diff options
Diffstat (limited to 'arch/arm/kernel/entry-common.S')
| -rw-r--r-- | arch/arm/kernel/entry-common.S | 326 |
1 files changed, 242 insertions, 84 deletions
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S index 366e5097a41a..1e7b04a40a31 100644 --- a/arch/arm/kernel/entry-common.S +++ b/arch/arm/kernel/entry-common.S @@ -29,18 +29,14 @@ 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 - @ fast_restore_user_regs - ldr r1, [sp, #S_OFF + S_PSR] @ get calling cpsr - ldr lr, [sp, #S_OFF + S_PC]! @ get pc - msr spsr_cxsf, r1 @ save in spsr_svc - ldmdb sp, {r1 - lr}^ @ get calling r1 - lr - mov r0, r0 - add sp, sp, #S_FRAME_SIZE - S_PC - movs pc, lr @ return & move spsr_svc into cpsr + restore_user_regs fast = 1, offset = S_OFF UNWIND(.fnend ) /* @@ -51,10 +47,12 @@ fast_work_pending: work_pending: tst r1, #_TIF_NEED_RESCHED bne work_resched - tst r1, #_TIF_SIGPENDING + 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 @@ -70,17 +68,13 @@ ret_slow_syscall: 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 - @ slow_restore_user_regs - ldr r1, [sp, #S_PSR] @ get calling cpsr - ldr lr, [sp, #S_PC]! @ get pc - msr spsr_cxsf, r1 @ save in spsr_svc - ldmdb sp, {r0 - lr}^ @ get calling r0 - lr - mov r0, r0 - add sp, sp, #S_FRAME_SIZE - S_PC - movs pc, lr @ return & move spsr_svc into cpsr + restore_user_regs fast = 0, offset = 0 ENDPROC(ret_to_user) /* @@ -106,56 +100,222 @@ ENDPROC(ret_from_fork) #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 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 + mov r0, lr @ instrumented function + sub r0, r0, #MCOUNT_INSN_SIZE + 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 + mov r0, lr @ instrumented function + sub r0, r0, #MCOUNT_INSN_SIZE + + .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) +#else + @ called from __mcount, untouched in lr + mov r1, lr @ instrumented routine (func) +#endif + sub r1, r1, #MCOUNT_INSN_SIZE + 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) - stmdb sp!, {r0-r3, lr} - mov r0, lr - sub r0, r0, #MCOUNT_INSN_SIZE +#ifdef CONFIG_DYNAMIC_FTRACE + stmdb sp!, {lr} + ldr lr, [fp, #-4] + ldmia sp!, {pc} +#else + __mcount _old +#endif +ENDPROC(mcount) - .globl mcount_call -mcount_call: - bl ftrace_stub - ldr lr, [fp, #-4] @ restore lr - ldmia sp!, {r0-r3, pc} +#ifdef CONFIG_DYNAMIC_FTRACE +ENTRY(ftrace_caller_old) + __ftrace_caller _old +ENDPROC(ftrace_caller_old) +#endif -ENTRY(ftrace_caller) - stmdb sp!, {r0-r3, lr} - ldr r1, [fp, #-4] - mov r0, lr - sub r0, r0, #MCOUNT_INSN_SIZE +#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 - .globl ftrace_call -ftrace_call: - bl ftrace_stub - ldr lr, [fp, #-4] @ restore lr - ldmia sp!, {r0-r3, pc} +/* + * __gnu_mcount_nc + */ +.macro mcount_enter + stmdb sp!, {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) +#ifdef CONFIG_DYNAMIC_FTRACE + mov ip, lr + ldmia sp!, {lr} + mov pc, ip #else + __mcount +#endif +ENDPROC(__gnu_mcount_nc) -ENTRY(mcount) - stmdb sp!, {r0-r3, lr} - ldr r0, =ftrace_trace_function - ldr r2, [r0] - adr r0, ftrace_stub - cmp r0, r2 - bne trace - ldr lr, [fp, #-4] @ restore lr - ldmia sp!, {r0-r3, pc} - -trace: - ldr r1, [fp, #-4] @ lr of instrumented routine - mov r0, lr - sub r0, r0, #MCOUNT_INSN_SIZE - mov lr, pc - mov pc, r2 - mov lr, r1 @ restore lr - ldmia sp!, {r0-r3, pc} - -#endif /* CONFIG_DYNAMIC_FTRACE */ - - .globl ftrace_stub -ftrace_stub: - mov pc, lr +#ifdef CONFIG_DYNAMIC_FTRACE +ENTRY(ftrace_caller) + __ftrace_caller +ENDPROC(ftrace_caller) +#endif + +#ifdef CONFIG_FUNCTION_GRAPH_TRACER +ENTRY(ftrace_graph_caller) + __ftrace_graph_caller +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 */ @@ -182,8 +342,10 @@ ftrace_stub: ENTRY(vector_swi) sub sp, sp, #S_FRAME_SIZE stmia sp, {r0 - r12} @ Calling r0 - r12 - add r8, sp, #S_PC - stmdb r8, {sp, lr}^ @ Calling sp, lr + 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 @@ -250,7 +412,6 @@ ENTRY(vector_swi) get_thread_info tsk adr tbl, sys_call_table @ load syscall table pointer - ldr ip, [tsk, #TI_FLAGS] @ check for syscall tracing #if defined(CONFIG_OABI_COMPAT) /* @@ -267,12 +428,24 @@ ENTRY(vector_swi) eor scno, scno, #__NR_SYSCALL_BASE @ check OS number #endif + ldr r10, [tsk, #TI_FLAGS] @ check for syscall tracing stmdb sp!, {r4, r5} @ push fifth and sixth args - tst ip, #_TIF_SYSCALL_TRACE @ are we tracing syscalls? + +#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_TRACE @ are we tracing syscalls? bne __sys_trace cmp scno, #NR_syscalls @ check upper syscall limit - adr lr, ret_fast_syscall @ return address + adr lr, BSYM(ret_fast_syscall) @ return address ldrcc pc, [tbl, scno, lsl #2] @ call sys_* routine add r1, sp, #S_OFF @@ -293,7 +466,7 @@ __sys_trace: mov r0, #0 @ trace entry [IP = 0] bl syscall_trace - adr lr, __sys_trace_return @ return address + 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 @@ -373,23 +546,15 @@ sys_clone_wrapper: b sys_clone ENDPROC(sys_clone_wrapper) -sys_sigsuspend_wrapper: - add r3, sp, #S_OFF - b sys_sigsuspend -ENDPROC(sys_sigsuspend_wrapper) - -sys_rt_sigsuspend_wrapper: - add r2, sp, #S_OFF - b sys_rt_sigsuspend -ENDPROC(sys_rt_sigsuspend_wrapper) - 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) @@ -419,22 +584,15 @@ sys_mmap2: tst r5, #PGOFF_MASK moveq r5, r5, lsr #PAGE_SHIFT - 12 streq r5, [sp, #4] - beq do_mmap2 + beq sys_mmap_pgoff mov r0, #-EINVAL mov pc, lr #else str r5, [sp, #4] - b do_mmap2 + b sys_mmap_pgoff #endif ENDPROC(sys_mmap2) -ENTRY(pabort_ifar) - mrc p15, 0, r0, cr6, cr0, 2 -ENTRY(pabort_noifar) - mov pc, lr -ENDPROC(pabort_ifar) -ENDPROC(pabort_noifar) - #ifdef CONFIG_OABI_COMPAT /* |