Fill correct stack info in pthread_getattr_np stub (#23887)

hoodmane · web-flow · commit d6ebc74b3648 · 2025-03-12T23:42:36.000+01:00
See use case here: https://github.com/python/cpython/pull/130398/files#diff-c22186367cbe20233e843261998dc027ae5f1f8c0d2e778abfa454ae74cc59deR365-R380 I guess for stack protection, this only enables introspecting whether we run out of the spill stack. I'm not sure whether to expect running out of spill stack or running out of true stack to be more common. But at least this unbreaks the code.
diff --git a/system/lib/pthread/library_pthread_stub.c b/system/lib/pthread/library_pthread_stub.c
@@ -276,10 +276,6 @@ int pthread_condattr_setpshared(pthread_condattr_t *attr, int shared) {
   return 0;
 }
 
-int pthread_getattr_np(pthread_t thread, pthread_attr_t *attr) {
-  return 0;
-}
-
 int pthread_setcancelstate(int state, int* oldstate) {
   return 0;
 }
diff --git a/system/lib/pthread/pthread_self_stub.c b/system/lib/pthread/pthread_self_stub.c
@@ -7,6 +7,7 @@
 
 #include "pthread_impl.h"
 #include <unistd.h>
+#include <emscripten/stack.h>
 
 static struct pthread __main_pthread;
 
@@ -24,8 +25,14 @@ pthread_t emscripten_main_runtime_thread_id() {
   return &__main_pthread;
 }
 
+extern int __stack_high;
+extern int __stack_low;
+
 __attribute__((constructor))
 static void init_pthread_self(void) {
   __main_pthread.locale = &libc.global_locale;
   __main_pthread.tid = getpid();
+  __main_pthread.stack = &__stack_high;
+  __main_pthread.stack_size = ((size_t)&__stack_high) - ((size_t)&__stack_low);
+  __main_pthread.guard_size = __default_guardsize;
 }
diff --git a/test/code_size/embind_val_wasm.json b/test/code_size/embind_val_wasm.json
@@ -3,8 +3,8 @@
   "a.html.gz": 380,
   "a.js": 7030,
   "a.js.gz": 3022,
-  "a.wasm": 9119,
-  "a.wasm.gz": 4701,
-  "total": 16701,
-  "total_gz": 8103
+  "a.wasm": 9155,
+  "a.wasm.gz": 4724,
+  "total": 16737,
+  "total_gz": 8126
 }
diff --git a/test/code_size/random_printf_wasm.json b/test/code_size/random_printf_wasm.json
@@ -1,6 +1,6 @@
 {
-  "a.html": 12442,
-  "a.html.gz": 6793,
-  "total": 12442,
-  "total_gz": 6793
+  "a.html": 12494,
+  "a.html.gz": 6812,
+  "total": 12494,
+  "total_gz": 6812
 }
diff --git a/test/code_size/random_printf_wasm2js.json b/test/code_size/random_printf_wasm2js.json
@@ -1,6 +1,6 @@
 {
-  "a.html": 17205,
-  "a.html.gz": 7516,
-  "total": 17205,
-  "total_gz": 7516
+  "a.html": 17262,
+  "a.html.gz": 7542,
+  "total": 17262,
+  "total_gz": 7542
 }
diff --git a/test/other/codesize/test_codesize_cxx_ctors1.size b/test/other/codesize/test_codesize_cxx_ctors1.size
@@ -1 +1 @@
-129166
+129206
diff --git a/test/other/codesize/test_codesize_cxx_ctors2.size b/test/other/codesize/test_codesize_cxx_ctors2.size
@@ -1 +1 @@
-128578
+128599
diff --git a/test/other/codesize/test_codesize_cxx_except.size b/test/other/codesize/test_codesize_cxx_except.size
@@ -1 +1 @@
-170787
+170827
diff --git a/test/other/codesize/test_codesize_cxx_except_wasm.size b/test/other/codesize/test_codesize_cxx_except_wasm.size
@@ -1 +1 @@
-144542
+144582
diff --git a/test/other/codesize/test_codesize_cxx_except_wasm_legacy.size b/test/other/codesize/test_codesize_cxx_except_wasm_legacy.size
@@ -1 +1 @@
-142117
+142157
diff --git a/test/other/codesize/test_codesize_cxx_lto.size b/test/other/codesize/test_codesize_cxx_lto.size
@@ -1 +1 @@
-122011
+122044
diff --git a/test/other/codesize/test_codesize_cxx_mangle.size b/test/other/codesize/test_codesize_cxx_mangle.size
@@ -1 +1 @@
-232560
+232600
diff --git a/test/other/codesize/test_codesize_cxx_noexcept.size b/test/other/codesize/test_codesize_cxx_noexcept.size
@@ -1 +1 @@
-131729
+131769
diff --git a/test/other/codesize/test_codesize_cxx_wasmfs.size b/test/other/codesize/test_codesize_cxx_wasmfs.size
@@ -1 +1 @@
-169089
+169129
diff --git a/test/other/codesize/test_codesize_hello_O0.size b/test/other/codesize/test_codesize_hello_O0.size
@@ -1 +1 @@
-15105
+15170
diff --git a/test/other/test_pthread_stub.c b/test/other/test_pthread_stub.c
@@ -1,3 +1,4 @@
+#define _GNU_SOURCE
 #include <assert.h>
 #include <errno.h>
 #include <stdint.h>
@@ -29,6 +30,7 @@ void* start_pthread(void* arg) {
 #define CHECK_C11_FAIL(X) CHECK_C11(X, thrd_nomem)
 
 void test_c11_threads() {
+  printf("test_c11_threads\n");
   int rtn;
   int res;
 
@@ -45,6 +47,7 @@ void test_c11_threads() {
 }
 
 void test_pthreads() {
+  printf("test_pthreads\n");
   int rtn;
   int res;
 
@@ -59,8 +62,23 @@ void test_pthreads() {
   pthread_cleanup_pop(1);
 }
 
+void test_pthread_getattr_np() {
+  printf("test_pthread_getattr_np\n");
+  int rtn;
+  pthread_attr_t attr;
+  size_t stack_size, guard_size;
+  void *stack_addr;
+
+  CHECK_SUCCESS(pthread_getattr_np(pthread_self(), &attr));
+  CHECK_SUCCESS(pthread_attr_getguardsize(&attr, &guard_size));
+  CHECK_SUCCESS(pthread_attr_getstack(&attr, &stack_addr, &stack_size));
+  CHECK_SUCCESS(pthread_attr_destroy(&attr));
+  printf("stack_addr: %p, stack_size: %zu, guard_size: %zu\n", stack_addr, stack_size, guard_size);
+}
+
 int main() {
   test_c11_threads();
   test_pthreads();
+  test_pthread_getattr_np();
   return 0;
 }
diff --git a/test/other/test_pthread_stub.out b/test/other/test_pthread_stub.out
@@ -1 +1,5 @@
+test_c11_threads
+test_pthreads
 cleanup: 42
+test_pthread_getattr_np
+stack_addr: 0, stack_size: 65536, guard_size: 8192
diff --git a/test/other/test_unoptimized_code_size.wasm.size b/test/other/test_unoptimized_code_size.wasm.size
@@ -1 +1 @@
-15105
+15170
diff --git a/test/other/test_unoptimized_code_size_no_asserts.wasm.size b/test/other/test_unoptimized_code_size_no_asserts.wasm.size
@@ -1 +1 @@
-12186
+12251
diff --git a/test/other/test_unoptimized_code_size_strict.wasm.size b/test/other/test_unoptimized_code_size_strict.wasm.size
@@ -1 +1 @@
-15105
+15170
diff --git a/tools/system_libs.py b/tools/system_libs.py
@@ -1168,6 +1168,7 @@ def get_files(self):
           'pthread_attr_setscope.c',
           'pthread_attr_setstack.c',
           'pthread_attr_setstacksize.c',
+          'pthread_getattr_np.c',
           'pthread_getconcurrency.c',
           'pthread_getcpuclockid.c',
           'pthread_getschedparam.c',

Original file line number	Diff line number	Diff line change
`@@ -276,10 +276,6 @@ int pthread_condattr_setpshared(pthread_condattr_t *attr, int shared) {`
`276`	`276`	`return 0;`
`277`	`277`	`}`
`278`	`278`
`279`		`-int pthread_getattr_np(pthread_t thread, pthread_attr_t *attr) {`
`280`		`- return 0;`
`281`		`-}`
`282`		`-`
`283`	`279`	`int pthread_setcancelstate(int state, int* oldstate) {`
`284`	`280`	`return 0;`
`285`	`281`	`}`
Original file line number	Diff line number	Diff line change
`@@ -1,6 +1,6 @@`
`1`	`1`	`{`
`2`		`- "a.html": 12442,`
`3`		`- "a.html.gz": 6793,`
`4`		`- "total": 12442,`
`5`		`- "total_gz": 6793`
	`2`	`+ "a.html": 12494,`
	`3`	`+ "a.html.gz": 6812,`
	`4`	`+ "total": 12494,`
	`5`	`+ "total_gz": 6812`
`6`	`6`	`}`
Original file line number	Diff line number	Diff line change
`@@ -1,6 +1,6 @@`
`1`	`1`	`{`
`2`		`- "a.html": 17205,`
`3`		`- "a.html.gz": 7516,`
`4`		`- "total": 17205,`
`5`		`- "total_gz": 7516`
	`2`	`+ "a.html": 17262,`
	`3`	`+ "a.html.gz": 7542,`
	`4`	`+ "total": 17262,`
	`5`	`+ "total_gz": 7542`
`6`	`6`	`}`