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eliasnaureliasnaur
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runtime,runtime/cgo: set up TLS storage for Android Q without cgo
Android Q frees a static TLS slot for us to use. Use the offset of that slot as the default for our TLS offset. As a result, runtime/cgo is no more a requirement for Android Q and newer. Updates golang#31343 Updates golang#29674 Change-Id: I759049b2e2865bd3d4fdc05a8cfc6db8b0da1f5d Reviewed-on: https://go-review.googlesource.com/c/go/+/170955 TryBot-Result: Gobot Gobot <[email protected]> Reviewed-by: Cherry Zhang <[email protected]>
1 parent 973c031 commit f18c31a

5 files changed

Lines changed: 22 additions & 2 deletions

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‎src/runtime/asm_386.s‎

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@@ -1564,5 +1564,8 @@ TEXT runtime·panicExtendSlice3CU(SB),NOSPLIT,$0-12
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JMP runtime·goPanicExtendSlice3CU(SB)
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#ifdef GOOS_android
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// Use the free TLS_SLOT_APP slot #2 on Android Q.
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// Earlier androids are set up in gcc_android.c.
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DATA runtime·tls_g+0(SB)/4, $8
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GLOBL runtime·tls_g+0(SB), NOPTR, $4
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#endif

‎src/runtime/asm_amd64.s‎

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@@ -1713,5 +1713,8 @@ TEXT runtime·panicSlice3CU(SB),NOSPLIT,$0-16
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JMP runtime·goPanicSlice3CU(SB)
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#ifdef GOOS_android
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// Use the free TLS_SLOT_APP slot #2 on Android Q.
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// Earlier androids are set up in gcc_android.c.
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DATA runtime·tls_g+0(SB)/8, $16
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GLOBL runtime·tls_g+0(SB), NOPTR, $8
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#endif

‎src/runtime/cgo/gcc_android.c‎

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@@ -47,7 +47,7 @@ inittls(void **tlsg, void **tlsbase)
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{
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pthread_key_t k;
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int i, err;
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void *handle, *get_ver;
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void *handle, *get_ver, *off;
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// Check for Android Q where we can use the free TLS_SLOT_APP slot.
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handle = dlopen("libc.so", RTLD_LAZY);
@@ -60,7 +60,11 @@ inittls(void **tlsg, void **tlsbase)
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get_ver = dlsym(handle, "android_get_device_api_level");
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dlclose(handle);
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if (get_ver != NULL) {
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*tlsg = (void *)(TLS_SLOT_APP*sizeof(void *));
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off = (void *)(TLS_SLOT_APP*sizeof(void *));
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// tlsg is initialized to Q's free TLS slot. Verify it while we're here.
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if (*tlsg != off) {
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fatalf("tlsg offset wrong, got %ld want %ld\n", *tlsg, off);
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}
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return;
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}
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‎src/runtime/tls_arm.s‎

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@@ -103,6 +103,11 @@ TEXT setg_gcc<>(SB),NOSPLIT,$0
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B runtime·save_g(SB)
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#ifdef TLSG_IS_VARIABLE
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#ifdef GOOS_android
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// Use the free TLS_SLOT_APP slot #2 on Android Q.
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// Earlier androids are set up in gcc_android.c.
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DATA runtime·tls_g+0(SB)/4, $8
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#endif
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GLOBL runtime·tls_g+0(SB), NOPTR, $4
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#else
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GLOBL runtime·tls_g+0(SB), TLSBSS, $4

‎src/runtime/tls_arm64.s‎

Lines changed: 5 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -43,6 +43,11 @@ nocgo:
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RET
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#ifdef TLSG_IS_VARIABLE
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#ifdef GOOS_android
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// Use the free TLS_SLOT_APP slot #2 on Android Q.
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// Earlier androids are set up in gcc_android.c.
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DATA runtime·tls_g+0(SB)/8, $16
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#endif
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GLOBL runtime·tls_g+0(SB), NOPTR, $8
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#else
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GLOBL runtime·tls_g+0(SB), TLSBSS, $8

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