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GP-6913 - try 2 to fix gccexceptionhandler analyzer absptr values

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Previous fix was also changing non-address values, which was bad.

Bonus fix: bump up max DWARF expression length to allow reading very
long exprs found in the example binary (sqlite)
This commit is contained in:
dev747368
2026-06-01 22:33:55 +00:00
parent cef869af04
commit b23a95e1e5
3 changed files with 17 additions and 23 deletions
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19
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/exceptionhandlers/gcc/AbstractDwarfEHDecoder.java
View File

@@ -15,6 +15,7 @@
*/ */
package ghidra.app.plugin.exceptionhandlers.gcc; package ghidra.app.plugin.exceptionhandlers.gcc;
import ghidra.app.util.opinion.ElfLoader;
import ghidra.program.model.address.*; import ghidra.program.model.address.*;
import ghidra.program.model.data.*; import ghidra.program.model.data.*;
import ghidra.program.model.listing.Program; import ghidra.program.model.listing.Program;
@@ -230,9 +231,22 @@ abstract class AbstractDwarfEHDecoder implements DwarfEHDecoder {
long offset = decode(context); long offset = decode(context);
if (appMode == DwarfEHDataApplicationMode.DW_EH_PE_absptr &&
prog.getRelocationTable().getRelocations(context.getAddress()).isEmpty()) {
offset += getImageBaseAdjustment(prog);
}
return addrFactory.getAddress(ram.getSpaceID(), offset); return addrFactory.getAddress(ram.getSpaceID(), offset);
} }
private static long getImageBaseAdjustment(Program program) {
Long originalImageBase = ElfLoader.getElfOriginalImageBase(program);
if (originalImageBase != null) {
return program.getImageBase().getOffset() - originalImageBase;
}
return 0;
}
/** /**
* Get the DWARF-encoded integer value as stored by the context * Get the DWARF-encoded integer value as stored by the context
* @param context Stores program location and decode parameters * @param context Stores program location and decode parameters
@@ -245,7 +259,6 @@ abstract class AbstractDwarfEHDecoder implements DwarfEHDecoder {
long val = doDecode(context); long val = doDecode(context);
return resolveRelativeOffset(val, context); return resolveRelativeOffset(val, context);
} }
private long resolveRelativeOffset(long val, DwarfDecodeContext context) private long resolveRelativeOffset(long val, DwarfDecodeContext context)
@@ -263,8 +276,8 @@ abstract class AbstractDwarfEHDecoder implements DwarfEHDecoder {
switch (appMode) { switch (appMode) {
case DW_EH_PE_absptr: case DW_EH_PE_absptr:
// adjust abs ptr for any changes to imagebase during import // This mode is used for counts, offsets, etc as well as pointer values, so it
val = context.getImageBaseAdjustment() + val; // shouldn't be 'fixed' here by applying imageBaseOffset from Elf loader
break; break;
case DW_EH_PE_aligned: case DW_EH_PE_aligned:

19
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/exceptionhandlers/gcc/DwarfDecodeContext.java
View File

@@ -15,7 +15,6 @@
*/ */
package ghidra.app.plugin.exceptionhandlers.gcc; package ghidra.app.plugin.exceptionhandlers.gcc;
import ghidra.app.util.opinion.ElfLoader;
import ghidra.program.model.address.Address; import ghidra.program.model.address.Address;
import ghidra.program.model.listing.Function; import ghidra.program.model.listing.Function;
import ghidra.program.model.listing.Program; import ghidra.program.model.listing.Program;
@@ -30,7 +29,6 @@ public class DwarfDecodeContext {
private final Address addr; private final Address addr;
private final MemoryBlock ehBlock; private final MemoryBlock ehBlock;
private final Address functionEntryPoint; private final Address functionEntryPoint;
private final long imageBaseAdjustment;
private Object decodedValue; private Object decodedValue;
private int encodedLength; private int encodedLength;
@@ -95,18 +93,9 @@ public class DwarfDecodeContext {
this.addr = readAddr; this.addr = readAddr;
this.ehBlock = ehBlock; this.ehBlock = ehBlock;
this.functionEntryPoint = entryPoint; this.functionEntryPoint = entryPoint;
this.imageBaseAdjustment = getImageBaseAdjustment(program);
} }
private static long getImageBaseAdjustment(Program program) {
Long originalImageBase = ElfLoader.getElfOriginalImageBase(program);
if (originalImageBase != null) {
return program.getImageBase().getOffset() - originalImageBase;
}
return 0;
}
/** /**
* Gets the program containing the encoded data. * Gets the program containing the encoded data.
* @return the program * @return the program
@@ -165,12 +154,4 @@ public class DwarfDecodeContext {
public Address getFunctionEntryPoint() { public Address getFunctionEntryPoint() {
return functionEntryPoint; return functionEntryPoint;
} }
/**
* {@return any adjustment needed to be applied to absolute addresses (because the program's
* base address was modified during import)}
*/
public long getImageBaseAdjustment() {
return imageBaseAdjustment;
}
} }

2
Ghidra/Features/Base/src/main/java/ghidra/app/util/bin/format/dwarf/expression/DWARFExpression.java
View File

@@ -31,7 +31,7 @@ import ghidra.app.util.bin.format.dwarf.DWARFRegisterMappings;
* Use a {@link DWARFExpressionEvaluator} to execute a {@link DWARFExpression}. * Use a {@link DWARFExpressionEvaluator} to execute a {@link DWARFExpression}.
*/ */
public class DWARFExpression { public class DWARFExpression {
public static final int MAX_SANE_EXPR = 256; public static final int MAX_SANE_EXPR = 512;
/** /**
* Deserializes a {@link DWARFExpression} from its raw bytes. * Deserializes a {@link DWARFExpression} from its raw bytes.