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Disable malloc instrumentation for VM (#2)

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When the malloc code is instrumented, the global _brksize variable
should not be transferred.  However, when the malloc code is not
instrumented, failing to transfer _brksize would reset the heap
upon state transfer.  In this patch, the magic pass stores the flag
indicating whether memory function instrumentation is disabled, in
the target process.  This allows libmagic to check this flag during
state transfer, to see whether it should transfer _brksize or not.

Change-Id: Ia004651e21e08b0ed3f5305865c53c6659e18f38
This commit is contained in:
David van Moolenbroek 2015-09-06 11:16:12 +02:00
parent 76b68f9f99
commit c07c198b5f
7 changed files with 33 additions and 2 deletions
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3
minix/llvm/include/magic.h
View file

@ -869,6 +869,9 @@ EXTERN void* __stop_magic_functions_st;
#define _magic_asr_map_max_padding_pages ( \
_magic_vars->asr_map_max_padding_pages)
/* Runtime flags. */
#define _magic_no_mem_inst (_magic_vars->no_mem_inst)
/* Magic type array. */
#define _magic_types (_magic_vars->types)
#define _magic_types_num (_magic_vars->types_num)

2
minix/llvm/include/magic_common.h
View file

@ -179,6 +179,7 @@
#define MAGIC_RSTRUCT_FIELD_ASR_HEAP_MAX_PADDING "asr_heap_max_padding"
#define MAGIC_RSTRUCT_FIELD_ASR_MAP_MAX_OFFSET_PAGES "asr_map_max_offset_pages"
#define MAGIC_RSTRUCT_FIELD_ASR_MAP_MAX_PADDING_PAGES "asr_map_max_padding_pages"
#define MAGIC_RSTRUCT_FIELD_NO_MEM_INST "no_mem_inst"
#define MAGIC_RSTRUCT_FIELD_TYPES "types"
#define MAGIC_RSTRUCT_FIELD_TYPES_NUM "types_num"
#define MAGIC_RSTRUCT_FIELD_TYPES_NEXT_ID "types_next_id"
@ -199,6 +200,7 @@
MAGIC_RSTRUCT_FIELD_ASR_HEAP_MAX_PADDING, \
MAGIC_RSTRUCT_FIELD_ASR_MAP_MAX_OFFSET_PAGES, \
MAGIC_RSTRUCT_FIELD_ASR_MAP_MAX_PADDING_PAGES, \
MAGIC_RSTRUCT_FIELD_NO_MEM_INST, \
MAGIC_RSTRUCT_FIELD_TYPES, \
MAGIC_RSTRUCT_FIELD_TYPES_NUM, \
MAGIC_RSTRUCT_FIELD_TYPES_NEXT_ID, \

3
minix/llvm/include/magic_structs.h
View file

@ -234,6 +234,9 @@ struct _magic_vars_t {
int asr_map_max_offset_pages;
int asr_map_max_padding_pages;
/* Runtime flags. */
int no_mem_inst;
/* Magic type array. */
struct _magic_type *types;
int types_num;

5
minix/llvm/include/st/typedefs.h
View file

@ -41,11 +41,12 @@
ST_DECLARE_STD_PTRINT_TYPEDEFS(pxfer_);
#define ST_TYPENAME_STRUCT_TRANSFER_NAMES "sxfer_*"
#ifdef __MINIX
#define ST_SENTRYNAME_NO_TRANSFER_NAMES "noxfer_*", "sef_*", "st_*", "_brksize", "etext"
#define ST_SENTRYNAME_NO_TRANSFER_NAMES "noxfer_*", "sef_*", "st_*", "etext"
#else
#define ST_SENTRYNAME_NO_TRANSFER_NAMES "noxfer_*", "st_*", "_brksize", "etext", "allocatedDescs*", "ep.*" /* nginx specific */
#define ST_SENTRYNAME_NO_TRANSFER_NAMES "noxfer_*", "st_*", "etext", "allocatedDescs*", "ep.*" /* nginx specific */
#define ST_DSENTRYLIB_NO_TRANSFER_NAMES "*/libst.so", "*/libcommon.so", "*/libtaskctl.so"
#endif
#define ST_SENTRYNAME_NO_TRANSFER_MEM_NAMES "_brksize"
#define ST_SENTRYNAME_IDENTITY_TRANSFER_NAMES "ixfer_*"
#define ST_SENTRYNAME_CIDENTITY_TRANSFER_NAMES "cixfer_*"
#define ST_SENTRYNAME_PTR_TRANSFER_NAMES "pxfer_*"

10
minix/llvm/passes/magic/MagicPass.cpp
View file

@ -193,6 +193,13 @@ bool MagicPass::runOnModule(Module &M) {
}
Instruction *magicArrayBuildFuncInst = magicDataInitFunc->back().getTerminator();
//look up pointer to magic memory instrumentation flag
Value* magicNoMemInst = MagicUtil::getMagicRStructFieldPtr(M, magicArrayBuildFuncInst, magicRootVar, MAGIC_RSTRUCT_FIELD_NO_MEM_INST);
if(!magicNoMemInst) {
magicPassErr("Error: no " << MAGIC_RSTRUCT_FIELD_NO_MEM_INST << " field found");
exit(1);
}
//look up pointer to magic array and magic struct type
Value* magicArrayPtr = MagicUtil::getMagicRStructFieldPtr(M, magicArrayBuildFuncInst, magicRootVar, MAGIC_RSTRUCT_FIELD_SENTRIES);
if(!magicArrayPtr) {
@ -1684,6 +1691,9 @@ bool MagicPass::runOnModule(Module &M) {
//set pointer to magic type array in build function
new StoreInst(MagicUtil::getArrayPtr(M, magicTypeArray), magicTypeArrayPtr, false, magicArrayBuildFuncInst);
// set runtime flags
new StoreInst(ConstantInt::get(M.getContext(), APInt(32, DisableMemFunctions ? 1 : 0)), magicNoMemInst, false, magicArrayBuildFuncInst);
//set magic type array size in build function
new StoreInst(ConstantInt::get(M.getContext(), APInt(32, globalTypeInfos.size())), magicTypeArraySize, false, magicArrayBuildFuncInst);

3
minix/llvm/static/magic/magic.c
View file

@ -57,6 +57,9 @@ MAGIC_VAR struct _magic_vars_t _magic_vars_buff = {
0, /* asr_map_max_offset_pages */
0, /* asr_map_max_padding_pages */
/* Runtime flags. */
0, /* no_mem_inst */
/* Magic type array. */
NULL, /* types */
0, /* types_num */

9
minix/llvm/static/magic/magic_st.c
View file

@ -214,6 +214,7 @@ char *st_sentryname_noxfers[] = {
#endif
#undef __X
NULL };
char *st_sentryname_noxfers_mem[] = { ST_SENTRYNAME_NO_TRANSFER_MEM_NAMES, NULL };
/* Exclude the data segments of certain libs from state transfer. */
char *st_dsentry_lib_noxfer[] = {
@ -730,6 +731,14 @@ PUBLIC int st_cb_transfer_sentry_default(_magic_selement_t *selement, _magic_sel
return MAGIC_SENTRY_ANALYZE_SKIP_PATH;
}
/* Skip memory management related sentries only when memory functions have
* been instrumented (which is *not* the case for the MINIX3 VM service).
*/
if (_magic_no_mem_inst == 0 && ST_SENTRY_NAME_MATCH_ANY(st_sentryname_noxfers_mem, sentry_name)) {
ST_CB_PRINT(ST_CB_DBG, "sentry name matches noxfer", selement, sel_analyzed, sel_stats, cb_info);
return MAGIC_SENTRY_ANALYZE_SKIP_PATH;
}
if (ST_SENTRY_NAME_MATCH_ANY(st_sentryname_pxfers, sentry_name)) {
ST_CB_PRINT(ST_CB_DBG, "sentry name matches pxfer", selement, sel_analyzed, sel_stats, cb_info);
return transfer_ptr_sel_cb(selement, sel_analyzed, sel_stats, cb_info);