[PATCH v12 2/7] x86/arch_prctl/64: Rename do_arch_prctl to do_arch_prctl_64

From: Kyle Huey
Date: Wed Nov 16 2016 - 21:06:56 EST

In order to introduce new arch_prctls that are not 64 bit only, rename the
existing 64 bit implementation to do_arch_prctl_64(). Also rename the second
argument to arch_prctl(), which will no longer always be an address.

Signed-off-by: Kyle Huey <khuey@xxxxxxxxxxxx>
Reviewed-by: Andy Lutomirski <luto@xxxxxxxxxx>
---
arch/um/include/shared/os.h | 2 +-
arch/x86/include/asm/proto.h | 3 +--
arch/x86/kernel/process_64.c | 32 +++++++++++++++++---------------
arch/x86/kernel/ptrace.c | 8 ++++----
arch/x86/um/os-Linux/prctl.c | 4 ++--
arch/x86/um/syscalls_64.c | 12 ++++++------
6 files changed, 31 insertions(+), 30 deletions(-)

diff --git a/arch/um/include/shared/os.h b/arch/um/include/shared/os.h
index de5d572..2b47e0e 100644
--- a/arch/um/include/shared/os.h
+++ b/arch/um/include/shared/os.h
@@ -298,17 +298,17 @@ extern void os_set_ioignore(void);

/* sigio.c */
extern int add_sigio_fd(int fd);
extern int ignore_sigio_fd(int fd);
extern void maybe_sigio_broken(int fd, int read);
extern void sigio_broken(int fd, int read);

/* sys-x86_64/prctl.c */
-extern int os_arch_prctl(int pid, int code, unsigned long *addr);
+extern int os_arch_prctl(int pid, int code, unsigned long *arg2);

/* tty.c */
extern int get_pty(void);

/* sys-$ARCH/task_size.c */
extern unsigned long os_get_top_address(void);

long syscall(long number, ...);
diff --git a/arch/x86/include/asm/proto.h b/arch/x86/include/asm/proto.h
index 9b9b30b..f8e9194 100644
--- a/arch/x86/include/asm/proto.h
+++ b/arch/x86/include/asm/proto.h
@@ -4,16 +4,17 @@
#include <asm/ldt.h>

/* misc architecture specific prototypes */

void syscall_init(void);

#ifdef CONFIG_X86_64
void entry_SYSCALL_64(void);
+long do_arch_prctl_64(struct task_struct *task, int code, unsigned long arg2);
#endif

#ifdef CONFIG_X86_32
void entry_INT80_32(void);
void entry_SYSENTER_32(void);
void __begin_SYSENTER_singlestep_region(void);
void __end_SYSENTER_singlestep_region(void);
#endif
@@ -25,11 +26,9 @@ void entry_SYSCALL_compat(void);
void entry_INT80_compat(void);
#endif

void x86_configure_nx(void);
void x86_report_nx(void);

extern int reboot_force;

-long do_arch_prctl(struct task_struct *task, int code, unsigned long addr);
-
#endif /* _ASM_X86_PROTO_H */
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 2718cf9..611df20 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -193,17 +193,17 @@ int copy_thread_tls(unsigned long clone_flags, unsigned long sp,
*/
if (clone_flags & CLONE_SETTLS) {
#ifdef CONFIG_IA32_EMULATION
if (in_ia32_syscall())
err = do_set_thread_area(p, -1,
(struct user_desc __user *)tls, 0);
else
#endif
- err = do_arch_prctl(p, ARCH_SET_FS, tls);
+ err = do_arch_prctl_64(p, ARCH_SET_FS, tls);
if (err)
goto out;
}
err = 0;
out:
if (err && p->thread.io_bitmap_ptr) {
kfree(p->thread.io_bitmap_ptr);
p->thread.io_bitmap_max = 0;
@@ -534,91 +534,93 @@ static long prctl_map_vdso(const struct vdso_image *image, unsigned long addr)
ret = map_vdso_once(image, addr);
if (ret)
return ret;

return (long)image->size;
}
#endif

-long do_arch_prctl(struct task_struct *task, int code, unsigned long addr)
+long do_arch_prctl_64(struct task_struct *task, int code, unsigned long arg2)
{
int ret = 0;
int doit = task == current;
int cpu;

switch (code) {
case ARCH_SET_GS:
- if (addr >= TASK_SIZE_MAX)
+ if (arg2 >= TASK_SIZE_MAX)
return -EPERM;
cpu = get_cpu();
task->thread.gsindex = 0;
- task->thread.gsbase = addr;
+ task->thread.gsbase = arg2;
if (doit) {
load_gs_index(0);
- ret = wrmsrl_safe(MSR_KERNEL_GS_BASE, addr);
+ ret = wrmsrl_safe(MSR_KERNEL_GS_BASE, arg2);
}
put_cpu();
break;
case ARCH_SET_FS:
/* Not strictly needed for fs, but do it for symmetry
with gs */
- if (addr >= TASK_SIZE_MAX)
+ if (arg2 >= TASK_SIZE_MAX)
return -EPERM;
cpu = get_cpu();
task->thread.fsindex = 0;
- task->thread.fsbase = addr;
+ task->thread.fsbase = arg2;
if (doit) {
/* set the selector to 0 to not confuse __switch_to */
loadsegment(fs, 0);
- ret = wrmsrl_safe(MSR_FS_BASE, addr);
+ ret = wrmsrl_safe(MSR_FS_BASE, arg2);
}
put_cpu();
break;
case ARCH_GET_FS: {
unsigned long base;
+
if (doit)
rdmsrl(MSR_FS_BASE, base);
else
base = task->thread.fsbase;
- ret = put_user(base, (unsigned long __user *)addr);
+ ret = put_user(base, (unsigned long __user *)arg2);
break;
}
case ARCH_GET_GS: {
unsigned long base;
+
if (doit)
rdmsrl(MSR_KERNEL_GS_BASE, base);
else
base = task->thread.gsbase;
- ret = put_user(base, (unsigned long __user *)addr);
+ ret = put_user(base, (unsigned long __user *)arg2);
break;
}

#ifdef CONFIG_CHECKPOINT_RESTORE
# ifdef CONFIG_X86_X32_ABI
case ARCH_MAP_VDSO_X32:
- return prctl_map_vdso(&vdso_image_x32, addr);
+ return prctl_map_vdso(&vdso_image_x32, arg2);
# endif
# if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
case ARCH_MAP_VDSO_32:
- return prctl_map_vdso(&vdso_image_32, addr);
+ return prctl_map_vdso(&vdso_image_32, arg2);
# endif
case ARCH_MAP_VDSO_64:
- return prctl_map_vdso(&vdso_image_64, addr);
+ return prctl_map_vdso(&vdso_image_64, arg2);
#endif

default:
ret = -EINVAL;
break;
}

return ret;
}

-SYSCALL_DEFINE2(arch_prctl, int, code, unsigned long, addr)
+SYSCALL_DEFINE2(arch_prctl, int, code, unsigned long, arg2)
{
- return do_arch_prctl(current, code, addr);
+ return do_arch_prctl_64(current, code, arg2);
}

unsigned long KSTK_ESP(struct task_struct *task)
{
return task_pt_regs(task)->sp;
}
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index 0e63c02..5004302 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -390,31 +390,31 @@ static int putreg(struct task_struct *child,
case offsetof(struct user_regs_struct, flags):
return set_flags(child, value);

#ifdef CONFIG_X86_64
case offsetof(struct user_regs_struct,fs_base):
if (value >= TASK_SIZE_MAX)
return -EIO;
/*
- * When changing the segment base, use do_arch_prctl
+ * When changing the segment base, use do_arch_prctl_64
* to set either thread.fs or thread.fsindex and the
* corresponding GDT slot.
*/
if (child->thread.fsbase != value)
- return do_arch_prctl(child, ARCH_SET_FS, value);
+ return do_arch_prctl_64(child, ARCH_SET_FS, value);
return 0;
case offsetof(struct user_regs_struct,gs_base):
/*
* Exactly the same here as the %fs handling above.
*/
if (value >= TASK_SIZE_MAX)
return -EIO;
if (child->thread.gsbase != value)
- return do_arch_prctl(child, ARCH_SET_GS, value);
+ return do_arch_prctl_64(child, ARCH_SET_GS, value);
return 0;
#endif
}

*pt_regs_access(task_pt_regs(child), offset) = value;
return 0;
}

@@ -863,17 +863,17 @@ long arch_ptrace(struct task_struct *child, long request,
break;
#endif

#ifdef CONFIG_X86_64
/* normal 64bit interface to access TLS data.
Works just like arch_prctl, except that the arguments
are reversed. */
case PTRACE_ARCH_PRCTL:
- ret = do_arch_prctl(child, data, addr);
+ ret = do_arch_prctl_64(child, data, addr);
break;
#endif

default:
ret = ptrace_request(child, request, addr, data);
break;
}

diff --git a/arch/x86/um/os-Linux/prctl.c b/arch/x86/um/os-Linux/prctl.c
index 96eb2bd..efc9d74 100644
--- a/arch/x86/um/os-Linux/prctl.c
+++ b/arch/x86/um/os-Linux/prctl.c
@@ -1,12 +1,12 @@
/*
* Copyright (C) 2007 Jeff Dike (jdike@{addtoit.com,linux.intel.com})
* Licensed under the GPL
*/

#include <sys/ptrace.h>
#include <asm/ptrace.h>

-int os_arch_prctl(int pid, int code, unsigned long *addr)
+int os_arch_prctl(int pid, int code, unsigned long *arg2)
{
- return ptrace(PTRACE_ARCH_PRCTL, pid, (unsigned long) addr, code);
+ return ptrace(PTRACE_ARCH_PRCTL, pid, (unsigned long) arg2, code);
}
diff --git a/arch/x86/um/syscalls_64.c b/arch/x86/um/syscalls_64.c
index ab3f7f4..d472c6b 100644
--- a/arch/x86/um/syscalls_64.c
+++ b/arch/x86/um/syscalls_64.c
@@ -6,19 +6,19 @@
*/

#include <linux/sched.h>
#include <linux/syscalls.h>
#include <linux/uaccess.h>
#include <asm/prctl.h> /* XXX This should get the constants from libc */
#include <os.h>

-long arch_prctl(struct task_struct *task, int code, unsigned long __user *addr)
+long arch_prctl(struct task_struct *task, int code, unsigned long __user *arg2)
{
- unsigned long *ptr = addr, tmp;
+ unsigned long *ptr = arg2, tmp;
long ret;
int pid = task->mm->context.id.u.pid;

/*
* With ARCH_SET_FS (and ARCH_SET_GS is treated similarly to
* be safe), we need to call arch_prctl on the host because
* setting %fs may result in something else happening (like a
* GDT or thread.fs being set instead). So, we let the host
@@ -58,29 +58,29 @@ long arch_prctl(struct task_struct *task, int code, unsigned long __user *addr)
case ARCH_SET_FS:
current->thread.arch.fs = (unsigned long) ptr;
ret = save_registers(pid, &current->thread.regs.regs);
break;
case ARCH_SET_GS:
ret = save_registers(pid, &current->thread.regs.regs);
break;
case ARCH_GET_FS:
- ret = put_user(tmp, addr);
+ ret = put_user(tmp, arg2);
break;
case ARCH_GET_GS:
- ret = put_user(tmp, addr);
+ ret = put_user(tmp, arg2);
break;
}

return ret;
}

-SYSCALL_DEFINE2(arch_prctl, int, code, unsigned long, addr)
+SYSCALL_DEFINE2(arch_prctl, int, code, unsigned long, arg2)
{
- return arch_prctl(current, code, (unsigned long __user *) addr);
+ return arch_prctl(current, code, (unsigned long __user *) arg2);
}

void arch_switch_to(struct task_struct *to)
{
if ((to->thread.arch.fs == 0) || (to->mm == NULL))
return;

arch_prctl(to, ARCH_SET_FS, (void __user *) to->thread.arch.fs);
--
2.10.2