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/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright IBM Corp. 2008, 2009
*
*/
#include <linux/linkage.h>
#include <asm/asm-offsets.h>
#include <asm/ftrace.h>
#include <asm/nospec-insn.h>
#include <asm/ptrace.h>
#include <asm/march.h>
#define STACK_FRAME_SIZE_PTREGS (STACK_FRAME_OVERHEAD + __PT_SIZE)
#define STACK_PTREGS (STACK_FRAME_OVERHEAD)
#define STACK_PTREGS_GPRS (STACK_PTREGS + __PT_GPRS)
#define STACK_PTREGS_PSW (STACK_PTREGS + __PT_PSW)
#define STACK_FRAME_SIZE_FREGS (STACK_FRAME_OVERHEAD + __FTRACE_REGS_SIZE)
#define STACK_FREGS (STACK_FRAME_OVERHEAD)
#define STACK_FREGS_PTREGS (STACK_FRAME_OVERHEAD + __FTRACE_REGS_PT_REGS)
#define STACK_FREGS_PTREGS_GPRS (STACK_FREGS_PTREGS + __PT_GPRS)
#define STACK_FREGS_PTREGS_PSW (STACK_FREGS_PTREGS + __PT_PSW)
#define STACK_FREGS_PTREGS_ORIG_GPR2 (STACK_FREGS_PTREGS + __PT_ORIG_GPR2)
#define STACK_FREGS_PTREGS_FLAGS (STACK_FREGS_PTREGS + __PT_FLAGS)
/* packed stack: allocate just enough for r14, r15 and backchain */
#define TRACED_FUNC_FRAME_SIZE 24
#ifdef CONFIG_FUNCTION_TRACER
GEN_BR_THUNK %r1
GEN_BR_THUNK %r14
.section .kprobes.text, "ax"
SYM_FUNC_START(ftrace_stub)
BR_EX %r14
SYM_FUNC_END(ftrace_stub)
SYM_CODE_START(ftrace_stub_direct_tramp)
lgr %r1, %r0
BR_EX %r1
SYM_CODE_END(ftrace_stub_direct_tramp)
.macro ftrace_regs_entry, allregs=0
stg %r14,(__SF_GPRS+8*8)(%r15) # save traced function caller
.if \allregs == 1
# save psw mask
# don't put any instructions clobbering CC before this point
epsw %r1,%r14
risbg %r14,%r1,0,31,32
.endif
lgr %r1,%r15
# allocate stack frame for ftrace_caller to contain traced function
aghi %r15,-TRACED_FUNC_FRAME_SIZE
stg %r1,__SF_BACKCHAIN(%r15)
stg %r0,(__SF_GPRS+8*8)(%r15)
stg %r15,(__SF_GPRS+9*8)(%r15)
# allocate ftrace_regs and stack frame for ftrace_trace_function
aghi %r15,-STACK_FRAME_SIZE_FREGS
stg %r1,(STACK_FREGS_PTREGS_GPRS+15*8)(%r15)
xc STACK_FREGS_PTREGS_ORIG_GPR2(8,%r15),STACK_FREGS_PTREGS_ORIG_GPR2(%r15)
.if \allregs == 1
stg %r14,(STACK_FREGS_PTREGS_PSW)(%r15)
mvghi STACK_FREGS_PTREGS_FLAGS(%r15),_PIF_FTRACE_FULL_REGS
.else
xc STACK_FREGS_PTREGS_FLAGS(8,%r15),STACK_FREGS_PTREGS_FLAGS(%r15)
.endif
lg %r14,(__SF_GPRS+8*8)(%r1) # restore original return address
aghi %r1,-TRACED_FUNC_FRAME_SIZE
stg %r1,__SF_BACKCHAIN(%r15)
stg %r0,(STACK_FREGS_PTREGS_PSW+8)(%r15)
stmg %r2,%r14,(STACK_FREGS_PTREGS_GPRS+2*8)(%r15)
.endm
SYM_CODE_START(ftrace_regs_caller)
ftrace_regs_entry 1
j ftrace_common
SYM_CODE_END(ftrace_regs_caller)
SYM_CODE_START(ftrace_caller)
ftrace_regs_entry 0
j ftrace_common
SYM_CODE_END(ftrace_caller)
SYM_CODE_START(ftrace_common)
#ifdef MARCH_HAS_Z196_FEATURES
aghik %r2,%r0,-MCOUNT_INSN_SIZE
lgrl %r4,function_trace_op
lgrl %r1,ftrace_func
#else
lgr %r2,%r0
aghi %r2,-MCOUNT_INSN_SIZE
larl %r4,function_trace_op
lg %r4,0(%r4)
larl %r1,ftrace_func
lg %r1,0(%r1)
#endif
lgr %r3,%r14
la %r5,STACK_FREGS(%r15)
BASR_EX %r14,%r1
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
# The j instruction gets runtime patched to a nop instruction.
# See ftrace_enable_ftrace_graph_caller.
SYM_INNER_LABEL(ftrace_graph_caller, SYM_L_GLOBAL)
j .Lftrace_graph_caller_end
lmg %r2,%r3,(STACK_FREGS_PTREGS_GPRS+14*8)(%r15)
lg %r4,(STACK_FREGS_PTREGS_PSW+8)(%r15)
brasl %r14,prepare_ftrace_return
stg %r2,(STACK_FREGS_PTREGS_GPRS+14*8)(%r15)
.Lftrace_graph_caller_end:
#endif
lg %r0,(STACK_FREGS_PTREGS_PSW+8)(%r15)
#ifdef MARCH_HAS_Z196_FEATURES
ltg %r1,STACK_FREGS_PTREGS_ORIG_GPR2(%r15)
locgrz %r1,%r0
#else
lg %r1,STACK_FREGS_PTREGS_ORIG_GPR2(%r15)
ltgr %r1,%r1
jnz 0f
lgr %r1,%r0
#endif
0: lmg %r2,%r15,(STACK_FREGS_PTREGS_GPRS+2*8)(%r15)
BR_EX %r1
SYM_CODE_END(ftrace_common)
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
SYM_FUNC_START(return_to_handler)
stmg %r2,%r5,32(%r15)
lgr %r1,%r15
aghi %r15,-(STACK_FRAME_OVERHEAD+__FGRAPH_RET_SIZE)
stg %r1,__SF_BACKCHAIN(%r15)
la %r3,STACK_FRAME_OVERHEAD(%r15)
stg %r1,__FGRAPH_RET_FP(%r3)
stg %r2,__FGRAPH_RET_GPR2(%r3)
lgr %r2,%r3
brasl %r14,ftrace_return_to_handler
aghi %r15,STACK_FRAME_OVERHEAD+__FGRAPH_RET_SIZE
lgr %r14,%r2
lmg %r2,%r5,32(%r15)
BR_EX %r14
SYM_FUNC_END(return_to_handler)
#endif
#endif /* CONFIG_FUNCTION_TRACER */
SYM_CODE_START(ftrace_shared_hotpatch_trampoline_br)
lmg %r0,%r1,2(%r1)
br %r1
SYM_INNER_LABEL(ftrace_shared_hotpatch_trampoline_br_end, SYM_L_GLOBAL)
SYM_CODE_END(ftrace_shared_hotpatch_trampoline_br)
#ifdef CONFIG_EXPOLINE
SYM_CODE_START(ftrace_shared_hotpatch_trampoline_exrl)
lmg %r0,%r1,2(%r1)
exrl %r0,0f
j .
0: br %r1
SYM_INNER_LABEL(ftrace_shared_hotpatch_trampoline_exrl_end, SYM_L_GLOBAL)
SYM_CODE_END(ftrace_shared_hotpatch_trampoline_exrl)
#endif /* CONFIG_EXPOLINE */
#ifdef CONFIG_RETHOOK
SYM_CODE_START(arch_rethook_trampoline)
stg %r14,(__SF_GPRS+8*8)(%r15)
lay %r15,-STACK_FRAME_SIZE_PTREGS(%r15)
stmg %r0,%r14,STACK_PTREGS_GPRS(%r15)
# store original stack pointer in backchain and pt_regs
lay %r7,STACK_FRAME_SIZE_PTREGS(%r15)
stg %r7,__SF_BACKCHAIN(%r15)
stg %r7,STACK_PTREGS_GPRS+(15*8)(%r15)
# store full psw
epsw %r2,%r3
risbg %r3,%r2,0,31,32
stg %r3,STACK_PTREGS_PSW(%r15)
larl %r1,arch_rethook_trampoline
stg %r1,STACK_PTREGS_PSW+8(%r15)
lay %r2,STACK_PTREGS(%r15)
brasl %r14,arch_rethook_trampoline_callback
mvc __SF_EMPTY(16,%r7),STACK_PTREGS_PSW(%r15)
lmg %r0,%r15,STACK_PTREGS_GPRS(%r15)
lpswe __SF_EMPTY(%r15)
SYM_CODE_END(arch_rethook_trampoline)
#endif /* CONFIG_RETHOOK */
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