mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 01:10:04 +00:00
![Tejun Heo](/assets/img/avatar_default.png)
Impact: pt_regs changed, lazy gs handling made optional, add slight overhead to SAVE_ALL, simplifies error_code path a bit On x86_32, %gs hasn't been used by kernel and handled lazily. pt_regs doesn't have place for it and gs is saved/loaded only when necessary. In preparation for stack protector support, this patch makes lazy %gs handling optional by doing the followings. * Add CONFIG_X86_32_LAZY_GS and place for gs in pt_regs. * Save and restore %gs along with other registers in entry_32.S unless LAZY_GS. Note that this unfortunately adds "pushl $0" on SAVE_ALL even when LAZY_GS. However, it adds no overhead to common exit path and simplifies entry path with error code. * Define different user_gs accessors depending on LAZY_GS and add lazy_save_gs() and lazy_load_gs() which are noop if !LAZY_GS. The lazy_*_gs() ops are used to save, load and clear %gs lazily. * Define ELF_CORE_COPY_KERNEL_REGS() which always read %gs directly. xen and lguest changes need to be verified. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
249 lines
5.3 KiB
C
249 lines
5.3 KiB
C
#ifndef _ASM_X86_PTRACE_H
|
|
#define _ASM_X86_PTRACE_H
|
|
|
|
#include <linux/compiler.h> /* For __user */
|
|
#include <asm/ptrace-abi.h>
|
|
#include <asm/processor-flags.h>
|
|
|
|
#ifdef __KERNEL__
|
|
#include <asm/segment.h>
|
|
#endif
|
|
|
|
#ifndef __ASSEMBLY__
|
|
|
|
#ifdef __i386__
|
|
/* this struct defines the way the registers are stored on the
|
|
stack during a system call. */
|
|
|
|
#ifndef __KERNEL__
|
|
|
|
struct pt_regs {
|
|
long ebx;
|
|
long ecx;
|
|
long edx;
|
|
long esi;
|
|
long edi;
|
|
long ebp;
|
|
long eax;
|
|
int xds;
|
|
int xes;
|
|
int xfs;
|
|
int xgs;
|
|
long orig_eax;
|
|
long eip;
|
|
int xcs;
|
|
long eflags;
|
|
long esp;
|
|
int xss;
|
|
};
|
|
|
|
#else /* __KERNEL__ */
|
|
|
|
struct pt_regs {
|
|
unsigned long bx;
|
|
unsigned long cx;
|
|
unsigned long dx;
|
|
unsigned long si;
|
|
unsigned long di;
|
|
unsigned long bp;
|
|
unsigned long ax;
|
|
unsigned long ds;
|
|
unsigned long es;
|
|
unsigned long fs;
|
|
unsigned long gs;
|
|
unsigned long orig_ax;
|
|
unsigned long ip;
|
|
unsigned long cs;
|
|
unsigned long flags;
|
|
unsigned long sp;
|
|
unsigned long ss;
|
|
};
|
|
|
|
#endif /* __KERNEL__ */
|
|
|
|
#else /* __i386__ */
|
|
|
|
#ifndef __KERNEL__
|
|
|
|
struct pt_regs {
|
|
unsigned long r15;
|
|
unsigned long r14;
|
|
unsigned long r13;
|
|
unsigned long r12;
|
|
unsigned long rbp;
|
|
unsigned long rbx;
|
|
/* arguments: non interrupts/non tracing syscalls only save upto here*/
|
|
unsigned long r11;
|
|
unsigned long r10;
|
|
unsigned long r9;
|
|
unsigned long r8;
|
|
unsigned long rax;
|
|
unsigned long rcx;
|
|
unsigned long rdx;
|
|
unsigned long rsi;
|
|
unsigned long rdi;
|
|
unsigned long orig_rax;
|
|
/* end of arguments */
|
|
/* cpu exception frame or undefined */
|
|
unsigned long rip;
|
|
unsigned long cs;
|
|
unsigned long eflags;
|
|
unsigned long rsp;
|
|
unsigned long ss;
|
|
/* top of stack page */
|
|
};
|
|
|
|
#else /* __KERNEL__ */
|
|
|
|
struct pt_regs {
|
|
unsigned long r15;
|
|
unsigned long r14;
|
|
unsigned long r13;
|
|
unsigned long r12;
|
|
unsigned long bp;
|
|
unsigned long bx;
|
|
/* arguments: non interrupts/non tracing syscalls only save upto here*/
|
|
unsigned long r11;
|
|
unsigned long r10;
|
|
unsigned long r9;
|
|
unsigned long r8;
|
|
unsigned long ax;
|
|
unsigned long cx;
|
|
unsigned long dx;
|
|
unsigned long si;
|
|
unsigned long di;
|
|
unsigned long orig_ax;
|
|
/* end of arguments */
|
|
/* cpu exception frame or undefined */
|
|
unsigned long ip;
|
|
unsigned long cs;
|
|
unsigned long flags;
|
|
unsigned long sp;
|
|
unsigned long ss;
|
|
/* top of stack page */
|
|
};
|
|
|
|
#endif /* __KERNEL__ */
|
|
#endif /* !__i386__ */
|
|
|
|
|
|
#ifdef __KERNEL__
|
|
|
|
#include <linux/init.h>
|
|
|
|
struct cpuinfo_x86;
|
|
struct task_struct;
|
|
|
|
extern unsigned long profile_pc(struct pt_regs *regs);
|
|
|
|
extern unsigned long
|
|
convert_ip_to_linear(struct task_struct *child, struct pt_regs *regs);
|
|
extern void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
|
|
int error_code, int si_code);
|
|
void signal_fault(struct pt_regs *regs, void __user *frame, char *where);
|
|
|
|
extern long syscall_trace_enter(struct pt_regs *);
|
|
extern void syscall_trace_leave(struct pt_regs *);
|
|
|
|
static inline unsigned long regs_return_value(struct pt_regs *regs)
|
|
{
|
|
return regs->ax;
|
|
}
|
|
|
|
/*
|
|
* user_mode_vm(regs) determines whether a register set came from user mode.
|
|
* This is true if V8086 mode was enabled OR if the register set was from
|
|
* protected mode with RPL-3 CS value. This tricky test checks that with
|
|
* one comparison. Many places in the kernel can bypass this full check
|
|
* if they have already ruled out V8086 mode, so user_mode(regs) can be used.
|
|
*/
|
|
static inline int user_mode(struct pt_regs *regs)
|
|
{
|
|
#ifdef CONFIG_X86_32
|
|
return (regs->cs & SEGMENT_RPL_MASK) == USER_RPL;
|
|
#else
|
|
return !!(regs->cs & 3);
|
|
#endif
|
|
}
|
|
|
|
static inline int user_mode_vm(struct pt_regs *regs)
|
|
{
|
|
#ifdef CONFIG_X86_32
|
|
return ((regs->cs & SEGMENT_RPL_MASK) | (regs->flags & X86_VM_MASK)) >=
|
|
USER_RPL;
|
|
#else
|
|
return user_mode(regs);
|
|
#endif
|
|
}
|
|
|
|
static inline int v8086_mode(struct pt_regs *regs)
|
|
{
|
|
#ifdef CONFIG_X86_32
|
|
return (regs->flags & X86_VM_MASK);
|
|
#else
|
|
return 0; /* No V86 mode support in long mode */
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* X86_32 CPUs don't save ss and esp if the CPU is already in kernel mode
|
|
* when it traps. So regs will be the current sp.
|
|
*
|
|
* This is valid only for kernel mode traps.
|
|
*/
|
|
static inline unsigned long kernel_trap_sp(struct pt_regs *regs)
|
|
{
|
|
#ifdef CONFIG_X86_32
|
|
return (unsigned long)regs;
|
|
#else
|
|
return regs->sp;
|
|
#endif
|
|
}
|
|
|
|
static inline unsigned long instruction_pointer(struct pt_regs *regs)
|
|
{
|
|
return regs->ip;
|
|
}
|
|
|
|
static inline unsigned long frame_pointer(struct pt_regs *regs)
|
|
{
|
|
return regs->bp;
|
|
}
|
|
|
|
static inline unsigned long user_stack_pointer(struct pt_regs *regs)
|
|
{
|
|
return regs->sp;
|
|
}
|
|
|
|
/*
|
|
* These are defined as per linux/ptrace.h, which see.
|
|
*/
|
|
#define arch_has_single_step() (1)
|
|
extern void user_enable_single_step(struct task_struct *);
|
|
extern void user_disable_single_step(struct task_struct *);
|
|
|
|
extern void user_enable_block_step(struct task_struct *);
|
|
#ifdef CONFIG_X86_DEBUGCTLMSR
|
|
#define arch_has_block_step() (1)
|
|
#else
|
|
#define arch_has_block_step() (boot_cpu_data.x86 >= 6)
|
|
#endif
|
|
|
|
struct user_desc;
|
|
extern int do_get_thread_area(struct task_struct *p, int idx,
|
|
struct user_desc __user *info);
|
|
extern int do_set_thread_area(struct task_struct *p, int idx,
|
|
struct user_desc __user *info, int can_allocate);
|
|
|
|
extern void x86_ptrace_untrace(struct task_struct *);
|
|
extern void x86_ptrace_fork(struct task_struct *child,
|
|
unsigned long clone_flags);
|
|
|
|
#define arch_ptrace_untrace(tsk) x86_ptrace_untrace(tsk)
|
|
#define arch_ptrace_fork(child, flags) x86_ptrace_fork(child, flags)
|
|
|
|
#endif /* __KERNEL__ */
|
|
|
|
#endif /* !__ASSEMBLY__ */
|
|
|
|
#endif /* _ASM_X86_PTRACE_H */
|