219 строки
6.0 KiB
C
219 строки
6.0 KiB
C
#include <linux/jump_label.h>
|
|
|
|
/*
|
|
|
|
x86 function call convention, 64-bit:
|
|
-------------------------------------
|
|
arguments | callee-saved | extra caller-saved | return
|
|
[callee-clobbered] | | [callee-clobbered] |
|
|
---------------------------------------------------------------------------
|
|
rdi rsi rdx rcx r8-9 | rbx rbp [*] r12-15 | r10-11 | rax, rdx [**]
|
|
|
|
( rsp is obviously invariant across normal function calls. (gcc can 'merge'
|
|
functions when it sees tail-call optimization possibilities) rflags is
|
|
clobbered. Leftover arguments are passed over the stack frame.)
|
|
|
|
[*] In the frame-pointers case rbp is fixed to the stack frame.
|
|
|
|
[**] for struct return values wider than 64 bits the return convention is a
|
|
bit more complex: up to 128 bits width we return small structures
|
|
straight in rax, rdx. For structures larger than that (3 words or
|
|
larger) the caller puts a pointer to an on-stack return struct
|
|
[allocated in the caller's stack frame] into the first argument - i.e.
|
|
into rdi. All other arguments shift up by one in this case.
|
|
Fortunately this case is rare in the kernel.
|
|
|
|
For 32-bit we have the following conventions - kernel is built with
|
|
-mregparm=3 and -freg-struct-return:
|
|
|
|
x86 function calling convention, 32-bit:
|
|
----------------------------------------
|
|
arguments | callee-saved | extra caller-saved | return
|
|
[callee-clobbered] | | [callee-clobbered] |
|
|
-------------------------------------------------------------------------
|
|
eax edx ecx | ebx edi esi ebp [*] | <none> | eax, edx [**]
|
|
|
|
( here too esp is obviously invariant across normal function calls. eflags
|
|
is clobbered. Leftover arguments are passed over the stack frame. )
|
|
|
|
[*] In the frame-pointers case ebp is fixed to the stack frame.
|
|
|
|
[**] We build with -freg-struct-return, which on 32-bit means similar
|
|
semantics as on 64-bit: edx can be used for a second return value
|
|
(i.e. covering integer and structure sizes up to 64 bits) - after that
|
|
it gets more complex and more expensive: 3-word or larger struct returns
|
|
get done in the caller's frame and the pointer to the return struct goes
|
|
into regparm0, i.e. eax - the other arguments shift up and the
|
|
function's register parameters degenerate to regparm=2 in essence.
|
|
|
|
*/
|
|
|
|
#ifdef CONFIG_X86_64
|
|
|
|
/*
|
|
* 64-bit system call stack frame layout defines and helpers,
|
|
* for assembly code:
|
|
*/
|
|
|
|
/* The layout forms the "struct pt_regs" on the stack: */
|
|
/*
|
|
* 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".
|
|
*/
|
|
#define R15 0*8
|
|
#define R14 1*8
|
|
#define R13 2*8
|
|
#define R12 3*8
|
|
#define RBP 4*8
|
|
#define RBX 5*8
|
|
/* These regs are callee-clobbered. Always saved on kernel entry. */
|
|
#define R11 6*8
|
|
#define R10 7*8
|
|
#define R9 8*8
|
|
#define R8 9*8
|
|
#define RAX 10*8
|
|
#define RCX 11*8
|
|
#define RDX 12*8
|
|
#define RSI 13*8
|
|
#define RDI 14*8
|
|
/*
|
|
* On syscall entry, this is syscall#. On CPU exception, this is error code.
|
|
* On hw interrupt, it's IRQ number:
|
|
*/
|
|
#define ORIG_RAX 15*8
|
|
/* Return frame for iretq */
|
|
#define RIP 16*8
|
|
#define CS 17*8
|
|
#define EFLAGS 18*8
|
|
#define RSP 19*8
|
|
#define SS 20*8
|
|
|
|
#define SIZEOF_PTREGS 21*8
|
|
|
|
.macro ALLOC_PT_GPREGS_ON_STACK addskip=0
|
|
addq $-(15*8+\addskip), %rsp
|
|
.endm
|
|
|
|
.macro SAVE_C_REGS_HELPER offset=0 rax=1 rcx=1 r8910=1 r11=1
|
|
.if \r11
|
|
movq %r11, 6*8+\offset(%rsp)
|
|
.endif
|
|
.if \r8910
|
|
movq %r10, 7*8+\offset(%rsp)
|
|
movq %r9, 8*8+\offset(%rsp)
|
|
movq %r8, 9*8+\offset(%rsp)
|
|
.endif
|
|
.if \rax
|
|
movq %rax, 10*8+\offset(%rsp)
|
|
.endif
|
|
.if \rcx
|
|
movq %rcx, 11*8+\offset(%rsp)
|
|
.endif
|
|
movq %rdx, 12*8+\offset(%rsp)
|
|
movq %rsi, 13*8+\offset(%rsp)
|
|
movq %rdi, 14*8+\offset(%rsp)
|
|
.endm
|
|
.macro SAVE_C_REGS offset=0
|
|
SAVE_C_REGS_HELPER \offset, 1, 1, 1, 1
|
|
.endm
|
|
.macro SAVE_C_REGS_EXCEPT_RAX_RCX offset=0
|
|
SAVE_C_REGS_HELPER \offset, 0, 0, 1, 1
|
|
.endm
|
|
.macro SAVE_C_REGS_EXCEPT_R891011
|
|
SAVE_C_REGS_HELPER 0, 1, 1, 0, 0
|
|
.endm
|
|
.macro SAVE_C_REGS_EXCEPT_RCX_R891011
|
|
SAVE_C_REGS_HELPER 0, 1, 0, 0, 0
|
|
.endm
|
|
.macro SAVE_C_REGS_EXCEPT_RAX_RCX_R11
|
|
SAVE_C_REGS_HELPER 0, 0, 0, 1, 0
|
|
.endm
|
|
|
|
.macro SAVE_EXTRA_REGS offset=0
|
|
movq %r15, 0*8+\offset(%rsp)
|
|
movq %r14, 1*8+\offset(%rsp)
|
|
movq %r13, 2*8+\offset(%rsp)
|
|
movq %r12, 3*8+\offset(%rsp)
|
|
movq %rbp, 4*8+\offset(%rsp)
|
|
movq %rbx, 5*8+\offset(%rsp)
|
|
.endm
|
|
|
|
.macro RESTORE_EXTRA_REGS offset=0
|
|
movq 0*8+\offset(%rsp), %r15
|
|
movq 1*8+\offset(%rsp), %r14
|
|
movq 2*8+\offset(%rsp), %r13
|
|
movq 3*8+\offset(%rsp), %r12
|
|
movq 4*8+\offset(%rsp), %rbp
|
|
movq 5*8+\offset(%rsp), %rbx
|
|
.endm
|
|
|
|
.macro ZERO_EXTRA_REGS
|
|
xorl %r15d, %r15d
|
|
xorl %r14d, %r14d
|
|
xorl %r13d, %r13d
|
|
xorl %r12d, %r12d
|
|
xorl %ebp, %ebp
|
|
xorl %ebx, %ebx
|
|
.endm
|
|
|
|
.macro RESTORE_C_REGS_HELPER rstor_rax=1, rstor_rcx=1, rstor_r11=1, rstor_r8910=1, rstor_rdx=1
|
|
.if \rstor_r11
|
|
movq 6*8(%rsp), %r11
|
|
.endif
|
|
.if \rstor_r8910
|
|
movq 7*8(%rsp), %r10
|
|
movq 8*8(%rsp), %r9
|
|
movq 9*8(%rsp), %r8
|
|
.endif
|
|
.if \rstor_rax
|
|
movq 10*8(%rsp), %rax
|
|
.endif
|
|
.if \rstor_rcx
|
|
movq 11*8(%rsp), %rcx
|
|
.endif
|
|
.if \rstor_rdx
|
|
movq 12*8(%rsp), %rdx
|
|
.endif
|
|
movq 13*8(%rsp), %rsi
|
|
movq 14*8(%rsp), %rdi
|
|
.endm
|
|
.macro RESTORE_C_REGS
|
|
RESTORE_C_REGS_HELPER 1,1,1,1,1
|
|
.endm
|
|
.macro RESTORE_C_REGS_EXCEPT_RAX
|
|
RESTORE_C_REGS_HELPER 0,1,1,1,1
|
|
.endm
|
|
.macro RESTORE_C_REGS_EXCEPT_RCX
|
|
RESTORE_C_REGS_HELPER 1,0,1,1,1
|
|
.endm
|
|
.macro RESTORE_C_REGS_EXCEPT_R11
|
|
RESTORE_C_REGS_HELPER 1,1,0,1,1
|
|
.endm
|
|
.macro RESTORE_C_REGS_EXCEPT_RCX_R11
|
|
RESTORE_C_REGS_HELPER 1,0,0,1,1
|
|
.endm
|
|
|
|
.macro REMOVE_PT_GPREGS_FROM_STACK addskip=0
|
|
subq $-(15*8+\addskip), %rsp
|
|
.endm
|
|
|
|
.macro icebp
|
|
.byte 0xf1
|
|
.endm
|
|
|
|
#endif /* CONFIG_X86_64 */
|
|
|
|
/*
|
|
* This does 'call enter_from_user_mode' unless we can avoid it based on
|
|
* kernel config or using the static jump infrastructure.
|
|
*/
|
|
.macro CALL_enter_from_user_mode
|
|
#ifdef CONFIG_CONTEXT_TRACKING
|
|
#ifdef HAVE_JUMP_LABEL
|
|
STATIC_JUMP_IF_FALSE .Lafter_call_\@, context_tracking_enabled, def=0
|
|
#endif
|
|
call enter_from_user_mode
|
|
.Lafter_call_\@:
|
|
#endif
|
|
.endm
|