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// Copyright 2014 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
#include <stdarg.h>
#include <android/log.h>
#include <pthread.h>
#include <dlfcn.h>
#include "libcgo.h"
void
fatalf(const char* format, ...)
{
va_list ap;
// Write to both stderr and logcat.
//
// When running from an .apk, /dev/stderr and /dev/stdout
// redirect to /dev/null. And when running a test binary
// via adb shell, it's easy to miss logcat.
fprintf(stderr, "runtime/cgo: ");
va_start(ap, format);
vfprintf(stderr, format, ap);
va_end(ap);
fprintf(stderr, "\n");
va_start(ap, format);
__android_log_vprint(ANDROID_LOG_FATAL, "runtime/cgo", format, ap);
va_end(ap);
abort();
}
// Truncated to a different magic value on 32-bit; that's ok.
#define magic1 (0x23581321345589ULL)
// From https://android.googlesource.com/platform/bionic/+/refs/heads/android10-tests-release/libc/private/bionic_asm_tls.h#69.
#define TLS_SLOT_APP 2
// inittls allocates a thread-local storage slot for g.
//
// It finds the first available slot using pthread_key_create and uses
// it as the offset value for runtime.tls_g.
static void
inittls(void **tlsg, void **tlsbase)
{
pthread_key_t k;
int i, err;
void *handle, *get_ver, *off;
// Check for Android Q where we can use the free TLS_SLOT_APP slot.
handle = dlopen("libc.so", RTLD_LAZY);
if (handle == NULL) {
fatalf("inittls: failed to dlopen main program");
return;
}
// android_get_device_api_level is introduced in Android Q, so its mere presence
// is enough.
get_ver = dlsym(handle, "android_get_device_api_level");
dlclose(handle);
if (get_ver != NULL) {
off = (void *)(TLS_SLOT_APP*sizeof(void *));
// tlsg is initialized to Q's free TLS slot. Verify it while we're here.
if (*tlsg != off) {
fatalf("tlsg offset wrong, got %ld want %ld\n", *tlsg, off);
}
return;
}
err = pthread_key_create(&k, nil);
if(err != 0) {
fatalf("pthread_key_create failed: %d", err);
}
pthread_setspecific(k, (void*)magic1);
// If thread local slots are laid out as we expect, our magic word will
// be located at some low offset from tlsbase. However, just in case something went
// wrong, the search is limited to sensible offsets. PTHREAD_KEYS_MAX was the
// original limit, but issue 19472 made a higher limit necessary.
for (i=0; i<384; i++) {
if (*(tlsbase+i) == (void*)magic1) {
*tlsg = (void*)(i*sizeof(void *));
pthread_setspecific(k, 0);
return;
}
}
fatalf("inittls: could not find pthread key");
}
void (*x_cgo_inittls)(void **tlsg, void **tlsbase) = inittls;
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