x86-64: make compat_start_thread() match start_thread()
For no real good reason, compat_start_thread() was embedded inline in
<asm/elf.h> whereas the native start_thread() lives in process_*.c.
Move compat_start_thread() to process_64.c, remove gratuitious
differences, and fix a few items which mostly look like bit rot.
In particular, compat_start_thread() didn't do free_thread_xstate(),
which means it was hanging on to the xstate store area even when it
was not needed. It was also not setting old_rsp, but it looks like
that generally shouldn't matter for a 32-bit process.
Note: compat_start_thread *has* to be a macro, since it is tested with
start_thread_ia32() as the out of line function name.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h
index 456a304..8a024ba 100644
--- a/arch/x86/include/asm/elf.h
+++ b/arch/x86/include/asm/elf.h
@@ -157,19 +157,6 @@
#define compat_elf_check_arch(x) elf_check_arch_ia32(x)
-static inline void start_ia32_thread(struct pt_regs *regs, u32 ip, u32 sp)
-{
- loadsegment(fs, 0);
- loadsegment(ds, __USER32_DS);
- loadsegment(es, __USER32_DS);
- load_gs_index(0);
- regs->ip = ip;
- regs->sp = sp;
- regs->flags = X86_EFLAGS_IF;
- regs->cs = __USER32_CS;
- regs->ss = __USER32_DS;
-}
-
static inline void elf_common_init(struct thread_struct *t,
struct pt_regs *regs, const u16 ds)
{
@@ -191,11 +178,8 @@
#define COMPAT_ELF_PLAT_INIT(regs, load_addr) \
elf_common_init(¤t->thread, regs, __USER_DS)
-#define compat_start_thread(regs, ip, sp) \
-do { \
- start_ia32_thread(regs, ip, sp); \
- set_fs(USER_DS); \
-} while (0)
+void start_thread_ia32(struct pt_regs *regs, u32 new_ip, u32 new_sp);
+#define compat_start_thread start_thread_ia32
#define COMPAT_SET_PERSONALITY(ex) \
do { \