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  1. Sep 27, 2024
    • Al Viro's avatar
      [tree-wide] finally take no_llseek out · cb787f4a
      Al Viro authored 
      
no_llseek had been defined to NULL two years ago, in commit 868941b1
("fs: remove no_llseek")

To quote that commit,

  At -rc1 we'll need do a mechanical removal of no_llseek -

  git grep -l -w no_llseek | grep -v porting.rst | while read i; do
	sed -i '/\<no_llseek\>/d' $i
  done

  would do it.

Unfortunately, that hadn't been done.  Linus, could you do that now, so
that we could finally put that thing to rest? All instances are of the
form
	.llseek = no_llseek,
so it's obviously safe.

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      cb787f4a
  3. Sep 16, 2024
  5. Sep 04, 2024
  7. Sep 02, 2024
    • Pavel Tikhomirov's avatar
      kmemleak-test: add percpu leak · e0b2fdb3
      Pavel Tikhomirov authored 
      Add a per-CPU memory leak, which will be reported like:

unreferenced object 0x3efa840195f8 (size 64):
  comm "modprobe", pid 4667, jiffies 4294688677
  hex dump (first 32 bytes on cpu 0):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace (crc 0):
    [<ffffffffa7fa87af>] pcpu_alloc+0x3df/0x840
    [<ffffffffc11642d9>] kmemleak_test_init+0x2c9/0x2f0 [kmemleak_test]
    [<ffffffffa7c02264>] do_one_initcall+0x44/0x300
    [<ffffffffa7de9e10>] do_init_module+0x60/0x240
    [<ffffffffa7deb946>] init_module_from_file+0x86/0xc0
    [<ffffffffa7deba99>] idempotent_init_module+0x109/0x2a0
    [<ffffffffa7debd2a>] __x64_sys_finit_module+0x5a/0xb0
    [<ffffffffa88f4f3a>] do_syscall_64+0x7a/0x160
    [<ffffffffa8a0012b>] entry_SYSCALL_64_after_hwframe+0x76/0x7e

Link: https://lkml.kernel.org/r/20240725041223.872472-3-ptikhomirov@virtuozzo.com


Signed-off-by: default avatarPavel Tikhomirov <ptikhomirov@virtuozzo.com>
Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Cc: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Cc: Chen Jun <chenjun102@huawei.com>
Cc: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      e0b2fdb3
  9. Aug 27, 2024
  11. Aug 15, 2024
  13. Aug 12, 2024
  15. Jul 17, 2024
  17. Jul 10, 2024
  19. Jul 08, 2024
  21. Jul 05, 2024
  23. Jul 04, 2024
  25. Jun 29, 2024
  27. Jun 14, 2024
  29. Jun 11, 2024
  31. Jun 04, 2024
  33. May 27, 2024
  35. May 23, 2024
    • Steven Rostedt (Google)'s avatar
      tracing/treewide: Remove second parameter of __assign_str() · 2c92ca84
      Steven Rostedt (Google) authored 
      With the rework of how the __string() handles dynamic strings where it
saves off the source string in field in the helper structure[1], the
assignment of that value to the trace event field is stored in the helper
value and does not need to be passed in again.

This means that with:

  __string(field, mystring)

Which use to be assigned with __assign_str(field, mystring), no longer
needs the second parameter and it is unused. With this, __assign_str()
will now only get a single parameter.

There's over 700 users of __assign_str() and because coccinelle does not
handle the TRACE_EVENT() macro I ended up using the following sed script:

  git grep -l __assign_str | while read a ; do
      sed -e 's/\(__assign_str([^,]*[^ ,]\) *,[^;]*/\1)/' $a > /tmp/test-file;
      mv /tmp/test-file $a;
  done

I then searched for __assign_str() that did not end with ';' as those
were multi line assignments that the sed script above would fail to catch.

Note, the same updates will need to be done for:

  __assign_str_len()
  __assign_rel_str()
  __assign_rel_str_len()

I tested this with both an allmodconfig and an allyesconfig (build only for both).

[1] https://lore.kernel.org/linux-trace-kernel/20240222211442.634192653@goodmis.org/

Link: https://lore.kernel.org/linux-trace-kernel/20240516133454.681ba6a0@rorschach.local.home



Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Julia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: default avatarJani Nikula <jani.nikula@intel.com>
Acked-by: Christian König <christian.koenig@amd.com> for the amdgpu parts.
Acked-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> #for
Acked-by: Rafael J. Wysocki <rafael@kernel.org> # for thermal
Acked-by: default avatarTakashi Iwai <tiwai@suse.de>
Acked-by: Darrick J. Wong <djwong@kernel.org>	# xfs
Tested-by: default avatarGuenter Roeck <linux@roeck-us.net>
      2c92ca84
  37. May 21, 2024
  39. May 13, 2024
  41. May 09, 2024
    • Masahiro Yamada's avatar
      kbuild: use $(src) instead of $(srctree)/$(src) for source directory · b1992c37
      Masahiro Yamada authored 
      
Kbuild conventionally uses $(obj)/ for generated files, and $(src)/ for
checked-in source files. It is merely a convention without any functional
difference. In fact, $(obj) and $(src) are exactly the same, as defined
in scripts/Makefile.build:

    src := $(obj)

When the kernel is built in a separate output directory, $(src) does
not accurately reflect the source directory location. While Kbuild
resolves this discrepancy by specifying VPATH=$(srctree) to search for
source files, it does not cover all cases. For example, when adding a
header search path for local headers, -I$(srctree)/$(src) is typically
passed to the compiler.

This introduces inconsistency between upstream and downstream Makefiles
because $(src) is used instead of $(srctree)/$(src) for the latter.

To address this inconsistency, this commit changes the semantics of
$(src) so that it always points to the directory in the source tree.

Going forward, the variables used in Makefiles will have the following
meanings:

  $(obj)     - directory in the object tree
  $(src)     - directory in the source tree  (changed by this commit)
  $(objtree) - the top of the kernel object tree
  $(srctree) - the top of the kernel source tree

Consequently, $(srctree)/$(src) in upstream Makefiles need to be replaced
with $(src).

Signed-off-by: default avatarMasahiro Yamada <masahiroy@kernel.org>
Reviewed-by: default avatarNicolas Schier <nicolas@fjasle.eu>
      b1992c37
  43. May 08, 2024
  45. May 04, 2024
  47. Apr 29, 2024
  49. Apr 16, 2024
  51. Mar 18, 2024
  53. Mar 08, 2024
  55. Mar 05, 2024
  57. Feb 29, 2024
    • Kees Cook's avatar
      bpf: Replace bpf_lpm_trie_key 0-length array with flexible array · 896880ff
      Kees Cook authored 
      
Replace deprecated 0-length array in struct bpf_lpm_trie_key with
flexible array. Found with GCC 13:

../kernel/bpf/lpm_trie.c:207:51: warning: array subscript i is outside array bounds of 'const __u8[0]' {aka 'const unsigned char[]'} [-Warray-bounds=]
  207 |                                        *(__be16 *)&key->data[i]);
      |                                                   ^~~~~~~~~~~~~
../include/uapi/linux/swab.h:102:54: note: in definition of macro '__swab16'
  102 | #define __swab16(x) (__u16)__builtin_bswap16((__u16)(x))
      |                                                      ^
../include/linux/byteorder/generic.h:97:21: note: in expansion of macro '__be16_to_cpu'
   97 | #define be16_to_cpu __be16_to_cpu
      |                     ^~~~~~~~~~~~~
../kernel/bpf/lpm_trie.c:206:28: note: in expansion of macro 'be16_to_cpu'
  206 |                 u16 diff = be16_to_cpu(*(__be16 *)&node->data[i]
^
      |                            ^~~~~~~~~~~
In file included from ../include/linux/bpf.h:7:
../include/uapi/linux/bpf.h:82:17: note: while referencing 'data'
   82 |         __u8    data[0];        /* Arbitrary size */
      |                 ^~~~

And found at run-time under CONFIG_FORTIFY_SOURCE:

  UBSAN: array-index-out-of-bounds in kernel/bpf/lpm_trie.c:218:49
  index 0 is out of range for type '__u8 [*]'

Changing struct bpf_lpm_trie_key is difficult since has been used by
userspace. For example, in Cilium:

	struct egress_gw_policy_key {
	        struct bpf_lpm_trie_key lpm_key;
	        __u32 saddr;
	        __u32 daddr;
	};

While direct references to the "data" member haven't been found, there
are static initializers what include the final member. For example,
the "{}" here:

        struct egress_gw_policy_key in_key = {
                .lpm_key = { 32 + 24, {} },
                .saddr   = CLIENT_IP,
                .daddr   = EXTERNAL_SVC_IP & 0Xffffff,
        };

To avoid the build time and run time warnings seen with a 0-sized
trailing array for struct bpf_lpm_trie_key, introduce a new struct
that correctly uses a flexible array for the trailing bytes,
struct bpf_lpm_trie_key_u8. As part of this, include the "header"
portion (which is just the "prefixlen" member), so it can be used
by anything building a bpf_lpr_trie_key that has trailing members that
aren't a u8 flexible array (like the self-test[1]), which is named
struct bpf_lpm_trie_key_hdr.

Unfortunately, C++ refuses to parse the __struct_group() helper, so
it is not possible to define struct bpf_lpm_trie_key_hdr directly in
struct bpf_lpm_trie_key_u8, so we must open-code the union directly.

Adjust the kernel code to use struct bpf_lpm_trie_key_u8 through-out,
and for the selftest to use struct bpf_lpm_trie_key_hdr. Add a comment
to the UAPI header directing folks to the two new options.

Reported-by: default avatarMark Rutland <mark.rutland@arm.com>
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarGustavo A. R. Silva <gustavoars@kernel.org>
Closes: https://paste.debian.net/hidden/ca500597/
Link: https://lore.kernel.org/all/202206281009.4332AA33@keescook/ [1]
Link: https://lore.kernel.org/bpf/20240222155612.it.533-kees@kernel.org
      896880ff
  59. Feb 12, 2024
  61. Feb 09, 2024
    • Linus Torvalds's avatar
      work around gcc bugs with 'asm goto' with outputs · 4356e9f8
      Linus Torvalds authored 
      We've had issues with gcc and 'asm goto' before, and we created a
'asm_volatile_goto()' macro for that in the past: see commits
3f0116c3 ("compiler/gcc4: Add quirk for 'asm goto' miscompilation
bug") and a9f18034 ("compiler/gcc4: Make quirk for
asm_volatile_goto() unconditional").

Then, much later, we ended up removing the workaround in commit
43c249ea ("compiler-gcc.h: remove ancient workaround for gcc PR
58670") because we no longer supported building the kernel with the
affected gcc versions, but we left the macro uses around.

Now, Sean Christopherson reports a new version of a very similar
problem, which is fixed by re-applying that ancient workaround.  But the
problem in question is limited to only the 'asm goto with outputs'
cases, so instead of re-introducing the old workaround as-is, let's
rename and limit the workaround to just that much less common case.

It looks like there are at least two separate issues that all hit in
this area:

 (a) some versions of gcc don't mark the asm goto as 'volatile' when it
     has outputs:

        https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98619
        https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110420

     which is easy to work around by just adding the 'volatile' by hand.

 (b) Internal compiler errors:

        https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110422



     which are worked around by adding the extra empty 'asm' as a
     barrier, as in the original workaround.

but the problem Sean sees may be a third thing since it involves bad
code generation (not an ICE) even with the manually added 'volatile'.

but the same old workaround works for this case, even if this feels a
bit like voodoo programming and may only be hiding the issue.

Reported-and-tested-by: default avatarSean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/all/20240208220604.140859-1-seanjc@google.com/


Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Uros Bizjak <ubizjak@gmail.com>
Cc: Jakub Jelinek <jakub@redhat.com>
Cc: Andrew Pinski <quic_apinski@quicinc.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      4356e9f8
  63. Jan 24, 2024
  65. Jan 18, 2024