linux-stable.git/tools/objtool, branch linux-5.6.y

objtool: Fix stack offset tracking for indirect CFAs

2020-05-14T05:59:27+00:00

commit d8dd25a461e4eec7190cb9d66616aceacc5110ad upstream.

When the current frame address (CFA) is stored on the stack (i.e.,
cfa->base == CFI_SP_INDIRECT), objtool neglects to adjust the stack
offset when there are subsequent pushes or pops.  This results in bad
ORC data at the end of the ENTER_IRQ_STACK macro, when it puts the
previous stack pointer on the stack and does a subsequent push.

This fixes the following unwinder warning:

  WARNING: can't dereference registers at 00000000f0a6bdba for ip interrupt_entry+0x9f/0xa0

Fixes: 627fce14809b ("objtool: Add ORC unwind table generation")
Reported-by: Vince Weaver 
Reported-by: Dave Jones 
Reported-by: Steven Rostedt 
Reported-by: Vegard Nossum 
Reported-by: Joe Mario 
Reviewed-by: Miroslav Benes 
Signed-off-by: Josh Poimboeuf 
Signed-off-by: Ingo Molnar 
Cc: Andy Lutomirski 
Cc: Jann Horn 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: https://lore.kernel.org/r/853d5d691b29e250333332f09b8e27410b2d9924.1587808742.git.jpoimboe@redhat.com
Signed-off-by: Greg Kroah-Hartman

objtool: Support Clang non-section symbols in ORC dump

2020-05-02T06:51:00+00:00

[ Upstream commit 8782e7cab51b6bf01a5a86471dd82228af1ac185 ]

Historically, the relocation symbols for ORC entries have only been
section symbols:

  .text+0: sp:sp+8 bp:(und) type:call end:0

However, the Clang assembler is aggressive about stripping section
symbols.  In that case we will need to use function symbols:

  freezing_slow_path+0: sp:sp+8 bp:(und) type:call end:0

In preparation for the generation of such entries in "objtool orc
generate", add support for reading them in "objtool orc dump".

Signed-off-by: Josh Poimboeuf 
Signed-off-by: Borislav Petkov 
Reviewed-by: Miroslav Benes 
Acked-by: Peter Zijlstra (Intel) 
Link: https://lkml.kernel.org/r/b811b5eb1a42602c3b523576dc5efab9ad1c174d.1585761021.git.jpoimboe@redhat.com
Signed-off-by: Sasha Levin

objtool: Fix CONFIG_UBSAN_TRAP unreachable warnings

2020-05-02T06:51:00+00:00

[ Upstream commit bd841d6154f5f41f8a32d3c1b0bc229e326e640a ]

CONFIG_UBSAN_TRAP causes GCC to emit a UD2 whenever it encounters an
unreachable code path.  This includes __builtin_unreachable().  Because
the BUG() macro uses __builtin_unreachable() after it emits its own UD2,
this results in a double UD2.  In this case objtool rightfully detects
that the second UD2 is unreachable:

  init/main.o: warning: objtool: repair_env_string()+0x1c8: unreachable instruction

We weren't able to figure out a way to get rid of the double UD2s, so
just silence the warning.

Reported-by: Randy Dunlap 
Signed-off-by: Josh Poimboeuf 
Signed-off-by: Borislav Petkov 
Reviewed-by: Kees Cook 
Reviewed-by: Miroslav Benes 
Acked-by: Peter Zijlstra (Intel) 
Link: https://lkml.kernel.org/r/6653ad73c6b59c049211bd7c11ed3809c20ee9f5.1585761021.git.jpoimboe@redhat.com
Signed-off-by: Sasha Levin

objtool: Fix switch table detection in .text.unlikely

2020-04-23T08:37:50+00:00

commit b401efc120a399dfda1f4d2858a4de365c9b08ef upstream.

If a switch jump table's indirect branch is in a ".cold" subfunction in
.text.unlikely, objtool doesn't detect it, and instead prints a false
warning:

  drivers/media/v4l2-core/v4l2-ioctl.o: warning: objtool: v4l_print_format.cold()+0xd6: sibling call from callable instruction with modified stack frame
  drivers/hwmon/max6650.o: warning: objtool: max6650_probe.cold()+0xa5: sibling call from callable instruction with modified stack frame
  drivers/media/dvb-frontends/drxk_hard.o: warning: objtool: init_drxk.cold()+0x16f: sibling call from callable instruction with modified stack frame

Fix it by comparing the function, instead of the section and offset.

Fixes: 13810435b9a7 ("objtool: Support GCC 8's cold subfunctions")
Signed-off-by: Josh Poimboeuf 
Signed-off-by: Borislav Petkov 
Reviewed-by: Miroslav Benes 
Acked-by: Peter Zijlstra (Intel) 
Link: https://lkml.kernel.org/r/157c35d42ca9b6354bbb1604fe9ad7d1153ccb21.1585761021.git.jpoimboe@redhat.com
Signed-off-by: Greg Kroah-Hartman

objtool: Fix ARCH=x86_64 build error

2020-01-22T06:54:57+00:00

Building objtool with ARCH=x86_64 fails with:

   $make ARCH=x86_64 -C tools/objtool
   ...
     CC       arch/x86/decode.o
   arch/x86/decode.c:10:22: fatal error: asm/insn.h: No such file or directory
    #include 
                         ^
   compilation terminated.
   mv: cannot stat ‘arch/x86/.decode.o.tmp’: No such file or directory
   make[2]: *** [arch/x86/decode.o] Error 1
   ...

The root cause is that the command-line variable 'ARCH' cannot be
overridden.  It can be replaced by 'SRCARCH', which is defined in
'tools/scripts/Makefile.arch'.

Signed-off-by: Shile Zhang 
Signed-off-by: Josh Poimboeuf 
Signed-off-by: Ingo Molnar 
Reviewed-by: Kamalesh Babulal 
Link: https://lore.kernel.org/r/d5d11370ae116df6c653493acd300ec3d7f5e925.1579543924.git.jpoimboe@redhat.com

objtool: Silence build output

2020-01-22T06:54:34+00:00

The sync-check.sh script prints out the path due to a "cd -" at the end
of the script, even on silent builds. This isn't even needed, since the
script is executed in our build instead of sourced (so it won't change
the working directory of the surrounding build anyway).

Just remove the cd to make the build silent.

Fixes: 2ffd84ae973b ("objtool: Update sync-check.sh from perf's check-headers.sh")
Signed-off-by: Olof Johansson 
Signed-off-by: Josh Poimboeuf 
Signed-off-by: Ingo Molnar 
Link: https://lore.kernel.org/r/cb002857fafa8186cfb9c3e43fb62e4108a1bab9.1579543924.git.jpoimboe@redhat.com

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

2019-11-26T23:04:47+00:00

Pull perf updates from Ingo Molnar:
 "The main kernel side changes in this cycle were:

   - Various Intel-PT updates and optimizations (Alexander Shishkin)

   - Prohibit kprobes on Xen/KVM emulate prefixes (Masami Hiramatsu)

   - Add support for LSM and SELinux checks to control access to the
     perf syscall (Joel Fernandes)

   - Misc other changes, optimizations, fixes and cleanups - see the
     shortlog for details.

  There were numerous tooling changes as well - 254 non-merge commits.
  Here are the main changes - too many to list in detail:

   - Enhancements to core tooling infrastructure, perf.data, libperf,
     libtraceevent, event parsing, vendor events, Intel PT, callchains,
     BPF support and instruction decoding.

   - There were updates to the following tools:

        perf annotate
        perf diff
        perf inject
        perf kvm
        perf list
        perf maps
        perf parse
        perf probe
        perf record
        perf report
        perf script
        perf stat
        perf test
        perf trace

   - And a lot of other changes: please see the shortlog and Git log for
     more details"

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (279 commits)
  perf parse: Fix potential memory leak when handling tracepoint errors
  perf probe: Fix spelling mistake "addrees" -> "address"
  libtraceevent: Fix memory leakage in copy_filter_type
  libtraceevent: Fix header installation
  perf intel-bts: Does not support AUX area sampling
  perf intel-pt: Add support for decoding AUX area samples
  perf intel-pt: Add support for recording AUX area samples
  perf pmu: When using default config, record which bits of config were changed by the user
  perf auxtrace: Add support for queuing AUX area samples
  perf session: Add facility to peek at all events
  perf auxtrace: Add support for dumping AUX area samples
  perf inject: Cut AUX area samples
  perf record: Add aux-sample-size config term
  perf record: Add support for AUX area sampling
  perf auxtrace: Add support for AUX area sample recording
  perf auxtrace: Move perf_evsel__find_pmu()
  perf record: Add a function to test for kernel support for AUX area sampling
  perf tools: Add kernel AUX area sampling definitions
  perf/core: Make the mlock accounting simple again
  perf report: Jump to symbol source view from total cycles view
  ...

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

2019-11-26T18:42:40+00:00

Pull x86 asm updates from Ingo Molnar:
 "The main changes in this cycle were:

   - Cross-arch changes to move the linker sections for NOTES and
     EXCEPTION_TABLE into the RO_DATA area, where they belong on most
     architectures. (Kees Cook)

   - Switch the x86 linker fill byte from x90 (NOP) to 0xcc (INT3), to
     trap jumps into the middle of those padding areas instead of
     sliding execution. (Kees Cook)

   - A thorough cleanup of symbol definitions within x86 assembler code.
     The rather randomly named macros got streamlined around a
     (hopefully) straightforward naming scheme:

        SYM_START(name, linkage, align...)
        SYM_END(name, sym_type)

        SYM_FUNC_START(name)
        SYM_FUNC_END(name)

        SYM_CODE_START(name)
        SYM_CODE_END(name)

        SYM_DATA_START(name)
        SYM_DATA_END(name)

     etc - with about three times of these basic primitives with some
     label, local symbol or attribute variant, expressed via postfixes.

     No change in functionality intended. (Jiri Slaby)

   - Misc other changes, cleanups and smaller fixes"

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (67 commits)
  x86/entry/64: Remove pointless jump in paranoid_exit
  x86/entry/32: Remove unused resume_userspace label
  x86/build/vdso: Remove meaningless CFLAGS_REMOVE_*.o
  m68k: Convert missed RODATA to RO_DATA
  x86/vmlinux: Use INT3 instead of NOP for linker fill bytes
  x86/mm: Report actual image regions in /proc/iomem
  x86/mm: Report which part of kernel image is freed
  x86/mm: Remove redundant address-of operators on addresses
  xtensa: Move EXCEPTION_TABLE to RO_DATA segment
  powerpc: Move EXCEPTION_TABLE to RO_DATA segment
  parisc: Move EXCEPTION_TABLE to RO_DATA segment
  microblaze: Move EXCEPTION_TABLE to RO_DATA segment
  ia64: Move EXCEPTION_TABLE to RO_DATA segment
  h8300: Move EXCEPTION_TABLE to RO_DATA segment
  c6x: Move EXCEPTION_TABLE to RO_DATA segment
  arm64: Move EXCEPTION_TABLE to RO_DATA segment
  alpha: Move EXCEPTION_TABLE to RO_DATA segment
  x86/vmlinux: Move EXCEPTION_TABLE to RO_DATA segment
  x86/vmlinux: Actually use _etext for the end of the text segment
  vmlinux.lds.h: Allow EXCEPTION_TABLE to live in RO_DATA
  ...

ubsan, x86: Annotate and allow __ubsan_handle_shift_out_of_bounds() in uaccess regions

2019-10-28T09:43:00+00:00

The new check_zeroed_user() function uses variable shifts inside of a
user_access_begin()/user_access_end() section and that results in GCC
emitting __ubsan_handle_shift_out_of_bounds() calls, even though
through value range analysis it would be able to see that the UB in
question is impossible.

Annotate and whitelist this UBSAN function; continued use of
user_access_begin()/user_access_end() will undoubtedly result in
further uses of function.

Reported-by: Randy Dunlap 
Tested-by: Randy Dunlap 
Signed-off-by: Peter Zijlstra (Intel) 
Acked-by: Randy Dunlap 
Acked-by: Christian Brauner 
Cc: Josh Poimboeuf 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Stephen Rothwell 
Cc: Thomas Gleixner 
Cc: cyphar@cyphar.com
Cc: keescook@chromium.org
Cc: linux@rasmusvillemoes.dk
Fixes: f5a1a536fa14 ("lib: introduce copy_struct_from_user() helper")
Link: https://lkml.kernel.org/r/20191021131149.GA19358@hirez.programming.kicks-ass.net
Signed-off-by: Ingo Molnar

x86: xen: insn: Decode Xen and KVM emulate-prefix signature

2019-10-17T19:31:57+00:00

Decode Xen and KVM's emulate-prefix signature by x86 insn decoder.
It is called "prefix" but actually not x86 instruction prefix, so
this adds insn.emulate_prefix_size field instead of reusing
insn.prefixes.

If x86 decoder finds a special sequence of instructions of
XEN_EMULATE_PREFIX and 'ud2a; .ascii "kvm"', it just counts the
length, set insn.emulate_prefix_size and fold it with the next
instruction. In other words, the signature and the next instruction
is treated as a single instruction.

Signed-off-by: Masami Hiramatsu 
Signed-off-by: Peter Zijlstra (Intel) 
Acked-by: Josh Poimboeuf 
Cc: Juergen Gross 
Cc: x86@kernel.org
Cc: Boris Ostrovsky 
Cc: Ingo Molnar 
Cc: Stefano Stabellini 
Cc: Andrew Cooper 
Cc: Borislav Petkov 
Cc: xen-devel@lists.xenproject.org
Cc: Randy Dunlap 
Link: https://lkml.kernel.org/r/156777564986.25081.4964537658500952557.stgit@devnote2