[compiler-rt] 4c32e3d - [SystemZ] [Sanitizer] Bugfixes in internal_clone().

[Jonas Paulsson via llvm-commits]

Author: Jonas Paulsson
Date: 2021-11-17T14:42:08-05:00
New Revision: 4c32e3d967ecbc4e7f90fef546b5ed38bbd2f7a6

URL: https://github.com/llvm/llvm-project/commit/4c32e3d967ecbc4e7f90fef546b5ed38bbd2f7a6
DIFF: https://github.com/llvm/llvm-project/commit/4c32e3d967ecbc4e7f90fef546b5ed38bbd2f7a6.diff

LOG: [SystemZ] [Sanitizer] Bugfixes in internal_clone().

The __flags variable needs to be of type 'long' in order to get sign extended
properly.

internal_clone() uses an svc (Supervisor Call) directly (as opposed to
internal_syscall), and therefore needs to take care to set errno and return
-1 as needed.

Review: Ulrich Weigand

Added: 
    

Modified: 
    compiler-rt/lib/sanitizer_common/sanitizer_linux_s390.cpp

Removed: 
    


################################################################################
diff  --git a/compiler-rt/lib/sanitizer_common/sanitizer_linux_s390.cpp b/compiler-rt/lib/sanitizer_common/sanitizer_linux_s390.cpp
index bb2f5b5f9f7df..74db831b0aadd 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_linux_s390.cpp
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_linux_s390.cpp
@@ -57,8 +57,10 @@ uptr internal_mmap(void *addr, uptr length, int prot, int flags, int fd,
 
 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
                     int *parent_tidptr, void *newtls, int *child_tidptr) {
-  if (!fn || !child_stack)
-    return -EINVAL;
+  if (!fn || !child_stack) {
+    errno = EINVAL;
+    return -1;
+  }
   CHECK_EQ(0, (uptr)child_stack % 16);
   // Minimum frame size.
 #ifdef __s390x__
@@ -71,9 +73,9 @@ uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
   // And pass parameters.
   ((unsigned long *)child_stack)[1] = (uptr)fn;
   ((unsigned long *)child_stack)[2] = (uptr)arg;
-  register long res __asm__("r2");
+  register uptr res __asm__("r2");
   register void *__cstack      __asm__("r2") = child_stack;
-  register int __flags         __asm__("r3") = flags;
+  register long __flags        __asm__("r3") = flags;
   register int * __ptidptr     __asm__("r4") = parent_tidptr;
   register int * __ctidptr     __asm__("r5") = child_tidptr;
   register void * __newtls     __asm__("r6") = newtls;
@@ -113,6 +115,10 @@ uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
                          "r"(__ctidptr),
                          "r"(__newtls)
                        : "memory", "cc");
+  if (res >= (uptr)-4095) {
+    errno = -res;
+    return -1;
+  }
   return res;
 }