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| author | Mark H Weaver <mhw@netris.org> | 2017-08-07 16:41:03 -0400 |
|---|---|---|
| committer | Mark H Weaver <mhw@netris.org> | 2017-08-07 16:41:03 -0400 |
| commit | a1aa5dabaa5d570710da7190a3c3dca5442b9daa (patch) | |
| tree | e19ba58b2535c3d838bd1cd5ee93636bfb4583fa | |
| parent | 73a203450d21241eca50375aeb26fb418b287414 (diff) | |
| download | gnu-guix-a1aa5dabaa5d570710da7190a3c3dca5442b9daa.tar gnu-guix-a1aa5dabaa5d570710da7190a3c3dca5442b9daa.tar.gz | |
daemon: Ensure the child stack is aligned on a 16-byte boundary.
* nix/libstore/build.cc (DerivationGoal::startBuilder): When calling 'clone',
ensure that the stack is aligned on a 16-byte boundary.
| -rw-r--r-- | nix/libstore/build.cc | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/nix/libstore/build.cc b/nix/libstore/build.cc index 693fa70c8d..63540ddfc1 100644 --- a/nix/libstore/build.cc +++ b/nix/libstore/build.cc @@ -26,6 +26,7 @@ #include <errno.h> #include <stdio.h> #include <cstring> +#include <stdint.h> #include <pwd.h> #include <grp.h> @@ -2008,11 +2009,11 @@ void DerivationGoal::startBuilder() char stack[32 * 1024]; int flags = CLONE_NEWPID | CLONE_NEWNS | CLONE_NEWIPC | CLONE_NEWUTS | SIGCHLD; if (!fixedOutput) flags |= CLONE_NEWNET; -#ifdef __aarch64__ - pid = clone(childEntry, stack + sizeof(stack) - 16, flags, this); -#else - pid = clone(childEntry, stack + sizeof(stack) - 8, flags, this); -#endif + /* Ensure proper alignment on the stack. On aarch64, it has to be 16 + bytes. */ + pid = clone(childEntry, + (char *)(((uintptr_t)stack + sizeof(stack) - 8) & ~(uintptr_t)0xf), + flags, this); if (pid == -1) throw SysError("cloning builder process"); } else |