[3.13] gh-125444: Fix illegal instruction for older Arm architectures (GH-125574...

On Arm v5 it is not possible to get the thread ID via c13 register
hence the illegal instruction. The c13 register started to provide
thread ID since Arm v6K architecture variant. Other variants of
Arm v6 (T2, Z and base) don’t provide the thread ID via c13.
For the sake of simplicity we group v5 and v6 together and
consider that instructions for Arm v7 only.
(cherry picked from commit feda9aa73ab95d17a291db22c416146f8e70edeb)

Co-authored-by: Diego Russo <diego.russo@arm.com>

diff --git a/Include/internal/mimalloc/mimalloc/prim.h b/Include/internal/mimalloc/mimalloc/prim.h
index 8a60d528458e6c2d5af8914c618dfb509cd0465f..322ab29e6b41c24bfaaa94c6d5af103f71bfc285 100644 (file)
--- a/Include/internal/mimalloc/mimalloc/prim.h
+++ b/Include/internal/mimalloc/mimalloc/prim.h
@@ -151,9 +151,9 @@ static inline mi_threadid_t _mi_prim_thread_id(void) mi_attr_noexcept {
 // If you test on another platform and it works please send a PR :-)
 // see also https://akkadia.org/drepper/tls.pdf for more info on the TLS register.
 #elif defined(__GNUC__) && ( \
-           (defined(__GLIBC__)   && (defined(__x86_64__) || defined(__i386__) || defined(__arm__) || defined(__aarch64__))) \
+           (defined(__GLIBC__)   && (defined(__x86_64__) || defined(__i386__) || (defined(__arm__) && __ARM_ARCH >= 7) || defined(__aarch64__))) \
         || (defined(__APPLE__)   && (defined(__x86_64__) || defined(__aarch64__))) \
-        || (defined(__BIONIC__)  && (defined(__x86_64__) || defined(__i386__) || defined(__arm__) || defined(__aarch64__))) \
+        || (defined(__BIONIC__)  && (defined(__x86_64__) || defined(__i386__) || (defined(__arm__) && __ARM_ARCH >= 7) || defined(__aarch64__))) \
         || (defined(__FreeBSD__) && (defined(__x86_64__) || defined(__i386__) || defined(__aarch64__))) \
         || (defined(__OpenBSD__) && (defined(__x86_64__) || defined(__i386__) || defined(__aarch64__))) \
       )

diff --git a/Include/object.h b/Include/object.h
index 78aa7ad0f459fff9576898079fcb7b6e681de515..b53f9acfebdb0c341a53fa27a5d3b9191e427692 100644 (file)
--- a/Include/object.h
+++ b/Include/object.h
@@ -259,7 +259,7 @@ _Py_ThreadId(void)
     __asm__("movq %%gs:0, %0" : "=r" (tid));  // x86_64 macOSX uses GS
 #elif defined(__x86_64__)
    __asm__("movq %%fs:0, %0" : "=r" (tid));  // x86_64 Linux, BSD uses FS
-#elif defined(__arm__)
+#elif defined(__arm__) && __ARM_ARCH >= 7
     __asm__ ("mrc p15, 0, %0, c13, c0, 3\nbic %0, %0, #3" : "=r" (tid));
 #elif defined(__aarch64__) && defined(__APPLE__)
     __asm__ ("mrs %0, tpidrro_el0" : "=r" (tid));

diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2024-10-16-12-12-39.gh-issue-125444.9tG2X6.rst b/Misc/NEWS.d/next/Core_and_Builtins/2024-10-16-12-12-39.gh-issue-125444.9tG2X6.rst
new file mode 100644 (file)
index 0000000..13c1e74
--- /dev/null
+++ b/Misc/NEWS.d/next/Core_and_Builtins/2024-10-16-12-12-39.gh-issue-125444.9tG2X6.rst
@@ -0,0 +1 @@
+Fix illegal instruction for older Arm architectures. Patch by Diego Russo, testing by Ross Burton.