platform_external_elfutils/libdwfl/linux-kernel-modules.c, branch android10-release

libdwfl: Initialize notes early in intuit_kernel_bounds.

2019-02-28T21:19:03+00:00

We fake initialization of notes with an empty asm statement.  But
it is simpler and less confusing to just initialize notes just
before the fopen.

Signed-off-by: Mark Wielaard

Recognize and parse GNU Property notes.

2018-10-28T23:57:57+00:00

GNU Property notes are different from normal notes because they use
variable alignment/padding of their fields. They are 8 byte aligned,
but use 4 byte fields. The name is aligned at 4 bytes and padded so
that, the desc is aligned at 8 bytes. The whole note is padded to
8 bytes again. For normal notes all fields are both 4 bytes wide and
4 bytes aligned.

To recognize these new kind of ELF Notes a new Elf_Type is introduced,
ELF_T_NHDR8. This type is used in the xlate functions to determine
how to align and pad the various fields. Since the fields themselves
can now have different alignments we will have to keep track of the
current alignement and use either NOTE_ALIGN4 or NOTE_ALIGN8 to
determine the padding.

To set the correct Elf_Type on the Elf_Data we use either the section
sh_addralign or the segment p_align values. Assuming 8 means the
section or segment contains the new style notes, otherwise normal
notes.

When we cannot determine the "alignment" directly, like when parsing
special kernel sys files, we check the name "GNU" and type
"GNU_PROPERTY_TYPE_0" fields.

ebl_object_note now parses the new NT_GNU_PROPERTY_TYPE_0 and can
extract the GNU_PROPERTY_STACK_SIZE, GNU_PROPERTY_NO_COPY_ON_PROTECTED
and GNU_PROPERTY_X86_FEATURE_1_AND types GNU_PROPERTY_X86_FEATURE_1_IBT
and GNU_PROPERTY_X86_FEATURE_1_SHSTK.

Tests are added for extracting the note from sections or segments
as set by gcc -fcf-protection.

Signed-off-by: Mark Wielaard

Don't look for kernel version if not running on linux

2017-05-02T21:24:53+00:00

We don't want to use it, even if it exists.

Signed-off-by: Ulf Hermann 
Signed-off-by: Mark Wielaard

Include sys/types.h before fts.h

2017-04-25T21:50:46+00:00

The bad fts not only needs to be included before config.h, but also
requires various special types without including sys/types.h.

Signed-off-by: Ulf Hermann

Check for existence of mempcpy

2017-02-17T09:45:39+00:00

If it doesn't exist, provide a definition based on memcpy.

Signed-off-by: Ulf Hermann

Always use the same method to query the system page size

2017-02-15T14:32:45+00:00

This makes it easier to write a replacement for it on systems where
sysconf(3) doesn't exist.

Signed-off-by: Ulf Hermann

Only workaround fts.h if we have a bad version that doesn't handle LFS.

2016-11-23T19:51:35+00:00

Older versions of glibc included an fts implementation that didn't have
Large File System support. We worked around that in linux-kernel-modules.c
by including it early before config.h and then redefining some symbols
to get the 64-bit versions. This is somewhat fragile and not necessary
with newer glibc. If possible we want the 64bit fts version always.

Signed-off-by: Mark Wielaard

libdwfl: Check for kernel debuginfo file without .debug extension as well

2016-02-22T19:46:30+00:00

Elfutils, looking for kernel debuginfo file, tries to find it at
various places. If elfutils finds /boot/vmlinu*x* file, it checks
for debufginfo section. If debuginfo is not present, it saves it as
'main elf' and continue looking for debuginfo file having .debug
extension i.e. vmlinux-RELEASE.debug.

'Ubuntu on powerpc' installs kernel as /boot/vmlinux and installs
debuginfo without any extension as /usr/lib/debug/boot/vmlinux-RELEASE
and hence, elfutils is not able to find the debuginfo file.

Here is the launchpad bug for the same:
  https://bugs.launchpad.net/ubuntu/+source/systemtap/+bug/1537125

This patch adds functionality to search for a kernel or debuginfo file
both with and without .debug extension.

Signed-off-by: Ravi Bangoria 
Signed-off-by: Mark Wielaard

Simplify code and build now that zlib support is no longer optional.

2016-01-08T12:35:48+00:00

Now that we always require zlib support we don't need to conditionally
build or compile code that depends on it.

Signed-off-by: Mark Wielaard

Trust AC_SYS_LARGEFILE to provide large file support

2015-10-09T17:10:37+00:00

AC_SYS_LARGEFILE defines _FILE_OFFSET_BITS in config.h if needed for
LFS, and this automatically maps things like open to open64.  But quite
a few places used explicit 64-bit names, which won't work on platforms
like FreeBSD where off_t is always 64-bit and there are no foo64 names.
It's better to just trust that AC_SYS_LARGEFILE is doing it correctly.

But we can verify this too, as some file could easily forget to include
config.h.  The new tests/run-lfs-symbols.sh checks all build targets
against lfs-symbols (taken from lintian) to make sure everything was
implicitly mapped to 64-bit variants when _FILE_OFFSET_BITS is set.

Signed-off-by: Josh Stone