git: 930a7c2ac67e - main - compiler-rt: re-exec with ASLR disabled when necessary

The branch main has been updated by emaste:

URL: https://cgit.FreeBSD.org/src/commit/?id=930a7c2ac67e1e8e511aa1d0a31a16c632060ebb

commit 930a7c2ac67e1e8e511aa1d0a31a16c632060ebb
Author:     Ed Maste <emaste@FreeBSD.org>
AuthorDate: 2022-01-16 19:22:05 +0000
Commit:     Ed Maste <emaste@FreeBSD.org>
CommitDate: 2022-02-04 16:20:00 +0000

    compiler-rt: re-exec with ASLR disabled when necessary
    
    Some sanitizers (at least msan) currently require ASLR to be disabled.
    When we detect that ASLR is enabled, re-exec with it disabled rather
    than exiting with an error.  See LLVM GitHub issue 53256 for more
    detail: https://github.com/llvm/llvm-project/issues/53256
    
    No objection:   dim
    MFC after:      2 weeks
    Sponsored by:   The FreeBSD Foundation
    Differential Revision:  https://reviews.freebsd.org/D33934
---
 .../compiler-rt/lib/sanitizer_common/sanitizer_linux.cpp           | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/contrib/llvm-project/compiler-rt/lib/sanitizer_common/sanitizer_linux.cpp b/contrib/llvm-project/compiler-rt/lib/sanitizer_common/sanitizer_linux.cpp
index 09b3f31831df..daa07c15490e 100644
--- a/contrib/llvm-project/compiler-rt/lib/sanitizer_common/sanitizer_linux.cpp
+++ b/contrib/llvm-project/compiler-rt/lib/sanitizer_common/sanitizer_linux.cpp
@@ -2197,8 +2197,11 @@ void CheckASLR() {
   }
   if ((aslr_status & PROC_ASLR_ACTIVE) != 0) {
     Printf("This sanitizer is not compatible with enabled ASLR "
-           "and binaries compiled with PIE\n");
-    Die();
+           "and binaries compiled with PIE\n"
+           "ASLR will be disabled and the program re-executed.\n");
+    int aslr_ctl = PROC_ASLR_FORCE_DISABLE;
+    CHECK_NE(procctl(P_PID, 0, PROC_ASLR_CTL, &aslr_ctl), -1);
+    ReExec();
   }
 #else
   // Do nothing