[lld] r259966 - Set max segment protection level.
Pete Cooper via llvm-commits
llvm-commits at lists.llvm.org
Fri Feb 5 16:51:16 PST 2016
Author: pete
Date: Fri Feb 5 18:51:16 2016
New Revision: 259966
URL: http://llvm.org/viewvc/llvm-project?rev=259966&view=rev
Log:
Set max segment protection level.
The initial segment protection was also being used to set the maximum
segment protection level. Instead, the maximum should be set according
to the architecture we are linking. For example on Mac OS it should be
RWX on most pages, but on iOS is often on R_X.
rdar://problem/24515136
Added:
lld/trunk/test/mach-o/seg-protection-arm64.yaml
lld/trunk/test/mach-o/seg-protection-x86_64.yaml
Modified:
lld/trunk/lib/ReaderWriter/MachO/MachONormalizedFile.h
lld/trunk/lib/ReaderWriter/MachO/MachONormalizedFileBinaryWriter.cpp
lld/trunk/lib/ReaderWriter/MachO/MachONormalizedFileFromAtoms.cpp
lld/trunk/lib/ReaderWriter/MachO/MachONormalizedFileYAML.cpp
Modified: lld/trunk/lib/ReaderWriter/MachO/MachONormalizedFile.h
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/lib/ReaderWriter/MachO/MachONormalizedFile.h?rev=259966&r1=259965&r2=259966&view=diff
==============================================================================
--- lld/trunk/lib/ReaderWriter/MachO/MachONormalizedFile.h (original)
+++ lld/trunk/lib/ReaderWriter/MachO/MachONormalizedFile.h Fri Feb 5 18:51:16 2016
@@ -172,7 +172,8 @@ struct Segment {
StringRef name;
Hex64 address;
Hex64 size;
- VMProtect access;
+ VMProtect init_access;
+ VMProtect max_access;
};
/// Only used in normalized final linked images to specify on which dylibs
Modified: lld/trunk/lib/ReaderWriter/MachO/MachONormalizedFileBinaryWriter.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/lib/ReaderWriter/MachO/MachONormalizedFileBinaryWriter.cpp?rev=259966&r1=259965&r2=259966&view=diff
==============================================================================
--- lld/trunk/lib/ReaderWriter/MachO/MachONormalizedFileBinaryWriter.cpp (original)
+++ lld/trunk/lib/ReaderWriter/MachO/MachONormalizedFileBinaryWriter.cpp Fri Feb 5 18:51:16 2016
@@ -570,7 +570,7 @@ void MachOFileLayout::buildFileOffsets()
llvm::dbgs() << "buildFileOffsets()\n");
for (const Segment &sg : _file.segments) {
_segInfo[&sg].fileOffset = fileOffset;
- if ((_seg1addr == INT64_MAX) && sg.access)
+ if ((_seg1addr == INT64_MAX) && sg.init_access)
_seg1addr = sg.address;
DEBUG_WITH_TYPE("MachOFileLayout",
llvm::dbgs() << " segment=" << sg.name
@@ -578,7 +578,7 @@ void MachOFileLayout::buildFileOffsets()
uint32_t segFileSize = 0;
// A segment that is not zero-fill must use a least one page of disk space.
- if (sg.access)
+ if (sg.init_access)
segFileSize = _file.pageSize;
for (const Section *s : _segInfo[&sg].sections) {
uint32_t sectOffset = s->address - sg.address;
@@ -711,8 +711,8 @@ std::error_code MachOFileLayout::writeSe
cmd->vmsize = llvm::alignTo(linkeditSize, _file.pageSize);
cmd->fileoff = _startOfLinkEdit;
cmd->filesize = linkeditSize;
- cmd->initprot = seg.access;
- cmd->maxprot = seg.access;
+ cmd->initprot = seg.init_access;
+ cmd->maxprot = seg.max_access;
cmd->nsects = 0;
cmd->flags = 0;
if (_swap)
@@ -731,8 +731,8 @@ std::error_code MachOFileLayout::writeSe
cmd->vmsize = seg.size;
cmd->fileoff = segInfo.fileOffset;
cmd->filesize = segInfo.fileSize;
- cmd->maxprot = seg.access;
- cmd->initprot = seg.access;
+ cmd->initprot = seg.init_access;
+ cmd->maxprot = seg.max_access;
cmd->nsects = segInfo.sections.size();
cmd->flags = 0;
if (_swap)
Modified: lld/trunk/lib/ReaderWriter/MachO/MachONormalizedFileFromAtoms.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/lib/ReaderWriter/MachO/MachONormalizedFileFromAtoms.cpp?rev=259966&r1=259965&r2=259966&view=diff
==============================================================================
--- lld/trunk/lib/ReaderWriter/MachO/MachONormalizedFileFromAtoms.cpp (original)
+++ lld/trunk/lib/ReaderWriter/MachO/MachONormalizedFileFromAtoms.cpp Fri Feb 5 18:51:16 2016
@@ -92,13 +92,15 @@ struct SegmentInfo {
StringRef name;
uint64_t address;
uint64_t size;
- uint32_t access;
+ uint32_t init_access;
+ uint32_t max_access;
std::vector<SectionInfo*> sections;
uint32_t normalizedSegmentIndex;
};
SegmentInfo::SegmentInfo(StringRef n)
- : name(n), address(0), size(0), access(0), normalizedSegmentIndex(0) {
+ : name(n), address(0), size(0), init_access(0), max_access(0),
+ normalizedSegmentIndex(0) {
}
class Util {
@@ -432,12 +434,38 @@ SegmentInfo *Util::segmentForName(String
return si;
}
auto *info = new (_allocator) SegmentInfo(segName);
+
+ // Set the initial segment protection.
if (segName.equals("__TEXT"))
- info->access = VM_PROT_READ | VM_PROT_EXECUTE;
- else if (segName.equals("__DATA"))
- info->access = VM_PROT_READ | VM_PROT_WRITE;
+ info->init_access = VM_PROT_READ | VM_PROT_EXECUTE;
else if (segName.equals("__PAGEZERO"))
- info->access = 0;
+ info->init_access = 0;
+ else if (segName.equals("__LINKEDIT"))
+ info->init_access = VM_PROT_READ;
+ else {
+ // All others default to read-write
+ info->init_access = VM_PROT_READ | VM_PROT_WRITE;
+ }
+
+ // Set max segment protection
+ // Note, its overkill to use a switch statement here, but makes it so much
+ // easier to use switch coverage to catch new cases.
+ switch (_ctx.os()) {
+ case lld::MachOLinkingContext::OS::unknown:
+ case lld::MachOLinkingContext::OS::macOSX:
+ case lld::MachOLinkingContext::OS::iOS_simulator:
+ if (segName.equals("__PAGEZERO")) {
+ info->max_access = 0;
+ break;
+ }
+ // All others default to all
+ info->max_access = VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE;
+ break;
+ case lld::MachOLinkingContext::OS::iOS:
+ // iPhoneOS always uses same protection for max and initial
+ info->max_access = info->init_access;
+ break;
+ }
_segmentInfos.push_back(info);
return info;
}
@@ -589,7 +617,8 @@ void Util::copySegmentInfo(NormalizedFil
seg.name = sgi->name;
seg.address = sgi->address;
seg.size = sgi->size;
- seg.access = sgi->access;
+ seg.init_access = sgi->init_access;
+ seg.max_access = sgi->max_access;
file.segments.push_back(seg);
}
}
Modified: lld/trunk/lib/ReaderWriter/MachO/MachONormalizedFileYAML.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/lib/ReaderWriter/MachO/MachONormalizedFileYAML.cpp?rev=259966&r1=259965&r2=259966&view=diff
==============================================================================
--- lld/trunk/lib/ReaderWriter/MachO/MachONormalizedFileYAML.cpp (original)
+++ lld/trunk/lib/ReaderWriter/MachO/MachONormalizedFileYAML.cpp Fri Feb 5 18:51:16 2016
@@ -504,10 +504,11 @@ struct ScalarTraits<VMProtect> {
template <>
struct MappingTraits<Segment> {
static void mapping(IO &io, Segment& seg) {
- io.mapRequired("name", seg.name);
- io.mapRequired("address", seg.address);
- io.mapRequired("size", seg.size);
- io.mapRequired("access", seg.access);
+ io.mapRequired("name", seg.name);
+ io.mapRequired("address", seg.address);
+ io.mapRequired("size", seg.size);
+ io.mapRequired("init-access", seg.init_access);
+ io.mapRequired("max-access", seg.max_access);
}
};
Added: lld/trunk/test/mach-o/seg-protection-arm64.yaml
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/mach-o/seg-protection-arm64.yaml?rev=259966&view=auto
==============================================================================
--- lld/trunk/test/mach-o/seg-protection-arm64.yaml (added)
+++ lld/trunk/test/mach-o/seg-protection-arm64.yaml Fri Feb 5 18:51:16 2016
@@ -0,0 +1,78 @@
+# RUN: lld -flavor darwin -arch arm64 %s %p/Inputs/hello-world-arm64.yaml -o %t && llvm-objdump -private-headers %t | FileCheck %s
+
+--- !mach-o
+arch: arm64
+file-type: MH_OBJECT
+flags: [ MH_SUBSECTIONS_VIA_SYMBOLS ]
+has-UUID: false
+OS: unknown
+sections:
+ - segment: __TEXT
+ section: __text
+ type: S_REGULAR
+ attributes: [ S_ATTR_PURE_INSTRUCTIONS, S_ATTR_SOME_INSTRUCTIONS ]
+ address: 0x0000000000000000
+ content: [ 0x00, 0x00 ]
+global-symbols:
+ - name: _main
+ type: N_SECT
+ scope: [ N_EXT ]
+ sect: 1
+ value: 0x0000000000000000
+ - name: start
+ type: N_SECT
+ scope: [ N_EXT ]
+ sect: 1
+ value: 0x0000000000000001
+
+...
+
+# CHECK: Load command 0
+# CHECK: cmd LC_SEGMENT_64
+# CHECK: cmdsize 72
+# CHECK: segname __PAGEZERO
+# CHECK: vmaddr
+# CHECK: vmsize
+# CHECK: fileoff
+# CHECK: filesize
+# CHECK: maxprot ---
+# CHECK: initprot ---
+# CHECK: nsects 0
+# CHECK: flags (none)
+# CHECK: Load command 1
+# CHECK: cmd LC_SEGMENT_64
+# CHECK: cmdsize 152
+# CHECK: segname __TEXT
+# CHECK: vmaddr
+# CHECK: vmsize
+# CHECK: fileoff
+# CHECK: filesize
+# CHECK: maxprot r-x
+# CHECK: initprot r-x
+# CHECK: nsects 1
+# CHECK: flags (none)
+# CHECK: Section
+# CHECK: sectname __text
+# CHECK: segname __TEXT
+# CHECK: addr
+# CHECK: size
+# CHECK: offset
+# CHECK: align 2^0 (1)
+# CHECK: reloff 0
+# CHECK: nreloc 0
+# CHECK: type S_REGULAR
+# CHECK: attributes PURE_INSTRUCTIONS SOME_INSTRUCTIONS
+# CHECK: reserved1 0
+# CHECK: reserved2 0
+# CHECK: Load command 2
+# CHECK: cmd LC_SEGMENT_64
+# CHECK: cmdsize 72
+# CHECK: segname __LINKEDIT
+# CHECK: vmaddr
+# CHECK: vmsize
+# CHECK: fileoff
+# CHECK: filesize
+# CHECK: maxprot r--
+# CHECK: initprot r--
+# CHECK: nsects 0
+# CHECK: flags (none)
Added: lld/trunk/test/mach-o/seg-protection-x86_64.yaml
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/mach-o/seg-protection-x86_64.yaml?rev=259966&view=auto
==============================================================================
--- lld/trunk/test/mach-o/seg-protection-x86_64.yaml (added)
+++ lld/trunk/test/mach-o/seg-protection-x86_64.yaml Fri Feb 5 18:51:16 2016
@@ -0,0 +1,78 @@
+# RUN: lld -flavor darwin -arch x86_64 %s %p/Inputs/hello-world-x86_64.yaml -o %t && llvm-objdump -private-headers %t | FileCheck %s
+
+--- !mach-o
+arch: x86_64
+file-type: MH_OBJECT
+flags: [ MH_SUBSECTIONS_VIA_SYMBOLS ]
+has-UUID: false
+OS: unknown
+sections:
+ - segment: __TEXT
+ section: __text
+ type: S_REGULAR
+ attributes: [ S_ATTR_PURE_INSTRUCTIONS, S_ATTR_SOME_INSTRUCTIONS ]
+ address: 0x0000000000000000
+ content: [ 0x00, 0x00 ]
+global-symbols:
+ - name: _main
+ type: N_SECT
+ scope: [ N_EXT ]
+ sect: 1
+ value: 0x0000000000000000
+ - name: start
+ type: N_SECT
+ scope: [ N_EXT ]
+ sect: 1
+ value: 0x0000000000000001
+
+...
+
+# CHECK: Load command 0
+# CHECK: cmd LC_SEGMENT_64
+# CHECK: cmdsize 72
+# CHECK: segname __PAGEZERO
+# CHECK: vmaddr
+# CHECK: vmsize
+# CHECK: fileoff
+# CHECK: filesize
+# CHECK: maxprot ---
+# CHECK: initprot ---
+# CHECK: nsects 0
+# CHECK: flags (none)
+# CHECK: Load command 1
+# CHECK: cmd LC_SEGMENT_64
+# CHECK: cmdsize 152
+# CHECK: segname __TEXT
+# CHECK: vmaddr
+# CHECK: vmsize
+# CHECK: fileoff
+# CHECK: filesize
+# CHECK: maxprot rwx
+# CHECK: initprot r-x
+# CHECK: nsects 1
+# CHECK: flags (none)
+# CHECK: Section
+# CHECK: sectname __text
+# CHECK: segname __TEXT
+# CHECK: addr
+# CHECK: size
+# CHECK: offset
+# CHECK: align 2^0 (1)
+# CHECK: reloff 0
+# CHECK: nreloc 0
+# CHECK: type S_REGULAR
+# CHECK: attributes PURE_INSTRUCTIONS SOME_INSTRUCTIONS
+# CHECK: reserved1 0
+# CHECK: reserved2 0
+# CHECK: Load command 2
+# CHECK: cmd LC_SEGMENT_64
+# CHECK: cmdsize 72
+# CHECK: segname __LINKEDIT
+# CHECK: vmaddr
+# CHECK: vmsize
+# CHECK: fileoff
+# CHECK: filesize
+# CHECK: maxprot rwx
+# CHECK: initprot r--
+# CHECK: nsects 0
+# CHECK: flags (none)
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