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add capability to override multiple entry points in windows dynamic override; and stop patching msvcrt, just crtbase

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daan 2019-07-04 12:06:15 -07:00
parent 74dc95c1d6
commit 5ff037f8f8
1 changed files with 40 additions and 29 deletions
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69
src/alloc-override-win.c
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@ -379,18 +379,19 @@ typedef enum patch_apply_e {
PATCH_TARGET_TERM
} patch_apply_t;
#define MAX_ENTRIES 4 // maximum number of patched entry points (like `malloc` in ucrtbase and msvcrt)
typedef struct mi_patch_s {
const char* name; // name of the function to patch
int priority; // priority to patch this one (used to prioritize over multiple entries in various dll's)
void* original; // the resolved address of the function (or NULL)
void* target; // the address of the new target (never NULL)
void* target_term;// the address of the target during termination (or NULL)
patch_apply_t applied; // what target has been applied?
mi_jump_t save; // the saved instructions in case it was applied
const char* name; // name of the function to patch
void* target; // the address of the new target (never NULL)
void* target_term; // the address of the target during termination (or NULL)
patch_apply_t applied; // what target has been applied?
void* originals[MAX_ENTRIES]; // the resolved addresses of the function (or NULLs)
mi_jump_t saves[MAX_ENTRIES]; // the saved instructions in case it was applied
} mi_patch_t;
#define MI_PATCH_NAME3(name,target,term) { name, 0, NULL, &target, &term, PATCH_NONE }
#define MI_PATCH_NAME2(name,target) { name, 0, NULL, &target, NULL, PATCH_NONE }
#define MI_PATCH_NAME3(name,target,term) { name, &target, &term, PATCH_NONE, {NULL,NULL,NULL,NULL} }
#define MI_PATCH_NAME2(name,target) { name, &target, NULL, PATCH_NONE, {NULL,NULL,NULL,NULL} }
#define MI_PATCH3(name,target,term) MI_PATCH_NAME3(#name, target, term)
#define MI_PATCH2(name,target) MI_PATCH_NAME2(#name, target)
#define MI_PATCH1(name) MI_PATCH2(name,mi_##name)
@ -463,29 +464,34 @@ static mi_patch_t patches[] = {
MI_PATCH_NAME3("??_V@YAXPAXABUnothrow_t@std@@@Z", mi_free, mi_free_term),
#endif
#endif
{ NULL, 0, NULL, NULL, NULL, PATCH_NONE }
{ NULL, NULL, NULL, PATCH_NONE, {NULL,NULL,NULL,NULL} }
};
// Apply a patch
static bool mi_patch_apply(mi_patch_t* patch, patch_apply_t apply)
{
if (patch->original == NULL) return true; // unresolved
if (patch->originals[0] == NULL) return true; // unresolved
if (apply == PATCH_TARGET_TERM && patch->target_term == NULL) apply = PATCH_TARGET; // avoid re-applying non-term variants
if (patch->applied == apply) return false;
DWORD protect = PAGE_READWRITE;
if (!VirtualProtect(patch->original, MI_JUMP_SIZE, PAGE_EXECUTE_READWRITE, &protect)) return false;
if (apply == PATCH_NONE) {
mi_jump_restore(patch->original, &patch->save);
}
else {
void* target = (apply == PATCH_TARGET ? patch->target : patch->target_term);
mi_assert_internal(target!=NULL);
if (target != NULL) mi_jump_write(patch->original, target, &patch->save);
for (int i = 0; i < MAX_ENTRIES; i++) {
void* original = patch->originals[i];
if (original == NULL) break; // no more
DWORD protect = PAGE_READWRITE;
if (!VirtualProtect(original, MI_JUMP_SIZE, PAGE_EXECUTE_READWRITE, &protect)) return false;
if (apply == PATCH_NONE) {
mi_jump_restore(original, &patch->saves[i]);
}
else {
void* target = (apply == PATCH_TARGET ? patch->target : patch->target_term);
mi_assert_internal(target != NULL);
if (target != NULL) mi_jump_write(original, target, &patch->saves[i]);
}
VirtualProtect(original, MI_JUMP_SIZE, protect, &protect);
}
patch->applied = apply;
VirtualProtect(patch->original, MI_JUMP_SIZE, protect, &protect);
return true;
}
@ -542,13 +548,17 @@ static void mi_module_resolve(const char* fname, HMODULE mod, int priority) {
// see if any patches apply
for (size_t i = 0; patches[i].name != NULL; i++) {
mi_patch_t* patch = &patches[i];
if (!patch->applied && patch->priority < priority) {
void* addr = GetProcAddress(mod, patch->name);
if (addr != NULL) {
// found it! set the address
patch->original = addr;
patch->priority = priority;
_mi_trace_message(" override %s at %s!%p, priority %i\n", patch->name, fname, addr, priority);
if (patch->applied == PATCH_NONE) {
// find an available entry
int i = 0;
while (i < MAX_ENTRIES && patch->originals[i] != NULL) i++;
if (i < MAX_ENTRIES) {
void* addr = GetProcAddress(mod, patch->name);
if (addr != NULL) {
// found it! set the address
patch->originals[i] = addr;
_mi_trace_message(" override %s at %s!%p (entry %i)\n", patch->name, fname, addr, i);
}
}
}
}
@ -595,7 +605,8 @@ static bool mi_patches_resolve(void) {
int priority = 0;
if (i == 0) priority = 2; // main module to allow static crt linking
else if (_strnicmp(basename, "ucrt", 4) == 0) priority = 3; // new ucrtbase.dll in windows 10
else if (_strnicmp(basename, "msvcr", 5) == 0) priority = 1; // older runtimes
// NOTE: don't override msvcr -- leads to crashes in setlocale (needs more testing)
// else if (_strnicmp(basename, "msvcr", 5) == 0) priority = 1; // older runtimes
if (priority > 0) {
// probably found a crt module, try to patch it