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elfutils: Backport some patches to fix errors
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On aarch64 musl gcc 14.x compiler, trying compiling elfutils 0.192 with
lto option enabled will cause null-dereference error.
Example error message:

...
elf_compress.c: In function 'elf_compress':
elf_compress.c:675:26: error: potential null pointer dereference [-Werror=null-dereference]
  675 |           shdr->sh_flags |= SHF_COMPRESSED;
      |                          ^
elf_compress_gnu.c: In function 'elf_compress_gnu':
elf_compress_gnu.c:127:25: error: potential null pointer dereference [-Werror=null-dereference]
  127 |           shdr->sh_size = new_size;
      |                         ^                      ^
...

This is a false postive warning but will abort compilation if gcc has
`-Werror` flag. This commit add a patch for this, see the bugzilla
report below.

This commit backports a series of patches to fix some errors.

Add patch:
- 007-add-libeu-symbols-to-libelf.patch
- 008-fix-autoconf-ENABLE_IMA_VERIFICATION.patch
- 009-fix-null-dereference-with-lto.patch

Link: https://sourceware.org/bugzilla/show_bug.cgi?id=32311
Signed-off-by: Ryan Keane <[email protected]>
Link: openwrt/openwrt#16886
Signed-off-by: Robert Marko <[email protected]>
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Ra2-IFV authored and robimarko committed Nov 16, 2024
1 parent 63caa2b commit afffcd0
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@@ -0,0 +1,31 @@
From f5d6e088f84dd05278c4698a21cbf1ff4569978d Mon Sep 17 00:00:00 2001
From: Mark Wielaard <[email protected]>
Date: Tue, 22 Oct 2024 15:03:42 +0200
Subject: [PATCH] libelf: Add libeu objects to libelf.a static archive

libelf might use some symbols from libeu.a, specifically the eu-search
wrappers. But we don't ship libeu.a separately. So include the libeu
objects in the libelf.a archive to facilitate static linking.

* libelf/Makefile.am (libeu_objects): New variable.
(libelf_a_LIBADD): New, add libeu_objects.

https://sourceware.org/bugzilla/show_bug.cgi?id=32293

Signed-off-by: Mark Wielaard <[email protected]>
---
libelf/Makefile.am | 3 +++
1 file changed, 3 insertions(+)

--- a/libelf/Makefile.am
+++ b/libelf/Makefile.am
@@ -122,6 +122,9 @@ libelf.so: $(srcdir)/libelf.map $(libelf
@$(textrel_check)
$(AM_V_at)ln -fs $@ $@.$(VERSION)

+libeu_objects = $(shell $(AR) t ../lib/libeu.a)
+libelf_a_LIBADD = $(addprefix ../lib/,$(libeu_objects))
+
install: install-am libelf.so
$(mkinstalldirs) $(DESTDIR)$(libdir)
$(INSTALL_PROGRAM) libelf.so $(DESTDIR)$(libdir)/libelf-$(PACKAGE_VERSION).so
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@@ -0,0 +1,24 @@
From f3c664d069d81a4872a1ec8241ee709f37c53e9c Mon Sep 17 00:00:00 2001
From: Aaron Merey <[email protected]>
Date: Tue, 29 Oct 2024 14:16:57 -0400
Subject: [PATCH] configure.ac: Fix ENABLE_IMA_VERIFICATION conditional

Fix test statement for ENABLE_IMA_VERIFICATION always evalutating to
false due to a missing 'x'.

Signed-off-by: Aaron Merey <[email protected]>
---
configure.ac | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/configure.ac
+++ b/configure.ac
@@ -895,7 +895,7 @@ AS_IF([test "x$enable_debuginfod" != "xn
AM_CONDITIONAL([DEBUGINFOD],[test "x$enable_debuginfod" = "xyes"])
AS_IF([test "x$enable_debuginfod_ima_verification" = "xyes"],AC_DEFINE([ENABLE_IMA_VERIFICATION],[1],[Build IMA verification]))
AS_IF([test "x$have_libarchive" = "xyes"],AC_DEFINE([HAVE_LIBARCHIVE],[1],[Define to 1 if libarchive is available]))
-AM_CONDITIONAL([ENABLE_IMA_VERIFICATION],[test "$enable_debuginfod_ima_verification" = "xyes"])
+AM_CONDITIONAL([ENABLE_IMA_VERIFICATION],[test "x$enable_debuginfod_ima_verification" = "xyes"])
AM_CONDITIONAL([OLD_LIBMICROHTTPD],[test "x$old_libmicrohttpd" = "xyes"])

dnl for /etc/profile.d/elfutils.{csh,sh}
193 changes: 193 additions & 0 deletions package/libs/elfutils/patches/009-fix-null-dereference-with-lto.patch
Original file line number Diff line number Diff line change
@@ -0,0 +1,193 @@
From 8707194a9f2f0b13e53041b03ebfdbdbd2942e43 Mon Sep 17 00:00:00 2001
From: Mark Wielaard <[email protected]>
Date: Tue, 5 Nov 2024 23:31:14 +0100
Subject: [PATCH 1/1] libelf: Only fetch shdr once in elf_compress[_gnu]

Some compilers assume the second call to elf[32|64]_getshdr can fail
and produce error: potential null pointer dereference. Just store the
result of the first call and reuse (when not NULL).

* libelf/elf_compress.c (elf_compress): Store getshdr result in
a shdr union var.
* libelf/elf_compress_gnu.c (): Likewise

https://sourceware.org/bugzilla/show_bug.cgi?id=32311

Signed-off-by: Mark Wielaard <[email protected]>
---
libelf/elf_compress.c | 55 +++++++++++++++++++++------------------
libelf/elf_compress_gnu.c | 45 ++++++++++++++------------------
2 files changed, 48 insertions(+), 52 deletions(-)

--- a/libelf/elf_compress.c
+++ b/libelf/elf_compress.c
@@ -584,25 +584,30 @@ elf_compress (Elf_Scn *scn, int type, un
Elf64_Xword sh_flags;
Elf64_Word sh_type;
Elf64_Xword sh_addralign;
+ union shdr
+ {
+ Elf32_Shdr *s32;
+ Elf64_Shdr *s64;
+ } shdr;
if (elfclass == ELFCLASS32)
{
- Elf32_Shdr *shdr = elf32_getshdr (scn);
- if (shdr == NULL)
+ shdr.s32 = elf32_getshdr (scn);
+ if (shdr.s32 == NULL)
return -1;

- sh_flags = shdr->sh_flags;
- sh_type = shdr->sh_type;
- sh_addralign = shdr->sh_addralign;
+ sh_flags = shdr.s32->sh_flags;
+ sh_type = shdr.s32->sh_type;
+ sh_addralign = shdr.s32->sh_addralign;
}
else
{
- Elf64_Shdr *shdr = elf64_getshdr (scn);
- if (shdr == NULL)
+ shdr.s64 = elf64_getshdr (scn);
+ if (shdr.s64 == NULL)
return -1;

- sh_flags = shdr->sh_flags;
- sh_type = shdr->sh_type;
- sh_addralign = shdr->sh_addralign;
+ sh_flags = shdr.s64->sh_flags;
+ sh_type = shdr.s64->sh_type;
+ sh_addralign = shdr.s64->sh_addralign;
}

if ((sh_flags & SHF_ALLOC) != 0)
@@ -679,17 +684,17 @@ elf_compress (Elf_Scn *scn, int type, un
correctly and ignored when SHF_COMPRESSED is set. */
if (elfclass == ELFCLASS32)
{
- Elf32_Shdr *shdr = elf32_getshdr (scn);
- shdr->sh_size = new_size;
- shdr->sh_addralign = __libelf_type_align (ELFCLASS32, ELF_T_CHDR);
- shdr->sh_flags |= SHF_COMPRESSED;
+ shdr.s32->sh_size = new_size;
+ shdr.s32->sh_addralign = __libelf_type_align (ELFCLASS32,
+ ELF_T_CHDR);
+ shdr.s32->sh_flags |= SHF_COMPRESSED;
}
else
{
- Elf64_Shdr *shdr = elf64_getshdr (scn);
- shdr->sh_size = new_size;
- shdr->sh_addralign = __libelf_type_align (ELFCLASS64, ELF_T_CHDR);
- shdr->sh_flags |= SHF_COMPRESSED;
+ shdr.s64->sh_size = new_size;
+ shdr.s64->sh_addralign = __libelf_type_align (ELFCLASS64,
+ ELF_T_CHDR);
+ shdr.s64->sh_flags |= SHF_COMPRESSED;
}

__libelf_reset_rawdata (scn, out_buf, new_size, 1, ELF_T_CHDR);
@@ -731,17 +736,15 @@ elf_compress (Elf_Scn *scn, int type, un
correctly and ignored when SHF_COMPRESSED is set. */
if (elfclass == ELFCLASS32)
{
- Elf32_Shdr *shdr = elf32_getshdr (scn);
- shdr->sh_size = scn->zdata_size;
- shdr->sh_addralign = scn->zdata_align;
- shdr->sh_flags &= ~SHF_COMPRESSED;
+ shdr.s32->sh_size = scn->zdata_size;
+ shdr.s32->sh_addralign = scn->zdata_align;
+ shdr.s32->sh_flags &= ~SHF_COMPRESSED;
}
else
{
- Elf64_Shdr *shdr = elf64_getshdr (scn);
- shdr->sh_size = scn->zdata_size;
- shdr->sh_addralign = scn->zdata_align;
- shdr->sh_flags &= ~SHF_COMPRESSED;
+ shdr.s64->sh_size = scn->zdata_size;
+ shdr.s64->sh_addralign = scn->zdata_align;
+ shdr.s64->sh_flags &= ~SHF_COMPRESSED;
}

__libelf_reset_rawdata (scn, scn->zdata_base,
--- a/libelf/elf_compress_gnu.c
+++ b/libelf/elf_compress_gnu.c
@@ -59,25 +59,30 @@ elf_compress_gnu (Elf_Scn *scn, int infl
Elf64_Xword sh_flags;
Elf64_Word sh_type;
Elf64_Xword sh_addralign;
+ union shdr
+ {
+ Elf32_Shdr *s32;
+ Elf64_Shdr *s64;
+ } shdr;
if (elfclass == ELFCLASS32)
{
- Elf32_Shdr *shdr = elf32_getshdr (scn);
- if (shdr == NULL)
+ shdr.s32 = elf32_getshdr (scn);
+ if (shdr.s32 == NULL)
return -1;

- sh_flags = shdr->sh_flags;
- sh_type = shdr->sh_type;
- sh_addralign = shdr->sh_addralign;
+ sh_flags = shdr.s32->sh_flags;
+ sh_type = shdr.s32->sh_type;
+ sh_addralign = shdr.s32->sh_addralign;
}
else
{
- Elf64_Shdr *shdr = elf64_getshdr (scn);
- if (shdr == NULL)
+ shdr.s64 = elf64_getshdr (scn);
+ if (shdr.s64 == NULL)
return -1;

- sh_flags = shdr->sh_flags;
- sh_type = shdr->sh_type;
- sh_addralign = shdr->sh_addralign;
+ sh_flags = shdr.s64->sh_flags;
+ sh_type = shdr.s64->sh_type;
+ sh_addralign = shdr.s64->sh_addralign;
}

/* Allocated sections, or sections that are already are compressed
@@ -122,15 +127,9 @@ elf_compress_gnu (Elf_Scn *scn, int infl
sh_flags won't have a SHF_COMPRESSED hint in the GNU format.
Just adjust the sh_size. */
if (elfclass == ELFCLASS32)
- {
- Elf32_Shdr *shdr = elf32_getshdr (scn);
- shdr->sh_size = new_size;
- }
+ shdr.s32->sh_size = new_size;
else
- {
- Elf64_Shdr *shdr = elf64_getshdr (scn);
- shdr->sh_size = new_size;
- }
+ shdr.s64->sh_size = new_size;

__libelf_reset_rawdata (scn, out_buf, new_size, 1, ELF_T_BYTE);

@@ -187,15 +186,9 @@ elf_compress_gnu (Elf_Scn *scn, int infl
sh_flags won't have a SHF_COMPRESSED hint in the GNU format.
Just adjust the sh_size. */
if (elfclass == ELFCLASS32)
- {
- Elf32_Shdr *shdr = elf32_getshdr (scn);
- shdr->sh_size = size;
- }
+ shdr.s32->sh_size = size;
else
- {
- Elf64_Shdr *shdr = elf64_getshdr (scn);
- shdr->sh_size = size;
- }
+ shdr.s64->sh_size = size;

__libelf_reset_rawdata (scn, buf_out, size, sh_addralign,
__libelf_data_type (&ehdr, sh_type,

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