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  1. 10 Jun, 2022 30 commits
  3. 09 Jun, 2022 10 commits
    • David Howells's avatar
      netfs: Fix gcc-12 warning by embedding vfs inode in netfs_i_context · 874c8ca1
      David Howells authored 
      While randstruct was satisfied with using an open-coded "void *" offset
cast for the netfs_i_context <-> inode casting, __builtin_object_size() as
used by FORTIFY_SOURCE was not as easily fooled.  This was causing the
following complaint[1] from gcc v12:

  In file included from include/linux/string.h:253,
                   from include/linux/ceph/ceph_debug.h:7,
                   from fs/ceph/inode.c:2:
  In function 'fortify_memset_chk',
      inlined from 'netfs_i_context_init' at include/linux/netfs.h:326:2,
      inlined from 'ceph_alloc_inode' at fs/ceph/inode.c:463:2:
  include/linux/fortify-string.h:242:25: warning: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Wattribute-warning]
    242 |                         __write_overflow_field(p_size_field, size);
        |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Fix this by embedding a struct inode into struct netfs_i_context (which
should perhaps be renamed to struct netfs_inode).  The struct inode
vfs_inode fields are then removed from the 9p, afs, ceph and cifs inode
structs and vfs_inode is then simply changed to "netfs.inode" in those
filesystems.

Further, rename netfs_i_context to netfs_inode, get rid of the
netfs_inode() function that converted a netfs_i_context pointer to an
inode pointer (that can now be done with &ctx->inode) and rename the
netfs_i_context() function to netfs_inode() (which is now a wrapper
around container_of()).

Most of the changes were done with:

  perl -p -i -e 's/vfs_inode/netfs.inode/'g \
        `git grep -l 'vfs_inode' -- fs/{9p,afs,ceph,cifs}/*.[ch]`

Kees suggested doing it with a pair structure[2] and a special
declarator to insert that into the network filesystem's inode
wrapper[3], but I think it's cleaner to embed it - and then it doesn't
matter if struct randomisation reorders things.

Dave Chinner suggested using a filesystem-specific VFS_I() function in
each filesystem to convert that filesystem's own inode wrapper struct
into the VFS inode struct[4].

Version #2:
 - Fix a couple of missed name changes due to a disabled cifs option.
 - Rename nfs_i_context to nfs_inode
 - Use "netfs" instead of "nic" as the member name in per-fs inode wrapper
   structs.

[ This also undoes commit 507160f4 ("netfs: gcc-12: temporarily
  disable '-Wattribute-warning' for now") that is no longer needed ]

Fixes: bc899ee1 ("netfs: Add a netfs inode context")
Reported-by: default avatarJeff Layton <jlayton@kernel.org>
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Reviewed-by: default avatarJeff Layton <jlayton@kernel.org>
Reviewed-by: default avatarKees Cook <keescook@chromium.org>
Reviewed-by: default avatarXiubo Li <xiubli@redhat.com>
cc: Jonathan Corbet <corbet@lwn.net>
cc: Eric Van Hensbergen <ericvh@gmail.com>
cc: Latchesar Ionkov <lucho@ionkov.net>
cc: Dominique Martinet <asmadeus@codewreck.org>
cc: Christian Schoenebeck <linux_oss@crudebyte.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: Ilya Dryomov <idryomov@gmail.com>
cc: Steve French <smfrench@gmail.com>
cc: William Kucharski <william.kucharski@oracle.com>
cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
cc: Dave Chinner <david@fromorbit.com>
cc: linux-doc@vger.kernel.org
cc: v9fs-developer@lists.sourceforge.net
cc: linux-afs@lists.infradead.org
cc: ceph-devel@vger.kernel.org
cc: linux-cifs@vger.kernel.org
cc: samba-technical@lists.samba.org
cc: linux-fsdevel@vger.kernel.org
cc: linux-hardening@vger.kernel.org
Link: https://lore.kernel.org/r/d2ad3a3d7bdd794c6efb562d2f2b655fb67756b9.camel@kernel.org/ [1]
Link: https://lore.kernel.org/r/20220517210230.864239-1-keescook@chromium.org/ [2]
Link: https://lore.kernel.org/r/20220518202212.2322058-1-keescook@chromium.org/ [3]
Link: https://lore.kernel.org/r/20220524101205.GI2306852@dread.disaster.area/ [4]
Link: https://lore.kernel.org/r/165296786831.3591209.12111293034669289733.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/165305805651.4094995.7763502506786714216.stgit@warthog.procyon.org.uk # v2
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      874c8ca1
    • Yupeng Li's avatar
      MIPS: Loongson-3: fix compile mips cpu_hwmon as module build error. · 41e45640
      Yupeng Li authored 
        set cpu_hwmon as a module build with loongson_sysconf, loongson_chiptemp
  undefined error,fix cpu_hwmon compile options to be bool.Some kernel
  compilation error information is as follows:

  Checking missing-syscalls for N32
  CALL    scripts/checksyscalls.sh
  Checking missing-syscalls for O32
  CALL    scripts/checksyscalls.sh
  CALL    scripts/checksyscalls.sh
  CHK     include/generated/compile.h
  CC [M]  drivers/platform/mips/cpu_hwmon.o
  Building modules, stage 2.
  MODPOST 200 modules
ERROR: "loongson_sysconf" [drivers/platform/mips/cpu_hwmon.ko] undefined!
ERROR: "loongson_chiptemp" [drivers/platform/mips/cpu_hwmon.ko] undefined!
make[1]: *** [scripts/Makefile.modpost:92：__modpost] 错误 1
make: *** [Makefile:1261：modules] 错误 2
Signed-off-by: default avatarYupeng Li <liyupeng@zbhlos.com>
Reviewed-by: default avatarGuenter Roeck <linux@roeck-us.net>
Reviewed-by: default avatarHuacai Chen <chenhuacai@kernel.org>
Signed-off-by: default avatarThomas Bogendoerfer <tsbogend@alpha.franken.de>
      41e45640
    • Linus Torvalds's avatar
      Merge tag 'fs_for_v5.19-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs · 3d9f55c5
      Linus Torvalds authored 
      Pull ext2, writeback, and quota fixes and cleanups from Jan Kara:
 "A fix for race in writeback code and two cleanups in quota and ext2"

* tag 'fs_for_v5.19-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  quota: Prevent memory allocation recursion while holding dq_lock
  writeback: Fix inode->i_io_list not be protected by inode->i_lock error
  fs: Fix syntax errors in comments
      3d9f55c5
    • Linus Torvalds's avatar
      Merge tag 'powerpc-5.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux · 95fc76c8
      Linus Torvalds authored 
      Pull powerpc fixes from Michael Ellerman:

 - On 32-bit fix overread/overwrite of thread_struct via ptrace
   PEEK/POKE.

 - Fix softirqs not switching to the softirq stack since we moved
   irq_exit().

 - Force thread size increase when KASAN is enabled to avoid stack
   overflows.

 - On Book3s 64 mark more code as not to be instrumented by KASAN to
   avoid crashes.

 - Exempt __get_wchan() from KASAN checking, as it's inherently racy.

 - Fix a recently introduced crash in the papr_scm driver in some
   configurations.

 - Remove include of <generated/compile.h> which is forbidden.

Thanks to Ariel Miculas, Chen Jingwen, Christophe Leroy, Erhard Furtner,
He Ying, Kees Cook, Masahiro Yamada, Nageswara R Sastry, Paul Mackerras,
Sachin Sant, Vaibhav Jain, and Wanming Hu.

* tag 'powerpc-5.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/32: Fix overread/overwrite of thread_struct via ptrace
  powerpc/book3e: get rid of #include <generated/compile.h>
  powerpc/kasan: Force thread size increase with KASAN
  powerpc/papr_scm: don't requests stats with '0' sized stats buffer
  powerpc: Don't select HAVE_IRQ_EXIT_ON_IRQ_STACK
  powerpc/kasan: Silence KASAN warnings in __get_wchan()
  powerpc/kasan: Mark more real-mode code as not to be instrumented
      95fc76c8
    • Linus Torvalds's avatar
      Merge tag 'net-5.19-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net · 825464e7
      Linus Torvalds authored 
      Pull networking fixes from Paolo Abeni:
 "Including fixes from bpf and netfilter.

  Current release - regressions:

   - eth: amt: fix possible null-ptr-deref in amt_rcv()

  Previous releases - regressions:

   - tcp: use alloc_large_system_hash() to allocate table_perturb

   - af_unix: fix a data-race in unix_dgram_peer_wake_me()

   - nfc: st21nfca: fix memory leaks in EVT_TRANSACTION handling

   - eth: ixgbe: fix unexpected VLAN rx in promisc mode on VF

  Previous releases - always broken:

   - ipv6: fix signed integer overflow in __ip6_append_data

   - netfilter:
       - nat: really support inet nat without l3 address
       - nf_tables: memleak flow rule from commit path

   - bpf: fix calling global functions from BPF_PROG_TYPE_EXT programs

   - openvswitch: fix misuse of the cached connection on tuple changes

   - nfc: nfcmrvl: fix memory leak in nfcmrvl_play_deferred

   - eth: altera: fix refcount leak in altera_tse_mdio_create

  Misc:

   - add Quentin Monnet to bpftool maintainers"

* tag 'net-5.19-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (45 commits)
  net: amd-xgbe: fix clang -Wformat warning
  tcp: use alloc_large_system_hash() to allocate table_perturb
  net: dsa: realtek: rtl8365mb: fix GMII caps for ports with internal PHY
  net: dsa: mv88e6xxx: correctly report serdes link failure
  net: dsa: mv88e6xxx: fix BMSR error to be consistent with others
  net: dsa: mv88e6xxx: use BMSR_ANEGCOMPLETE bit for filling an_complete
  net: altera: Fix refcount leak in altera_tse_mdio_create
  net: openvswitch: fix misuse of the cached connection on tuple changes
  net: ethernet: mtk_eth_soc: fix misuse of mem alloc interface netdev[napi]_alloc_frag
  ip_gre: test csum_start instead of transport header
  au1000_eth: stop using virt_to_bus()
  ipv6: Fix signed integer overflow in l2tp_ip6_sendmsg
  ipv6: Fix signed integer overflow in __ip6_append_data
  nfc: nfcmrvl: Fix memory leak in nfcmrvl_play_deferred
  nfc: st21nfca: fix incorrect sizing calculations in EVT_TRANSACTION
  nfc: st21nfca: fix memory leaks in EVT_TRANSACTION handling
  nfc: st21nfca: fix incorrect validating logic in EVT_TRANSACTION
  net: ipv6: unexport __init-annotated seg6_hmac_init()
  net: xfrm: unexport __init-annotated xfrm4_protocol_init()
  net: mdio: unexport __init-annotated mdio_bus_init()
  ...
      825464e7
    • Simon Horman's avatar
      docs: arm: tcm: Fix typo in description of TCM and MMU usage · 387c67af
      Simon Horman authored 
      Correct a typo in the description of interaction between
the TCM and MMU.

Found by inspection.
Signed-off-by: default avatarSimon Horman <simon.horman@corigine.com>
Link: https://lore.kernel.org/r/20220609184230.627958-1-simon.horman@corigine.comSigned-off-by: default avatarJonathan Corbet <corbet@lwn.net>
      387c67af
    • Linus Torvalds's avatar
      netfs: gcc-12: temporarily disable '-Wattribute-warning' for now · 507160f4
      Linus Torvalds authored 
      This is a pure band-aid so that I can continue merging stuff from people
while some of the gcc-12 fallout gets sorted out.

In particular, gcc-12 is very unhappy about the kinds of pointer
arithmetic tricks that netfs does, and that makes the fortify checks
trigger in afs and ceph:

  In function ‘fortify_memset_chk’,
      inlined from ‘netfs_i_context_init’ at include/linux/netfs.h:327:2,
      inlined from ‘afs_set_netfs_context’ at fs/afs/inode.c:61:2,
      inlined from ‘afs_root_iget’ at fs/afs/inode.c:543:2:
  include/linux/fortify-string.h:258:25: warning: call to ‘__write_overflow_field’ declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Wattribute-warning]
    258 |                         __write_overflow_field(p_size_field, size);
        |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

and the reason is that netfs_i_context_init() is passed a 'struct inode'
pointer, and then it does

        struct netfs_i_context *ctx = netfs_i_context(inode);

        memset(ctx, 0, sizeof(*ctx));

where that netfs_i_context() function just does pointer arithmetic on
the inode pointer, knowing that the netfs_i_context is laid out
immediately after it in memory.

This is all truly disgusting, since the whole "netfs_i_context is laid
out immediately after it in memory" is not actually remotely true in
general, but is just made to be that way for afs and ceph.

See for example fs/cifs/cifsglob.h:

  struct cifsInodeInfo {
        struct {
                /* These must be contiguous */
                struct inode    vfs_inode;      /* the VFS's inode record */
                struct netfs_i_context netfs_ctx; /* Netfslib context */
        };
	[...]

and realize that this is all entirely wrong, and the pointer arithmetic
that netfs_i_context() is doing is also very very wrong and wouldn't
give the right answer if netfs_ctx had different alignment rules from a
'struct inode', for example).

Anyway, that's just a long-winded way to say "the gcc-12 warning is
actually quite reasonable, and our code happens to work but is pretty
disgusting".

This is getting fixed properly, but for now I made the mistake of
thinking "the week right after the merge window tends to be calm for me
as people take a breather" and I did a sustem upgrade.  And I got gcc-12
as a result, so to continue merging fixes from people and not have the
end result drown in warnings, I am fixing all these gcc-12 issues I hit.

Including with these kinds of temporary fixes.

Cc: Kees Cook <keescook@chromium.org>
Cc: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/all/AEEBCF5D-8402-441D-940B-105AA718C71F@chromium.org/Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      507160f4
    • Linus Torvalds's avatar
      gcc-12: disable '-Warray-bounds' universally for now · f0be87c4
      Linus Torvalds authored 
      In commit 8b202ee2 ("s390: disable -Warray-bounds") the s390 people
disabled the '-Warray-bounds' warning for gcc-12, because the new logic
in gcc would cause warnings for their use of the S390_lowcore macro,
which accesses absolute pointers.

It turns out gcc-12 has many other issues in this area, so this takes
that s390 warning disable logic, and turns it into a kernel build config
entry instead.

Part of the intent is that we can make this all much more targeted, and
use this conflig flag to disable it in only particular configurations
that cause problems, with the s390 case as an example:

        select GCC12_NO_ARRAY_BOUNDS

and we could do that for other configuration cases that cause issues.

Or we could possibly use the CONFIG_CC_NO_ARRAY_BOUNDS thing in a more
targeted way, and disable the warning only for particular uses: again
the s390 case as an example:

  KBUILD_CFLAGS_DECOMPRESSOR += $(if $(CONFIG_CC_NO_ARRAY_BOUNDS),-Wno-array-bounds)

but this ends up just doing it globally in the top-level Makefile, since
the current issues are spread fairly widely all over:

  KBUILD_CFLAGS-$(CONFIG_CC_NO_ARRAY_BOUNDS) += -Wno-array-bounds

We'll try to limit this later, since the gcc-12 problems are rare enough
that *much* of the kernel can be built with it without disabling this
warning.

Cc: Kees Cook <keescook@chromium.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      f0be87c4
    • Linus Torvalds's avatar
      mellanox: mlx5: avoid uninitialized variable warning with gcc-12 · 842c3b3d
      Linus Torvalds authored 
      gcc-12 started warning about 'tracker' being used uninitialized:

  drivers/net/ethernet/mellanox/mlx5/core/lag/lag.c: In function ‘mlx5_do_bond’:
  drivers/net/ethernet/mellanox/mlx5/core/lag/lag.c:786:28: warning: ‘tracker’ is used uninitialized [-Wuninitialized]
    786 |         struct lag_tracker tracker;
        |                            ^~~~~~~

which seems to be because it doesn't track how the use (and
initialization) is bound by the 'do_bond' flag.

But admittedly that 'do_bond' usage is fairly complicated, and involves
passing it around as an argument to helper functions, so it's somewhat
understandable that gcc doesn't see how that all works.

This function could be rewritten to make the use of that tracker
variable more obviously safe, but for now I'm just adding the forced
initialization of it.
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      842c3b3d
    • Linus Torvalds's avatar
      gcc-12: disable '-Wdangling-pointer' warning for now · 49beadbd
      Linus Torvalds authored 
      While the concept of checking for dangling pointers to local variables
at function exit is really interesting, the gcc-12 implementation is not
compatible with reality, and results in false positives.

For example, gcc sees us putting things on a local list head allocated
on the stack, which involves exactly those kinds of pointers to the
local stack entry:

  In function ‘__list_add’,
      inlined from ‘list_add_tail’ at include/linux/list.h:102:2,
      inlined from ‘rebuild_snap_realms’ at fs/ceph/snap.c:434:2:
  include/linux/list.h:74:19: warning: storing the address of local variable ‘realm_queue’ in ‘*&realm_27(D)->rebuild_item.prev’ [-Wdangling-pointer=]
     74 |         new->prev = prev;
        |         ~~~~~~~~~~^~~~~~

But then gcc - understandably - doesn't really understand the big
picture how the doubly linked list works, so doesn't see how we then end
up emptying said list head in a loop and the pointer we added has been
removed.

Gcc also complains about us (intentionally) using this as a way to store
a kind of fake stack trace, eg

  drivers/acpi/acpica/utdebug.c:40:38: warning: storing the address of local variable ‘current_sp’ in ‘acpi_gbl_entry_stack_pointer’ [-Wdangling-pointer=]
     40 |         acpi_gbl_entry_stack_pointer = &current_sp;
        |         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~

which is entirely reasonable from a compiler standpoint, and we may want
to change those kinds of patterns, but not not.

So this is one of those "it would be lovely if the compiler were to
complain about us leaving dangling pointers to the stack", but not this
way.
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      49beadbd
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