diff options
Diffstat (limited to 'arch/arm/kernel/entry-common.S')
| -rw-r--r-- | arch/arm/kernel/entry-common.S | 200 |
1 files changed, 85 insertions, 115 deletions
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S index 9fd0ba90c1d..7139d4a7dea 100644 --- a/arch/arm/kernel/entry-common.S +++ b/arch/arm/kernel/entry-common.S @@ -10,9 +10,15 @@ #include <asm/unistd.h> #include <asm/ftrace.h> -#include <mach/entry-macro.S> #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" @@ -29,12 +35,11 @@ ret_fast_syscall: ldr r1, [tsk, #TI_FLAGS] tst r1, #_TIF_WORK_MASK bne fast_work_pending -#if defined(CONFIG_IRQSOFF_TRACER) asm_trace_hardirqs_on -#endif /* 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 ) @@ -45,19 +50,15 @@ ret_fast_syscall: fast_work_pending: str r0, [sp, #S_R0+S_OFF]! @ returned r0 work_pending: - tst r1, #_TIF_NEED_RESCHED - bne work_resched - tst r1, #_TIF_SIGPENDING|_TIF_NOTIFY_RESUME - beq no_work_pending mov r0, sp @ 'regs' mov r2, why @ 'syscall' - tst r1, #_TIF_SIGPENDING @ delivering a signal? - movne why, #0 @ prevent further restarts - bl do_notify_resume - b ret_slow_syscall @ Check work again + 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 -work_resched: - bl schedule /* * "slow" syscall return path. "why" tells us if this was a real syscall. */ @@ -69,11 +70,11 @@ ENTRY(ret_to_user_from_irq) tst r1, #_TIF_WORK_MASK bne work_pending no_work_pending: -#if defined(CONFIG_IRQSOFF_TRACER) asm_trace_hardirqs_on -#endif + /* 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) @@ -84,20 +85,26 @@ ENDPROC(ret_to_user) */ ENTRY(ret_from_fork) bl schedule_tail - get_thread_info tsk - ldr r1, [tsk, #TI_FLAGS] @ check for syscall tracing - mov why, #1 - tst r1, #_TIF_SYSCALL_WORK @ are we tracing syscalls? - beq ret_slow_syscall - mov r1, sp - mov r0, #1 @ trace exit [IP = 1] - bl syscall_trace + 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 @@ -268,7 +275,13 @@ ENDPROC(ftrace_graph_caller_old) */ .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 @@ -281,6 +294,7 @@ ENDPROC(ftrace_graph_caller_old) .endm ENTRY(__gnu_mcount_nc) +UNWIND(.fnstart) #ifdef CONFIG_DYNAMIC_FTRACE mov ip, lr ldmia sp!, {lr} @@ -288,17 +302,22 @@ ENTRY(__gnu_mcount_nc) #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 @@ -329,22 +348,11 @@ ENDPROC(ftrace_stub) *----------------------------------------------------------------------------- */ - /* If we're optimising for StrongARM the resulting code won't - run on an ARM7 and we can save a couple of instructions. - --pb */ -#ifdef CONFIG_CPU_ARM710 -#define A710(code...) code -.Larm710bug: - ldmia sp, {r0 - lr}^ @ Get calling r0 - lr - mov r0, r0 - add sp, sp, #S_FRAME_SIZE - subs pc, lr, #4 -#else -#define A710(code...) -#endif - .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 ) @@ -355,7 +363,12 @@ ENTRY(vector_swi) 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 + alignment_trap ip, __cr_alignment + enable_irq + ct_user_exit + get_thread_info tsk /* * Get the system call number. @@ -370,52 +383,28 @@ ENTRY(vector_swi) #ifdef CONFIG_ARM_THUMB tst r8, #PSR_T_BIT movne r10, #0 @ no thumb OABI emulation - ldreq r10, [lr, #-4] @ get SWI instruction + USER( ldreq r10, [lr, #-4] ) @ get SWI instruction #else - ldr r10, [lr, #-4] @ get SWI instruction - A710( and ip, r10, #0x0f000000 @ check for SWI ) - A710( teq ip, #0x0f000000 ) - A710( bne .Larm710bug ) -#endif -#ifdef CONFIG_CPU_ENDIAN_BE8 - rev r10, r10 @ little endian instruction + USER( ldr r10, [lr, #-4] ) @ get SWI instruction #endif + ARM_BE8(rev r10, r10) @ little endian instruction #elif defined(CONFIG_AEABI) /* * Pure EABI user space always put syscall number into scno (r7). */ - A710( ldr ip, [lr, #-4] @ get SWI instruction ) - A710( and ip, ip, #0x0f000000 @ check for SWI ) - A710( teq ip, #0x0f000000 ) - A710( bne .Larm710bug ) - #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 - ldreq scno, [lr, #-4] + USER( ldreq scno, [lr, #-4] ) #else - /* Legacy ABI only. */ - ldr scno, [lr, #-4] @ get SWI instruction - A710( and ip, scno, #0x0f000000 @ check for SWI ) - A710( teq ip, #0x0f000000 ) - A710( bne .Larm710bug ) - + USER( ldr scno, [lr, #-4] ) @ get SWI instruction #endif -#ifdef CONFIG_ALIGNMENT_TRAP - ldr ip, __cr_alignment - ldr ip, [ip] - mcr p15, 0, ip, c1, c0 @ update control register -#endif - enable_irq - - get_thread_info tsk adr tbl, sys_call_table @ load syscall table pointer #if defined(CONFIG_OABI_COMPAT) @@ -433,19 +422,10 @@ ENTRY(vector_swi) 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 -#ifdef CONFIG_SECCOMP - tst r10, #_TIF_SECCOMP - beq 1f - mov r0, scno - bl __secure_computing - add r0, sp, #S_R0 + S_OFF @ pointer to regs - ldmia r0, {r0 - r3} @ have to reload r0 - r3 -1: -#endif - tst r10, #_TIF_SYSCALL_WORK @ are we tracing syscalls? bne __sys_trace @@ -454,11 +434,26 @@ ENTRY(vector_swi) ldrcc pc, [tbl, scno, lsl #2] @ call sys_* routine add r1, sp, #S_OFF -2: mov why, #0 @ no longer a real syscall - cmp scno, #(__ARM_NR_BASE - __NR_SYSCALL_BASE) +2: cmp scno, #(__ARM_NR_BASE - __NR_SYSCALL_BASE) eor r0, scno, #__NR_SYSCALL_BASE @ put OS number back - bcs arm_syscall + bcs arm_syscall + 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) /* @@ -466,25 +461,26 @@ ENDPROC(vector_swi) * context switches, and waiting for our parent to respond. */ __sys_trace: - mov r2, scno - add r1, sp, #S_OFF - mov r0, #0 @ trace entry [IP = 0] - bl syscall_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 - r3} @ have to reload r0 - r3 + 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 - b 2b + 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 r2, scno - mov r1, sp - mov r0, #1 @ trace exit [IP = 1] - bl syscall_trace + mov r0, sp + bl syscall_trace_exit b ret_slow_syscall .align 5 @@ -530,27 +526,6 @@ sys_syscall: b sys_ni_syscall ENDPROC(sys_syscall) -sys_fork_wrapper: - add r0, sp, #S_OFF - b sys_fork -ENDPROC(sys_fork_wrapper) - -sys_vfork_wrapper: - add r0, sp, #S_OFF - b sys_vfork -ENDPROC(sys_vfork_wrapper) - -sys_execve_wrapper: - add r3, sp, #S_OFF - b sys_execve -ENDPROC(sys_execve_wrapper) - -sys_clone_wrapper: - add ip, sp, #S_OFF - str ip, [sp, #4] - b sys_clone -ENDPROC(sys_clone_wrapper) - sys_sigreturn_wrapper: add r0, sp, #S_OFF mov why, #0 @ prevent syscall restart handling @@ -563,11 +538,6 @@ sys_rt_sigreturn_wrapper: b sys_rt_sigreturn ENDPROC(sys_rt_sigreturn_wrapper) -sys_sigaltstack_wrapper: - ldr r2, [sp, #S_OFF + S_SP] - b do_sigaltstack -ENDPROC(sys_sigaltstack_wrapper) - sys_statfs64_wrapper: teq r1, #88 moveq r1, #84 |