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-rw-r--r--arch/sh/lib/mcount.S287
1 files changed, 287 insertions, 0 deletions
diff --git a/arch/sh/lib/mcount.S b/arch/sh/lib/mcount.S
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+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * arch/sh/lib/mcount.S
+ *
+ * Copyright (C) 2008, 2009 Paul Mundt
+ * Copyright (C) 2008, 2009 Matt Fleming
+ */
+#include <asm/ftrace.h>
+#include <asm/thread_info.h>
+#include <asm/asm-offsets.h>
+
+#define MCOUNT_ENTER() \
+ mov.l r4, @-r15; \
+ mov.l r5, @-r15; \
+ mov.l r6, @-r15; \
+ mov.l r7, @-r15; \
+ sts.l pr, @-r15; \
+ \
+ mov.l @(20,r15),r4; \
+ sts pr, r5
+
+#define MCOUNT_LEAVE() \
+ lds.l @r15+, pr; \
+ mov.l @r15+, r7; \
+ mov.l @r15+, r6; \
+ mov.l @r15+, r5; \
+ rts; \
+ mov.l @r15+, r4
+
+#ifdef CONFIG_STACK_DEBUG
+/*
+ * Perform diagnostic checks on the state of the kernel stack.
+ *
+ * Check for stack overflow. If there is less than 1KB free
+ * then it has overflowed.
+ *
+ * Make sure the stack pointer contains a valid address. Valid
+ * addresses for kernel stacks are anywhere after the bss
+ * (after __bss_stop) and anywhere in init_thread_union (init_stack).
+ */
+#define STACK_CHECK() \
+ mov #(THREAD_SIZE >> 10), r0; \
+ shll8 r0; \
+ shll2 r0; \
+ \
+ /* r1 = sp & (THREAD_SIZE - 1) */ \
+ mov #-1, r1; \
+ add r0, r1; \
+ and r15, r1; \
+ \
+ mov #TI_SIZE, r3; \
+ mov #(STACK_WARN >> 8), r2; \
+ shll8 r2; \
+ add r3, r2; \
+ \
+ /* Is the stack overflowing? */ \
+ cmp/hi r2, r1; \
+ bf stack_panic; \
+ \
+ /* If sp > __bss_stop then we're OK. */ \
+ mov.l .L_ebss, r1; \
+ cmp/hi r1, r15; \
+ bt 1f; \
+ \
+ /* If sp < init_stack, we're not OK. */ \
+ mov.l .L_init_thread_union, r1; \
+ cmp/hs r1, r15; \
+ bf stack_panic; \
+ \
+ /* If sp > init_stack && sp < __bss_stop, not OK. */ \
+ add r0, r1; \
+ cmp/hs r1, r15; \
+ bt stack_panic; \
+1:
+#else
+#define STACK_CHECK()
+#endif /* CONFIG_STACK_DEBUG */
+
+ .align 2
+ .globl _mcount
+ .type _mcount,@function
+ .globl mcount
+ .type mcount,@function
+_mcount:
+mcount:
+ STACK_CHECK()
+
+#ifndef CONFIG_FUNCTION_TRACER
+ rts
+ nop
+#else
+ MCOUNT_ENTER()
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+ .globl mcount_call
+mcount_call:
+ mov.l .Lftrace_stub, r6
+#else
+ mov.l .Lftrace_trace_function, r6
+ mov.l ftrace_stub, r7
+ cmp/eq r6, r7
+ bt skip_trace
+ mov.l @r6, r6
+#endif
+
+ jsr @r6
+ nop
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ mov.l .Lftrace_graph_return, r6
+ mov.l .Lftrace_stub, r7
+ cmp/eq r6, r7
+ bt 1f
+
+ mov.l .Lftrace_graph_caller, r0
+ jmp @r0
+ nop
+
+1:
+ mov.l .Lftrace_graph_entry, r6
+ mov.l .Lftrace_graph_entry_stub, r7
+ cmp/eq r6, r7
+ bt skip_trace
+
+ mov.l .Lftrace_graph_caller, r0
+ jmp @r0
+ nop
+
+ .align 2
+.Lftrace_graph_return:
+ .long ftrace_graph_return
+.Lftrace_graph_entry:
+ .long ftrace_graph_entry
+.Lftrace_graph_entry_stub:
+ .long ftrace_graph_entry_stub
+.Lftrace_graph_caller:
+ .long ftrace_graph_caller
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+
+ .globl skip_trace
+skip_trace:
+ MCOUNT_LEAVE()
+
+ .align 2
+.Lftrace_trace_function:
+ .long ftrace_trace_function
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+/*
+ * NOTE: Do not move either ftrace_graph_call or ftrace_caller
+ * as this will affect the calculation of GRAPH_INSN_OFFSET.
+ */
+ .globl ftrace_graph_call
+ftrace_graph_call:
+ mov.l .Lskip_trace, r0
+ jmp @r0
+ nop
+
+ .align 2
+.Lskip_trace:
+ .long skip_trace
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+
+ .globl ftrace_caller
+ftrace_caller:
+ MCOUNT_ENTER()
+
+ .globl ftrace_call
+ftrace_call:
+ mov.l .Lftrace_stub, r6
+ jsr @r6
+ nop
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ bra ftrace_graph_call
+ nop
+#else
+ MCOUNT_LEAVE()
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+#endif /* CONFIG_DYNAMIC_FTRACE */
+
+ .align 2
+
+/*
+ * NOTE: From here on the locations of the .Lftrace_stub label and
+ * ftrace_stub itself are fixed. Adding additional data here will skew
+ * the displacement for the memory table and break the block replacement.
+ * Place new labels either after the ftrace_stub body, or before
+ * ftrace_caller. You have been warned.
+ */
+.Lftrace_stub:
+ .long ftrace_stub
+
+ .globl ftrace_stub
+ftrace_stub:
+ rts
+ nop
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ .globl ftrace_graph_caller
+ftrace_graph_caller:
+ mov.l 2f, r1
+ jmp @r1
+ nop
+1:
+ /*
+ * MCOUNT_ENTER() pushed 5 registers onto the stack, so
+ * the stack address containing our return address is
+ * r15 + 20.
+ */
+ mov #20, r0
+ add r15, r0
+ mov r0, r4
+
+ mov.l .Lprepare_ftrace_return, r0
+ jsr @r0
+ nop
+
+ MCOUNT_LEAVE()
+
+ .align 2
+2: .long skip_trace
+.Lprepare_ftrace_return:
+ .long prepare_ftrace_return
+
+ .globl return_to_handler
+return_to_handler:
+ /*
+ * Save the return values.
+ */
+ mov.l r0, @-r15
+ mov.l r1, @-r15
+
+ mov #0, r4
+
+ mov.l .Lftrace_return_to_handler, r0
+ jsr @r0
+ nop
+
+ /*
+ * The return value from ftrace_return_handler has the real
+ * address that we should return to.
+ */
+ lds r0, pr
+ mov.l @r15+, r1
+ rts
+ mov.l @r15+, r0
+
+
+ .align 2
+.Lftrace_return_to_handler:
+ .long ftrace_return_to_handler
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+#endif /* CONFIG_FUNCTION_TRACER */
+
+#ifdef CONFIG_STACK_DEBUG
+ .globl stack_panic
+stack_panic:
+ mov.l .Ldump_stack, r0
+ jsr @r0
+ nop
+
+ mov.l .Lpanic, r0
+ jsr @r0
+ mov.l .Lpanic_s, r4
+
+ rts
+ nop
+
+ .align 2
+.L_init_thread_union:
+ .long init_thread_union
+.L_ebss:
+ .long __bss_stop
+.Lpanic:
+ .long panic
+.Lpanic_s:
+ .long .Lpanic_str
+.Ldump_stack:
+ .long dump_stack
+
+ .section .rodata
+ .align 2
+.Lpanic_str:
+ .string "Stack error"
+#endif /* CONFIG_STACK_DEBUG */