linux-stable.git/arch/x86/tools, branch linux-5.4.y

x86/boot: Ignore relocations in .notes sections in walk_relocs() too

2024-06-16T11:28:33+00:00

[ Upstream commit 76e9762d66373354b45c33b60e9a53ef2a3c5ff2 ]

Commit:

  aaa8736370db ("x86, relocs: Ignore relocations in .notes section")

... only started ignoring the .notes sections in print_absolute_relocs(),
but the same logic should also by applied in walk_relocs() to avoid
such relocations.

[ mingo: Fixed various typos in the changelog, removed extra curly braces from the code. ]

Fixes: aaa8736370db ("x86, relocs: Ignore relocations in .notes section")
Fixes: 5ead97c84fa7 ("xen: Core Xen implementation")
Fixes: da1a679cde9b ("Add /sys/kernel/notes")
Signed-off-by: Guixiong Wei 
Signed-off-by: Ingo Molnar 
Reviewed-by: Kees Cook 
Link: https://lore.kernel.org/r/20240317150547.24910-1-weiguixiong@bytedance.com
Signed-off-by: Sasha Levin

x86, relocs: Ignore relocations in .notes section

2024-03-26T22:22:16+00:00

[ Upstream commit aaa8736370db1a78f0e8434344a484f9fd20be3b ]

When building with CONFIG_XEN_PV=y, .text symbols are emitted into
the .notes section so that Xen can find the "startup_xen" entry point.
This information is used prior to booting the kernel, so relocations
are not useful. In fact, performing relocations against the .notes
section means that the KASLR base is exposed since /sys/kernel/notes
is world-readable.

To avoid leaking the KASLR base without breaking unprivileged tools that
are expecting to read /sys/kernel/notes, skip performing relocations in
the .notes section. The values readable in .notes are then identical to
those found in System.map.

Reported-by: Guixiong Wei 
Closes: https://lore.kernel.org/all/20240218073501.54555-1-guixiongwei@gmail.com/
Fixes: 5ead97c84fa7 ("xen: Core Xen implementation")
Fixes: da1a679cde9b ("Add /sys/kernel/notes")
Reviewed-by: Juergen Gross 
Signed-off-by: Kees Cook 
Signed-off-by: Sasha Levin

x86/tools: Fix objdump version check again

2021-08-18T06:57:01+00:00

[ Upstream commit 839ad22f755132838f406751439363c07272ad87 ]

Skip (omit) any version string info that is parenthesized.

Warning: objdump version 15) is older than 2.19
Warning: Skipping posttest.

where 'objdump -v' says:
GNU objdump (GNU Binutils; SUSE Linux Enterprise 15) 2.35.1.20201123-7.18

Fixes: 8bee738bb1979 ("x86: Fix objdump version check in chkobjdump.awk for different formats.")
Signed-off-by: Randy Dunlap 
Signed-off-by: Thomas Gleixner 
Reviewed-by: Masami Hiramatsu 
Link: https://lore.kernel.org/r/20210731000146.2720-1-rdunlap@infradead.org
Signed-off-by: Sasha Levin

x86/build: Treat R_386_PLT32 relocation as R_386_PC32

2021-03-07T11:20:45+00:00

[ Upstream commit bb73d07148c405c293e576b40af37737faf23a6a ]

This is similar to commit

b21ebf2fb4cd ("x86: Treat R_X86_64_PLT32 as R_X86_64_PC32")

but for i386. As far as the kernel is concerned, R_386_PLT32 can be
treated the same as R_386_PC32.

R_386_PLT32/R_X86_64_PLT32 are PC-relative relocation types which
can only be used by branches. If the referenced symbol is defined
externally, a PLT will be used.

R_386_PC32/R_X86_64_PC32 are PC-relative relocation types which can be
used by address taking operations and branches. If the referenced symbol
is defined externally, a copy relocation/canonical PLT entry will be
created in the executable.

On x86-64, there is no PIC vs non-PIC PLT distinction and an
R_X86_64_PLT32 relocation is produced for both `call/jmp foo` and
`call/jmp foo@PLT` with newer (2018) GNU as/LLVM integrated assembler.
This avoids canonical PLT entries (st_shndx=0, st_value!=0).

On i386, there are 2 types of PLTs, PIC and non-PIC. Currently,
the GCC/GNU as convention is to use R_386_PC32 for non-PIC PLT and
R_386_PLT32 for PIC PLT. Copy relocations/canonical PLT entries
are possible ABI issues but GCC/GNU as will likely keep the status
quo because (1) the ABI is legacy (2) the change will drop a GNU
ld diagnostic for non-default visibility ifunc in shared objects.

clang-12 -fno-pic (since [1]) can emit R_386_PLT32 for compiler
generated function declarations, because preventing canonical PLT
entries is weighed over the rare ifunc diagnostic.

Further info for the more interested:

https://github.com/ClangBuiltLinux/linux/issues/1210
https://sourceware.org/bugzilla/show_bug.cgi?id=27169
https://github.com/llvm/llvm-project/commit/a084c0388e2a59b9556f2de0083333232da3f1d6 [1]

[ bp: Massage commit message. ]

Reported-by: Arnd Bergmann
Signed-off-by: Fangrui Song
Signed-off-by: Borislav Petkov
Reviewed-by: Nick Desaulniers
Reviewed-by: Nathan Chancellor
Tested-by: Nick Desaulniers
Tested-by: Nathan Chancellor
Tested-by: Sedat Dilek
Link: https://lkml.kernel.org/r/20210127205600.1227437-1-maskray@google.com
Signed-off-by: Sasha Levin

x86/insn: Fix awk regexp warnings

2019-11-29T09:09:45+00:00

commit 700c1018b86d0d4b3f1f2d459708c0cdf42b521d upstream.

gawk 5.0.1 generates the following regexp warnings:

  GEN      /home/sasha/torvalds/tools/objtool/arch/x86/lib/inat-tables.c
  awk: ../arch/x86/tools/gen-insn-attr-x86.awk:260: warning: regexp escape sequence `\:' is not a known regexp operator
  awk: ../arch/x86/tools/gen-insn-attr-x86.awk:350: (FILENAME=../arch/x86/lib/x86-opcode-map.txt FNR=41) warning: regexp escape sequence `\&' is  not a known regexp operator

Ealier versions of gawk are not known to generate these warnings. The
gawk manual referenced below does not list characters ':' and '&' as
needing escaping, so 'unescape' them. See

  https://www.gnu.org/software/gawk/manual/html_node/Escape-Sequences.html

for more info.

Running diff on the output generated by the script before and after
applying the patch reported no differences.

 [ bp: Massage commit message. ]

[ Caught the respective tools header discrepancy. ]
Reported-by: kbuild test robot 
Signed-off-by: Alexander Kapshuk 
Signed-off-by: Borislav Petkov 
Acked-by: Masami Hiramatsu 
Cc: "H. Peter Anvin" 
Cc: "Peter Zijlstra (Intel)" 
Cc: Arnaldo Carvalho de Melo 
Cc: Ingo Molnar 
Cc: Josh Poimboeuf 
Cc: Thomas Gleixner 
Cc: x86-ml 
Link: https://lkml.kernel.org/r/20190924044659.3785-1-alexander.kapshuk@gmail.com
Signed-off-by: Greg Kroah-Hartman

Merge branch 'x86-paravirt-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2019-07-09T00:34:44+00:00

Pull x86 paravirt updates from Ingo Molnar:
 "A handful of paravirt patching code enhancements to make it more
  robust against patching failures, and related cleanups and not so
  related cleanups - by Thomas Gleixner and myself"

* 'x86-paravirt-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/paravirt: Rename paravirt_patch_site::instrtype to paravirt_patch_site::type
  x86/paravirt: Standardize 'insn_buff' variable names
  x86/paravirt: Match paravirt patchlet field definition ordering to initialization ordering
  x86/paravirt: Replace the paravirt patch asm magic
  x86/paravirt: Unify the 32/64 bit paravirt patching code
  x86/paravirt: Detect over-sized patching bugs in paravirt_patch_call()
  x86/paravirt: Detect over-sized patching bugs in paravirt_patch_insns()
  x86/paravirt: Remove bogus extern declarations

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157

2019-05-30T18:26:37+00:00

Based on 3 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version this program is distributed in the
  hope that it will be useful but without any warranty without even
  the implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version [author] [kishon] [vijay] [abraham]
  [i] [kishon]@[ti] [com] this program is distributed in the hope that
  it will be useful but without any warranty without even the implied
  warranty of merchantability or fitness for a particular purpose see
  the gnu general public license for more details

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version [author] [graeme] [gregory]
  [gg]@[slimlogic] [co] [uk] [author] [kishon] [vijay] [abraham] [i]
  [kishon]@[ti] [com] [based] [on] [twl6030]_[usb] [c] [author] [hema]
  [hk] [hemahk]@[ti] [com] this program is distributed in the hope
  that it will be useful but without any warranty without even the
  implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1105 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Allison Randal 
Reviewed-by: Richard Fontana 
Reviewed-by: Kate Stewart 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.202006027@linutronix.de
Signed-off-by: Greg Kroah-Hartman

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156

2019-05-30T18:26:35+00:00

Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version this program is distributed in the
  hope that it will be useful but without any warranty without even
  the implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details you
  should have received a copy of the gnu general public license along
  with this program if not write to the free software foundation inc
  59 temple place suite 330 boston ma 02111 1307 usa

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1334 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Allison Randal 
Reviewed-by: Richard Fontana 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman

Merge branch 'x86-irq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2019-05-06T22:56:41+00:00

Pull x86 irq updates from Ingo Molnar:
 "Here are the main changes in this tree:

   - Introduce x86-64 IRQ/exception/debug stack guard pages to detect
     stack overflows immediately and deterministically.

   - Clean up over a decade worth of cruft accumulated.

  The outcome of this should be more clear-cut faults/crashes when any
  of the low level x86 CPU stacks overflow, instead of silent memory
  corruption and sporadic failures much later on"

* 'x86-irq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits)
  x86/irq: Fix outdated comments
  x86/irq/64: Remove stack overflow debug code
  x86/irq/64: Remap the IRQ stack with guard pages
  x86/irq/64: Split the IRQ stack into its own pages
  x86/irq/64: Init hardirq_stack_ptr during CPU hotplug
  x86/irq/32: Handle irq stack allocation failure proper
  x86/irq/32: Invoke irq_ctx_init() from init_IRQ()
  x86/irq/64: Rename irq_stack_ptr to hardirq_stack_ptr
  x86/irq/32: Rename hard/softirq_stack to hard/softirq_stack_ptr
  x86/irq/32: Make irq stack a character array
  x86/irq/32: Define IRQ_STACK_SIZE
  x86/dumpstack/64: Speedup in_exception_stack()
  x86/exceptions: Split debug IST stack
  x86/exceptions: Enable IST guard pages
  x86/exceptions: Disconnect IST index and stack order
  x86/cpu: Remove orig_ist array
  x86/cpu: Prepare TSS.IST setup for guard pages
  x86/dumpstack/64: Use cpu_entry_area instead of orig_ist
  x86/irq/64: Use cpu entry area instead of orig_ist
  x86/traps: Use cpu_entry_area instead of orig_ist
  ...

x86/paravirt: Standardize 'insn_buff' variable names

2019-04-29T14:05:49+00:00

We currently have 6 (!) separate naming variants to name temporary instruction
buffers that are used for code patching:

 - insnbuf
 - insnbuff
 - insn_buff
 - insn_buffer
 - ibuf
 - ibuffer

These are used as local variables, percpu fields and function parameters.

Standardize all the names to a single variant: 'insn_buff'.

Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Dave Hansen 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Juergen Gross 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Rik van Riel 
Cc: Thomas Gleixner 
Signed-off-by: Ingo Molnar