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  1. 22 Apr, 2022 3 commits
    • Peter Zijlstra's avatar
      Merge branch 'tip/x86/urgent' · 3398b12d
      Peter Zijlstra authored 
      Merge the x86/urgent objtool/IBT changes as a base
Signed-off-by: default avatarPeter Zijlstra <peterz@infradead.org>
      3398b12d
    • Peter Zijlstra's avatar
      objtool: Fix code relocs vs weak symbols · 4abff6d4
      Peter Zijlstra authored 
      Occasionally objtool driven code patching (think .static_call_sites
.retpoline_sites etc..) goes sideways and it tries to patch an
instruction that doesn't match.

Much head-scatching and cursing later the problem is as outlined below
and affects every section that objtool generates for us, very much
including the ORC data. The below uses .static_call_sites because it's
convenient for demonstration purposes, but as mentioned the ORC
sections, .retpoline_sites and __mount_loc are all similarly affected.

Consider:

foo-weak.c:

  extern void __SCT__foo(void);

  __attribute__((weak)) void foo(void)
  {
	  return __SCT__foo();
  }

foo.c:

  extern void __SCT__foo(void);
  extern void my_foo(void);

  void foo(void)
  {
	  my_foo();
	  return __SCT__foo();
  }

These generate the obvious code
(gcc -O2 -fcf-protection=none -fno-asynchronous-unwind-tables -c foo*.c):

foo-weak.o:
0000000000000000 <foo>:
   0:   e9 00 00 00 00          jmpq   5 <foo+0x5>      1: R_X86_64_PLT32       __SCT__foo-0x4

foo.o:
0000000000000000 <foo>:
   0:   48 83 ec 08             sub    $0x8,%rsp
   4:   e8 00 00 00 00          callq  9 <foo+0x9>      5: R_X86_64_PLT32       my_foo-0x4
   9:   48 83 c4 08             add    $0x8,%rsp
   d:   e9 00 00 00 00          jmpq   12 <foo+0x12>    e: R_X86_64_PLT32       __SCT__foo-0x4

Now, when we link these two files together, you get something like
(ld -r -o foos.o foo-weak.o foo.o):

foos.o:
0000000000000000 <foo-0x10>:
   0:   e9 00 00 00 00          jmpq   5 <foo-0xb>      1: R_X86_64_PLT32       __SCT__foo-0x4
   5:   66 2e 0f 1f 84 00 00 00 00 00   nopw   %cs:0x0(%rax,%rax,1)
   f:   90                      nop

0000000000000010 <foo>:
  10:   48 83 ec 08             sub    $0x8,%rsp
  14:   e8 00 00 00 00          callq  19 <foo+0x9>     15: R_X86_64_PLT32      my_foo-0x4
  19:   48 83 c4 08             add    $0x8,%rsp
  1d:   e9 00 00 00 00          jmpq   22 <foo+0x12>    1e: R_X86_64_PLT32      __SCT__foo-0x4

Noting that ld preserves the weak function text, but strips the symbol
off of it (hence objdump doing that funny negative offset thing). This
does lead to 'interesting' unused code issues with objtool when ran on
linked objects, but that seems to be working (fingers crossed).

So far so good.. Now lets consider the objtool static_call output
section (readelf output, old binutils):

foo-weak.o:

Relocation section '.rela.static_call_sites' at offset 0x2c8 contains 1 entry:
    Offset             Info             Type               Symbol's Value  Symbol's Name + Addend
0000000000000000  0000000200000002 R_X86_64_PC32          0000000000000000 .text + 0
0000000000000004  0000000d00000002 R_X86_64_PC32          0000000000000000 __SCT__foo + 1

foo.o:

Relocation section '.rela.static_call_sites' at offset 0x310 contains 2 entries:
    Offset             Info             Type               Symbol's Value  Symbol's Name + Addend
0000000000000000  0000000200000002 R_X86_64_PC32          0000000000000000 .text + d
0000000000000004  0000000d00000002 R_X86_64_PC32          0000000000000000 __SCT__foo + 1

foos.o:

Relocation section '.rela.static_call_sites' at offset 0x430 contains 4 entries:
    Offset             Info             Type               Symbol's Value  Symbol's Name + Addend
0000000000000000  0000000100000002 R_X86_64_PC32          0000000000000000 .text + 0
0000000000000004  0000000d00000002 R_X86_64_PC32          0000000000000000 __SCT__foo + 1
0000000000000008  0000000100000002 R_X86_64_PC32          0000000000000000 .text + 1d
000000000000000c  0000000d00000002 R_X86_64_PC32          0000000000000000 __SCT__foo + 1

So we have two patch sites, one in the dead code of the weak foo and one
in the real foo. All is well.

*HOWEVER*, when the toolchain strips unused section symbols it
generates things like this (using new enough binutils):

foo-weak.o:

Relocation section '.rela.static_call_sites' at offset 0x2c8 contains 1 entry:
    Offset             Info             Type               Symbol's Value  Symbol's Name + Addend
0000000000000000  0000000200000002 R_X86_64_PC32          0000000000000000 foo + 0
0000000000000004  0000000d00000002 R_X86_64_PC32          0000000000000000 __SCT__foo + 1

foo.o:

Relocation section '.rela.static_call_sites' at offset 0x310 contains 2 entries:
    Offset             Info             Type               Symbol's Value  Symbol's Name + Addend
0000000000000000  0000000200000002 R_X86_64_PC32          0000000000000000 foo + d
0000000000000004  0000000d00000002 R_X86_64_PC32          0000000000000000 __SCT__foo + 1

foos.o:

Relocation section '.rela.static_call_sites' at offset 0x430 contains 4 entries:
    Offset             Info             Type               Symbol's Value  Symbol's Name + Addend
0000000000000000  0000000100000002 R_X86_64_PC32          0000000000000000 foo + 0
0000000000000004  0000000d00000002 R_X86_64_PC32          0000000000000000 __SCT__foo + 1
0000000000000008  0000000100000002 R_X86_64_PC32          0000000000000000 foo + d
000000000000000c  0000000d00000002 R_X86_64_PC32          0000000000000000 __SCT__foo + 1

And now we can see how that foos.o .static_call_sites goes side-ways, we
now have _two_ patch sites in foo. One for the weak symbol at foo+0
(which is no longer a static_call site!) and one at foo+d which is in
fact the right location.

This seems to happen when objtool cannot find a section symbol, in which
case it falls back to any other symbol to key off of, however in this
case that goes terribly wrong!

As such, teach objtool to create a section symbol when there isn't
one.

Fixes: 44f6a7c0 ("objtool: Fix seg fault with Clang non-section symbols")
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: default avatarJosh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/20220419203807.655552918@infradead.org
      4abff6d4
    • Peter Zijlstra's avatar
      objtool: Fix type of reloc::addend · c087c6e7
      Peter Zijlstra authored 
      Elf{32,64}_Rela::r_addend is of type: Elf{32,64}_Sword, that means
that our reloc::addend needs to be long or face tuncation issues when
we do elf_rebuild_reloc_section():

  - 107:  48 b8 00 00 00 00 00 00 00 00   movabs $0x0,%rax        109: R_X86_64_64        level4_kernel_pgt+0x80000067
  + 107:  48 b8 00 00 00 00 00 00 00 00   movabs $0x0,%rax        109: R_X86_64_64        level4_kernel_pgt-0x7fffff99

Fixes: 627fce14 ("objtool: Add ORC unwind table generation")
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: default avatarJosh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/20220419203807.596871927@infradead.org
      c087c6e7
  3. 19 Apr, 2022 20 commits
  5. 17 Apr, 2022 10 commits
  7. 16 Apr, 2022 6 commits
    • Linus Torvalds's avatar
      Merge tag 'soc-fixes-5.18-2' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc · 70a0cec8
      Linus Torvalds authored 
      Pull ARM SoC fixes from Arnd Bergmann:
 "There are a number of SoC bugfixes that came in since the merge
  window, and more of them are already pending.

  This batch includes:

   - A boot time regression fix for davinci that triggered on
     multi_v5_defconfig when booting any platform

   - Defconfig updates to address removed features, changed symbol names
     or dependencies, for gemini, ux500, and pxa

   - Email address changes for Krzysztof Kozlowski

   - Build warning fixes for ep93xx and iop32x

   - Devicetree warning fixes across many platforms

   - Minor bugfixes for the reset controller, memory controller and SCMI
     firmware subsystems plus the versatile-express board"

* tag 'soc-fixes-5.18-2' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (34 commits)
  ARM: config: Update Gemini defconfig
  arm64: dts: qcom/sdm845-shift-axolotl: Fix boolean properties with values
  ARM: dts: align SPI NOR node name with dtschema
  ARM: dts: Fix more boolean properties with values
  arm/arm64: dts: qcom: Fix boolean properties with values
  arm64: dts: imx: Fix imx8*-var-som touchscreen property sizes
  arm: dts: imx: Fix boolean properties with values
  arm64: dts: tegra: Fix boolean properties with values
  arm: dts: at91: Fix boolean properties with values
  arm: configs: imote2: Drop defconfig as board support dropped.
  ep93xx: clock: Don't use plain integer as NULL pointer
  ep93xx: clock: Fix UAF in ep93xx_clk_register_gate()
  ARM: vexpress/spc: Fix all the kernel-doc build warnings
  ARM: vexpress/spc: Fix kernel-doc build warning for ve_spc_cpu_in_wfi
  ARM: config: u8500: Re-enable AB8500 battery charging
  ARM: config: u8500: Add some common hardware
  memory: fsl_ifc: populate child nodes of buses and mfd devices
  ARM: config: Refresh U8500 defconfig
  firmware: arm_scmi: Fix sparse warnings in OPTEE transport driver
  firmware: arm_scmi: Replace zero-length array with flexible-array member
  ...
      70a0cec8
    • Linus Torvalds's avatar
      Merge tag 'random-5.18-rc3-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random · 92edbe32
      Linus Torvalds authored 
      Pull random number generator fixes from Jason Donenfeld:

 - Per your suggestion, random reads now won't fail if there's a page
   fault after some non-zero amount of data has been read, which makes
   the behavior consistent with all other reads in the kernel.

 - Rather than an inconsistent mix of random_get_entropy() returning an
   unsigned long or a cycles_t, now it just returns an unsigned long.

 - A memcpy() was replaced with an memmove(), because the addresses are
   sometimes overlapping. In practice the destination is always before
   the source, so not really an issue, but better to be correct than
   not.

* tag 'random-5.18-rc3-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random:
  random: use memmove instead of memcpy for remaining 32 bytes
  random: make random_get_entropy() return an unsigned long
  random: allow partial reads if later user copies fail
      92edbe32
    • Linus Torvalds's avatar
      Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi · 90ea17a9
      Linus Torvalds authored 
      Pull SCSI fixes from James Bottomley:
 "13 fixes, all in drivers.

  The most extensive changes are in the iscsi series (affecting drivers
  qedi, cxgbi and bnx2i), the next most is scsi_debug, but that's just a
  simple revert and then minor updates to pm80xx"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: iscsi: MAINTAINERS: Add Mike Christie as co-maintainer
  scsi: qedi: Fix failed disconnect handling
  scsi: iscsi: Fix NOP handling during conn recovery
  scsi: iscsi: Merge suspend fields
  scsi: iscsi: Fix unbound endpoint error handling
  scsi: iscsi: Fix conn cleanup and stop race during iscsid restart
  scsi: iscsi: Fix endpoint reuse regression
  scsi: iscsi: Release endpoint ID when its freed
  scsi: iscsi: Fix offload conn cleanup when iscsid restarts
  scsi: iscsi: Move iscsi_ep_disconnect()
  scsi: pm80xx: Enable upper inbound, outbound queues
  scsi: pm80xx: Mask and unmask upper interrupt vectors 32-63
  Revert "scsi: scsi_debug: Address races following module load"
      90ea17a9
    • Bartosz Golaszewski's avatar
      Merge tag 'intel-gpio-v5.18-2' of... · 0ebb4fbe
      Bartosz Golaszewski authored 
      Merge tag 'intel-gpio-v5.18-2' of gitolite.kernel.org:pub/scm/linux/kernel/git/andy/linux-gpio-intel into gpio/for-current

intel-gpio for v5.18-2

* Couple of fixes related to handling unsigned value of the pin from ACPI

gpiolib:
 -  acpi: Convert type for pin to be unsigned
 -  acpi: use correct format characters
      0ebb4fbe
    • Linus Torvalds's avatar
      Merge tag 'dma-mapping-5.18-2' of git://git.infradead.org/users/hch/dma-mapping · b0086839
      Linus Torvalds authored 
      Pull dma-mapping fix from Christoph Hellwig:

 - avoid a double memory copy for swiotlb (Chao Gao)

* tag 'dma-mapping-5.18-2' of git://git.infradead.org/users/hch/dma-mapping:
  dma-direct: avoid redundant memory sync for swiotlb
      b0086839
    • Jason A. Donenfeld's avatar
      random: use memmove instead of memcpy for remaining 32 bytes · 35a33ff3
      Jason A. Donenfeld authored 
      In order to immediately overwrite the old key on the stack, before
servicing a userspace request for bytes, we use the remaining 32 bytes
of block 0 as the key. This means moving indices 8,9,a,b,c,d,e,f ->
4,5,6,7,8,9,a,b. Since 4 < 8, for the kernel implementations of
memcpy(), this doesn't actually appear to be a problem in practice. But
relying on that characteristic seems a bit brittle. So let's change that
to a proper memmove(), which is the by-the-books way of handling
overlapping memory copies.
Reviewed-by: default avatarDominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: default avatarJason A. Donenfeld <Jason@zx2c4.com>
      35a33ff3
  9. 15 Apr, 2022 1 commit
    • Linus Torvalds's avatar
      Merge branch 'akpm' (patches from Andrew) · 59250f8a
      Linus Torvalds authored 
      Merge misc fixes from Andrew Morton:
 "14 patches.

  Subsystems affected by this patch series: MAINTAINERS, binfmt, and
  mm (tmpfs, secretmem, kasan, kfence, pagealloc, zram, compaction,
  hugetlb, vmalloc, and kmemleak)"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  mm: kmemleak: take a full lowmem check in kmemleak_*_phys()
  mm/vmalloc: fix spinning drain_vmap_work after reading from /proc/vmcore
  revert "fs/binfmt_elf: use PT_LOAD p_align values for static PIE"
  revert "fs/binfmt_elf: fix PT_LOAD p_align values for loaders"
  hugetlb: do not demote poisoned hugetlb pages
  mm: compaction: fix compiler warning when CONFIG_COMPACTION=n
  mm: fix unexpected zeroed page mapping with zram swap
  mm, page_alloc: fix build_zonerefs_node()
  mm, kfence: support kmem_dump_obj() for KFENCE objects
  kasan: fix hw tags enablement when KUNIT tests are disabled
  irq_work: use kasan_record_aux_stack_noalloc() record callstack
  mm/secretmem: fix panic when growing a memfd_secret
  tmpfs: fix regressions from wider use of ZERO_PAGE
  MAINTAINERS: Broadcom internal lists aren't maintainers
      59250f8a
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