forked from Minki/linux
5606330627
Implement return_address() and use it instead of __builtin_return_address(n). __builtin_return_address(n) is not guaranteed to work for n > 0, therefore implement a private return_address() function which walks the stack frames and returns the proper return address. This way we get also rid of a compile warning which gcc 6.1 emits and look like all other architectures. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
87 lines
1.6 KiB
C
87 lines
1.6 KiB
C
#ifndef _ASM_S390_FTRACE_H
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#define _ASM_S390_FTRACE_H
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#define ARCH_SUPPORTS_FTRACE_OPS 1
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#ifdef CC_USING_HOTPATCH
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#define MCOUNT_INSN_SIZE 6
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#else
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#define MCOUNT_INSN_SIZE 24
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#define MCOUNT_RETURN_FIXUP 18
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#endif
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#ifndef __ASSEMBLY__
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unsigned long return_address(int depth);
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#define ftrace_return_address(n) return_address(n)
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void _mcount(void);
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void ftrace_caller(void);
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extern char ftrace_graph_caller_end;
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extern unsigned long ftrace_plt;
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struct dyn_arch_ftrace { };
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#define MCOUNT_ADDR ((unsigned long)_mcount)
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#define FTRACE_ADDR ((unsigned long)ftrace_caller)
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#define KPROBE_ON_FTRACE_NOP 0
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#define KPROBE_ON_FTRACE_CALL 1
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static inline unsigned long ftrace_call_adjust(unsigned long addr)
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{
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return addr;
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}
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struct ftrace_insn {
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u16 opc;
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s32 disp;
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} __packed;
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static inline void ftrace_generate_nop_insn(struct ftrace_insn *insn)
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{
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#ifdef CONFIG_FUNCTION_TRACER
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#ifdef CC_USING_HOTPATCH
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/* brcl 0,0 */
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insn->opc = 0xc004;
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insn->disp = 0;
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#else
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/* jg .+24 */
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insn->opc = 0xc0f4;
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insn->disp = MCOUNT_INSN_SIZE / 2;
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#endif
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#endif
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}
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static inline int is_ftrace_nop(struct ftrace_insn *insn)
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{
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#ifdef CONFIG_FUNCTION_TRACER
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#ifdef CC_USING_HOTPATCH
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if (insn->disp == 0)
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return 1;
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#else
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if (insn->disp == MCOUNT_INSN_SIZE / 2)
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return 1;
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#endif
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#endif
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return 0;
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}
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static inline void ftrace_generate_call_insn(struct ftrace_insn *insn,
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unsigned long ip)
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{
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#ifdef CONFIG_FUNCTION_TRACER
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unsigned long target;
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/* brasl r0,ftrace_caller */
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target = is_module_addr((void *) ip) ? ftrace_plt : FTRACE_ADDR;
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insn->opc = 0xc005;
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insn->disp = (target - ip) / 2;
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#endif
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}
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#endif /* __ASSEMBLY__ */
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#endif /* _ASM_S390_FTRACE_H */
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