OpenHarmony/third_party_mesa3d
2
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

mesa: Fix locking of GLsync objects.

Browse Source 
GLsync objects had a race condition when used from multiple threads
(which is the main point of the extension, really); it could be
validated as a sync object at the beginning of the function, and then
deleted by another thread before use, causing crashes. Fix this by
changing all casts from GLsync to struct gl_sync_object to a new
function _mesa_get_and_ref_sync() that validates and increases
the refcount.

In a similar vein, validation itself uses _mesa_set_search(), which
requires synchronization -- it was called without a mutex held, causing
spurious error returns and other issues. Since _mesa_get_and_ref_sync()
now takes the shared context mutex, this problem is also resolved.

Fixes bug #92757, found while developing Nageru, my live video mixer
(due for release at FOSDEM 2016).

v2: Marek: silence warnings, fix declaration after code

Signed-off-by: Steinar H. Gunderson <sesse@google.com>
Cc: "11.0 11.1" <mesa-stable@lists.freedesktop.org>
Signed-off-by: Marek Olšák <marek.olsak@amd.com>
This commit is contained in:
Steinar H. Gunderson
2016-02-02 01:16:51 +01:00
committed by Marek Olšák
parent 156e81f305
commit feb53912f8
4 changed files with 66 additions and 49 deletions
Download Patch File Download Diff File Expand all files Collapse all files

13
src/mesa/main/objectlabel.c
View File

@@ -288,16 +288,18 @@ void GLAPIENTRY
_mesa_ObjectPtrLabel(const void *ptr, GLsizei length, const GLchar *label)
{
GET_CURRENT_CONTEXT(ctx);
struct gl_sync_object *const syncObj = (struct gl_sync_object *) ptr;
struct gl_sync_object *syncObj;
const char *callerstr;
char **labelPtr;
syncObj = _mesa_get_and_ref_sync(ctx, (void*)ptr, true);
if (_mesa_is_desktop_gl(ctx))
callerstr = "glObjectPtrLabel";
else
callerstr = "glObjectPtrLabelKHR";
if (!_mesa_validate_sync(ctx, syncObj)) {
if (!syncObj) {
_mesa_error(ctx, GL_INVALID_VALUE, "%s (not a valid sync object)",
callerstr);
return;
@@ -306,6 +308,7 @@ _mesa_ObjectPtrLabel(const void *ptr, GLsizei length, const GLchar *label)
labelPtr = &syncObj->Label;
set_label(ctx, labelPtr, label, length, callerstr);
_mesa_unref_sync_object(ctx, syncObj, 1);
}
void GLAPIENTRY
@@ -313,7 +316,7 @@ _mesa_GetObjectPtrLabel(const void *ptr, GLsizei bufSize, GLsizei *length,
GLchar *label)
{
GET_CURRENT_CONTEXT(ctx);
struct gl_sync_object *const syncObj = (struct gl_sync_object *) ptr;
struct gl_sync_object *syncObj;
const char *callerstr;
char **labelPtr;
@@ -328,7 +331,8 @@ _mesa_GetObjectPtrLabel(const void *ptr, GLsizei bufSize, GLsizei *length,
return;
}
if (!_mesa_validate_sync(ctx, syncObj)) {
syncObj = _mesa_get_and_ref_sync(ctx, (void*)ptr, true);
if (!syncObj) {
_mesa_error(ctx, GL_INVALID_VALUE, "%s (not a valid sync object)",
callerstr);
return;
@@ -337,4 +341,5 @@ _mesa_GetObjectPtrLabel(const void *ptr, GLsizei bufSize, GLsizei *length,
labelPtr = &syncObj->Label;
copy_label(*labelPtr, label, length, bufSize);
_mesa_unref_sync_object(ctx, syncObj, 1);
}

2
src/mesa/main/shared.c
View File

@@ -338,7 +338,7 @@ free_shared_state(struct gl_context *ctx, struct gl_shared_state *shared)
struct set_entry *entry;
set_foreach(shared->SyncObjects, entry) {
_mesa_unref_sync_object(ctx, (struct gl_sync_object *) entry->key);
_mesa_unref_sync_object(ctx, (struct gl_sync_object *) entry->key, 1);
}
}
_mesa_set_destroy(shared->SyncObjects, NULL);

87
src/mesa/main/syncobj.c
View File

@@ -167,34 +167,42 @@ _mesa_free_sync_data(struct gl_context *ctx)
* - not in sync objects hash table
* - type is GL_SYNC_FENCE
* - not marked as deleted
*
* Returns the internal gl_sync_object pointer if the sync object is valid
* or NULL if it isn't.
*
* If "incRefCount" is true, the reference count is incremented, which is
* normally what you want; otherwise, a glDeleteSync from another thread
* could delete the sync object while you are still working on it.
*/
bool
_mesa_validate_sync(struct gl_context *ctx,
const struct gl_sync_object *syncObj)
struct gl_sync_object *
_mesa_get_and_ref_sync(struct gl_context *ctx, GLsync sync, bool incRefCount)
{
return (syncObj != NULL)
struct gl_sync_object *syncObj = (struct gl_sync_object *) sync;
mtx_lock(&ctx->Shared->Mutex);
if (syncObj != NULL
&& _mesa_set_search(ctx->Shared->SyncObjects, syncObj) != NULL
&& (syncObj->Type == GL_SYNC_FENCE)
&& !syncObj->DeletePending;
}
void
_mesa_ref_sync_object(struct gl_context *ctx, struct gl_sync_object *syncObj)
{
mtx_lock(&ctx->Shared->Mutex);
&& !syncObj->DeletePending) {
if (incRefCount) {
syncObj->RefCount++;
}
} else {
syncObj = NULL;
}
mtx_unlock(&ctx->Shared->Mutex);
return syncObj;
}
void
_mesa_unref_sync_object(struct gl_context *ctx, struct gl_sync_object *syncObj)
_mesa_unref_sync_object(struct gl_context *ctx, struct gl_sync_object *syncObj,
int amount)
{
struct set_entry *entry;
mtx_lock(&ctx->Shared->Mutex);
syncObj->RefCount--;
syncObj->RefCount -= amount;
if (syncObj->RefCount == 0) {
entry = _mesa_set_search(ctx->Shared->SyncObjects, syncObj);
assert (entry != NULL);
@@ -212,10 +220,9 @@ GLboolean GLAPIENTRY
_mesa_IsSync(GLsync sync)
{
GET_CURRENT_CONTEXT(ctx);
struct gl_sync_object *const syncObj = (struct gl_sync_object *) sync;
ASSERT_OUTSIDE_BEGIN_END_WITH_RETVAL(ctx, GL_FALSE);
return _mesa_validate_sync(ctx, syncObj) ? GL_TRUE : GL_FALSE;
return _mesa_get_and_ref_sync(ctx, sync, false) ? GL_TRUE : GL_FALSE;
}
@@ -223,7 +230,7 @@ void GLAPIENTRY
_mesa_DeleteSync(GLsync sync)
{
GET_CURRENT_CONTEXT(ctx);
struct gl_sync_object *const syncObj = (struct gl_sync_object *) sync;
struct gl_sync_object *syncObj;
/* From the GL_ARB_sync spec:
*
@@ -235,16 +242,19 @@ _mesa_DeleteSync(GLsync sync)
return;
}
if (!_mesa_validate_sync(ctx, syncObj)) {
syncObj = _mesa_get_and_ref_sync(ctx, sync, true);
if (!syncObj) {
_mesa_error(ctx, GL_INVALID_VALUE, "glDeleteSync (not a valid sync object)");
return;
}
/* If there are no client-waits or server-waits pending on this sync, delete
* the underlying object.
* the underlying object. Note that we double-unref the object, as
* _mesa_get_and_ref_sync above took an extra refcount to make sure the pointer
* is valid for us to manipulate.
*/
syncObj->DeletePending = GL_TRUE;
_mesa_unref_sync_object(ctx, syncObj);
_mesa_unref_sync_object(ctx, syncObj, 2);
}
@@ -299,21 +309,20 @@ GLenum GLAPIENTRY
_mesa_ClientWaitSync(GLsync sync, GLbitfield flags, GLuint64 timeout)
{
GET_CURRENT_CONTEXT(ctx);
struct gl_sync_object *const syncObj = (struct gl_sync_object *) sync;
struct gl_sync_object *syncObj;
GLenum ret;
ASSERT_OUTSIDE_BEGIN_END_WITH_RETVAL(ctx, GL_WAIT_FAILED);
if (!_mesa_validate_sync(ctx, syncObj)) {
_mesa_error(ctx, GL_INVALID_VALUE, "glClientWaitSync (not a valid sync object)");
return GL_WAIT_FAILED;
}
if ((flags & ~GL_SYNC_FLUSH_COMMANDS_BIT) != 0) {
_mesa_error(ctx, GL_INVALID_VALUE, "glClientWaitSync(flags=0x%x)", flags);
return GL_WAIT_FAILED;
}
_mesa_ref_sync_object(ctx, syncObj);
syncObj = _mesa_get_and_ref_sync(ctx, sync, true);
if (!syncObj) {
_mesa_error(ctx, GL_INVALID_VALUE, "glClientWaitSync (not a valid sync object)");
return GL_WAIT_FAILED;
}
/* From the GL_ARB_sync spec:
*
@@ -335,7 +344,7 @@ _mesa_ClientWaitSync(GLsync sync, GLbitfield flags, GLuint64 timeout)
}
}
_mesa_unref_sync_object(ctx, syncObj);
_mesa_unref_sync_object(ctx, syncObj, 1);
return ret;
}
@@ -344,12 +353,7 @@ void GLAPIENTRY
_mesa_WaitSync(GLsync sync, GLbitfield flags, GLuint64 timeout)
{
GET_CURRENT_CONTEXT(ctx);
struct gl_sync_object *const syncObj = (struct gl_sync_object *) sync;
if (!_mesa_validate_sync(ctx, syncObj)) {
_mesa_error(ctx, GL_INVALID_VALUE, "glWaitSync (not a valid sync object)");
return;
}
struct gl_sync_object *syncObj;
if (flags != 0) {
_mesa_error(ctx, GL_INVALID_VALUE, "glWaitSync(flags=0x%x)", flags);
@@ -362,7 +366,14 @@ _mesa_WaitSync(GLsync sync, GLbitfield flags, GLuint64 timeout)
return;
}
syncObj = _mesa_get_and_ref_sync(ctx, sync, true);
if (!syncObj) {
_mesa_error(ctx, GL_INVALID_VALUE, "glWaitSync (not a valid sync object)");
return;
}
ctx->Driver.ServerWaitSync(ctx, syncObj, flags, timeout);
_mesa_unref_sync_object(ctx, syncObj, 1);
}
@@ -371,11 +382,12 @@ _mesa_GetSynciv(GLsync sync, GLenum pname, GLsizei bufSize, GLsizei *length,
GLint *values)
{
GET_CURRENT_CONTEXT(ctx);
struct gl_sync_object *const syncObj = (struct gl_sync_object *) sync;
struct gl_sync_object *syncObj;
GLsizei size = 0;
GLint v[1];
if (!_mesa_validate_sync(ctx, syncObj)) {
syncObj = _mesa_get_and_ref_sync(ctx, sync, true);
if (!syncObj) {
_mesa_error(ctx, GL_INVALID_VALUE, "glGetSynciv (not a valid sync object)");
return;
}
@@ -409,6 +421,7 @@ _mesa_GetSynciv(GLsync sync, GLenum pname, GLsizei bufSize, GLsizei *length,
default:
_mesa_error(ctx, GL_INVALID_ENUM, "glGetSynciv(pname=0x%x)\n", pname);
_mesa_unref_sync_object(ctx, syncObj, 1);
return;
}
@@ -421,4 +434,6 @@ _mesa_GetSynciv(GLsync sync, GLenum pname, GLsizei bufSize, GLsizei *length,
if (length != NULL) {
*length = size;
}
_mesa_unref_sync_object(ctx, syncObj, 1);
}

11
src/mesa/main/syncobj.h
View File

@@ -47,15 +47,12 @@ _mesa_init_sync(struct gl_context *);
extern void
_mesa_free_sync_data(struct gl_context *);
extern void
_mesa_ref_sync_object(struct gl_context *ctx, struct gl_sync_object *syncObj);
struct gl_sync_object *
_mesa_get_and_ref_sync(struct gl_context *ctx, GLsync sync, bool incRefCount);
extern void
_mesa_unref_sync_object(struct gl_context *ctx, struct gl_sync_object *syncObj);
extern bool
_mesa_validate_sync(struct gl_context *ctx,
const struct gl_sync_object *syncObj);
_mesa_unref_sync_object(struct gl_context *ctx, struct gl_sync_object *syncObj,
int amount);
extern GLboolean GLAPIENTRY
_mesa_IsSync(GLsync sync);