From ec609cef016b8d3c191e599f4ca70aace4e11c53 Mon Sep 17 00:00:00 2001 From: "jan.nijtmans" Date: Thu, 25 Aug 2022 20:36:39 +0000 Subject: [37108037b9]: Code cleanups to support CHERI. Apply patch 0001 and 0003 (and a few more potential alignment problems, inspired by those patches) --- generic/tclCompile.c | 8 ++++++-- generic/tclDisassemble.c | 13 +++++++------ generic/tclExecute.c | 4 ++-- generic/tclInt.h | 26 +++++++++++++++++++------- 4 files changed, 34 insertions(+), 17 deletions(-) diff --git a/generic/tclCompile.c b/generic/tclCompile.c index 80d8a09..2d22dc1 100644 --- a/generic/tclCompile.c +++ b/generic/tclCompile.c @@ -2838,9 +2838,13 @@ TclInitByteCode( /* * Compute the total number of bytes needed for this bytecode. + * + * Note that code bytes need not be aligned but since later elements are we + * need to pad anyway, either directly after ByteCode or after codeBytes, + * and it's easier and more consistent to do the former. */ - structureSize = sizeof(ByteCode); + structureSize = TCL_ALIGN(sizeof(ByteCode)); /* align code bytes */ structureSize += TCL_ALIGN(codeBytes); /* align object array */ structureSize += TCL_ALIGN(objArrayBytes); /* align exc range arr */ structureSize += TCL_ALIGN(exceptArrayBytes); /* align AuxData array */ @@ -2879,7 +2883,7 @@ TclInitByteCode( codePtr->maxExceptDepth = envPtr->maxExceptDepth; codePtr->maxStackDepth = envPtr->maxStackDepth; - p += sizeof(ByteCode); + p += TCL_ALIGN(sizeof(ByteCode)); /* align code bytes */ codePtr->codeStart = p; memcpy(p, envPtr->codeStart, codeBytes); diff --git a/generic/tclDisassemble.c b/generic/tclDisassemble.c index 2653630..0bc3de1 100644 --- a/generic/tclDisassemble.c +++ b/generic/tclDisassemble.c @@ -301,13 +301,14 @@ DisassembleByteCodeObj( #ifdef TCL_COMPILE_STATS Tcl_AppendPrintfToObj(bufferObj, - " Code %lu = header %lu+inst %d+litObj %lu+exc %lu+aux %lu+cmdMap %d\n", - (unsigned long) codePtr->structureSize, - (unsigned long) (sizeof(ByteCode) - sizeof(size_t) - sizeof(Tcl_Time)), + " Code %" TCL_Z_MODIFIER "u = header %" TCL_Z_MODIFIER "u+inst %d+litObj %" + TCL_Z_MODIFIER "u+exc %" TCL_Z_MODIFIER "u+aux %" TCL_Z_MODIFIER "u+cmdMap %d\n", + codePtr->structureSize, + offsetof(ByteCode, localCachePtr), codePtr->numCodeBytes, - (unsigned long) (codePtr->numLitObjects * sizeof(Tcl_Obj *)), - (unsigned long) (codePtr->numExceptRanges*sizeof(ExceptionRange)), - (unsigned long) (codePtr->numAuxDataItems * sizeof(AuxData)), + codePtr->numLitObjects * sizeof(Tcl_Obj *), + codePtr->numExceptRanges*sizeof(ExceptionRange), + codePtr->numAuxDataItems * sizeof(AuxData), codePtr->numCmdLocBytes); #endif /* TCL_COMPILE_STATS */ diff --git a/generic/tclExecute.c b/generic/tclExecute.c index dd50be0..3fb7e07 100644 --- a/generic/tclExecute.c +++ b/generic/tclExecute.c @@ -9080,7 +9080,7 @@ PrintByteCodeInfo( #ifdef TCL_COMPILE_STATS fprintf(stdout, " Code %lu = header %lu+inst %d+litObj %lu+exc %lu+aux %lu+cmdMap %d\n", (unsigned long) codePtr->structureSize, - (unsigned long) (sizeof(ByteCode)-sizeof(size_t)-sizeof(Tcl_Time)), + (unsigned long) offsetof(ByteCode, localCachePtr), codePtr->numCodeBytes, (unsigned long) (codePtr->numLitObjects * sizeof(Tcl_Obj *)), (unsigned long) (codePtr->numExceptRanges*sizeof(ExceptionRange)), @@ -9723,7 +9723,7 @@ EvalStatsCmd( numCurrentByteCodes = statsPtr->numCompilations - statsPtr->numByteCodesFreed; currentHeaderBytes = numCurrentByteCodes - * (sizeof(ByteCode) - sizeof(size_t) - sizeof(Tcl_Time)); + * offsetof(ByteCode, localCachePtr); literalMgmtBytes = sizeof(LiteralTable) + (iPtr->literalTable.numBuckets * sizeof(LiteralEntry *)) + (iPtr->literalTable.numEntries * sizeof(LiteralEntry)); diff --git a/generic/tclInt.h b/generic/tclInt.h index ac6fb54..f032efb 100644 --- a/generic/tclInt.h +++ b/generic/tclInt.h @@ -2358,22 +2358,34 @@ typedef struct Interp { #endif /* - * This macro is used to determine the offset needed to safely allocate any + * TCL_ALIGN is used to determine the offset needed to safely allocate any * data structure in memory. Given a starting offset or size, it "rounds up" - * or "aligns" the offset to the next 8-byte boundary so that any data - * structure can be placed at the resulting offset without fear of an - * alignment error. + * or "aligns" the offset to the next aligned (typically 8-byte) boundary so + * that any data structure can be placed at the resulting offset without fear + * of an alignment error. Note this is clamped to a minimum of 8 for API + * compatibility. * * WARNING!! DO NOT USE THIS MACRO TO ALIGN POINTERS: it will produce the - * wrong result on platforms that allocate addresses that are divisible by 4 - * or 2. Only use it for offsets or sizes. + * wrong result on platforms that allocate addresses that are divisible by a + * non-trivial factor of this alignment. Only use it for offsets or sizes. * * This macro is only used by tclCompile.c in the core (Bug 926445). It * however not be made file static, as extensions that touch bytecodes * (notably tbcload) require it. */ -#define TCL_ALIGN(x) (((int)(x) + 7) & ~7) +struct TclMaxAlignment { + char unalign[8]; + union { + long long maxAlignLongLong; + double maxAlignDouble; + void *maxAlignPointer; + } aligned; +}; +#define TCL_ALIGN_BYTES \ + offsetof(struct TclMaxAlignment, aligned) +#define TCL_ALIGN(x) \ + (((x) + (TCL_ALIGN_BYTES - 1)) & ~(TCL_ALIGN_BYTES - 1)) /* * A common panic alert when memory allocation fails. -- cgit v0.12