[PATCH] exec: Allow loading x86_64 executables on x86_64

[Sergey Bugaev]

Since we don't support mixing i386 and x86_64 binaries on the same
system (as running them requires different build-time gnumach
configurations), the exec server can simply require the binary being
loaded to have been built for the same architecture as the exec server
itself.
---
 exec/exec.c     | 8 +++++++-
 exec/hostarch.c | 7 +++++++
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/exec/exec.c b/exec/exec.c
index 8944167d..2e5fbfcd 100644
--- a/exec/exec.c
+++ b/exec/exec.c
@@ -518,6 +518,12 @@ prepare (file_t file, struct execdata *e)
 #define host_ELFDATA ELFDATA2LSB
 #endif
 
+#ifdef __LP64__
+#define host_ELFCLASS ELFCLASS64
+#else
+#define host_ELFCLASS ELFCLASS32
+#endif
+
 static void
 check_elf (struct execdata *e)
 {
@@ -539,7 +545,7 @@ check_elf (struct execdata *e)
       return;
     }
 
-  if (ehdr->e_ident[EI_CLASS] != ELFCLASS32 ||
+  if (ehdr->e_ident[EI_CLASS] != host_ELFCLASS ||
       ehdr->e_ident[EI_DATA] != host_ELFDATA ||
       ehdr->e_ident[EI_VERSION] != EV_CURRENT ||
       ehdr->e_version != EV_CURRENT ||
diff --git a/exec/hostarch.c b/exec/hostarch.c
index 363fda69..58ddc6b9 100644
--- a/exec/hostarch.c
+++ b/exec/hostarch.c
@@ -70,7 +70,14 @@ elf_machine_matches_host (ElfW(Half) e_machine)
     case CPU_TYPE_I486:
     case CPU_TYPE_PENTIUM:
     case CPU_TYPE_PENTIUMPRO:
+      /* We do not support running i386 binaries if the Hurd servers were
+         built for x86_64, or vice versa.  So our build architecture must
+         match that of the executable.  */
+#ifdef __x86_64__
+      CACHE (e_machine == EM_X86_64);
+#else
       CACHE (e_machine == EM_386);
+#endif
 
     case CPU_TYPE_POWERPC:
       CACHE (e_machine == EM_PPC);
-- 
2.40.1