x86: hook up execveat system call

Hook up x86-64, i386 and x32 ABIs.

Signed-off-by: David Drysdale <drysdale@google.com>
Cc: Meredydd Luff <meredydd@senatehouse.org>
Cc: Shuah Khan <shuah.kh@samsung.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rich Felker <dalias@aerifal.cx>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

7 files changed, 35 insertions, 0 deletions

diff --git a/arch/x86/ia32/audit.c b/arch/x86/ia32/audit.c
index 5d7b381da692..2eccc8932ae6 100644
--- a/arch/x86/ia32/audit.c
+++ b/arch/x86/ia32/audit.c
@@ -35,6 +35,7 @@ int ia32_classify_syscall(unsigned syscall)
         case __NR_socketcall:
                 return 4;
         case __NR_execve:
+        case __NR_execveat:
                 return 5;
         default:
                 return 1;
diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S
index ffe71228fc10..82e8a1d44658 100644
--- a/arch/x86/ia32/ia32entry.S
+++ b/arch/x86/ia32/ia32entry.S
@@ -480,6 +480,7 @@ GLOBAL(\label)
         PTREGSCALL stub32_rt_sigreturn, sys32_rt_sigreturn
         PTREGSCALL stub32_sigreturn, sys32_sigreturn
         PTREGSCALL stub32_execve, compat_sys_execve
+        PTREGSCALL stub32_execveat, compat_sys_execveat
         PTREGSCALL stub32_fork, sys_fork
         PTREGSCALL stub32_vfork, sys_vfork
 
diff --git a/arch/x86/kernel/audit_64.c b/arch/x86/kernel/audit_64.c
index 06d3e5a14d9d..f3672508b249 100644
--- a/arch/x86/kernel/audit_64.c
+++ b/arch/x86/kernel/audit_64.c
@@ -50,6 +50,7 @@ int audit_classify_syscall(int abi, unsigned syscall)
         case __NR_openat:
                 return 3;
         case __NR_execve:
+        case __NR_execveat:
                 return 5;
         default:
                 return 0;
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index c0226ab54106..90878aa38dbd 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -652,6 +652,20 @@ ENTRY(stub_execve)
         CFI_ENDPROC
 END(stub_execve)
 
+ENTRY(stub_execveat)
+        CFI_STARTPROC
+        addq $8, %rsp
+        PARTIAL_FRAME 0
+        SAVE_REST
+        FIXUP_TOP_OF_STACK %r11
+        call sys_execveat
+        RESTORE_TOP_OF_STACK %r11
+        movq %rax,RAX(%rsp)
+        RESTORE_REST
+        jmp int_ret_from_sys_call
+        CFI_ENDPROC
+END(stub_execveat)
+
 /*
  * sigreturn is special because it needs to restore all registers on return.
  * This cannot be done with SYSRET, so use the IRET return path instead.
@@ -697,6 +711,20 @@ ENTRY(stub_x32_execve)
         CFI_ENDPROC
 END(stub_x32_execve)
 
+ENTRY(stub_x32_execveat)
+        CFI_STARTPROC
+        addq $8, %rsp
+        PARTIAL_FRAME 0
+        SAVE_REST
+        FIXUP_TOP_OF_STACK %r11
+        call compat_sys_execveat
+        RESTORE_TOP_OF_STACK %r11
+        movq %rax,RAX(%rsp)
+        RESTORE_REST
+        jmp int_ret_from_sys_call
+        CFI_ENDPROC
+END(stub_x32_execveat)
+
 #endif
 
 /*
diff --git a/arch/x86/syscalls/syscall_32.tbl b/arch/x86/syscalls/syscall_32.tbl
index 9fe1b5d002f0..b3560ece1c9f 100644
--- a/arch/x86/syscalls/syscall_32.tbl
+++ b/arch/x86/syscalls/syscall_32.tbl
@@ -364,3 +364,4 @@
 355     i386    getrandom               sys_getrandom
 356     i386    memfd_create            sys_memfd_create
 357     i386    bpf                     sys_bpf
+358     i386    execveat                sys_execveat                    stub32_execveat
diff --git a/arch/x86/syscalls/syscall_64.tbl b/arch/x86/syscalls/syscall_64.tbl
index 281150b539a2..8d656fbb57aa 100644
--- a/arch/x86/syscalls/syscall_64.tbl
+++ b/arch/x86/syscalls/syscall_64.tbl
@@ -328,6 +328,7 @@
 319     common  memfd_create            sys_memfd_create
 320     common  kexec_file_load         sys_kexec_file_load
 321     common  bpf                     sys_bpf
+322     64      execveat                stub_execveat
 
 #
 # x32-specific system call numbers start at 512 to avoid cache impact
@@ -366,3 +367,4 @@
 542     x32     getsockopt              compat_sys_getsockopt
 543     x32     io_setup                compat_sys_io_setup
 544     x32     io_submit               compat_sys_io_submit
+545     x32     execveat                stub_x32_execveat
diff --git a/arch/x86/um/sys_call_table_64.c b/arch/x86/um/sys_call_table_64.c
index f2f0723070ca..20c3649d0691 100644
--- a/arch/x86/um/sys_call_table_64.c
+++ b/arch/x86/um/sys_call_table_64.c
@@ -31,6 +31,7 @@
 #define stub_fork sys_fork
 #define stub_vfork sys_vfork
 #define stub_execve sys_execve
+#define stub_execveat sys_execveat
 #define stub_rt_sigreturn sys_rt_sigreturn
 
 #define __SYSCALL_COMMON(nr, sym, compat) __SYSCALL_64(nr, sym, compat)