit_memory_pressure()

   - tls:
      - fix return value for async crypto
      - avoid hanging tasks on the tx_lock

   - eth: ice: copy last block omitted in ice_get_module_eeprom()

  Previous releases - always broken:

   - core: avoid double iput when sock_alloc_file fails

   - af_unix: fix struct pid leaks in OOB support

   - tls:
      - fix possible race condition
      - fix device-offloaded sendpage straddling records

   - bpf:
      - sockmap: fix an infinite loop error
      - test_run: fix &amp;xdp_frame misplacement for LIVE_FRAMES
      - fix resolving BTF_KIND_VAR after ARRAY, STRUCT, UNION, PTR

   - netfilter: tproxy: fix deadlock due to missing BH disable

   - phylib: get rid of unnecessary locking

   - eth: bgmac: fix *initial* chip reset to support BCM5358

   - eth: nfp: fix csum for ipsec offload

   - eth: mtk_eth_soc: fix RX data corruption issue

  Misc:

   - usb: qmi_wwan: add telit 0x1080 composition"

* tag 'net-6.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (64 commits)
  tools: ynl: fix enum-as-flags in the generic CLI
  tools: ynl: move the enum classes to shared code
  net: avoid double iput when sock_alloc_file fails
  af_unix: fix struct pid leaks in OOB support
  eth: fealnx: bring back this old driver
  net: dsa: mt7530: permit port 5 to work without port 6 on MT7621 SoC
  net: microchip: sparx5: fix deletion of existing DSCP mappings
  octeontx2-af: Unlock contexts in the queue context cache in case of fault detection
  net/smc: fix fallback failed while sendmsg with fastopen
  ynl: re-license uniformly under GPL-2.0 OR BSD-3-Clause
  mailmap: update entries for Stephen Hemminger
  mailmap: add entry for Maxim Mikityanskiy
  nfc: change order inside nfc_se_io error path
  ethernet: ice: avoid gcc-9 integer overflow warning
  ice: don't ignore return codes in VSI related code
  ice: Fix DSCP PFC TLV creation
  net: usb: qmi_wwan: add Telit 0x1080 composition
  net: usb: cdc_mbim: avoid altsetting toggling for Telit FE990
  netfilter: conntrack: adopt safer max chain length
  net: tls: fix device-offloaded sendpage straddling records
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>selftests/bpf: check that modifier resolves after pointer</title>
<updated>2023-03-06T19:44:14+00:00</updated>
<author>
<name>Lorenz Bauer</name>
<email>lorenz.bauer@isovalent.com</email>
</author>
<published>2023-03-06T11:21:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=dfdd608c3b365f0fd49d7e13911ebcde06b9865b'/>
<id>dfdd608c3b365f0fd49d7e13911ebcde06b9865b</id>
<content type='text'>
Add a regression test that ensures that a VAR pointing at a
modifier which follows a PTR (or STRUCT or ARRAY) is resolved
correctly by the datasec validator.

Signed-off-by: Lorenz Bauer &lt;lmb@isovalent.com&gt;
Link: https://lore.kernel.org/r/20230306112138.155352-3-lmb@isovalent.com
Signed-off-by: Martin KaFai Lau &lt;martin.lau@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add a regression test that ensures that a VAR pointing at a
modifier which follows a PTR (or STRUCT or ARRAY) is resolved
correctly by the datasec validator.

Signed-off-by: Lorenz Bauer &lt;lmb@isovalent.com&gt;
Link: https://lore.kernel.org/r/20230306112138.155352-3-lmb@isovalent.com
Signed-off-by: Martin KaFai Lau &lt;martin.lau@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf, test_run: fix &amp;xdp_frame misplacement for LIVE_FRAMES</title>
<updated>2023-03-06T19:15:54+00:00</updated>
<author>
<name>Alexander Lobakin</name>
<email>aleksander.lobakin@intel.com</email>
</author>
<published>2023-02-24T16:36:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=294635a8165a31408a8b3a24f9c74849ca3d8701'/>
<id>294635a8165a31408a8b3a24f9c74849ca3d8701</id>
<content type='text'>
&amp;xdp_buff and &amp;xdp_frame are bound in a way that

xdp_buff-&gt;data_hard_start == xdp_frame

It's always the case and e.g. xdp_convert_buff_to_frame() relies on
this.
IOW, the following:

	for (u32 i = 0; i &lt; 0xdead; i++) {
		xdpf = xdp_convert_buff_to_frame(&amp;xdp);
		xdp_convert_frame_to_buff(xdpf, &amp;xdp);
	}

shouldn't ever modify @xdpf's contents or the pointer itself.
However, "live packet" code wrongly treats &amp;xdp_frame as part of its
context placed *before* the data_hard_start. With such flow,
data_hard_start is sizeof(*xdpf) off to the right and no longer points
to the XDP frame.

Instead of replacing `sizeof(ctx)` with `offsetof(ctx, xdpf)` in several
places and praying that there are no more miscalcs left somewhere in the
code, unionize ::frm with ::data in a flex array, so that both starts
pointing to the actual data_hard_start and the XDP frame actually starts
being a part of it, i.e. a part of the headroom, not the context.
A nice side effect is that the maximum frame size for this mode gets
increased by 40 bytes, as xdp_buff::frame_sz includes everything from
data_hard_start (-&gt; includes xdpf already) to the end of XDP/skb shared
info.
Also update %MAX_PKT_SIZE accordingly in the selftests code. Leave it
hardcoded for 64 bit &amp;&amp; 4k pages, it can be made more flexible later on.

Minor: align `&amp;head-&gt;data` with how `head-&gt;frm` is assigned for
consistency.
Minor #2: rename 'frm' to 'frame' in &amp;xdp_page_head while at it for
clarity.

(was found while testing XDP traffic generator on ice, which calls
 xdp_convert_frame_to_buff() for each XDP frame)

Fixes: b530e9e1063e ("bpf: Add "live packet" mode for XDP in BPF_PROG_RUN")
Acked-by: Toke Høiland-Jørgensen &lt;toke@redhat.com&gt;
Signed-off-by: Alexander Lobakin &lt;aleksander.lobakin@intel.com&gt;
Link: https://lore.kernel.org/r/20230224163607.2994755-1-aleksander.lobakin@intel.com
Signed-off-by: Martin KaFai Lau &lt;martin.lau@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
&amp;xdp_buff and &amp;xdp_frame are bound in a way that

xdp_buff-&gt;data_hard_start == xdp_frame

It's always the case and e.g. xdp_convert_buff_to_frame() relies on
this.
IOW, the following:

	for (u32 i = 0; i &lt; 0xdead; i++) {
		xdpf = xdp_convert_buff_to_frame(&amp;xdp);
		xdp_convert_frame_to_buff(xdpf, &amp;xdp);
	}

shouldn't ever modify @xdpf's contents or the pointer itself.
However, "live packet" code wrongly treats &amp;xdp_frame as part of its
context placed *before* the data_hard_start. With such flow,
data_hard_start is sizeof(*xdpf) off to the right and no longer points
to the XDP frame.

Instead of replacing `sizeof(ctx)` with `offsetof(ctx, xdpf)` in several
places and praying that there are no more miscalcs left somewhere in the
code, unionize ::frm with ::data in a flex array, so that both starts
pointing to the actual data_hard_start and the XDP frame actually starts
being a part of it, i.e. a part of the headroom, not the context.
A nice side effect is that the maximum frame size for this mode gets
increased by 40 bytes, as xdp_buff::frame_sz includes everything from
data_hard_start (-&gt; includes xdpf already) to the end of XDP/skb shared
info.
Also update %MAX_PKT_SIZE accordingly in the selftests code. Leave it
hardcoded for 64 bit &amp;&amp; 4k pages, it can be made more flexible later on.

Minor: align `&amp;head-&gt;data` with how `head-&gt;frm` is assigned for
consistency.
Minor #2: rename 'frm' to 'frame' in &amp;xdp_page_head while at it for
clarity.

(was found while testing XDP traffic generator on ice, which calls
 xdp_convert_frame_to_buff() for each XDP frame)

Fixes: b530e9e1063e ("bpf: Add "live packet" mode for XDP in BPF_PROG_RUN")
Acked-by: Toke Høiland-Jørgensen &lt;toke@redhat.com&gt;
Signed-off-by: Alexander Lobakin &lt;aleksander.lobakin@intel.com&gt;
Link: https://lore.kernel.org/r/20230224163607.2994755-1-aleksander.lobakin@intel.com
Signed-off-by: Martin KaFai Lau &lt;martin.lau@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>capability: just use a 'u64' instead of a 'u32[2]' array</title>
<updated>2023-03-01T18:01:22+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-02-28T19:39:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f122a08b197d076ccf136c73fae0146875812a88'/>
<id>f122a08b197d076ccf136c73fae0146875812a88</id>
<content type='text'>
Back in 2008 we extended the capability bits from 32 to 64, and we did
it by extending the single 32-bit capability word from one word to an
array of two words.  It was then obfuscated by hiding the "2" behind two
macro expansions, with the reasoning being that maybe it gets extended
further some day.

That reasoning may have been valid at the time, but the last thing we
want to do is to extend the capability set any more.  And the array of
values not only causes source code oddities (with loops to deal with
it), but also results in worse code generation.  It's a lose-lose
situation.

So just change the 'u32[2]' into a 'u64' and be done with it.

We still have to deal with the fact that the user space interface is
designed around an array of these 32-bit values, but that was the case
before too, since the array layouts were different (ie user space
doesn't use an array of 32-bit values for individual capability masks,
but an array of 32-bit slices of multiple masks).

So that marshalling of data is actually simplified too, even if it does
remain somewhat obscure and odd.

This was all triggered by my reaction to the new "cap_isidentical()"
introduced recently.  By just using a saner data structure, it went from

	unsigned __capi;
	CAP_FOR_EACH_U32(__capi) {
		if (a.cap[__capi] != b.cap[__capi])
			return false;
	}
	return true;

to just being

	return a.val == b.val;

instead.  Which is rather more obvious both to humans and to compilers.

Cc: Mateusz Guzik &lt;mjguzik@gmail.com&gt;
Cc: Casey Schaufler &lt;casey@schaufler-ca.com&gt;
Cc: Serge Hallyn &lt;serge@hallyn.com&gt;
Cc: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Cc: Paul Moore &lt;paul@paul-moore.com&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
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<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Back in 2008 we extended the capability bits from 32 to 64, and we did
it by extending the single 32-bit capability word from one word to an
array of two words.  It was then obfuscated by hiding the "2" behind two
macro expansions, with the reasoning being that maybe it gets extended
further some day.

That reasoning may have been valid at the time, but the last thing we
want to do is to extend the capability set any more.  And the array of
values not only causes source code oddities (with loops to deal with
it), but also results in worse code generation.  It's a lose-lose
situation.

So just change the 'u32[2]' into a 'u64' and be done with it.

We still have to deal with the fact that the user space interface is
designed around an array of these 32-bit values, but that was the case
before too, since the array layouts were different (ie user space
doesn't use an array of 32-bit values for individual capability masks,
but an array of 32-bit slices of multiple masks).

So that marshalling of data is actually simplified too, even if it does
remain somewhat obscure and odd.

This was all triggered by my reaction to the new "cap_isidentical()"
introduced recently.  By just using a saner data structure, it went from

	unsigned __capi;
	CAP_FOR_EACH_U32(__capi) {
		if (a.cap[__capi] != b.cap[__capi])
			return false;
	}
	return true;

to just being

	return a.val == b.val;

instead.  Which is rather more obvious both to humans and to compilers.

Cc: Mateusz Guzik &lt;mjguzik@gmail.com&gt;
Cc: Casey Schaufler &lt;casey@schaufler-ca.com&gt;
Cc: Serge Hallyn &lt;serge@hallyn.com&gt;
Cc: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Cc: Paul Moore &lt;paul@paul-moore.com&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
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