[Buildroot] [git commit branch/2020.08.x] package/patchelf: pull in upstream bugfixes

Peter Korsgaard peter at korsgaard.com
Wed Oct 28 13:20:50 UTC 2020


commit: https://git.buildroot.net/buildroot/commit/?id=9709552fc9ef051714612a8126fe3e67b2a1ce6d
branch: https://git.buildroot.net/buildroot/commit/?id=refs/heads/2020.08.x

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 at rockwellcollins.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni at bootlin.com>
(cherry picked from commit 1be8b22f48cec8f834b02957429253f64282a0bc)
Signed-off-by: Peter Korsgaard <peter at korsgaard.com>
---
 ...ting-file-sizes-needlessly-and-allow-bina.patch | 176 +++++++++++++++++++++
 ...library-corruption-when-rerunning-patchel.patch |  55 +++++++
 .../patchelf/0007-fix-adjusting-startPage.patch    |  45 ++++++
 ...et-instead-of-sh_addr-when-checking-alrea.patch |  38 +++++
 ...6-by-ignoring-the-first-section-header-wh.patch |  41 +++++
 ...010-Fix-endianness-issues-for-powerpc-PIE.patch |  80 ++++++++++
 6 files changed, 435 insertions(+)

diff --git a/package/patchelf/0005-Avoid-inflating-file-sizes-needlessly-and-allow-bina.patch b/package/patchelf/0005-Avoid-inflating-file-sizes-needlessly-and-allow-bina.patch
new file mode 100644
index 0000000000..0d7931cd52
--- /dev/null
+++ b/package/patchelf/0005-Avoid-inflating-file-sizes-needlessly-and-allow-bina.patch
@@ -0,0 +1,176 @@
+From 79c093226e609b99fa889f6e37480b92b399610d Mon Sep 17 00:00:00 2001
+From: Richard Purdie <richard.purdie at 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 at linuxfoundation.org>
+
+Fetch from: https://github.com/NixOS/patchelf/commit/c4deb5e9e1ce9c98a48e0d5bb37d87739b8cfee4
+
+Backported to v0.9
+
+Signed-off-by: Conrad Ratschan <conrad.ratschan at 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
+
diff --git a/package/patchelf/0006-Fix-shared-library-corruption-when-rerunning-patchel.patch b/package/patchelf/0006-Fix-shared-library-corruption-when-rerunning-patchel.patch
new file mode 100644
index 0000000000..9fb3e260c1
--- /dev/null
+++ b/package/patchelf/0006-Fix-shared-library-corruption-when-rerunning-patchel.patch
@@ -0,0 +1,55 @@
+From 5df4791bf077127684faceeeea8bfab063e43774 Mon Sep 17 00:00:00 2001
+From: Richard Purdie <richard.purdie at 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 at linuxfoundation.org>
+
+Fetch from: https://github.com/NixOS/patchelf/commit/ad5f1f078b716802dfb8f7226cb1d5c720348a78
+
+Backported to v0.9
+
+Signed-off-by: Conrad Ratschan <conrad.ratschan at 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
+
diff --git a/package/patchelf/0007-fix-adjusting-startPage.patch b/package/patchelf/0007-fix-adjusting-startPage.patch
new file mode 100644
index 0000000000..fd044964e0
--- /dev/null
+++ b/package/patchelf/0007-fix-adjusting-startPage.patch
@@ -0,0 +1,45 @@
+From 4a82c97e8a0677706d1d532812daaa73249768a8 Mon Sep 17 00:00:00 2001
+From: Ed Bartosh <ed.bartosh at 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 at linux.intel.com>
+
+Fetch from: https://github.com/NixOS/patchelf/commit/1cc234fea5600190d872329aca60e2365cefc39e
+
+Backported to v0.9
+
+Signed-off-by: Conrad Ratschan <conrad.ratschan at 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
+
diff --git a/package/patchelf/0008-Use-sh_offset-instead-of-sh_addr-when-checking-alrea.patch b/package/patchelf/0008-Use-sh_offset-instead-of-sh_addr-when-checking-alrea.patch
new file mode 100644
index 0000000000..d423cad23a
--- /dev/null
+++ b/package/patchelf/0008-Use-sh_offset-instead-of-sh_addr-when-checking-alrea.patch
@@ -0,0 +1,38 @@
+From cb8326de54ad7a56658b0dc8efb7da5e71684a7c Mon Sep 17 00:00:00 2001
+From: Pablo Galindo <pablogsal at 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 at 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
+
diff --git a/package/patchelf/0009-Fix-issue-66-by-ignoring-the-first-section-header-wh.patch b/package/patchelf/0009-Fix-issue-66-by-ignoring-the-first-section-header-wh.patch
new file mode 100644
index 0000000000..a820f2d1d2
--- /dev/null
+++ b/package/patchelf/0009-Fix-issue-66-by-ignoring-the-first-section-header-wh.patch
@@ -0,0 +1,41 @@
+From e22ca2f593aa8fd392f1ac4f8dd104bc56d0d100 Mon Sep 17 00:00:00 2001
+From: Ezra Cooper <ezra at 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 at 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
+
diff --git a/package/patchelf/0010-Fix-endianness-issues-for-powerpc-PIE.patch b/package/patchelf/0010-Fix-endianness-issues-for-powerpc-PIE.patch
new file mode 100644
index 0000000000..6a3500b91e
--- /dev/null
+++ b/package/patchelf/0010-Fix-endianness-issues-for-powerpc-PIE.patch
@@ -0,0 +1,80 @@
+From c61c2960d782c67566790b210163ff9c799f018a Mon Sep 17 00:00:00 2001
+From: Conrad Ratschan <ratschance at 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 at 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
+


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