x32: Handle process creation
Allow an x32 process to be started.
Originally-by: H. J. Lu <hjl.tools@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
diff --git a/arch/x86/include/asm/compat.h b/arch/x86/include/asm/compat.h
index 7938b84..e7f68b4 100644
--- a/arch/x86/include/asm/compat.h
+++ b/arch/x86/include/asm/compat.h
@@ -6,6 +6,7 @@
*/
#include <linux/types.h>
#include <linux/sched.h>
+#include <asm/processor.h>
#include <asm/user32.h>
#include <asm/unistd.h>
@@ -187,7 +188,20 @@
/*
* The type of struct elf_prstatus.pr_reg in compatible core dumps.
*/
+#ifdef CONFIG_X86_X32_ABI
+typedef struct user_regs_struct compat_elf_gregset_t;
+
+#define PR_REG_SIZE(S) (test_thread_flag(TIF_IA32) ? 68 : 216)
+#define PRSTATUS_SIZE(S) (test_thread_flag(TIF_IA32) ? 144 : 296)
+#define SET_PR_FPVALID(S,V) \
+ do { *(int *) (((void *) &((S)->pr_reg)) + PR_REG_SIZE(0)) = (V); } \
+ while (0)
+
+#define COMPAT_USE_64BIT_TIME \
+ (!!(task_pt_regs(current)->orig_ax & __X32_SYSCALL_BIT))
+#else
typedef struct user_regs_struct32 compat_elf_gregset_t;
+#endif
/*
* A pointer passed in from user mode. This should not
@@ -209,8 +223,16 @@
static inline void __user *arch_compat_alloc_user_space(long len)
{
- struct pt_regs *regs = task_pt_regs(current);
- return (void __user *)regs->sp - len;
+ compat_uptr_t sp;
+
+ if (test_thread_flag(TIF_IA32)) {
+ sp = task_pt_regs(current)->sp;
+ } else {
+ /* -128 for the x32 ABI redzone */
+ sp = percpu_read(old_rsp) - 128;
+ }
+
+ return (void __user *)round_down(sp - len, 16);
}
static inline bool is_compat_task(void)
diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h
index 410fa6a..83aabea9 100644
--- a/arch/x86/include/asm/elf.h
+++ b/arch/x86/include/asm/elf.h
@@ -156,7 +156,12 @@
#define elf_check_arch(x) \
((x)->e_machine == EM_X86_64)
-#define compat_elf_check_arch(x) elf_check_arch_ia32(x)
+#define compat_elf_check_arch(x) \
+ (elf_check_arch_ia32(x) || (x)->e_machine == EM_X86_64)
+
+#if __USER32_DS != __USER_DS
+# error "The following code assumes __USER32_DS == __USER_DS"
+#endif
static inline void elf_common_init(struct thread_struct *t,
struct pt_regs *regs, const u16 ds)
@@ -179,8 +184,9 @@
void start_thread_ia32(struct pt_regs *regs, u32 new_ip, u32 new_sp);
#define compat_start_thread start_thread_ia32
-void set_personality_ia32(void);
-#define COMPAT_SET_PERSONALITY(ex) set_personality_ia32()
+void set_personality_ia32(bool);
+#define COMPAT_SET_PERSONALITY(ex) \
+ set_personality_ia32((ex).e_machine == EM_X86_64)
#define COMPAT_ELF_PLATFORM ("i686")
@@ -296,9 +302,20 @@
(unsigned long)current->mm->context.vdso); \
} while (0)
+#define ARCH_DLINFO_X32 \
+do { \
+ if (vdso_enabled) \
+ NEW_AUX_ENT(AT_SYSINFO_EHDR, \
+ (unsigned long)current->mm->context.vdso); \
+} while (0)
+
#define AT_SYSINFO 32
-#define COMPAT_ARCH_DLINFO ARCH_DLINFO_IA32(sysctl_vsyscall32)
+#define COMPAT_ARCH_DLINFO \
+if (test_thread_flag(TIF_X32)) \
+ ARCH_DLINFO_X32; \
+else \
+ ARCH_DLINFO_IA32(sysctl_vsyscall32)
#define COMPAT_ELF_ET_DYN_BASE (TASK_UNMAPPED_BASE + 0x1000000)