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[GR-41748] Use version script to control symbol visibility on Linux. #5249

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merged 1 commit into from
Oct 19, 2022
Merged

[GR-41748] Use version script to control symbol visibility on Linux. #5249

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48 changes: 22 additions & 26 deletions ...tratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/image/CCLinkerInvocation.java
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Original file line number Diff line number Diff line change
Expand Up @@ -37,7 +37,6 @@
import java.util.stream.Collectors;
import java.util.stream.Stream;

import com.oracle.svm.hosted.c.libc.HostedLibCBase;
import org.graalvm.compiler.options.Option;
import org.graalvm.nativeimage.ImageSingletons;
import org.graalvm.nativeimage.Platform;
Expand All @@ -57,6 +56,7 @@
import com.oracle.svm.hosted.c.CGlobalDataFeature;
import com.oracle.svm.hosted.c.NativeLibraries;
import com.oracle.svm.hosted.c.codegen.CCompilerInvoker;
import com.oracle.svm.hosted.c.libc.HostedLibCBase;

public abstract class CCLinkerInvocation implements LinkerInvocation {

Expand Down Expand Up @@ -258,34 +258,28 @@ private static class BinutilsCCLinkerInvocation extends CCLinkerInvocation {
additionalPreOptions.add("-Wl,--gc-sections");
}

/*
* On Linux we use --dynamic-list to ensure only our defined entrypoints end up as
* global symbols in the dynamic symbol table of the image. However, when compiling a
* static image these are not needed, and some linkers interpret them wrong, creating a
* corrupt binary.
*/
if (!SubstrateOptions.StaticExecutable.getValue()) {
try {
StringBuilder exportedSymbols = new StringBuilder();
exportedSymbols.append("{\n");
for (String symbol : getImageSymbols(true)) {
exportedSymbols.append('\"').append(symbol).append("\";\n");
}
exportedSymbols.append("};");
Path exportedSymbolsPath = nativeLibs.tempDirectory.resolve("exported_symbols.list");
Files.write(exportedSymbolsPath, Collections.singleton(exportedSymbols.toString()));
additionalPreOptions.add("-Wl,--dynamic-list");
additionalPreOptions.add("-Wl," + exportedSymbolsPath.toAbsolutePath());

// Drop global symbols in linked static libraries: not covered by --dynamic-list
additionalPreOptions.add("-Wl,--exclude-libs,ALL");

additionalPreOptions.addAll(HostedLibCBase.singleton().getAdditionalLinkerOptions(imageKind));
} catch (IOException e) {
VMError.shouldNotReachHere();
/* Use --version-script to control the visibility of image symbols. */
try {
StringBuilder exportedSymbols = new StringBuilder();
exportedSymbols.append("{\n");
/* Only exported symbols are global ... */
exportedSymbols.append("global:\n");
for (String symbol : getImageSymbols(true)) {
exportedSymbols.append('\"').append(symbol).append("\";\n");
}
/* ... everything else is local. */
exportedSymbols.append("local: *;\n");
exportedSymbols.append("};");

Path exportedSymbolsPath = nativeLibs.tempDirectory.resolve("exported_symbols.list");
Files.write(exportedSymbolsPath, Collections.singleton(exportedSymbols.toString()));
additionalPreOptions.add("-Wl,--version-script," + exportedSymbolsPath.toAbsolutePath());
} catch (IOException e) {
VMError.shouldNotReachHere();
}

additionalPreOptions.addAll(HostedLibCBase.singleton().getAdditionalLinkerOptions(imageKind));

if (SubstrateOptions.DeleteLocalSymbols.getValue()) {
additionalPreOptions.add("-Wl,-x");
}
Expand All @@ -300,6 +294,8 @@ String getSymbolName(ObjectFile.Symbol symbol) {
protected void setOutputKind(List<String> cmd) {
switch (imageKind) {
case EXECUTABLE:
/* Export global symbols. */
cmd.add("-Wl,--export-dynamic");
break;
case STATIC_EXECUTABLE:
if (!staticExecWithDynamicallyLinkLibC) {
Expand Down