#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}
- ret ip
-.endm
-
-ENTRY(__gnu_mcount_nc)
-UNWIND(.fnstart)
-#ifdef CONFIG_DYNAMIC_FTRACE
- mov ip, lr
- ldmia sp!, {lr}
- ret 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}
- ret lr
-#endif
-
-ENTRY(ftrace_stub)
-.Lftrace_stub:
- ret lr
-ENDPROC(ftrace_stub)
-
-#endif /* CONFIG_FUNCTION_TRACER */
-
/*=============================================================================
* SWI handler
*-----------------------------------------------------------------------------
projects / cascardo / linux.git / blobdiff