lix/src/libstore/build/personality.cc

46 lines
1.4 KiB
C++

#include "personality.hh"
#include "globals.hh"
#if __linux__
#include <sys/utsname.h>
#include <sys/personality.h>
#endif
#include <cstring>
namespace nix {
void setPersonality(std::string_view system)
{
#if __linux__
/* Change the personality to 32-bit if we're doing an
i686-linux build on an x86_64-linux machine. */
struct utsname utsbuf;
uname(&utsbuf);
if ((system == "i686-linux"
&& (std::string_view(SYSTEM) == "x86_64-linux"
|| (!strcmp(utsbuf.sysname, "Linux") && !strcmp(utsbuf.machine, "x86_64"))))
|| system == "armv7l-linux"
|| system == "armv6l-linux"
|| system == "armv5tel-linux")
{
if (personality(PER_LINUX32) == -1)
throw SysError("cannot set 32-bit personality");
}
/* Impersonate a Linux 2.6 machine to get some determinism in
builds that depend on the kernel version. */
if ((system == "i686-linux" || system == "x86_64-linux") && settings.impersonateLinux26) {
int cur = personality(0xffffffff);
if (cur != -1) personality(cur | 0x0020000 /* == UNAME26 */);
}
/* Disable address space randomization for improved
determinism. */
int cur = personality(0xffffffff);
if (cur != -1) personality(cur | ADDR_NO_RANDOMIZE);
#endif
}
}