On Mon, Jun 15, 2020 at 4:43 PM Christoph Hellwig [off-list ref] wrote:

On Mon, Jun 15, 2020 at 04:40:28PM +0200, Arnd Bergmann wrote:

quoted

quoted

ld: arch/x86/entry/syscall_x32.o:(.rodata+0x1040): undefined reference to
`__x32_sys_execve'
ld: arch/x86/entry/syscall_x32.o:(.rodata+0x1108): undefined reference to
`__x32_sys_execveat'
make: *** [Makefile:1139: vmlinux] Error 1

Ah, I see: it's marked x32-only, so arch/x86/entry/syscall_x32.c
uses the __x32 prefix instead of the __x64 one. Marking it 'common'
instead would make it work, but also create an extra entry point
for native processes, something that commit
6365b842aae4 ("x86/syscalls: Split the x32 syscalls into their own table")
was trying to avoid.

Marking it common also doesn't compile at all because __NR_execve
and __NR_execveat get redefined in unistd_64.h.  I then tried to rename
the x32 versions, which failed in yet another way.  At that point I gave
up instead of digging myself into a deeper hole..

How about this one:

diff --git a/arch/x86/entry/syscall_x32.c b/arch/x86/entry/syscall_x32.c
index 3d8d70d3896c..0ce15807cf54 100644
--- a/arch/x86/entry/syscall_x32.c
+++ b/arch/x86/entry/syscall_x32.c

@@ -16,6 +16,9 @@
 #undef __SYSCALL_X32
 #undef __SYSCALL_COMMON

+#define __x32_sys_execve __x64_sys_execve
+#define __x32_sys_execveat __x64_sys_execveat
+
 #define __SYSCALL_X32(nr, sym) [nr] = __x32_##sym,
 #define __SYSCALL_COMMON(nr, sym) [nr] = __x64_##sym,

Still ugly, but much simpler and more localized (if it works).

        Arnd