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x32: Handle process creation

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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>
This commit is contained in:
H. Peter Anvin 2012-02-19 10:06:34 -08:00
parent c5a373942b
commit d1a797f388
5 changed files with 79 additions and 14 deletions
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26
arch/x86/include/asm/compat.h
View File

@ -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)

25
arch/x86/include/asm/elf.h
View File

@ -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)

4
arch/x86/kernel/cpu/perf_event.c
View File

@ -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)
{

15
arch/x86/kernel/entry_64.S
View File

@ -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
/*

23
arch/x86/kernel/process_64.c
View File

@ -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);
@ -522,22 +525,28 @@ 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;
/* Prepare the first "return" to user space */
current_thread_info()->status |= TS_COMPAT;
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)