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package/patchelf: pull in upstream bugfixes

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When building iputils for powerpc with BR2_PIC_PIE enabled, the
arping/rdisc/tftpd binaries will segfault at runtime. This can be
traced back to a few bugs in patchelf corrupting the ELFs when
resizing the RPATH to replace "$ORIGIN/" with "/usr/sbin".

This patch pulls in upstream fixes to prevent the binaries from being
needlessly inflated, prevent the startPage from always being adjusted,
fix a few minor bugs, and fix incorrect endianness handling.

Signed-off-by: Conrad Ratschan <conrad.ratschan@rockwellcollins.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
This commit is contained in:
Conrad Ratschan 2020-10-05 13:50:34 -05:00 committed by Thomas Petazzoni
parent 0238dce6bb
commit 1be8b22f48
6 changed files with 435 additions and 0 deletions
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176
package/patchelf/0005-Avoid-inflating-file-sizes-needlessly-and-allow-bina.patch Normal file
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@ -0,0 +1,176 @@
From 79c093226e609b99fa889f6e37480b92b399610d Mon Sep 17 00:00:00 2001
From: Richard Purdie <richard.purdie@linuxfoundation.org>
Date: Tue, 7 Mar 2017 21:08:34 +0000
Subject: [PATCH] Avoid inflating file sizes needlessly and allow binaries to
be stripped
The current approach to changing sections in ET_DYN executables is to move
the INTERP section to the end of the file. +This means changing PT_PHDR to
add an extra PT_LOAD section so that the new section is mmaped into memory
by the elf loader in the kernel. In order to extend PHDR, this means moving
it to the end of the file.
Its documented in BUGS there is a kernel 'bug' which means that if you have holes
in memory between the base load address and the PT_LOAD segment that contains PHDR,
it will pass an incorrect PHDR address to ld.so and fail to load the binary, segfaulting.
To avoid this, the code currently inserts space into the binary to ensure that when
loaded into memory there are no holes between the PT_LOAD sections. This inflates the
binaries by many MBs in some cases. Whilst we could make them sparse, there is a second
issue which is that strip can fail to process these binaries:
$ strip fixincl
Not enough room for program headers, try linking with -N
[.note.ABI-tag]: Bad value
This turns out to be due to libbfd not liking the relocated PHDR section either
(https://github.com/NixOS/patchelf/issues/10).
Instead this patch implements a different approach, leaving PHDR where it is but extending
it in place to allow addition of a new PT_LOAD section. This overwrites sections in the
binary but those get moved to the end of the file in the new PT_LOAD section.
This is based on patches linked from the above github issue, however whilst the idea
was good, the implementation wasn't correct and they've been rewritten here.
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Fetch from: https://github.com/NixOS/patchelf/commit/c4deb5e9e1ce9c98a48e0d5bb37d87739b8cfee4
Backported to v0.9
Signed-off-by: Conrad Ratschan <conrad.ratschan@rockwellcollins.com>
---
src/patchelf.cc | 71 ++++++++++++++++++++++++++++---------------------
1 file changed, 40 insertions(+), 31 deletions(-)
diff --git a/src/patchelf.cc b/src/patchelf.cc
index 1d58061..c2147af 100644
--- a/src/patchelf.cc
+++ b/src/patchelf.cc
@@ -209,6 +209,8 @@ private:
string & replaceSection(const SectionName & sectionName,
unsigned int size);
+ bool haveReplacedSection(const SectionName & sectionName);
+
void writeReplacedSections(Elf_Off & curOff,
Elf_Addr startAddr, Elf_Off startOffset);
@@ -632,6 +634,15 @@ void ElfFile<ElfFileParamNames>::writeReplacedSections(Elf_Off & curOff,
replacedSections.clear();
}
+template<ElfFileParams>
+bool ElfFile<ElfFileParamNames>::haveReplacedSection(const SectionName & sectionName)
+{
+ ReplacedSections::iterator i = replacedSections.find(sectionName);
+
+ if (i != replacedSections.end())
+ return true;
+ return false;
+}
template<ElfFileParams>
void ElfFile<ElfFileParamNames>::rewriteSectionsLibrary()
@@ -648,52 +659,53 @@ void ElfFile<ElfFileParamNames>::rewriteSectionsLibrary()
debug("last page is 0x%llx\n", (unsigned long long) startPage);
+ /* Because we're adding a new section header, we're necessarily increasing
+ the size of the program header table. This can cause the first section
+ to overlap the program header table in memory; we need to shift the first
+ few segments to someplace else. */
+ /* Some sections may already be replaced so account for that */
+ unsigned int i = 1;
+ Elf_Addr pht_size = sizeof(Elf_Ehdr) + (phdrs.size() + 1)*sizeof(Elf_Phdr);
+ while( shdrs[i].sh_addr <= pht_size && i < rdi(hdr->e_shnum) ) {
+ if (not haveReplacedSection(getSectionName(shdrs[i])))
+ replaceSection(getSectionName(shdrs[i]), shdrs[i].sh_size);
+ i++;
+ }
- /* Compute the total space needed for the replaced sections and
- the program headers. */
- off_t neededSpace = (phdrs.size() + 1) * sizeof(Elf_Phdr);
+ /* Compute the total space needed for the replaced sections */
+ off_t neededSpace = 0;
for (ReplacedSections::iterator i = replacedSections.begin();
i != replacedSections.end(); ++i)
neededSpace += roundUp(i->second.size(), sectionAlignment);
debug("needed space is %d\n", neededSpace);
-
size_t startOffset = roundUp(fileSize, getPageSize());
growFile(startOffset + neededSpace);
-
/* Even though this file is of type ET_DYN, it could actually be
an executable. For instance, Gold produces executables marked
- ET_DYN. In that case we can still hit the kernel bug that
- necessitated rewriteSectionsExecutable(). However, such
- executables also tend to start at virtual address 0, so
+ ET_DYN as does LD when linking with pie. If we move PT_PHDR, it
+ has to stay in the first PT_LOAD segment or any subsequent ones
+ if they're continuous in memory due to linux kernel constraints
+ (see BUGS). Since the end of the file would be after bss, we can't
+ move PHDR there, we therefore choose to leave PT_PHDR where it is but
+ move enough following sections such that we can add the extra PT_LOAD
+ section to it. This PT_LOAD segment ensures the sections at the end of
+ the file are mapped into memory for ld.so to process.
+ We can't use the approach in rewriteSectionsExecutable()
+ since DYN executables tend to start at virtual address 0, so
rewriteSectionsExecutable() won't work because it doesn't have
- any virtual address space to grow downwards into. As a
- workaround, make sure that the virtual address of our new
- PT_LOAD segment relative to the first PT_LOAD segment is equal
- to its offset; otherwise we hit the kernel bug. This may
- require creating a hole in the executable. The bigger the size
- of the uninitialised data segment, the bigger the hole. */
+ any virtual address space to grow downwards into. */
if (isExecutable) {
if (startOffset >= startPage) {
debug("shifting new PT_LOAD segment by %d bytes to work around a Linux kernel bug\n", startOffset - startPage);
- } else {
- size_t hole = startPage - startOffset;
- /* Print a warning, because the hole could be very big. */
- fprintf(stderr, "warning: working around a Linux kernel bug by creating a hole of %zu bytes in ‘%s’\n", hole, fileName.c_str());
- assert(hole % getPageSize() == 0);
- /* !!! We could create an actual hole in the file here,
- but it's probably not worth the effort. */
- growFile(fileSize + hole);
- startOffset += hole;
}
startPage = startOffset;
}
- /* Add a segment that maps the replaced sections and program
- headers into memory. */
+ /* Add a segment that maps the replaced sections into memory. */
phdrs.resize(rdi(hdr->e_phnum) + 1);
wri(hdr->e_phnum, rdi(hdr->e_phnum) + 1);
Elf_Phdr & phdr = phdrs[rdi(hdr->e_phnum) - 1];
@@ -706,15 +718,12 @@ void ElfFile<ElfFileParamNames>::rewriteSectionsLibrary()
/* Write out the replaced sections. */
- Elf_Off curOff = startOffset + phdrs.size() * sizeof(Elf_Phdr);
+ Elf_Off curOff = startOffset;
writeReplacedSections(curOff, startPage, startOffset);
assert(curOff == startOffset + neededSpace);
-
- /* Move the program header to the start of the new area. */
- wri(hdr->e_phoff, startOffset);
-
- rewriteHeaders(startPage);
+ /* Write out the updated program and section headers */
+ rewriteHeaders(hdr->e_phoff);
}
--
2.17.1

55
package/patchelf/0006-Fix-shared-library-corruption-when-rerunning-patchel.patch Normal file
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@ -0,0 +1,55 @@
From 5df4791bf077127684faceeeea8bfab063e43774 Mon Sep 17 00:00:00 2001
From: Richard Purdie <richard.purdie@linuxfoundation.org>
Date: Wed, 3 Jun 2020 12:14:58 +0100
Subject: [PATCH] Fix shared library corruption when rerunning patchelf
When running patchelf on some existing patchelf'd binaries to change to longer
RPATHS, ldd would report the binaries as invalid. The output of objdump -x on
those libraryies should show the top of the .dynamic section is getting trashed,
something like:
0x600000001 0x0000000000429000
0x335000 0x0000000000335000
0xc740 0x000000000000c740
0x1000 0x0000000000009098
SONAME libglib-2.0.so.0
(which should be RPATH and DT_NEEDED entries)
This was tracked down to the code which injects the PT_LOAD section.
The issue is that if the program headers were previously relocated to the end
of the file which was how patchelf operated previously, the relocation code
wouldn't work properly on a second run as it now assumes they're located after
the elf header. This change forces them back to immediately follow the elf
header which is where the code has made space for them.
Should fix https://github.com/NixOS/patchelf/issues/170
and https://github.com/NixOS/patchelf/issues/192
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Fetch from: https://github.com/NixOS/patchelf/commit/ad5f1f078b716802dfb8f7226cb1d5c720348a78
Backported to v0.9
Signed-off-by: Conrad Ratschan <conrad.ratschan@rockwellcollins.com>
---
src/patchelf.cc | 1 +
1 file changed, 1 insertion(+)
diff --git a/src/patchelf.cc b/src/patchelf.cc
index c2147af..1224a89 100644
--- a/src/patchelf.cc
+++ b/src/patchelf.cc
@@ -706,6 +706,7 @@ void ElfFile<ElfFileParamNames>::rewriteSectionsLibrary()
/* Add a segment that maps the replaced sections into memory. */
+ wri(hdr->e_phoff, sizeof(Elf_Ehdr));
phdrs.resize(rdi(hdr->e_phnum) + 1);
wri(hdr->e_phnum, rdi(hdr->e_phnum) + 1);
Elf_Phdr & phdr = phdrs[rdi(hdr->e_phnum) - 1];
--
2.17.1

45
package/patchelf/0007-fix-adjusting-startPage.patch Normal file
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@ -0,0 +1,45 @@
From 4a82c97e8a0677706d1d532812daaa73249768a8 Mon Sep 17 00:00:00 2001
From: Ed Bartosh <ed.bartosh@linux.intel.com>
Date: Fri, 21 Jul 2017 12:33:53 +0300
Subject: [PATCH] fix adjusting startPage
startPage is adjusted unconditionally for all executables.
This results in incorrect addresses assigned to INTERP and LOAD
program headers, which breaks patched executable.
Adjusting startPage variable only when startOffset > startPage
should fix this.
This change is related to the issue NixOS#10
Signed-off-by: Ed Bartosh <ed.bartosh@linux.intel.com>
Fetch from: https://github.com/NixOS/patchelf/commit/1cc234fea5600190d872329aca60e2365cefc39e
Backported to v0.9
Signed-off-by: Conrad Ratschan <conrad.ratschan@rockwellcollins.com>
---
src/patchelf.cc | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/src/patchelf.cc b/src/patchelf.cc
index 1224a89..4676157 100644
--- a/src/patchelf.cc
+++ b/src/patchelf.cc
@@ -697,10 +697,8 @@ void ElfFile<ElfFileParamNames>::rewriteSectionsLibrary()
since DYN executables tend to start at virtual address 0, so
rewriteSectionsExecutable() won't work because it doesn't have
any virtual address space to grow downwards into. */
- if (isExecutable) {
- if (startOffset >= startPage) {
- debug("shifting new PT_LOAD segment by %d bytes to work around a Linux kernel bug\n", startOffset - startPage);
- }
+ if (isExecutable && startOffset > startPage) {
+ debug("shifting new PT_LOAD segment by %d bytes to work around a Linux kernel bug\n", startOffset - startPage);
startPage = startOffset;
}
--
2.17.1

38
package/patchelf/0008-Use-sh_offset-instead-of-sh_addr-when-checking-alrea.patch Normal file
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@ -0,0 +1,38 @@
From cb8326de54ad7a56658b0dc8efb7da5e71684a7c Mon Sep 17 00:00:00 2001
From: Pablo Galindo <pablogsal@gmail.com>
Date: Tue, 22 Sep 2020 01:33:47 +0100
Subject: [PATCH] Use sh_offset instead of sh_addr when checking already
replaced libs
When checking for already replaced libs, the check against the size must
be done using the section header offset, not the section file address.
This was not crashing in many situations because normally sh_address and
sh_offset have the same value but these two may differ and using the
sh_address value instead can cause library corruption in these
situations.
Fetch from: https://github.com/NixOS/patchelf/commit/83aa89addf8757e2d63aa73222f2fa9bc6d7321a
Backported to v0.9
Signed-off-by: Conrad Ratschan <conrad.ratschan@rockwellcollins.com>
---
src/patchelf.cc | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/src/patchelf.cc b/src/patchelf.cc
index 4676157..c025ae2 100644
--- a/src/patchelf.cc
+++ b/src/patchelf.cc
@@ -666,7 +666,7 @@ void ElfFile<ElfFileParamNames>::rewriteSectionsLibrary()
/* Some sections may already be replaced so account for that */
unsigned int i = 1;
Elf_Addr pht_size = sizeof(Elf_Ehdr) + (phdrs.size() + 1)*sizeof(Elf_Phdr);
- while( shdrs[i].sh_addr <= pht_size && i < rdi(hdr->e_shnum) ) {
+ while( shdrs[i].sh_offset <= pht_size && i < rdi(hdr->e_shnum) ) {
if (not haveReplacedSection(getSectionName(shdrs[i])))
replaceSection(getSectionName(shdrs[i]), shdrs[i].sh_size);
i++;
--
2.17.1

41
package/patchelf/0009-Fix-issue-66-by-ignoring-the-first-section-header-wh.patch Normal file
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@ -0,0 +1,41 @@
From e22ca2f593aa8fd392f1ac4f8dd104bc56d0d100 Mon Sep 17 00:00:00 2001
From: Ezra Cooper <ezra@qumulo.com>
Date: Thu, 21 Jun 2018 11:07:35 -0700
Subject: [PATCH] Fix issue #66 by ignoring the first section header when
sorting, and not overwriting NOBITS entries.
Fetch from: https://github.com/NixOS/patchelf/commit/52ab908394958a2a5d0476e306e2cad4da4fdeae
Backported to v0.9
Signed-off-by: Conrad Ratschan <conrad.ratschan@rockwellcollins.com>
---
src/patchelf.cc | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/src/patchelf.cc b/src/patchelf.cc
index c025ae2..fa2945e 100644
--- a/src/patchelf.cc
+++ b/src/patchelf.cc
@@ -435,7 +435,7 @@ void ElfFile<ElfFileParamNames>::sortShdrs()
/* Sort the sections by offset. */
CompShdr comp;
comp.elfFile = this;
- sort(shdrs.begin(), shdrs.end(), comp);
+ sort(shdrs.begin() + 1, shdrs.end(), comp);
/* Restore the sh_link mappings. */
for (unsigned int i = 1; i < rdi(hdr->e_shnum); ++i)
@@ -586,7 +586,8 @@ void ElfFile<ElfFileParamNames>::writeReplacedSections(Elf_Off & curOff,
{
string sectionName = i->first;
Elf_Shdr & shdr = findSection(sectionName);
- memset(contents + rdi(shdr.sh_offset), 'X', rdi(shdr.sh_size));
+ if (shdr.sh_type != SHT_NOBITS)
+ memset(contents + rdi(shdr.sh_offset), 'X', rdi(shdr.sh_size));
}
for (ReplacedSections::iterator i = replacedSections.begin();
--
2.17.1

80
package/patchelf/0010-Fix-endianness-issues-for-powerpc-PIE.patch Normal file
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@ -0,0 +1,80 @@
From c61c2960d782c67566790b210163ff9c799f018a Mon Sep 17 00:00:00 2001
From: Conrad Ratschan <ratschance@gmail.com>
Date: Sat, 3 Oct 2020 20:17:24 -0500
Subject: [PATCH] Fix endianness issues for powerpc PIE
Previously when running `patchelf --set-rpath "/usr/sbin" my_bin` on a
PIE ppc32 binary that had no RPATH a few issues were encountered.
This commit fixes:
1. The PT_PHDR being sorted improperly due to the type being read in
incorrect endianness
3. The interpreter being clobbered due to the replace sections routine
reading sh_offset and sh_size in incorrect endianness
4. The PHDR segment having an incorrect virt and phys address due to
reading the e_phoff in the incorrect endianness
This also fixes a read of the shdr.sh_type in writeReplacedSections but
this was not encountered during testing.
Fetch from: https://github.com/NixOS/patchelf/commit/884eccc4f061a3dbdbe63a4c73f1cc9bbf77fa7d
Backported to v0.9. Removed item 2 from the fix list as it is not
applicable to v0.9.
Signed-off-by: Conrad Ratschan <conrad.ratschan@rockwellcollins.com>
---
src/patchelf.cc | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/src/patchelf.cc b/src/patchelf.cc
index fa2945e..e60b17c 100644
--- a/src/patchelf.cc
+++ b/src/patchelf.cc
@@ -173,8 +173,8 @@ private:
ElfFile * elfFile;
bool operator ()(const Elf_Phdr & x, const Elf_Phdr & y)
{
- if (x.p_type == PT_PHDR) return true;
- if (y.p_type == PT_PHDR) return false;
+ if (elfFile->rdi(x.p_type) == PT_PHDR) return true;
+ if (elfFile->rdi(y.p_type) == PT_PHDR) return false;
return elfFile->rdi(x.p_paddr) < elfFile->rdi(y.p_paddr);
}
};
@@ -586,7 +586,7 @@ void ElfFile<ElfFileParamNames>::writeReplacedSections(Elf_Off & curOff,
{
string sectionName = i->first;
Elf_Shdr & shdr = findSection(sectionName);
- if (shdr.sh_type != SHT_NOBITS)
+ if (rdi(shdr.sh_type) != SHT_NOBITS)
memset(contents + rdi(shdr.sh_offset), 'X', rdi(shdr.sh_size));
}
@@ -667,9 +667,9 @@ void ElfFile<ElfFileParamNames>::rewriteSectionsLibrary()
/* Some sections may already be replaced so account for that */
unsigned int i = 1;
Elf_Addr pht_size = sizeof(Elf_Ehdr) + (phdrs.size() + 1)*sizeof(Elf_Phdr);
- while( shdrs[i].sh_offset <= pht_size && i < rdi(hdr->e_shnum) ) {
+ while( rdi(shdrs[i].sh_offset) <= pht_size && i < rdi(hdr->e_shnum) ) {
if (not haveReplacedSection(getSectionName(shdrs[i])))
- replaceSection(getSectionName(shdrs[i]), shdrs[i].sh_size);
+ replaceSection(getSectionName(shdrs[i]), rdi(shdrs[i].sh_size));
i++;
}
@@ -723,7 +723,7 @@ void ElfFile<ElfFileParamNames>::rewriteSectionsLibrary()
assert(curOff == startOffset + neededSpace);
/* Write out the updated program and section headers */
- rewriteHeaders(hdr->e_phoff);
+ rewriteHeaders(rdi(hdr->e_phoff));
}
--
2.17.1