aarch64: patch mkl-dnn for xbyak crashes due to /sys not accessible (#1648)

There are platforms with /sys not mounted. skip handling HW caps
for such platforms.

cherry-pick of: uxlfoundation/oneDNN#1773
This fixes the issue# pytorch/pytorch#115482

Author: snadampal

aarch64_linux/aarch64_wheel_ci_build.py

@@ -106,6 +106,10 @@ def parse_arguments():
     else:
         print("build pytorch without mkldnn backend")
 
+    # patch mkldnn to fix aarch64 mac and aws lambda crash
+    print("Applying mkl-dnn patch to fix crash due to /sys not accesible")
+    os.system("cd /pytorch/third_party/ideep/mkl-dnn && patch -p1 < /builder/mkldnn_fix/fix-xbyak-failure.patch")
+
     os.system(f"cd /pytorch; {build_vars} python3 setup.py bdist_wheel")
     pytorch_wheel_name = complete_wheel("pytorch")
     print(f"Build Compelete. Created {pytorch_wheel_name}..")

aarch64_linux/build_aarch64_wheel.py

@@ -556,6 +556,8 @@ def start_build(host: RemoteHost, *,
         build_ArmComputeLibrary(host, git_clone_flags)
         print("build pytorch with mkldnn+acl backend")
         build_vars += " USE_MKLDNN=ON USE_MKLDNN_ACL=ON"
+        host.run_cmd("cd $HOME && git clone https://github.com/pytorch/builder.git")
+        host.run_cmd("cd $HOME/pytorch/third_party/ideep/mkl-dnn && patch -p1 < $HOME/builder/mkldnn_fix/fix-xbyak-failure.patch")  # noqa: E501
         host.run_cmd(f"cd $HOME/pytorch && export ACL_ROOT_DIR=$HOME/ComputeLibrary && {build_vars} python3 setup.py bdist_wheel{build_opts}")  # noqa: E501
         print('Repair the wheel')
         pytorch_wheel_name = host.list_dir("pytorch/dist")[0]

mkldnn_fix/fix-xbyak-failure.patch

@@ -0,0 +1,96 @@
+cpu: aarch64: fix xbyak functions for /sys access failures
+
+There are platforms with /sys not mounted. skip handling HW caps
+for such platforms.
+
+This fixes the issue# pytorch/pytorch#115482
+---
+ .../xbyak_aarch64/src/util_impl_linux.h       | 24 ++++++++++++++-----
+ .../aarch64/xbyak_aarch64/src/util_impl_mac.h |  9 ++++---
+ 2 files changed, 24 insertions(+), 9 deletions(-)
+
+diff --git a/src/cpu/aarch64/xbyak_aarch64/src/util_impl_linux.h b/src/cpu/aarch64/xbyak_aarch64/src/util_impl_linux.h
+index 2c7b28e58b..860a05700f 100644
+--- a/src/cpu/aarch64/xbyak_aarch64/src/util_impl_linux.h
++++ b/src/cpu/aarch64/xbyak_aarch64/src/util_impl_linux.h
+@@ -144,8 +144,13 @@ private:
+     regex_t regexBuf;
+     regmatch_t match[1];
+ 
+-    if (regcomp(&regexBuf, regex, REG_EXTENDED) != 0)
+-      throw ERR_INTERNAL;
++    if (regcomp(&regexBuf, regex, REG_EXTENDED) != 0) {
++      /* There are platforms with /sys not mounted. return empty buffers
++       * in these scenarios
++       */
++      buf[0] = '\0';
++      return 0;
++    }
+ 
+     const int retVal = regexec(&regexBuf, path, 1, match, 0);
+     regfree(&regexBuf);
+@@ -187,8 +192,12 @@ private:
+       regex_t regexBuf;
+       regmatch_t match[2];
+ 
+-      if (regcomp(&regexBuf, "index[0-9]*$", REG_EXTENDED) != 0)
+-        throw ERR_INTERNAL;
++      if (regcomp(&regexBuf, "index[0-9]*$", REG_EXTENDED) != 0) {
++        /* There are platforms with /sys not mounted. return gracefully
++         * in these scenarios
++         */
++        goto init_and_return_false;
++      }
+ 
+       if (regexec(&regexBuf, dp->d_name, 1, match, 0) == 0) { // Found index[1-9][0-9]. directory
+         char *dir_name = buf0;
+@@ -438,12 +447,15 @@ private:
+ 
+     FILE *file = fopen(path_midr_el1, "r");
+     if (file == nullptr) {
+-      throw Error(ERR_INTERNAL);
++      /* There are platforms with /sys not mounted. return empty buffer
++       * in these scenarios
++       */
++      cacheInfo_.midr_el1 = 0xFE << 24;
+       return;
+     }
+ 
+     if (fread(buf, sizeof(char), 64, file) == 0) {
+-      throw Error(ERR_INTERNAL);
++      cacheInfo_.midr_el1 = 0xFE << 24;
+       return;
+     }
+ 
+diff --git a/src/cpu/aarch64/xbyak_aarch64/src/util_impl_mac.h b/src/cpu/aarch64/xbyak_aarch64/src/util_impl_mac.h
+index ebd6dba7c0..93bdae1d7a 100644
+--- a/src/cpu/aarch64/xbyak_aarch64/src/util_impl_mac.h
++++ b/src/cpu/aarch64/xbyak_aarch64/src/util_impl_mac.h
+@@ -102,18 +102,21 @@ private:
+     size_t val = 0;
+     size_t len = sizeof(val);
+ 
++    /* There are platforms with /sys not mounted. skip
++     * handling HW caps for such platforms.
++     */
+     if (sysctlbyname(hw_opt_atomics, &val, &len, NULL, 0) != 0)
+-      throw Error(ERR_INTERNAL);
++      type_ = 0;
+     else
+       type_ |= (val == 1) ? (Type)XBYAK_AARCH64_HWCAP_ATOMIC : 0;
+ 
+     if (sysctlbyname(hw_opt_fp, &val, &len, NULL, 0) != 0)
+-      throw Error(ERR_INTERNAL);
++      type_ = 0;
+     else
+       type_ |= (val == 1) ? (Type)XBYAK_AARCH64_HWCAP_FP : 0;
+ 
+     if (sysctlbyname(hw_opt_neon, &val, &len, NULL, 0) != 0)
+-      throw Error(ERR_INTERNAL);
++      type_ = 0;
+     else
+       type_ |= (val == 1) ? (Type)XBYAK_AARCH64_HWCAP_ADVSIMD : 0;
+   }
+-- 
+2.34.1
+