Commit d1a797f3 authored by H. Peter Anvin's avatar H. Peter Anvin
Browse files

x32: Handle process creation 



Allow an x32 process to be started.

Originally-by: default avatarH. J. Lu <hjl.tools@gmail.com>
Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
parent c5a37394

arch/x86/include/asm/compat.h

+24 −2
Original line number Diff line number Diff line
@@ -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 @@ struct compat_shmid64_ds { 
/*

 * 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 compat_uptr_t ptr_to_compat(void __user *uptr) 


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)

arch/x86/include/asm/elf.h

+21 −4
Original line number Diff line number Diff line
@@ -156,7 +156,12 @@ do { \ 
#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 @@ static inline void elf_common_init(struct thread_struct *t, 
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 @@ do { \ 
			    (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)

arch/x86/kernel/cpu/perf_event.c

+3 −1
Original line number Diff line number Diff line
@@ -28,7 +28,6 @@ 
#include <asm/apic.h>

#include <asm/stacktrace.h>

#include <asm/nmi.h>

#include <asm/compat.h>

#include <asm/smp.h>

#include <asm/alternative.h>
@@ -1595,6 +1594,9 @@ perf_callchain_kernel(struct perf_callchain_entry *entry, struct pt_regs *regs) 
}



#ifdef CONFIG_COMPAT



#include <asm/compat.h>



static inline int

perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry *entry)

{

arch/x86/kernel/entry_64.S

+15 −0
Original line number Diff line number Diff line
@@ -763,6 +763,21 @@ ENTRY(stub_x32_rt_sigreturn) 
	CFI_ENDPROC

END(stub_x32_rt_sigreturn)



ENTRY(stub_x32_execve)

	CFI_STARTPROC

	addq $8, %rsp

	PARTIAL_FRAME 0

	SAVE_REST

	FIXUP_TOP_OF_STACK %r11

	movq %rsp, %rcx

	call sys32_execve

	RESTORE_TOP_OF_STACK %r11

	movq %rax,RAX(%rsp)

	RESTORE_REST

	jmp int_ret_from_sys_call

	CFI_ENDPROC

END(stub_x32_execve)



#endif



/*

arch/x86/kernel/process_64.c

+16 −7
Original line number Diff line number Diff line
@@ -364,7 +364,9 @@ start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp) 
void start_thread_ia32(struct pt_regs *regs, u32 new_ip, u32 new_sp)

{

	start_thread_common(regs, new_ip, new_sp,

			    __USER32_CS, __USER32_DS, __USER32_DS);

			    test_thread_flag(TIF_X32)

			    ? __USER_CS : __USER32_CS,

			    __USER_DS, __USER_DS);

}

#endif
@@ -508,6 +510,7 @@ void set_personality_64bit(void) 


	/* Make sure to be in 64bit mode */

	clear_thread_flag(TIF_IA32);

	clear_thread_flag(TIF_X32);

	clear_thread_flag(TIF_ADDR32);

	clear_thread_flag(TIF_X32);
@@ -522,23 +525,29 @@ void set_personality_64bit(void) 
	current->personality &= ~READ_IMPLIES_EXEC;

}



void set_personality_ia32(void)

void set_personality_ia32(bool x32)

{

	/* inherit personality from parent */



	/* Make sure to be in 32bit mode */

	set_thread_flag(TIF_IA32);

	set_thread_flag(TIF_ADDR32);

	clear_thread_flag(TIF_X32);

	current->personality |= force_personality32;



	/* Mark the associated mm as containing 32-bit tasks. */

	if (current->mm)

		current->mm->context.ia32_compat = 1;



	if (x32) {

		clear_thread_flag(TIF_IA32);

		set_thread_flag(TIF_X32);

		current->personality &= ~READ_IMPLIES_EXEC;

	} else {

		set_thread_flag(TIF_IA32);

		clear_thread_flag(TIF_X32);

		current->personality |= force_personality32;

		/* Prepare the first "return" to user space */

		current_thread_info()->status |= TS_COMPAT;

	}

}



unsigned long get_wchan(struct task_struct *p)

{