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[PATCH] Recognize NT_VERSION notes.
- From: Mark Wielaard <mark at klomp dot org>
- To: elfutils-devel at sourceware dot org
- Cc: Mark Wielaard <mark at klomp dot org>
- Date: Mon, 12 Nov 2018 00:08:25 +0100
- Subject: [PATCH] Recognize NT_VERSION notes.
NT_VERSION notes are emitted by the gas .version directive.
They have an empty description and (ab)use the owner name to store the
version data string.
Signed-off-by: Mark Wielaard <mark@klomp.org>
---
libebl/ChangeLog | 9 +++++++++
libebl/eblobjnote.c | 10 +++++++++-
libebl/eblobjnotetypename.c | 8 +++++++-
libebl/libebl.h | 4 ++--
src/ChangeLog | 7 +++++++
src/elflint.c | 27 +++++++++++++++++++++------
src/readelf.c | 1 +
tests/ChangeLog | 5 +++++
tests/run-readelf-n.sh | 19 ++++++++++++++++++-
9 files changed, 79 insertions(+), 11 deletions(-)
diff --git a/libebl/ChangeLog b/libebl/ChangeLog
index 120c84c06..076596f09 100644
--- a/libebl/ChangeLog
+++ b/libebl/ChangeLog
@@ -1,3 +1,12 @@
+2018-11-11 Mark Wielaard <mark@klomp.org>
+
+ * eblobjnote.c (ebl_object_note): Recognize NT_VERSION with zero
+ descriptor. Add explicit "GNU" name check.
+ * eblobjnotetypename.c (ebl_object_note_type_name): Add extra
+ argument descsz. Recognize NT_VERSION using descsz. With "GNU"
+ name it is NT_GNU_ABI_TAG.
+ * libebl.h (ebl_object_note_type_name): Add extra argument descsz.
+
2018-10-18 Mark Wielaard <mark@klomp.org>
* eblobjnote.c (ebl_object_note): Handle NT_GNU_PROPERTY_TYPE_0.
diff --git a/libebl/eblobjnote.c b/libebl/eblobjnote.c
index 57e9f52f4..8fda7d992 100644
--- a/libebl/eblobjnote.c
+++ b/libebl/eblobjnote.c
@@ -135,6 +135,14 @@ ebl_object_note (Ebl *ebl, const char *name, uint32_t type,
return;
}
+ /* NT_VERSION doesn't have any info. All data is in the name. */
+ if (descsz == 0 && type == NT_VERSION)
+ return;
+
+ /* Everything else should have the "GNU" owner name. */
+ if (strcmp ("GNU", name) != 0)
+ return;
+
switch (type)
{
case NT_GNU_BUILD_ID:
@@ -337,7 +345,7 @@ ebl_object_note (Ebl *ebl, const char *name, uint32_t type,
break;
case NT_GNU_ABI_TAG:
- if (strcmp (name, "GNU") == 0 && descsz >= 8 && descsz % 4 == 0)
+ if (descsz >= 8 && descsz % 4 == 0)
{
Elf_Data in =
{
diff --git a/libebl/eblobjnotetypename.c b/libebl/eblobjnotetypename.c
index af23caea8..8cdd78199 100644
--- a/libebl/eblobjnotetypename.c
+++ b/libebl/eblobjnotetypename.c
@@ -39,6 +39,7 @@
const char *
ebl_object_note_type_name (Ebl *ebl, const char *name, uint32_t type,
+ GElf_Word descsz,
char *buf, size_t len)
{
const char *res = ebl->object_note_type_name (name, type, buf, len);
@@ -80,14 +81,19 @@ ebl_object_note_type_name (Ebl *ebl, const char *name, uint32_t type,
if (strcmp (name, "GNU") != 0)
{
+ /* NT_VERSION is special, all data is in the name. */
+ if (descsz == 0 && type == NT_VERSION)
+ return "VERSION";
+
snprintf (buf, len, "%s: %" PRIu32, gettext ("<unknown>"), type);
return buf;
}
+ /* And finally all the "GNU" note types. */
static const char *knowntypes[] =
{
#define KNOWNSTYPE(name) [NT_##name] = #name
- KNOWNSTYPE (VERSION),
+ KNOWNSTYPE (GNU_ABI_TAG),
KNOWNSTYPE (GNU_HWCAP),
KNOWNSTYPE (GNU_BUILD_ID),
KNOWNSTYPE (GNU_GOLD_VERSION),
diff --git a/libebl/libebl.h b/libebl/libebl.h
index a34fe48dd..583065475 100644
--- a/libebl/libebl.h
+++ b/libebl/libebl.h
@@ -175,8 +175,8 @@ extern const char *ebl_core_note_type_name (Ebl *ebl, uint32_t type, char *buf,
/* Return name of the note section type for an object file. */
extern const char *ebl_object_note_type_name (Ebl *ebl, const char *name,
- uint32_t type, char *buf,
- size_t len);
+ uint32_t type, GElf_Word descsz,
+ char *buf, size_t len);
/* Print information about object note if available. */
extern void ebl_object_note (Ebl *ebl, const char *name, uint32_t type,
diff --git a/src/ChangeLog b/src/ChangeLog
index fc6d414ff..9f26b259a 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,10 @@
+2018-11-11 Mark Wielaard <mark@klomp.org>
+
+ * readelf.c (handle_notes_data): Pass n_descsz to
+ ebl_object_note_type_name.
+ * elflint.c (check_note_data): Recognize NT_VERSION, add owner
+ name to unknown note error.
+
2018-11-10 Mark Wielaard <mark@klomp.org>
* elflint.c (check_program_header): Allow PT_GNU_EH_FRAME segment
diff --git a/src/elflint.c b/src/elflint.c
index 658f2ae2c..bddb8dd8e 100644
--- a/src/elflint.c
+++ b/src/elflint.c
@@ -1,5 +1,5 @@
/* Pedantic checking of ELF files compliance with gABI/psABI spec.
- Copyright (C) 2001-2015, 2017 Red Hat, Inc.
+ Copyright (C) 2001-2015, 2017, 2018 Red Hat, Inc.
This file is part of elfutils.
Written by Ulrich Drepper <drepper@redhat.com>, 2001.
@@ -4332,7 +4332,17 @@ section [%2d] '%s': unknown core file note type %" PRIu32
case NT_GNU_BUILD_ID:
case NT_GNU_GOLD_VERSION:
case NT_GNU_PROPERTY_TYPE_0:
- break;
+ if (nhdr.n_namesz == sizeof ELF_NOTE_GNU
+ && strcmp (data->d_buf + name_offset, ELF_NOTE_GNU) == 0)
+ break;
+ else
+ {
+ /* NT_VERSION is 1, same as NT_GNU_ABI_TAG. It has no
+ descriptor and (ab)uses the name as version string. */
+ if (nhdr.n_descsz == 0 && nhdr.n_type == NT_VERSION)
+ break;
+ }
+ goto unknown_note;
case 0:
/* Linux vDSOs use a type 0 note for the kernel version word. */
@@ -4341,16 +4351,21 @@ section [%2d] '%s': unknown core file note type %" PRIu32
break;
FALLTHROUGH;
default:
+ {
+ unknown_note:
if (shndx == 0)
ERROR (gettext ("\
-phdr[%d]: unknown object file note type %" PRIu32 " at offset %zu\n"),
- phndx, (uint32_t) nhdr.n_type, offset);
+phdr[%d]: unknown object file note type %" PRIu32 " with owner name '%s' at offset %zu\n"),
+ phndx, (uint32_t) nhdr.n_type,
+ (char *) data->d_buf + name_offset, offset);
else
ERROR (gettext ("\
section [%2d] '%s': unknown object file note type %" PRIu32
- " at offset %zu\n"),
+ " with owner name '%s' at offset %zu\n"),
shndx, section_name (ebl, shndx),
- (uint32_t) nhdr.n_type, offset);
+ (uint32_t) nhdr.n_type,
+ (char *) data->d_buf + name_offset, offset);
+ }
}
}
diff --git a/src/readelf.c b/src/readelf.c
index c6c3fb323..659e34fb5 100644
--- a/src/readelf.c
+++ b/src/readelf.c
@@ -12201,6 +12201,7 @@ handle_notes_data (Ebl *ebl, const GElf_Ehdr *ehdr,
? ebl_core_note_type_name (ebl, nhdr.n_type,
buf, sizeof (buf))
: ebl_object_note_type_name (ebl, name, nhdr.n_type,
+ nhdr.n_descsz,
buf2, sizeof (buf2)));
/* Filter out invalid entries. */
diff --git a/tests/ChangeLog b/tests/ChangeLog
index 92dfb95d7..d92b8e3ac 100644
--- a/tests/ChangeLog
+++ b/tests/ChangeLog
@@ -1,3 +1,8 @@
+2018-11-11 Mark Wielaard <mark@klomp.org>
+
+ * run-readelf-n.sh: Fix NT_GNU_ABI_TAG type. Add testfile11 test
+ for NT_VERSION.
+
2018-11-04 Mark Wielaard <mark@klomp.org>
* testfile-bpf-reloc.expect.bz2: Update with new expected jump
diff --git a/tests/run-readelf-n.sh b/tests/run-readelf-n.sh
index 3ae7cf02f..7e2a845e6 100755
--- a/tests/run-readelf-n.sh
+++ b/tests/run-readelf-n.sh
@@ -48,8 +48,25 @@ Note segment of 32 bytes at offset 0x300:
Note segment of 68 bytes at offset 0x320:
Owner Data size Type
- GNU 16 VERSION
+ GNU 16 GNU_ABI_TAG
OS: Linux, ABI: 3.2.0
GNU 20 GNU_BUILD_ID
Build ID: 83cb2229fabd2065d1361f5b46424cd75270f94b
EOF
+
+# NT_VERSION note type clashes with "GNU" owner type NT_GNU_ABI_TAG.
+# Uses owner name (with zero desc) for version string.
+testfiles testfile11
+testrun_compare ${abs_top_builddir}/src/readelf -n testfile11 << EOF
+
+Note section [ 2] '.note.ABI-tag' of 32 bytes at offset 0x128:
+ Owner Data size Type
+ GNU 16 GNU_ABI_TAG
+ OS: Linux, ABI: 2.2.5
+
+Note section [35] '.note' of 60 bytes at offset 0x13364:
+ Owner Data size Type
+ 01.01 0 VERSION
+ 01.01 0 VERSION
+ 01.01 0 VERSION
+EOF
--
2.19.1