Skip to content

Commit

Permalink
Fix LinuxImageHeapProvider with Valgrind by not relying on /proc/self…
Browse files Browse the repository at this point in the history 
…/exe.
  • Loading branch information
@peter-hofer
peter-hofer committed Jan 31, 2019
1 parent b88c8b3 commit 4f9c6e8
Showing 1 changed file with 16 additions and 21 deletions.
37 changes: 16 additions & 21 deletions ...com.oracle.svm.core.posix/src/com/oracle/svm/core/posix/linux/LinuxImageHeapProvider.java
View file
Original file line number Diff line number Diff line change
Expand Up @@ -26,6 +26,7 @@

import static com.oracle.svm.core.Isolates.IMAGE_HEAP_RELOCATABLE_BEGIN;
import static com.oracle.svm.core.Isolates.IMAGE_HEAP_RELOCATABLE_END;
import static com.oracle.svm.core.Isolates.IMAGE_HEAP_RELOCATABLE_FIRST_RELOC_POINTER;
import static com.oracle.svm.core.Isolates.IMAGE_HEAP_WRITABLE_BEGIN;
import static com.oracle.svm.core.Isolates.IMAGE_HEAP_WRITABLE_END;
import static com.oracle.svm.core.posix.headers.LibC.memcpy;
Expand All @@ -45,6 +46,7 @@
import org.graalvm.nativeimage.c.type.CIntPointer;
import org.graalvm.nativeimage.c.type.CLongPointer;
import org.graalvm.nativeimage.c.type.WordPointer;
import org.graalvm.word.ComparableWord;
import org.graalvm.word.LocationIdentity;
import org.graalvm.word.Pointer;
import org.graalvm.word.PointerBase;
Expand All @@ -59,7 +61,6 @@
import com.oracle.svm.core.c.CGlobalData;
import com.oracle.svm.core.c.CGlobalDataFactory;
import com.oracle.svm.core.c.function.CEntryPointErrors;
import com.oracle.svm.core.os.CopyingImageHeapProvider;
import com.oracle.svm.core.os.ImageHeapProvider;
import com.oracle.svm.core.os.VirtualMemoryProvider;
import com.oracle.svm.core.os.VirtualMemoryProvider.Access;
Expand Down Expand Up @@ -96,18 +97,12 @@ public void afterRegistration(AfterRegistrationAccess access) {
* architecture is not supported, or an error occurs during the mapping process.
*/
public class LinuxImageHeapProvider implements ImageHeapProvider {
private static final CGlobalData<CCharPointer> SELF_EXE = CGlobalDataFactory.createCString("/proc/self/exe");
private static final CGlobalData<CCharPointer> MAPS = CGlobalDataFactory.createCString("/proc/self/maps");
private static final CGlobalData<Pointer> OBJECT_FD = CGlobalDataFactory.createWord(WordFactory.signed(-1), null);
private static final CGlobalData<Pointer> FD_OFFSET = CGlobalDataFactory.createWord(WordFactory.signed(-1), null);

private static final int MAX_PATHLEN = 4096;

@Fold
static boolean isExecutable() {
return ImageInfo.isExecutable();
}

@Override
@Uninterruptible(reason = "Called during isolate initialization.")
public int initialize(PointerBase begin, UnsignedWord reservedSize, WordPointer basePointer, WordPointer endPointer) {
Expand All @@ -117,8 +112,6 @@ public int initialize(PointerBase begin, UnsignedWord reservedSize, WordPointer
return CEntryPointErrors.UNSPECIFIED;
}

boolean executable = isExecutable();

/*
* Reuse the already loaded file descriptor and discovered offset for all subsequent isolate
* initializations. To avoid stalling threads we intentionally allow for racing during
Expand All @@ -131,7 +124,7 @@ public int initialize(PointerBase begin, UnsignedWord reservedSize, WordPointer
int fd = (int) OBJECT_FD.get().readLong(0);

if (fd != -1) {
return createMapping(begin, basePointer, endPointer, imageHeapBegin, imageHeapSize, fd, FD_OFFSET.get().readLong(0), !executable);
return createMapping(begin, basePointer, endPointer, imageHeapBegin, imageHeapSize, fd, FD_OFFSET.get().readLong(0));
}

int mapFD = Fcntl.NoTransitions.open(MAPS.get(), Fcntl.O_RDONLY(), 0);
Expand All @@ -145,15 +138,15 @@ public int initialize(PointerBase begin, UnsignedWord reservedSize, WordPointer
final CIntPointer dev = StackValue.get(CIntPointer.class);
final CLongPointer inode = StackValue.get(CLongPointer.class);

boolean found = findMapping(mapFD, buffer, MAX_PATHLEN, imageHeapBegin.rawValue(), startAddr, offset, dev, inode, !executable);
boolean found = findMapping(mapFD, buffer, MAX_PATHLEN, imageHeapBegin.rawValue(), startAddr, offset, dev, inode, true);
Unistd.NoTransitions.close(mapFD);

if (!found) {
LibC.free(buffer);
return CEntryPointErrors.MAP_HEAP_FAILED;
}

fd = Fcntl.NoTransitions.open(executable ? SELF_EXE.get() : buffer, Fcntl.O_RDONLY(), 0);
fd = Fcntl.NoTransitions.open(buffer, Fcntl.O_RDONLY(), 0);
LibC.free(buffer);

if (fd == -1) {
Expand All @@ -177,12 +170,10 @@ public int initialize(PointerBase begin, UnsignedWord reservedSize, WordPointer
* mapped in original. In the case it does not we must abort and fall back to the copy
* strategy. In the case of native executables, it will always match due to /proc/self/exe.
*/
if (!executable) {
Stat.stat stat = StackValue.get(Stat.stat.class);
if (Stat.fstat_no_transition(fd, stat) != 0 && stat.st_ino() != inode.read() && stat.st_dev() != dev.read()) {
Unistd.NoTransitions.close(fd);
return CEntryPointErrors.MAP_HEAP_FAILED;
}
Stat.stat stat = StackValue.get(Stat.stat.class);
if (Stat.fstat_no_transition(fd, stat) != 0 && stat.st_ino() != inode.read() && stat.st_dev() != dev.read()) {
Unistd.NoTransitions.close(fd);
return CEntryPointErrors.MAP_HEAP_FAILED;
}

long newOffset = offset.read() + (imageHeapBegin.rawValue() - startAddr.read());
Expand All @@ -202,18 +193,22 @@ public int initialize(PointerBase begin, UnsignedWord reservedSize, WordPointer
UnsafeAccess.UNSAFE.fullFence();
}

return createMapping(begin, basePointer, endPointer, imageHeapBegin, imageHeapSize, fd, newOffset, !executable);
return createMapping(begin, basePointer, endPointer, imageHeapBegin, imageHeapSize, fd, newOffset);
}

@Uninterruptible(reason = "Called during isolate initialization.")
private static int createMapping(PointerBase begin, WordPointer basePointer, WordPointer endPointer, Word imageHeapBegin, Word imageHeapSize, int fd, long offset, boolean patch) {
private static int createMapping(PointerBase begin, WordPointer basePointer, WordPointer endPointer, Word imageHeapBegin, Word imageHeapSize, int fd, long offset) {
Pointer heap = VirtualMemoryProvider.get().mapFile(begin, imageHeapSize, WordFactory.unsigned(fd), WordFactory.unsigned(offset), Access.READ | Access.WRITE);
if (heap.isNull()) {
return CEntryPointErrors.MAP_HEAP_FAILED;
}

UnsignedWord pageSize = VirtualMemoryProvider.get().getGranularity();
if (patch) {

Pointer firstRelocPointer = IMAGE_HEAP_RELOCATABLE_FIRST_RELOC_POINTER.get();
ComparableWord relocatedValue = firstRelocPointer.readWord(0);
ComparableWord mappedValue = heap.readWord(firstRelocPointer.subtract(imageHeapBegin));
if (relocatedValue.notEqual(mappedValue)) {
/*
* Addresses were relocated by dynamic linker, so copy them, but first remap the pages
* to avoid swapping them in from disk.
Expand Down

0 comments on commit 4f9c6e8

Please sign in to comment.