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Teach the kernel KUBSAN runtime about alignment_assumption

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This checks the alignment of a given pointer is sufficient for the
requested alignment asked for. This fixes the build with a recent
llvm/clang.

Sponsored by:	DARPA, AFRL
This commit is contained in:
Andrew Turner 2019-05-28 09:12:15 +00:00
parent 0d5de29a10
commit 5393cbce3d
1 changed files with 55 additions and 0 deletions
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55
sys/kern/kern_ubsan.c
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@ -244,6 +244,12 @@ struct CFloatCastOverflowData {
struct CTypeDescriptor *mToType;
};
struct CAlignmentAssumptionData {
struct CSourceLocation mLocation;
struct CSourceLocation mAssumptionLocation;
struct CTypeDescriptor *mType;
};
/* Local utility functions */
static void Report(bool isFatal, const char *pFormat, ...) __printflike(2, 3);
static bool isAlreadyReported(struct CSourceLocation *pLocation);
@ -276,6 +282,8 @@ intptr_t __ubsan_vptr_type_cache[128];
/* Public symbols used in the instrumentation of the code generation part */
void __ubsan_handle_add_overflow(struct COverflowData *pData, unsigned long ulLHS, unsigned long ulRHS);
void __ubsan_handle_add_overflow_abort(struct COverflowData *pData, unsigned long ulLHS, unsigned long ulRHS);
void __ubsan_handle_alignment_assumption(struct CAlignmentAssumptionData *pData, unsigned long ulPointer, unsigned long ulAlignment, unsigned long ulOffset);
void __ubsan_handle_alignment_assumption_abort(struct CAlignmentAssumptionData *pData, unsigned long ulPointer, unsigned long ulAlignment, unsigned long ulOffset);
void __ubsan_handle_builtin_unreachable(struct CUnreachableData *pData);
void __ubsan_handle_cfi_bad_type(struct CCFICheckFailData *pData, unsigned long ulVtable, bool bValidVtable, bool FromUnrecoverableHandler, unsigned long ProgramCounter, unsigned long FramePointer);
void __ubsan_handle_cfi_check_fail(struct CCFICheckFailData *pData, unsigned long ulValue, unsigned long ulValidVtable);
@ -338,6 +346,7 @@ static void HandleMissingReturn(bool isFatal, struct CUnreachableData *pData);
static void HandleNonnullArg(bool isFatal, struct CNonNullArgData *pData);
static void HandleNonnullReturn(bool isFatal, struct CNonNullReturnData *pData, struct CSourceLocation *pLocationPointer);
static void HandlePointerOverflow(bool isFatal, struct CPointerOverflowData *pData, unsigned long ulBase, unsigned long ulResult);
static void HandleAlignmentAssumption(bool isFatal, struct CAlignmentAssumptionData *pData, unsigned long ulPointer, unsigned long ulAlignment, unsigned long ulOffset);
static void
HandleOverflow(bool isFatal, struct COverflowData *pData, unsigned long ulLHS, unsigned long ulRHS, const char *szOperation)
@ -690,6 +699,34 @@ HandlePointerOverflow(bool isFatal, struct CPointerOverflowData *pData, unsigned
szLocation, ulBase, ulResult);
}
static void
HandleAlignmentAssumption(bool isFatal, struct CAlignmentAssumptionData *pData, unsigned long ulPointer, unsigned long ulAlignment, unsigned long ulOffset)
{
char szLocation[LOCATION_MAXLEN];
char szAssumptionLocation[LOCATION_MAXLEN];
unsigned long ulRealPointer;
ASSERT(pData);
if (isAlreadyReported(&pData->mLocation))
return;
DeserializeLocation(szLocation, LOCATION_MAXLEN, &pData->mLocation);
ulRealPointer = ulPointer - ulOffset;
if (pData->mAssumptionLocation.mFilename != NULL) {
DeserializeLocation(szAssumptionLocation, LOCATION_MAXLEN,
&pData->mAssumptionLocation);
Report(isFatal, "UBSan: Undefined Behavior in %s, alignment assumption of %#lx for pointer %#lx (offset %#lx), asumption made in %s\n",
szLocation, ulAlignment, ulRealPointer, ulOffset,
szAssumptionLocation);
} else {
Report(isFatal, "UBSan: Undefined Behavior in %s, alignment assumption of %#lx for pointer %#lx (offset %#lx)\n",
szLocation, ulAlignment, ulRealPointer, ulOffset);
}
}
/* Definions of public symbols emitted by the instrumentation code */
void
__ubsan_handle_add_overflow(struct COverflowData *pData, unsigned long ulLHS, unsigned long ulRHS)
@ -709,6 +746,24 @@ __ubsan_handle_add_overflow_abort(struct COverflowData *pData, unsigned long ulL
HandleOverflow(true, pData, ulLHS, ulRHS, PLUS_STRING);
}
void
__ubsan_handle_alignment_assumption(struct CAlignmentAssumptionData *pData, unsigned long ulPointer, unsigned long ulAlignment, unsigned long ulOffset)
{
ASSERT(pData);
HandleAlignmentAssumption(false, pData, ulPointer, ulAlignment, ulOffset);
}
void
__ubsan_handle_alignment_assumption_abort(struct CAlignmentAssumptionData *pData, unsigned long ulPointer, unsigned long ulAlignment, unsigned long ulOffset)
{
ASSERT(pData);
HandleAlignmentAssumption(true, pData, ulPointer, ulAlignment, ulOffset);
}
void
__ubsan_handle_builtin_unreachable(struct CUnreachableData *pData)
{