<feed xmlns='http://www.w3.org/2005/Atom'>
<title>user/sven/linux.git/include/linux/compiler-gcc.h, branch v6.1.4</title>
<subtitle>Linux Kernel
</subtitle>
<id>https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v6.1.4</id>
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<updated>2022-10-03T21:03:19Z</updated>
<entry>
<title>kmsan: introduce __no_sanitize_memory and __no_kmsan_checks</title>
<updated>2022-10-03T21:03:19Z</updated>
<author>
<name>Alexander Potapenko</name>
<email>glider@google.com</email>
</author>
<published>2022-09-15T15:03:41Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=9b448bc25b776daab3215393c3ce6953dd3bb8ad'/>
<id>urn:sha1:9b448bc25b776daab3215393c3ce6953dd3bb8ad</id>
<content type='text'>
__no_sanitize_memory is a function attribute that instructs KMSAN to skip
a function during instrumentation.  This is needed to e.g.  implement the
noinstr functions.

__no_kmsan_checks is a function attribute that makes KMSAN ignore the
uninitialized values coming from the function's inputs, and initialize the
function's outputs.

Functions marked with this attribute can't be inlined into functions not
marked with it, and vice versa.  This behavior is overridden by
__always_inline.

__SANITIZE_MEMORY__ is a macro that's defined iff the file is instrumented
with KMSAN.  This is not the same as CONFIG_KMSAN, which is defined for
every file.

Link: https://lkml.kernel.org/r/20220915150417.722975-8-glider@google.com
Signed-off-by: Alexander Potapenko &lt;glider@google.com&gt;
Reviewed-by: Marco Elver &lt;elver@google.com&gt;
Cc: Alexander Viro &lt;viro@zeniv.linux.org.uk&gt;
Cc: Alexei Starovoitov &lt;ast@kernel.org&gt;
Cc: Andrey Konovalov &lt;andreyknvl@gmail.com&gt;
Cc: Andrey Konovalov &lt;andreyknvl@google.com&gt;
Cc: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Christoph Hellwig &lt;hch@lst.de&gt;
Cc: Christoph Lameter &lt;cl@linux.com&gt;
Cc: David Rientjes &lt;rientjes@google.com&gt;
Cc: Dmitry Vyukov &lt;dvyukov@google.com&gt;
Cc: Eric Biggers &lt;ebiggers@google.com&gt;
Cc: Eric Biggers &lt;ebiggers@kernel.org&gt;
Cc: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
Cc: Ilya Leoshkevich &lt;iii@linux.ibm.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Jens Axboe &lt;axboe@kernel.dk&gt;
Cc: Joonsoo Kim &lt;iamjoonsoo.kim@lge.com&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Matthew Wilcox &lt;willy@infradead.org&gt;
Cc: Michael S. Tsirkin &lt;mst@redhat.com&gt;
Cc: Pekka Enberg &lt;penberg@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Petr Mladek &lt;pmladek@suse.com&gt;
Cc: Stephen Rothwell &lt;sfr@canb.auug.org.au&gt;
Cc: Steven Rostedt &lt;rostedt@goodmis.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Cc: Vegard Nossum &lt;vegard.nossum@oracle.com&gt;
Cc: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>compiler-gcc.h: remove ancient workaround for gcc PR 58670</title>
<updated>2022-07-18T00:31:38Z</updated>
<author>
<name>Uros Bizjak</name>
<email>ubizjak@gmail.com</email>
</author>
<published>2022-06-24T14:14:12Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=43c249ea0b1e10baac4a1264a25d69723ce5d2c2'/>
<id>urn:sha1:43c249ea0b1e10baac4a1264a25d69723ce5d2c2</id>
<content type='text'>
The workaround for 'asm goto' miscompilation introduces a compiler barrier
quirk that inhibits many useful compiler optimizations.  For example,
__try_cmpxchg_user compiles to:

   11375:	41 8b 4d 00          	mov    0x0(%r13),%ecx
   11379:	41 8b 02             	mov    (%r10),%eax
   1137c:	f0 0f b1 0a          	lock cmpxchg %ecx,(%rdx)
   11380:	0f 94 c2             	sete   %dl
   11383:	84 d2                	test   %dl,%dl
   11385:	75 c4                	jne    1134b &lt;...&gt;
   11387:	41 89 02             	mov    %eax,(%r10)

where the barrier inhibits flags propagation from asm when compiled with
gcc-12.

When the mentioned quirk is removed, the following code is generated:

   11553:	41 8b 4d 00          	mov    0x0(%r13),%ecx
   11557:	41 8b 02             	mov    (%r10),%eax
   1155a:	f0 0f b1 0a          	lock cmpxchg %ecx,(%rdx)
   1155e:	74 c9                	je     11529 &lt;...&gt;
   11560:	41 89 02             	mov    %eax,(%r10)

The refered compiler bug:

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670

was fixed for gcc-4.8.2.

Current minimum required version of GCC is version 5.1 which has the above
'asm goto' miscompilation fixed, so remove the workaround.

Link: https://lkml.kernel.org/r/20220624141412.72274-1-ubizjak@gmail.com
Signed-off-by: Uros Bizjak &lt;ubizjak@gmail.com&gt;
Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>randstruct: Reorganize Kconfigs and attribute macros</title>
<updated>2022-05-08T08:33:06Z</updated>
<author>
<name>Kees Cook</name>
<email>keescook@chromium.org</email>
</author>
<published>2022-05-03T20:55:00Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=595b893e2087de306d0781795fb8ec47873596a6'/>
<id>urn:sha1:595b893e2087de306d0781795fb8ec47873596a6</id>
<content type='text'>
In preparation for Clang supporting randstruct, reorganize the Kconfigs,
move the attribute macros, and generalize the feature to be named
CONFIG_RANDSTRUCT for on/off, CONFIG_RANDSTRUCT_FULL for the full
randomization mode, and CONFIG_RANDSTRUCT_PERFORMANCE for the cache-line
sized mode.

Cc: linux-hardening@vger.kernel.org
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Link: https://lore.kernel.org/r/20220503205503.3054173-4-keescook@chromium.org
</content>
</entry>
<entry>
<title>Merge tag 'net-next-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next</title>
<updated>2022-03-24T20:13:26Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-03-24T20:13:26Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=169e77764adc041b1dacba84ea90516a895d43b2'/>
<id>urn:sha1:169e77764adc041b1dacba84ea90516a895d43b2</id>
<content type='text'>
Pull networking updates from Jakub Kicinski:
 "The sprinkling of SPI drivers is because we added a new one and Mark
  sent us a SPI driver interface conversion pull request.

  Core
  ----

   - Introduce XDP multi-buffer support, allowing the use of XDP with
     jumbo frame MTUs and combination with Rx coalescing offloads (LRO).

   - Speed up netns dismantling (5x) and lower the memory cost a little.
     Remove unnecessary per-netns sockets. Scope some lists to a netns.
     Cut down RCU syncing. Use batch methods. Allow netdev registration
     to complete out of order.

   - Support distinguishing timestamp types (ingress vs egress) and
     maintaining them across packet scrubbing points (e.g. redirect).

   - Continue the work of annotating packet drop reasons throughout the
     stack.

   - Switch netdev error counters from an atomic to dynamically
     allocated per-CPU counters.

   - Rework a few preempt_disable(), local_irq_save() and busy waiting
     sections problematic on PREEMPT_RT.

   - Extend the ref_tracker to allow catching use-after-free bugs.

  BPF
  ---

   - Introduce "packing allocator" for BPF JIT images. JITed code is
     marked read only, and used to be allocated at page granularity.
     Custom allocator allows for more efficient memory use, lower iTLB
     pressure and prevents identity mapping huge pages from getting
     split.

   - Make use of BTF type annotations (e.g. __user, __percpu) to enforce
     the correct probe read access method, add appropriate helpers.

   - Convert the BPF preload to use light skeleton and drop the
     user-mode-driver dependency.

   - Allow XDP BPF_PROG_RUN test infra to send real packets, enabling
     its use as a packet generator.

   - Allow local storage memory to be allocated with GFP_KERNEL if
     called from a hook allowed to sleep.

   - Introduce fprobe (multi kprobe) to speed up mass attachment (arch
     bits to come later).

   - Add unstable conntrack lookup helpers for BPF by using the BPF
     kfunc infra.

   - Allow cgroup BPF progs to return custom errors to user space.

   - Add support for AF_UNIX iterator batching.

   - Allow iterator programs to use sleepable helpers.

   - Support JIT of add, and, or, xor and xchg atomic ops on arm64.

   - Add BTFGen support to bpftool which allows to use CO-RE in kernels
     without BTF info.

   - Large number of libbpf API improvements, cleanups and deprecations.

  Protocols
  ---------

   - Micro-optimize UDPv6 Tx, gaining up to 5% in test on dummy netdev.

   - Adjust TSO packet sizes based on min_rtt, allowing very low latency
     links (data centers) to always send full-sized TSO super-frames.

   - Make IPv6 flow label changes (AKA hash rethink) more configurable,
     via sysctl and setsockopt. Distinguish between server and client
     behavior.

   - VxLAN support to "collect metadata" devices to terminate only
     configured VNIs. This is similar to VLAN filtering in the bridge.

   - Support inserting IPv6 IOAM information to a fraction of frames.

   - Add protocol attribute to IP addresses to allow identifying where
     given address comes from (kernel-generated, DHCP etc.)

   - Support setting socket and IPv6 options via cmsg on ping6 sockets.

   - Reject mis-use of ECN bits in IP headers as part of DSCP/TOS.
     Define dscp_t and stop taking ECN bits into account in fib-rules.

   - Add support for locked bridge ports (for 802.1X).

   - tun: support NAPI for packets received from batched XDP buffs,
     doubling the performance in some scenarios.

   - IPv6 extension header handling in Open vSwitch.

   - Support IPv6 control message load balancing in bonding, prevent
     neighbor solicitation and advertisement from using the wrong port.
     Support NS/NA monitor selection similar to existing ARP monitor.

   - SMC
      - improve performance with TCP_CORK and sendfile()
      - support auto-corking
      - support TCP_NODELAY

   - MCTP (Management Component Transport Protocol)
      - add user space tag control interface
      - I2C binding driver (as specified by DMTF DSP0237)

   - Multi-BSSID beacon handling in AP mode for WiFi.

   - Bluetooth:
      - handle MSFT Monitor Device Event
      - add MGMT Adv Monitor Device Found/Lost events

   - Multi-Path TCP:
      - add support for the SO_SNDTIMEO socket option
      - lots of selftest cleanups and improvements

   - Increase the max PDU size in CAN ISOTP to 64 kB.

  Driver API
  ----------

   - Add HW counters for SW netdevs, a mechanism for devices which
     offload packet forwarding to report packet statistics back to
     software interfaces such as tunnels.

   - Select the default NIC queue count as a fraction of number of
     physical CPU cores, instead of hard-coding to 8.

   - Expose devlink instance locks to drivers. Allow device layer of
     drivers to use that lock directly instead of creating their own
     which always runs into ordering issues in devlink callbacks.

   - Add header/data split indication to guide user space enabling of
     TCP zero-copy Rx.

   - Allow configuring completion queue event size.

   - Refactor page_pool to enable fragmenting after allocation.

   - Add allocation and page reuse statistics to page_pool.

   - Improve Multiple Spanning Trees support in the bridge to allow
     reuse of topologies across VLANs, saving HW resources in switches.

   - DSA (Distributed Switch Architecture):
      - replay and offload of host VLAN entries
      - offload of static and local FDB entries on LAG interfaces
      - FDB isolation and unicast filtering

  New hardware / drivers
  ----------------------

   - Ethernet:
      - LAN937x T1 PHYs
      - Davicom DM9051 SPI NIC driver
      - Realtek RTL8367S, RTL8367RB-VB switch and MDIO
      - Microchip ksz8563 switches
      - Netronome NFP3800 SmartNICs
      - Fungible SmartNICs
      - MediaTek MT8195 switches

   - WiFi:
      - mt76: MediaTek mt7916
      - mt76: MediaTek mt7921u USB adapters
      - brcmfmac: Broadcom BCM43454/6

   - Mobile:
      - iosm: Intel M.2 7360 WWAN card

  Drivers
  -------

   - Convert many drivers to the new phylink API built for split PCS
     designs but also simplifying other cases.

   - Intel Ethernet NICs:
      - add TTY for GNSS module for E810T device
      - improve AF_XDP performance
      - GTP-C and GTP-U filter offload
      - QinQ VLAN support

   - Mellanox Ethernet NICs (mlx5):
      - support xdp-&gt;data_meta
      - multi-buffer XDP
      - offload tc push_eth and pop_eth actions

   - Netronome Ethernet NICs (nfp):
      - flow-independent tc action hardware offload (police / meter)
      - AF_XDP

   - Other Ethernet NICs:
      - at803x: fiber and SFP support
      - xgmac: mdio: preamble suppression and custom MDC frequencies
      - r8169: enable ASPM L1.2 if system vendor flags it as safe
      - macb/gem: ZynqMP SGMII
      - hns3: add TX push mode
      - dpaa2-eth: software TSO
      - lan743x: multi-queue, mdio, SGMII, PTP
      - axienet: NAPI and GRO support

   - Mellanox Ethernet switches (mlxsw):
      - source and dest IP address rewrites
      - RJ45 ports

   - Marvell Ethernet switches (prestera):
      - basic routing offload
      - multi-chain TC ACL offload

   - NXP embedded Ethernet switches (ocelot &amp; felix):
      - PTP over UDP with the ocelot-8021q DSA tagging protocol
      - basic QoS classification on Felix DSA switch using dcbnl
      - port mirroring for ocelot switches

   - Microchip high-speed industrial Ethernet (sparx5):
      - offloading of bridge port flooding flags
      - PTP Hardware Clock

   - Other embedded switches:
      - lan966x: PTP Hardward Clock
      - qca8k: mdio read/write operations via crafted Ethernet packets

   - Qualcomm 802.11ax WiFi (ath11k):
      - add LDPC FEC type and 802.11ax High Efficiency data in radiotap
      - enable RX PPDU stats in monitor co-exist mode

   - Intel WiFi (iwlwifi):
      - UHB TAS enablement via BIOS
      - band disablement via BIOS
      - channel switch offload
      - 32 Rx AMPDU sessions in newer devices

   - MediaTek WiFi (mt76):
      - background radar detection
      - thermal management improvements on mt7915
      - SAR support for more mt76 platforms
      - MBSSID and 6 GHz band on mt7915

   - RealTek WiFi:
      - rtw89: AP mode
      - rtw89: 160 MHz channels and 6 GHz band
      - rtw89: hardware scan

   - Bluetooth:
      - mt7921s: wake on Bluetooth, SCO over I2S, wide-band-speed (WBS)

   - Microchip CAN (mcp251xfd):
      - multiple RX-FIFOs and runtime configurable RX/TX rings
      - internal PLL, runtime PM handling simplification
      - improve chip detection and error handling after wakeup"

* tag 'net-next-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2521 commits)
  llc: fix netdevice reference leaks in llc_ui_bind()
  drivers: ethernet: cpsw: fix panic when interrupt coaleceing is set via ethtool
  ice: don't allow to run ice_send_event_to_aux() in atomic ctx
  ice: fix 'scheduling while atomic' on aux critical err interrupt
  net/sched: fix incorrect vlan_push_eth dest field
  net: bridge: mst: Restrict info size queries to bridge ports
  net: marvell: prestera: add missing destroy_workqueue() in prestera_module_init()
  drivers: net: xgene: Fix regression in CRC stripping
  net: geneve: add missing netlink policy and size for IFLA_GENEVE_INNER_PROTO_INHERIT
  net: dsa: fix missing host-filtered multicast addresses
  net/mlx5e: Fix build warning, detected write beyond size of field
  iwlwifi: mvm: Don't fail if PPAG isn't supported
  selftests/bpf: Fix kprobe_multi test.
  Revert "rethook: x86: Add rethook x86 implementation"
  Revert "arm64: rethook: Add arm64 rethook implementation"
  Revert "powerpc: Add rethook support"
  Revert "ARM: rethook: Add rethook arm implementation"
  netdevice: add missing dm_private kdoc
  net: bridge: mst: prevent NULL deref in br_mst_info_size()
  selftests: forwarding: Use same VRF for port and VLAN upper
  ...
</content>
</entry>
<entry>
<title>arm64: Add gcc Shadow Call Stack support</title>
<updated>2022-03-10T17:22:09Z</updated>
<author>
<name>Dan Li</name>
<email>ashimida@linux.alibaba.com</email>
</author>
<published>2022-03-03T07:43:23Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=afcf5441b9ff22ac57244cd45ff102ebc2e32d1a'/>
<id>urn:sha1:afcf5441b9ff22ac57244cd45ff102ebc2e32d1a</id>
<content type='text'>
Shadow call stacks will be available in GCC &gt;= 12, this patch makes
the corresponding kernel configuration available when compiling
the kernel with the gcc.

Note that the implementation in GCC is slightly different from Clang.
With SCS enabled, functions will only pop x30 once in the epilogue,
like:

   str     x30, [x18], #8
   stp     x29, x30, [sp, #-16]!
   ......
-  ldp     x29, x30, [sp], #16	  //clang
+  ldr     x29, [sp], #16	  //GCC
   ldr     x30, [x18, #-8]!

Link: https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=ce09ab17ddd21f73ff2caf6eec3b0ee9b0e1a11e

Reviewed-by: Nathan Chancellor &lt;nathan@kernel.org&gt;
Reviewed-by: Kees Cook &lt;keescook@chromium.org&gt;
Reviewed-by: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Signed-off-by: Dan Li &lt;ashimida@linux.alibaba.com&gt;
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Link: https://lore.kernel.org/r/20220303074323.86282-1-ashimida@linux.alibaba.com
</content>
</entry>
<entry>
<title>compiler_types.h: Add unified __diag_ignore_all for GCC/LLVM</title>
<updated>2022-03-05T23:29:36Z</updated>
<author>
<name>Kumar Kartikeya Dwivedi</name>
<email>memxor@gmail.com</email>
</author>
<published>2022-03-04T22:46:43Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=4d1ea705d797e66edd70ffa708b83888a210a437'/>
<id>urn:sha1:4d1ea705d797e66edd70ffa708b83888a210a437</id>
<content type='text'>
Add a __diag_ignore_all macro, to ignore warnings for both GCC and LLVM,
without having to specify the compiler type and version. By default, GCC
8 and clang 11 are used. This will be used by bpf subsystem to ignore
-Wmissing-prototypes warning for functions that are meant to be global
functions so that they are in vmlinux BTF, but don't have a prototype.

Signed-off-by: Kumar Kartikeya Dwivedi &lt;memxor@gmail.com&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20220304224645.3677453-7-memxor@gmail.com
</content>
</entry>
<entry>
<title>Merge branch 'akpm' (patches from Andrew)</title>
<updated>2021-11-06T21:08:17Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2021-11-06T21:08:17Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=512b7931ad0561ffe14265f9ff554a3c081b476b'/>
<id>urn:sha1:512b7931ad0561ffe14265f9ff554a3c081b476b</id>
<content type='text'>
Merge misc updates from Andrew Morton:
 "257 patches.

  Subsystems affected by this patch series: scripts, ocfs2, vfs, and
  mm (slab-generic, slab, slub, kconfig, dax, kasan, debug, pagecache,
  gup, swap, memcg, pagemap, mprotect, mremap, iomap, tracing, vmalloc,
  pagealloc, memory-failure, hugetlb, userfaultfd, vmscan, tools,
  memblock, oom-kill, hugetlbfs, migration, thp, readahead, nommu, ksm,
  vmstat, madvise, memory-hotplug, rmap, zsmalloc, highmem, zram,
  cleanups, kfence, and damon)"

* emailed patches from Andrew Morton &lt;akpm@linux-foundation.org&gt;: (257 commits)
  mm/damon: remove return value from before_terminate callback
  mm/damon: fix a few spelling mistakes in comments and a pr_debug message
  mm/damon: simplify stop mechanism
  Docs/admin-guide/mm/pagemap: wordsmith page flags descriptions
  Docs/admin-guide/mm/damon/start: simplify the content
  Docs/admin-guide/mm/damon/start: fix a wrong link
  Docs/admin-guide/mm/damon/start: fix wrong example commands
  mm/damon/dbgfs: add adaptive_targets list check before enable monitor_on
  mm/damon: remove unnecessary variable initialization
  Documentation/admin-guide/mm/damon: add a document for DAMON_RECLAIM
  mm/damon: introduce DAMON-based Reclamation (DAMON_RECLAIM)
  selftests/damon: support watermarks
  mm/damon/dbgfs: support watermarks
  mm/damon/schemes: activate schemes based on a watermarks mechanism
  tools/selftests/damon: update for regions prioritization of schemes
  mm/damon/dbgfs: support prioritization weights
  mm/damon/vaddr,paddr: support pageout prioritization
  mm/damon/schemes: prioritize regions within the quotas
  mm/damon/selftests: support schemes quotas
  mm/damon/dbgfs: support quotas of schemes
  ...
</content>
</entry>
<entry>
<title>Compiler Attributes: add __alloc_size() for better bounds checking</title>
<updated>2021-11-06T20:30:33Z</updated>
<author>
<name>Kees Cook</name>
<email>keescook@chromium.org</email>
</author>
<published>2021-11-05T20:36:19Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=86cffecdeaa278444870c8745ab166a65865dbf0'/>
<id>urn:sha1:86cffecdeaa278444870c8745ab166a65865dbf0</id>
<content type='text'>
GCC and Clang can use the "alloc_size" attribute to better inform the
results of __builtin_object_size() (for compile-time constant values).
Clang can additionally use alloc_size to inform the results of
__builtin_dynamic_object_size() (for run-time values).

Because GCC sees the frequent use of struct_size() as an allocator size
argument, and notices it can return SIZE_MAX (the overflow indication),
it complains about these call sites overflowing (since SIZE_MAX is
greater than the default -Walloc-size-larger-than=PTRDIFF_MAX).  This
isn't helpful since we already know a SIZE_MAX will be caught at
run-time (this was an intentional design).  To deal with this, we must
disable this check as it is both a false positive and redundant.  (Clang
does not have this warning option.)

Unfortunately, just checking the -Wno-alloc-size-larger-than is not
sufficient to make the __alloc_size attribute behave correctly under
older GCC versions.  The attribute itself must be disabled in those
situations too, as there appears to be no way to reliably silence the
SIZE_MAX constant expression cases for GCC versions less than 9.1:

   In file included from ./include/linux/resource_ext.h:11,
                    from ./include/linux/pci.h:40,
                    from drivers/net/ethernet/intel/ixgbe/ixgbe.h:9,
                    from drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c:4:
   In function 'kmalloc_node',
       inlined from 'ixgbe_alloc_q_vector' at ./include/linux/slab.h:743:9:
   ./include/linux/slab.h:618:9: error: argument 1 value '18446744073709551615' exceeds maximum object size 9223372036854775807 [-Werror=alloc-size-larger-than=]
     return __kmalloc_node(size, flags, node);
            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   ./include/linux/slab.h: In function 'ixgbe_alloc_q_vector':
   ./include/linux/slab.h:455:7: note: in a call to allocation function '__kmalloc_node' declared here
    void *__kmalloc_node(size_t size, gfp_t flags, int node) __assume_slab_alignment __malloc;
          ^~~~~~~~~~~~~~

Specifically:
 '-Wno-alloc-size-larger-than' is not correctly handled by GCC &lt; 9.1
    https://godbolt.org/z/hqsfG7q84 (doesn't disable)
    https://godbolt.org/z/P9jdrPTYh (doesn't admit to not knowing about option)
    https://godbolt.org/z/465TPMWKb (only warns when other warnings appear)

 '-Walloc-size-larger-than=18446744073709551615' is not handled by GCC &lt; 8.2
    https://godbolt.org/z/73hh1EPxz (ignores numeric value)

Since anything marked with __alloc_size would also qualify for marking
with __malloc, just include __malloc along with it to avoid redundant
markings.  (Suggested by Linus Torvalds.)

Finally, make sure checkpatch.pl doesn't get confused about finding the
__alloc_size attribute on functions.  (Thanks to Joe Perches.)

Link: https://lkml.kernel.org/r/20210930222704.2631604-3-keescook@chromium.org
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Tested-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Cc: Andy Whitcroft &lt;apw@canonical.com&gt;
Cc: Christoph Lameter &lt;cl@linux.com&gt;
Cc: Daniel Micay &lt;danielmicay@gmail.com&gt;
Cc: David Rientjes &lt;rientjes@google.com&gt;
Cc: Dennis Zhou &lt;dennis@kernel.org&gt;
Cc: Dwaipayan Ray &lt;dwaipayanray1@gmail.com&gt;
Cc: Joe Perches &lt;joe@perches.com&gt;
Cc: Joonsoo Kim &lt;iamjoonsoo.kim@lge.com&gt;
Cc: Lukas Bulwahn &lt;lukas.bulwahn@gmail.com&gt;
Cc: Pekka Enberg &lt;penberg@kernel.org&gt;
Cc: Tejun Heo &lt;tj@kernel.org&gt;
Cc: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Cc: Alexandre Bounine &lt;alex.bou9@gmail.com&gt;
Cc: Gustavo A. R. Silva &lt;gustavoars@kernel.org&gt;
Cc: Ira Weiny &lt;ira.weiny@intel.com&gt;
Cc: Jing Xiangfeng &lt;jingxiangfeng@huawei.com&gt;
Cc: John Hubbard &lt;jhubbard@nvidia.com&gt;
Cc: kernel test robot &lt;lkp@intel.com&gt;
Cc: Matt Porter &lt;mporter@kernel.crashing.org&gt;
Cc: Miguel Ojeda &lt;ojeda@kernel.org&gt;
Cc: Nathan Chancellor &lt;nathan@kernel.org&gt;
Cc: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Cc: Souptick Joarder &lt;jrdr.linux@gmail.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>compiler-gcc.h: Define __SANITIZE_ADDRESS__ under hwaddress sanitizer</title>
<updated>2021-10-21T08:37:46Z</updated>
<author>
<name>Kees Cook</name>
<email>keescook@chromium.org</email>
</author>
<published>2021-10-20T20:00:39Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=9a48e7564ac83fb0f1d5b0eac5fe8a7af62da398'/>
<id>urn:sha1:9a48e7564ac83fb0f1d5b0eac5fe8a7af62da398</id>
<content type='text'>
When Clang is using the hwaddress sanitizer, it sets __SANITIZE_ADDRESS__
explicitly:

 #if __has_feature(address_sanitizer) || __has_feature(hwaddress_sanitizer)
 /* Emulate GCC's __SANITIZE_ADDRESS__ flag */
 #define __SANITIZE_ADDRESS__
 #endif

Once hwaddress sanitizer was added to GCC, however, a separate define
was created, __SANITIZE_HWADDRESS__. The kernel is expecting to find
__SANITIZE_ADDRESS__ in either case, though, and the existing string
macros break on supported architectures:

 #if (defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)) &amp;&amp; \
          !defined(__SANITIZE_ADDRESS__)

where as other architectures (like arm32) have no idea about hwaddress
sanitizer and just check for __SANITIZE_ADDRESS__:

 #if defined(CONFIG_KASAN) &amp;&amp; !defined(__SANITIZE_ADDRESS__)

This would lead to compiler foritfy self-test warnings when building
with CONFIG_KASAN_SW_TAGS=y:

warning: unsafe memmove() usage lacked '__read_overflow2' symbol in lib/test_fortify/read_overflow2-memmove.c
warning: unsafe memcpy() usage lacked '__write_overflow' symbol in lib/test_fortify/write_overflow-memcpy.c
...

Sort this out by also defining __SANITIZE_ADDRESS__ in GCC under the
hwaddress sanitizer.

Suggested-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Cc: Arvind Sankar &lt;nivedita@alum.mit.edu&gt;
Cc: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
Cc: llvm@lists.linux.dev
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Reviewed-by: Nathan Chancellor &lt;nathan@kernel.org&gt;
Acked-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
Reviewed-by: Marco Elver &lt;elver@google.com&gt;
Link: https://lore.kernel.org/r/20211020200039.170424-1-keescook@chromium.org
</content>
</entry>
<entry>
<title>compiler_types.h: Remove __compiletime_object_size()</title>
<updated>2021-09-25T15:20:49Z</updated>
<author>
<name>Kees Cook</name>
<email>keescook@chromium.org</email>
</author>
<published>2021-06-18T05:48:05Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=c80d92fbb67b2c80b8eeb8759ee79d676eb33520'/>
<id>urn:sha1:c80d92fbb67b2c80b8eeb8759ee79d676eb33520</id>
<content type='text'>
Since all compilers support __builtin_object_size(), and there is only
one user of __compiletime_object_size, remove it to avoid the needless
indirection. This lets Clang reason about check_copy_size() correctly.

Link: https://github.com/ClangBuiltLinux/linux/issues/1179
Suggested-by: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Cc: Nathan Chancellor &lt;nathan@kernel.org&gt;
Cc: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Cc: Sedat Dilek &lt;sedat.dilek@gmail.com&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Cc: Marco Elver &lt;elver@google.com&gt;
Cc: Arvind Sankar &lt;nivedita@alum.mit.edu&gt;
Cc: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
Cc: Luc Van Oostenryck &lt;luc.vanoostenryck@gmail.com&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Sami Tolvanen &lt;samitolvanen@google.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Gabriel Krisman Bertazi &lt;krisman@collabora.com&gt;
Cc: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: Oleg Nesterov &lt;oleg@redhat.com&gt;
Reviewed-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
</content>
</entry>
</feed>
