629 lines
14 KiB
ArmAsm
629 lines
14 KiB
ArmAsm
/*
|
|
* linux/arch/arm/kernel/entry-common.S
|
|
*
|
|
* Copyright (C) 2000 Russell King
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*/
|
|
|
|
#include <asm/unistd.h>
|
|
#include <asm/ftrace.h>
|
|
#include <asm/unwind.h>
|
|
|
|
#ifdef CONFIG_NEED_RET_TO_USER
|
|
#include <mach/entry-macro.S>
|
|
#else
|
|
.macro arch_ret_to_user, tmp1, tmp2
|
|
.endm
|
|
#endif
|
|
|
|
#include "entry-header.S"
|
|
|
|
|
|
.align 5
|
|
/*
|
|
* This is the fast syscall return path. We do as little as
|
|
* possible here, and this includes saving r0 back into the SVC
|
|
* stack.
|
|
*/
|
|
ret_fast_syscall:
|
|
UNWIND(.fnstart )
|
|
UNWIND(.cantunwind )
|
|
disable_irq @ disable interrupts
|
|
ldr r1, [tsk, #TI_FLAGS]
|
|
tst r1, #_TIF_WORK_MASK
|
|
bne fast_work_pending
|
|
asm_trace_hardirqs_on
|
|
|
|
/* perform architecture specific actions before user return */
|
|
arch_ret_to_user r1, lr
|
|
ct_user_enter
|
|
|
|
restore_user_regs fast = 1, offset = S_OFF
|
|
UNWIND(.fnend )
|
|
|
|
/*
|
|
* Ok, we need to do extra processing, enter the slow path.
|
|
*/
|
|
fast_work_pending:
|
|
str r0, [sp, #S_R0+S_OFF]! @ returned r0
|
|
work_pending:
|
|
mov r0, sp @ 'regs'
|
|
mov r2, why @ 'syscall'
|
|
bl do_work_pending
|
|
cmp r0, #0
|
|
beq no_work_pending
|
|
movlt scno, #(__NR_restart_syscall - __NR_SYSCALL_BASE)
|
|
ldmia sp, {r0 - r6} @ have to reload r0 - r6
|
|
b local_restart @ ... and off we go
|
|
|
|
/*
|
|
* "slow" syscall return path. "why" tells us if this was a real syscall.
|
|
*/
|
|
ENTRY(ret_to_user)
|
|
ret_slow_syscall:
|
|
disable_irq @ disable interrupts
|
|
ENTRY(ret_to_user_from_irq)
|
|
ldr r1, [tsk, #TI_FLAGS]
|
|
tst r1, #_TIF_WORK_MASK
|
|
bne work_pending
|
|
no_work_pending:
|
|
asm_trace_hardirqs_on
|
|
|
|
/* perform architecture specific actions before user return */
|
|
arch_ret_to_user r1, lr
|
|
ct_user_enter save = 0
|
|
|
|
restore_user_regs fast = 0, offset = 0
|
|
ENDPROC(ret_to_user_from_irq)
|
|
ENDPROC(ret_to_user)
|
|
|
|
/*
|
|
* This is how we return from a fork.
|
|
*/
|
|
ENTRY(ret_from_fork)
|
|
bl schedule_tail
|
|
cmp r5, #0
|
|
movne r0, r4
|
|
adrne lr, BSYM(1f)
|
|
movne pc, r5
|
|
1: get_thread_info tsk
|
|
b ret_slow_syscall
|
|
ENDPROC(ret_from_fork)
|
|
|
|
.equ NR_syscalls,0
|
|
#define CALL(x) .equ NR_syscalls,NR_syscalls+1
|
|
#include "calls.S"
|
|
|
|
/*
|
|
* Ensure that the system call table is equal to __NR_syscalls,
|
|
* which is the value the rest of the system sees
|
|
*/
|
|
.ifne NR_syscalls - __NR_syscalls
|
|
.error "__NR_syscalls is not equal to the size of the syscall table"
|
|
.endif
|
|
|
|
#undef CALL
|
|
#define CALL(x) .long x
|
|
|
|
#ifdef CONFIG_FUNCTION_TRACER
|
|
/*
|
|
* When compiling with -pg, gcc inserts a call to the mcount routine at the
|
|
* start of every function. In mcount, apart from the function's address (in
|
|
* lr), we need to get hold of the function's caller's address.
|
|
*
|
|
* Older GCCs (pre-4.4) inserted a call to a routine called mcount like this:
|
|
*
|
|
* bl mcount
|
|
*
|
|
* These versions have the limitation that in order for the mcount routine to
|
|
* be able to determine the function's caller's address, an APCS-style frame
|
|
* pointer (which is set up with something like the code below) is required.
|
|
*
|
|
* mov ip, sp
|
|
* push {fp, ip, lr, pc}
|
|
* sub fp, ip, #4
|
|
*
|
|
* With EABI, these frame pointers are not available unless -mapcs-frame is
|
|
* specified, and if building as Thumb-2, not even then.
|
|
*
|
|
* Newer GCCs (4.4+) solve this problem by introducing a new version of mcount,
|
|
* with call sites like:
|
|
*
|
|
* push {lr}
|
|
* bl __gnu_mcount_nc
|
|
*
|
|
* With these compilers, frame pointers are not necessary.
|
|
*
|
|
* mcount can be thought of as a function called in the middle of a subroutine
|
|
* call. As such, it needs to be transparent for both the caller and the
|
|
* callee: the original lr needs to be restored when leaving mcount, and no
|
|
* registers should be clobbered. (In the __gnu_mcount_nc implementation, we
|
|
* clobber the ip register. This is OK because the ARM calling convention
|
|
* allows it to be clobbered in subroutines and doesn't use it to hold
|
|
* parameters.)
|
|
*
|
|
* When using dynamic ftrace, we patch out the mcount call by a "mov r0, r0"
|
|
* for the mcount case, and a "pop {lr}" for the __gnu_mcount_nc case (see
|
|
* arch/arm/kernel/ftrace.c).
|
|
*/
|
|
|
|
#ifndef CONFIG_OLD_MCOUNT
|
|
#if (__GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 4))
|
|
#error Ftrace requires CONFIG_FRAME_POINTER=y with GCC older than 4.4.0.
|
|
#endif
|
|
#endif
|
|
|
|
.macro mcount_adjust_addr rd, rn
|
|
bic \rd, \rn, #1 @ clear the Thumb bit if present
|
|
sub \rd, \rd, #MCOUNT_INSN_SIZE
|
|
.endm
|
|
|
|
.macro __mcount suffix
|
|
mcount_enter
|
|
ldr r0, =ftrace_trace_function
|
|
ldr r2, [r0]
|
|
adr r0, .Lftrace_stub
|
|
cmp r0, r2
|
|
bne 1f
|
|
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
ldr r1, =ftrace_graph_return
|
|
ldr r2, [r1]
|
|
cmp r0, r2
|
|
bne ftrace_graph_caller\suffix
|
|
|
|
ldr r1, =ftrace_graph_entry
|
|
ldr r2, [r1]
|
|
ldr r0, =ftrace_graph_entry_stub
|
|
cmp r0, r2
|
|
bne ftrace_graph_caller\suffix
|
|
#endif
|
|
|
|
mcount_exit
|
|
|
|
1: mcount_get_lr r1 @ lr of instrumented func
|
|
mcount_adjust_addr r0, lr @ instrumented function
|
|
adr lr, BSYM(2f)
|
|
mov pc, r2
|
|
2: mcount_exit
|
|
.endm
|
|
|
|
.macro __ftrace_caller suffix
|
|
mcount_enter
|
|
|
|
mcount_get_lr r1 @ lr of instrumented func
|
|
mcount_adjust_addr r0, lr @ instrumented function
|
|
|
|
.globl ftrace_call\suffix
|
|
ftrace_call\suffix:
|
|
bl ftrace_stub
|
|
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
.globl ftrace_graph_call\suffix
|
|
ftrace_graph_call\suffix:
|
|
mov r0, r0
|
|
#endif
|
|
|
|
mcount_exit
|
|
.endm
|
|
|
|
.macro __ftrace_graph_caller
|
|
sub r0, fp, #4 @ &lr of instrumented routine (&parent)
|
|
#ifdef CONFIG_DYNAMIC_FTRACE
|
|
@ called from __ftrace_caller, saved in mcount_enter
|
|
ldr r1, [sp, #16] @ instrumented routine (func)
|
|
mcount_adjust_addr r1, r1
|
|
#else
|
|
@ called from __mcount, untouched in lr
|
|
mcount_adjust_addr r1, lr @ instrumented routine (func)
|
|
#endif
|
|
mov r2, fp @ frame pointer
|
|
bl prepare_ftrace_return
|
|
mcount_exit
|
|
.endm
|
|
|
|
#ifdef CONFIG_OLD_MCOUNT
|
|
/*
|
|
* mcount
|
|
*/
|
|
|
|
.macro mcount_enter
|
|
stmdb sp!, {r0-r3, lr}
|
|
.endm
|
|
|
|
.macro mcount_get_lr reg
|
|
ldr \reg, [fp, #-4]
|
|
.endm
|
|
|
|
.macro mcount_exit
|
|
ldr lr, [fp, #-4]
|
|
ldmia sp!, {r0-r3, pc}
|
|
.endm
|
|
|
|
ENTRY(mcount)
|
|
#ifdef CONFIG_DYNAMIC_FTRACE
|
|
stmdb sp!, {lr}
|
|
ldr lr, [fp, #-4]
|
|
ldmia sp!, {pc}
|
|
#else
|
|
__mcount _old
|
|
#endif
|
|
ENDPROC(mcount)
|
|
|
|
#ifdef CONFIG_DYNAMIC_FTRACE
|
|
ENTRY(ftrace_caller_old)
|
|
__ftrace_caller _old
|
|
ENDPROC(ftrace_caller_old)
|
|
#endif
|
|
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
ENTRY(ftrace_graph_caller_old)
|
|
__ftrace_graph_caller
|
|
ENDPROC(ftrace_graph_caller_old)
|
|
#endif
|
|
|
|
.purgem mcount_enter
|
|
.purgem mcount_get_lr
|
|
.purgem mcount_exit
|
|
#endif
|
|
|
|
/*
|
|
* __gnu_mcount_nc
|
|
*/
|
|
|
|
.macro mcount_enter
|
|
/*
|
|
* This pad compensates for the push {lr} at the call site. Note that we are
|
|
* unable to unwind through a function which does not otherwise save its lr.
|
|
*/
|
|
UNWIND(.pad #4)
|
|
stmdb sp!, {r0-r3, lr}
|
|
UNWIND(.save {r0-r3, lr})
|
|
.endm
|
|
|
|
.macro mcount_get_lr reg
|
|
ldr \reg, [sp, #20]
|
|
.endm
|
|
|
|
.macro mcount_exit
|
|
ldmia sp!, {r0-r3, ip, lr}
|
|
mov pc, ip
|
|
.endm
|
|
|
|
ENTRY(__gnu_mcount_nc)
|
|
UNWIND(.fnstart)
|
|
#ifdef CONFIG_DYNAMIC_FTRACE
|
|
mov ip, lr
|
|
ldmia sp!, {lr}
|
|
mov pc, ip
|
|
#else
|
|
__mcount
|
|
#endif
|
|
UNWIND(.fnend)
|
|
ENDPROC(__gnu_mcount_nc)
|
|
|
|
#ifdef CONFIG_DYNAMIC_FTRACE
|
|
ENTRY(ftrace_caller)
|
|
UNWIND(.fnstart)
|
|
__ftrace_caller
|
|
UNWIND(.fnend)
|
|
ENDPROC(ftrace_caller)
|
|
#endif
|
|
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
ENTRY(ftrace_graph_caller)
|
|
UNWIND(.fnstart)
|
|
__ftrace_graph_caller
|
|
UNWIND(.fnend)
|
|
ENDPROC(ftrace_graph_caller)
|
|
#endif
|
|
|
|
.purgem mcount_enter
|
|
.purgem mcount_get_lr
|
|
.purgem mcount_exit
|
|
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
.globl return_to_handler
|
|
return_to_handler:
|
|
stmdb sp!, {r0-r3}
|
|
mov r0, fp @ frame pointer
|
|
bl ftrace_return_to_handler
|
|
mov lr, r0 @ r0 has real ret addr
|
|
ldmia sp!, {r0-r3}
|
|
mov pc, lr
|
|
#endif
|
|
|
|
ENTRY(ftrace_stub)
|
|
.Lftrace_stub:
|
|
mov pc, lr
|
|
ENDPROC(ftrace_stub)
|
|
|
|
#endif /* CONFIG_FUNCTION_TRACER */
|
|
|
|
/*=============================================================================
|
|
* SWI handler
|
|
*-----------------------------------------------------------------------------
|
|
*/
|
|
|
|
.align 5
|
|
ENTRY(vector_swi)
|
|
#ifdef CONFIG_CPU_V7M
|
|
v7m_exception_entry
|
|
#else
|
|
sub sp, sp, #S_FRAME_SIZE
|
|
stmia sp, {r0 - r12} @ Calling r0 - r12
|
|
ARM( add r8, sp, #S_PC )
|
|
ARM( stmdb r8, {sp, lr}^ ) @ Calling sp, lr
|
|
THUMB( mov r8, sp )
|
|
THUMB( store_user_sp_lr r8, r10, S_SP ) @ calling sp, lr
|
|
mrs r8, spsr @ called from non-FIQ mode, so ok.
|
|
str lr, [sp, #S_PC] @ Save calling PC
|
|
str r8, [sp, #S_PSR] @ Save CPSR
|
|
str r0, [sp, #S_OLD_R0] @ Save OLD_R0
|
|
#endif
|
|
zero_fp
|
|
|
|
#ifdef CONFIG_ALIGNMENT_TRAP
|
|
ldr ip, __cr_alignment
|
|
ldr ip, [ip]
|
|
mcr p15, 0, ip, c1, c0 @ update control register
|
|
#endif
|
|
|
|
enable_irq
|
|
ct_user_exit
|
|
get_thread_info tsk
|
|
|
|
/*
|
|
* Get the system call number.
|
|
*/
|
|
|
|
#if defined(CONFIG_OABI_COMPAT)
|
|
|
|
/*
|
|
* If we have CONFIG_OABI_COMPAT then we need to look at the swi
|
|
* value to determine if it is an EABI or an old ABI call.
|
|
*/
|
|
#ifdef CONFIG_ARM_THUMB
|
|
tst r8, #PSR_T_BIT
|
|
movne r10, #0 @ no thumb OABI emulation
|
|
USER( ldreq r10, [lr, #-4] ) @ get SWI instruction
|
|
#else
|
|
USER( ldr r10, [lr, #-4] ) @ get SWI instruction
|
|
#endif
|
|
#ifdef CONFIG_CPU_ENDIAN_BE8
|
|
rev r10, r10 @ little endian instruction
|
|
#endif
|
|
|
|
#elif defined(CONFIG_AEABI)
|
|
|
|
/*
|
|
* Pure EABI user space always put syscall number into scno (r7).
|
|
*/
|
|
#elif defined(CONFIG_ARM_THUMB)
|
|
/* Legacy ABI only, possibly thumb mode. */
|
|
tst r8, #PSR_T_BIT @ this is SPSR from save_user_regs
|
|
addne scno, r7, #__NR_SYSCALL_BASE @ put OS number in
|
|
USER( ldreq scno, [lr, #-4] )
|
|
|
|
#else
|
|
/* Legacy ABI only. */
|
|
USER( ldr scno, [lr, #-4] ) @ get SWI instruction
|
|
#endif
|
|
|
|
adr tbl, sys_call_table @ load syscall table pointer
|
|
|
|
#if defined(CONFIG_OABI_COMPAT)
|
|
/*
|
|
* If the swi argument is zero, this is an EABI call and we do nothing.
|
|
*
|
|
* If this is an old ABI call, get the syscall number into scno and
|
|
* get the old ABI syscall table address.
|
|
*/
|
|
bics r10, r10, #0xff000000
|
|
eorne scno, r10, #__NR_OABI_SYSCALL_BASE
|
|
ldrne tbl, =sys_oabi_call_table
|
|
#elif !defined(CONFIG_AEABI)
|
|
bic scno, scno, #0xff000000 @ mask off SWI op-code
|
|
eor scno, scno, #__NR_SYSCALL_BASE @ check OS number
|
|
#endif
|
|
|
|
local_restart:
|
|
ldr r10, [tsk, #TI_FLAGS] @ check for syscall tracing
|
|
stmdb sp!, {r4, r5} @ push fifth and sixth args
|
|
|
|
tst r10, #_TIF_SYSCALL_WORK @ are we tracing syscalls?
|
|
bne __sys_trace
|
|
|
|
cmp scno, #NR_syscalls @ check upper syscall limit
|
|
adr lr, BSYM(ret_fast_syscall) @ return address
|
|
ldrcc pc, [tbl, scno, lsl #2] @ call sys_* routine
|
|
|
|
add r1, sp, #S_OFF
|
|
cmp scno, #(__ARM_NR_BASE - __NR_SYSCALL_BASE)
|
|
eor r0, scno, #__NR_SYSCALL_BASE @ put OS number back
|
|
bcs arm_syscall
|
|
2: mov why, #0 @ no longer a real syscall
|
|
b sys_ni_syscall @ not private func
|
|
|
|
#if defined(CONFIG_OABI_COMPAT) || !defined(CONFIG_AEABI)
|
|
/*
|
|
* We failed to handle a fault trying to access the page
|
|
* containing the swi instruction, but we're not really in a
|
|
* position to return -EFAULT. Instead, return back to the
|
|
* instruction and re-enter the user fault handling path trying
|
|
* to page it in. This will likely result in sending SEGV to the
|
|
* current task.
|
|
*/
|
|
9001:
|
|
sub lr, lr, #4
|
|
str lr, [sp, #S_PC]
|
|
b ret_fast_syscall
|
|
#endif
|
|
ENDPROC(vector_swi)
|
|
|
|
/*
|
|
* This is the really slow path. We're going to be doing
|
|
* context switches, and waiting for our parent to respond.
|
|
*/
|
|
__sys_trace:
|
|
mov r1, scno
|
|
add r0, sp, #S_OFF
|
|
bl syscall_trace_enter
|
|
|
|
adr lr, BSYM(__sys_trace_return) @ return address
|
|
mov scno, r0 @ syscall number (possibly new)
|
|
add r1, sp, #S_R0 + S_OFF @ pointer to regs
|
|
cmp scno, #NR_syscalls @ check upper syscall limit
|
|
ldmccia r1, {r0 - r6} @ have to reload r0 - r6
|
|
stmccia sp, {r4, r5} @ and update the stack args
|
|
ldrcc pc, [tbl, scno, lsl #2] @ call sys_* routine
|
|
cmp scno, #-1 @ skip the syscall?
|
|
bne 2b
|
|
add sp, sp, #S_OFF @ restore stack
|
|
b ret_slow_syscall
|
|
|
|
__sys_trace_return:
|
|
str r0, [sp, #S_R0 + S_OFF]! @ save returned r0
|
|
mov r0, sp
|
|
bl syscall_trace_exit
|
|
b ret_slow_syscall
|
|
|
|
.align 5
|
|
#ifdef CONFIG_ALIGNMENT_TRAP
|
|
.type __cr_alignment, #object
|
|
__cr_alignment:
|
|
.word cr_alignment
|
|
#endif
|
|
.ltorg
|
|
|
|
/*
|
|
* This is the syscall table declaration for native ABI syscalls.
|
|
* With EABI a couple syscalls are obsolete and defined as sys_ni_syscall.
|
|
*/
|
|
#define ABI(native, compat) native
|
|
#ifdef CONFIG_AEABI
|
|
#define OBSOLETE(syscall) sys_ni_syscall
|
|
#else
|
|
#define OBSOLETE(syscall) syscall
|
|
#endif
|
|
|
|
.type sys_call_table, #object
|
|
ENTRY(sys_call_table)
|
|
#include "calls.S"
|
|
#undef ABI
|
|
#undef OBSOLETE
|
|
|
|
/*============================================================================
|
|
* Special system call wrappers
|
|
*/
|
|
@ r0 = syscall number
|
|
@ r8 = syscall table
|
|
sys_syscall:
|
|
bic scno, r0, #__NR_OABI_SYSCALL_BASE
|
|
cmp scno, #__NR_syscall - __NR_SYSCALL_BASE
|
|
cmpne scno, #NR_syscalls @ check range
|
|
stmloia sp, {r5, r6} @ shuffle args
|
|
movlo r0, r1
|
|
movlo r1, r2
|
|
movlo r2, r3
|
|
movlo r3, r4
|
|
ldrlo pc, [tbl, scno, lsl #2]
|
|
b sys_ni_syscall
|
|
ENDPROC(sys_syscall)
|
|
|
|
sys_sigreturn_wrapper:
|
|
add r0, sp, #S_OFF
|
|
mov why, #0 @ prevent syscall restart handling
|
|
b sys_sigreturn
|
|
ENDPROC(sys_sigreturn_wrapper)
|
|
|
|
sys_rt_sigreturn_wrapper:
|
|
add r0, sp, #S_OFF
|
|
mov why, #0 @ prevent syscall restart handling
|
|
b sys_rt_sigreturn
|
|
ENDPROC(sys_rt_sigreturn_wrapper)
|
|
|
|
sys_statfs64_wrapper:
|
|
teq r1, #88
|
|
moveq r1, #84
|
|
b sys_statfs64
|
|
ENDPROC(sys_statfs64_wrapper)
|
|
|
|
sys_fstatfs64_wrapper:
|
|
teq r1, #88
|
|
moveq r1, #84
|
|
b sys_fstatfs64
|
|
ENDPROC(sys_fstatfs64_wrapper)
|
|
|
|
/*
|
|
* Note: off_4k (r5) is always units of 4K. If we can't do the requested
|
|
* offset, we return EINVAL.
|
|
*/
|
|
sys_mmap2:
|
|
#if PAGE_SHIFT > 12
|
|
tst r5, #PGOFF_MASK
|
|
moveq r5, r5, lsr #PAGE_SHIFT - 12
|
|
streq r5, [sp, #4]
|
|
beq sys_mmap_pgoff
|
|
mov r0, #-EINVAL
|
|
mov pc, lr
|
|
#else
|
|
str r5, [sp, #4]
|
|
b sys_mmap_pgoff
|
|
#endif
|
|
ENDPROC(sys_mmap2)
|
|
|
|
#ifdef CONFIG_OABI_COMPAT
|
|
|
|
/*
|
|
* These are syscalls with argument register differences
|
|
*/
|
|
|
|
sys_oabi_pread64:
|
|
stmia sp, {r3, r4}
|
|
b sys_pread64
|
|
ENDPROC(sys_oabi_pread64)
|
|
|
|
sys_oabi_pwrite64:
|
|
stmia sp, {r3, r4}
|
|
b sys_pwrite64
|
|
ENDPROC(sys_oabi_pwrite64)
|
|
|
|
sys_oabi_truncate64:
|
|
mov r3, r2
|
|
mov r2, r1
|
|
b sys_truncate64
|
|
ENDPROC(sys_oabi_truncate64)
|
|
|
|
sys_oabi_ftruncate64:
|
|
mov r3, r2
|
|
mov r2, r1
|
|
b sys_ftruncate64
|
|
ENDPROC(sys_oabi_ftruncate64)
|
|
|
|
sys_oabi_readahead:
|
|
str r3, [sp]
|
|
mov r3, r2
|
|
mov r2, r1
|
|
b sys_readahead
|
|
ENDPROC(sys_oabi_readahead)
|
|
|
|
/*
|
|
* Let's declare a second syscall table for old ABI binaries
|
|
* using the compatibility syscall entries.
|
|
*/
|
|
#define ABI(native, compat) compat
|
|
#define OBSOLETE(syscall) syscall
|
|
|
|
.type sys_oabi_call_table, #object
|
|
ENTRY(sys_oabi_call_table)
|
|
#include "calls.S"
|
|
#undef ABI
|
|
#undef OBSOLETE
|
|
|
|
#endif
|
|
|