linux.git/tools/objtool, branch v4.14.30

objtool: Fix 32-bit build

2018-03-15T09:54:38+00:00

commit 63474dc4ac7ed3848a4786b9592dd061901f606d upstream.

Fix the objtool build when cross-compiling a 64-bit kernel on a 32-bit
host.  This also simplifies read_retpoline_hints() a bit and makes its
implementation similar to most of the other annotation reading
functions.

Reported-by: Sven Joachim 
Signed-off-by: Josh Poimboeuf 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Fixes: b5bc2231b8ad ("objtool: Add retpoline validation")
Link: http://lkml.kernel.org/r/2ca46c636c23aa9c9d57d53c75de4ee3ddf7a7df.1520380691.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

objtool: Fix another switch table detection issue

2018-03-15T09:54:38+00:00

commit 1402fd8ed7e5bda1b3e7613b70780b0db392d1e6 upstream.

Continue the switch table detection whack-a-mole.  Add a check to
distinguish KASAN data reads from switch data reads.  The switch jump
tables in .rodata have relocations associated with them.

This fixes the following warning:

  crypto/asymmetric_keys/x509_cert_parser.o: warning: objtool: x509_note_pkey_algo()+0xa4: sibling call from callable instruction with modified stack frame

Reported-by: Arnd Bergmann 
Signed-off-by: Josh Poimboeuf 
Signed-off-by: Thomas Gleixner 
Tested-by: Arnd Bergmann 
Cc: Peter Zijlstra 
Link: https://lkml.kernel.org/r/d7c8853022ad47d158cb81e953a40469fc08a95e.1519784382.git.jpoimboe@redhat.com
Signed-off-by: Greg Kroah-Hartman

objtool: Add module specific retpoline rules

2018-03-15T09:54:38+00:00

commit ca41b97ed9124fd62323a162de5852f6e28f94b8 upstream.

David allowed retpolines in .init.text, except for modules, which will
trip up objtool retpoline validation, fix that.

Requested-by: David Woodhouse 
Signed-off-by: Peter Zijlstra (Intel) 
Acked-by: Thomas Gleixner 
Acked-by: Josh Poimboeuf 
Cc: Andy Lutomirski 
Cc: Arjan van de Ven 
Cc: Borislav Petkov 
Cc: Dan Williams 
Cc: Dave Hansen 
Cc: David Woodhouse 
Cc: Greg Kroah-Hartman 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

objtool: Add retpoline validation

2018-03-15T09:54:37+00:00

commit b5bc2231b8ad4387c9641f235ca0ad8cd300b6df upstream.

David requested a objtool validation pass for CONFIG_RETPOLINE=y enabled
builds, where it validates no unannotated indirect  jumps or calls are
left.

Add an additional .discard.retpoline_safe section to allow annotating
the few indirect sites that are required and safe.

Requested-by: David Woodhouse 
Signed-off-by: Peter Zijlstra (Intel) 
Reviewed-by: David Woodhouse 
Acked-by: Thomas Gleixner 
Acked-by: Josh Poimboeuf 
Cc: Andy Lutomirski 
Cc: Arjan van de Ven 
Cc: Borislav Petkov 
Cc: Dan Williams 
Cc: Dave Hansen 
Cc: Greg Kroah-Hartman 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

objtool: Use existing global variables for options

2018-03-15T09:54:37+00:00

commit 43a4525f80534530077683f6472d8971646b0ace upstream.

Use the existing global variables instead of passing them around and
creating duplicate global variables.

Signed-off-by: Peter Zijlstra (Intel) 
Acked-by: Thomas Gleixner 
Acked-by: Josh Poimboeuf 
Cc: Andy Lutomirski 
Cc: Arjan van de Ven 
Cc: Borislav Petkov 
Cc: Dan Williams 
Cc: Dave Hansen 
Cc: David Woodhouse 
Cc: Greg Kroah-Hartman 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

objtool: Fix segfault in ignore_unreachable_insn()

2018-02-22T14:42:22+00:00

commit fe24e27128252c230a34a6c628da2bf1676781ea upstream.

Peter Zijlstra's patch for converting WARN() to use UD2 triggered a
bunch of false "unreachable instruction" warnings, which then triggered
a seg fault in ignore_unreachable_insn().

The seg fault happened when it tried to dereference a NULL 'insn->func'
pointer.  Thanks to static_cpu_has(), some functions can jump to a
non-function area in the .altinstr_aux section.  That breaks
ignore_unreachable_insn()'s assumption that it's always inside the
original function.

Make sure ignore_unreachable_insn() only follows jumps within the
current function.

Reported-by: Borislav Petkov 
Signed-off-by: Josh Poimboeuf 
Signed-off-by: Peter Zijlstra (Intel) 
Cc: Andy Lutomirski 
Cc: Arjan van de Ven 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: kbuild test robot 
Link: http://lkml.kernel.org/r/bace77a60d5af9b45eddb8f8fb9c776c8de657ef.1518130694.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

objtool: Fix switch-table detection

2018-02-16T19:23:09+00:00

commit 99ce7962d52d1948ad6f2785e308d48e76e0a6ef upstream.

Linus reported that GCC-7.3 generated a switch-table construct that
confused objtool. It turns out that, in particular due to KASAN, it is
possible to have unrelated .rodata usage in between the .rodata setup
for the switch-table and the following indirect jump.

The simple linear reverse search from the indirect jump would hit upon
the KASAN .rodata usage first and fail to find a switch_table,
resulting in a spurious 'sibling call with modified stack frame'
warning.

Fix this by creating a 'jump-stack' which we can 'unwind' during
reversal, thereby skipping over much of the in-between code.

This is not fool proof by any means, but is sufficient to make the
known cases work. Future work would be to construct more comprehensive
flow analysis code.

Reported-and-tested-by: Linus Torvalds 
Signed-off-by: Peter Zijlstra (Intel) 
Acked-by: Josh Poimboeuf 
Cc: Borislav Petkov 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/20180208130232.GF25235@hirez.programming.kicks-ass.net
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

objtool: Warn on stripped section symbol

2018-02-07T19:12:21+00:00

commit 830c1e3d16b2c1733cd1ec9c8f4d47a398ae31bc

With the following fix:

  2a0098d70640 ("objtool: Fix seg fault with gold linker")

... a seg fault was avoided, but the original seg fault condition in
objtool wasn't fixed.  Replace the seg fault with an error message.

Suggested-by: Ingo Molnar 
Signed-off-by: Josh Poimboeuf 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Dave Hansen 
Cc: David Woodhouse 
Cc: Greg Kroah-Hartman 
Cc: Guenter Roeck 
Cc: H. Peter Anvin 
Cc: Juergen Gross 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/dc4585a70d6b975c99fc51d1957ccdde7bd52f3a.1517284349.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

objtool: Add support for alternatives at the end of a section

2018-02-07T19:12:21+00:00

commit 17bc33914bcc98ba3c6b426fd1c49587a25c0597

Now that the previous patch gave objtool the ability to read retpoline
alternatives, it shows a new warning:

  arch/x86/entry/entry_64.o: warning: objtool: .entry_trampoline: don't know how to handle alternatives at end of section

This is due to the JMP_NOSPEC in entry_SYSCALL_64_trampoline().

Previously, objtool ignored this situation because it wasn't needed, and
it would have required a bit of extra code.  Now that this case exists,
add proper support for it.

Signed-off-by: Josh Poimboeuf 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Dave Hansen 
Cc: David Woodhouse 
Cc: Greg Kroah-Hartman 
Cc: Guenter Roeck 
Cc: H. Peter Anvin 
Cc: Juergen Gross 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/2a30a3c2158af47d891a76e69bb1ef347e0443fd.1517284349.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

objtool: Improve retpoline alternative handling

2018-02-07T19:12:21+00:00

commit a845c7cf4b4cb5e9e3b2823867892b27646f3a98

Currently objtool requires all retpolines to be:

  a) patched in with alternatives; and

  b) annotated with ANNOTATE_NOSPEC_ALTERNATIVE.

If you forget to do both of the above, objtool segfaults trying to
dereference a NULL 'insn->call_dest' pointer.

Avoid that situation and print a more helpful error message:

  quirks.o: warning: objtool: efi_delete_dummy_variable()+0x99: unsupported intra-function call
  quirks.o: warning: objtool: If this is a retpoline, please patch it in with alternatives and annotate it with ANNOTATE_NOSPEC_ALTERNATIVE.

Future improvements can be made to make objtool smarter with respect to
retpolines, but this is a good incremental improvement for now.

Reported-and-tested-by: Guenter Roeck 
Signed-off-by: Josh Poimboeuf 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Dave Hansen 
Cc: David Woodhouse 
Cc: Greg Kroah-Hartman 
Cc: H. Peter Anvin 
Cc: Juergen Gross 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/819e50b6d9c2e1a22e34c1a636c0b2057cc8c6e5.1517284349.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman