mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-28 03:15:23 +07:00
55474c48b4
user_mode_ignore_vm86() can be used instead of user_mode(), in places where we have already done a v8086_mode() security check of ptregs. But doing this check in the wrong place would be a bug that could result in security problems, and also the naming still isn't very clear. Furthermore, it only affects 32-bit kernels, while most development happens on 64-bit kernels. If we replace them with user_mode() checks then the cost is only a very minor increase in various slowpaths: text data bss dec hex filename 10573391 703562 1753042 13029995 c6d26b vmlinux.o.before 10573423 703562 1753042 13030027 c6d28b vmlinux.o.after So lets get rid of this distinction once and for all. Acked-by: Borislav Petkov <bp@suse.de> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Andrew Lutomirski <luto@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brad Spengler <spender@grsecurity.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20150329090233.GA1963@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
258 lines
6.8 KiB
C
258 lines
6.8 KiB
C
#ifndef _ASM_X86_PTRACE_H
|
|
#define _ASM_X86_PTRACE_H
|
|
|
|
#include <asm/segment.h>
|
|
#include <asm/page_types.h>
|
|
#include <uapi/asm/ptrace.h>
|
|
|
|
#ifndef __ASSEMBLY__
|
|
#ifdef __i386__
|
|
|
|
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;
|
|
};
|
|
|
|
#else /* __i386__ */
|
|
|
|
struct pt_regs {
|
|
/*
|
|
* C ABI says these regs are callee-preserved. They aren't saved on kernel entry
|
|
* unless syscall needs a complete, fully filled "struct pt_regs".
|
|
*/
|
|
unsigned long r15;
|
|
unsigned long r14;
|
|
unsigned long r13;
|
|
unsigned long r12;
|
|
unsigned long bp;
|
|
unsigned long bx;
|
|
/* These regs are callee-clobbered. Always saved on kernel entry. */
|
|
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;
|
|
/*
|
|
* On syscall entry, this is syscall#. On CPU exception, this is error code.
|
|
* On hw interrupt, it's IRQ number:
|
|
*/
|
|
unsigned long orig_ax;
|
|
/* Return frame for iretq */
|
|
unsigned long ip;
|
|
unsigned long cs;
|
|
unsigned long flags;
|
|
unsigned long sp;
|
|
unsigned long ss;
|
|
/* top of stack page */
|
|
};
|
|
|
|
#endif /* !__i386__ */
|
|
|
|
#ifdef CONFIG_PARAVIRT
|
|
#include <asm/paravirt_types.h>
|
|
#endif
|
|
|
|
struct cpuinfo_x86;
|
|
struct task_struct;
|
|
|
|
extern unsigned long profile_pc(struct pt_regs *regs);
|
|
#define profile_pc profile_pc
|
|
|
|
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);
|
|
|
|
|
|
extern unsigned long syscall_trace_enter_phase1(struct pt_regs *, u32 arch);
|
|
extern long syscall_trace_enter_phase2(struct pt_regs *, u32 arch,
|
|
unsigned long phase1_result);
|
|
|
|
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(regs) determines whether a register set came from user
|
|
* mode. On x86_32, 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.
|
|
*
|
|
* On x86_64, vm86 mode is mercifully nonexistent, and we don't need
|
|
* the extra check.
|
|
*/
|
|
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 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
|
|
}
|
|
|
|
#ifdef CONFIG_X86_64
|
|
static inline bool user_64bit_mode(struct pt_regs *regs)
|
|
{
|
|
#ifndef CONFIG_PARAVIRT
|
|
/*
|
|
* On non-paravirt systems, this is the only long mode CPL 3
|
|
* selector. We do not allow long mode selectors in the LDT.
|
|
*/
|
|
return regs->cs == __USER_CS;
|
|
#else
|
|
/* Headers are too twisted for this to go in paravirt.h. */
|
|
return regs->cs == __USER_CS || regs->cs == pv_info.extra_user_64bit_cs;
|
|
#endif
|
|
}
|
|
|
|
#define current_user_stack_pointer() current_pt_regs()->sp
|
|
#define compat_user_stack_pointer() current_pt_regs()->sp
|
|
#endif
|
|
|
|
#ifdef CONFIG_X86_32
|
|
extern unsigned long kernel_stack_pointer(struct pt_regs *regs);
|
|
#else
|
|
static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
|
|
{
|
|
return regs->sp;
|
|
}
|
|
#endif
|
|
|
|
#define GET_IP(regs) ((regs)->ip)
|
|
#define GET_FP(regs) ((regs)->bp)
|
|
#define GET_USP(regs) ((regs)->sp)
|
|
|
|
#include <asm-generic/ptrace.h>
|
|
|
|
/* Query offset/name of register from its name/offset */
|
|
extern int regs_query_register_offset(const char *name);
|
|
extern const char *regs_query_register_name(unsigned int offset);
|
|
#define MAX_REG_OFFSET (offsetof(struct pt_regs, ss))
|
|
|
|
/**
|
|
* regs_get_register() - get register value from its offset
|
|
* @regs: pt_regs from which register value is gotten.
|
|
* @offset: offset number of the register.
|
|
*
|
|
* regs_get_register returns the value of a register. The @offset is the
|
|
* offset of the register in struct pt_regs address which specified by @regs.
|
|
* If @offset is bigger than MAX_REG_OFFSET, this returns 0.
|
|
*/
|
|
static inline unsigned long regs_get_register(struct pt_regs *regs,
|
|
unsigned int offset)
|
|
{
|
|
if (unlikely(offset > MAX_REG_OFFSET))
|
|
return 0;
|
|
#ifdef CONFIG_X86_32
|
|
/*
|
|
* Traps from the kernel do not save sp and ss.
|
|
* Use the helper function to retrieve sp.
|
|
*/
|
|
if (offset == offsetof(struct pt_regs, sp) &&
|
|
regs->cs == __KERNEL_CS)
|
|
return kernel_stack_pointer(regs);
|
|
#endif
|
|
return *(unsigned long *)((unsigned long)regs + offset);
|
|
}
|
|
|
|
/**
|
|
* regs_within_kernel_stack() - check the address in the stack
|
|
* @regs: pt_regs which contains kernel stack pointer.
|
|
* @addr: address which is checked.
|
|
*
|
|
* regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
|
|
* If @addr is within the kernel stack, it returns true. If not, returns false.
|
|
*/
|
|
static inline int regs_within_kernel_stack(struct pt_regs *regs,
|
|
unsigned long addr)
|
|
{
|
|
return ((addr & ~(THREAD_SIZE - 1)) ==
|
|
(kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
|
|
}
|
|
|
|
/**
|
|
* regs_get_kernel_stack_nth() - get Nth entry of the stack
|
|
* @regs: pt_regs which contains kernel stack pointer.
|
|
* @n: stack entry number.
|
|
*
|
|
* regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
|
|
* is specified by @regs. If the @n th entry is NOT in the kernel stack,
|
|
* this returns 0.
|
|
*/
|
|
static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
|
|
unsigned int n)
|
|
{
|
|
unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
|
|
addr += n;
|
|
if (regs_within_kernel_stack(regs, (unsigned long)addr))
|
|
return *addr;
|
|
else
|
|
return 0;
|
|
}
|
|
|
|
#define arch_has_single_step() (1)
|
|
#ifdef CONFIG_X86_DEBUGCTLMSR
|
|
#define arch_has_block_step() (1)
|
|
#else
|
|
#define arch_has_block_step() (boot_cpu_data.x86 >= 6)
|
|
#endif
|
|
|
|
#define ARCH_HAS_USER_SINGLE_STEP_INFO
|
|
|
|
/*
|
|
* When hitting ptrace_stop(), we cannot return using SYSRET because
|
|
* that does not restore the full CPU state, only a minimal set. The
|
|
* ptracer can change arbitrary register values, which is usually okay
|
|
* because the usual ptrace stops run off the signal delivery path which
|
|
* forces IRET; however, ptrace_event() stops happen in arbitrary places
|
|
* in the kernel and don't force IRET path.
|
|
*
|
|
* So force IRET path after a ptrace stop.
|
|
*/
|
|
#define arch_ptrace_stop_needed(code, info) \
|
|
({ \
|
|
force_iret(); \
|
|
false; \
|
|
})
|
|
|
|
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);
|
|
|
|
#endif /* !__ASSEMBLY__ */
|
|
#endif /* _ASM_X86_PTRACE_H */
|