linux/arch/s390/include/asm/ftrace.h
Mark Rutland 94d095ffa0 ftrace: abstract DYNAMIC_FTRACE_WITH_ARGS accesses
In subsequent patches we'll arrange for architectures to have an
ftrace_regs which is entirely distinct from pt_regs. In preparation for
this, we need to minimize the use of pt_regs to where strictly necessary
in the core ftrace code.

This patch adds new ftrace_regs_{get,set}_*() helpers which can be used
to manipulate ftrace_regs. When CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS=y,
these can always be used on any ftrace_regs, and when
CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS=n these can be used when regs are
available. A new ftrace_regs_has_args(fregs) helper is added which code
can use to check when these are usable.

Co-developed-by: Florent Revest <revest@chromium.org>
Signed-off-by: Florent Revest <revest@chromium.org>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20221103170520.931305-4-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2022-11-18 13:56:41 +00:00

153 lines
4.0 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_S390_FTRACE_H
#define _ASM_S390_FTRACE_H
#define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
#define ARCH_SUPPORTS_FTRACE_OPS 1
#define MCOUNT_INSN_SIZE 6
#ifndef __ASSEMBLY__
#ifdef CONFIG_CC_IS_CLANG
/* https://bugs.llvm.org/show_bug.cgi?id=41424 */
#define ftrace_return_address(n) 0UL
#else
#define ftrace_return_address(n) __builtin_return_address(n)
#endif
void ftrace_caller(void);
extern void *ftrace_func;
struct dyn_arch_ftrace { };
#define MCOUNT_ADDR 0
#define FTRACE_ADDR ((unsigned long)ftrace_caller)
#define KPROBE_ON_FTRACE_NOP 0
#define KPROBE_ON_FTRACE_CALL 1
struct module;
struct dyn_ftrace;
bool ftrace_need_init_nop(void);
#define ftrace_need_init_nop ftrace_need_init_nop
int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec);
#define ftrace_init_nop ftrace_init_nop
static inline unsigned long ftrace_call_adjust(unsigned long addr)
{
return addr;
}
struct ftrace_regs {
struct pt_regs regs;
};
static __always_inline struct pt_regs *arch_ftrace_get_regs(struct ftrace_regs *fregs)
{
struct pt_regs *regs = &fregs->regs;
if (test_pt_regs_flag(regs, PIF_FTRACE_FULL_REGS))
return regs;
return NULL;
}
static __always_inline unsigned long
ftrace_regs_get_instruction_pointer(const struct ftrace_regs *fregs)
{
return fregs->regs.psw.addr;
}
static __always_inline void
ftrace_regs_set_instruction_pointer(struct ftrace_regs *fregs,
unsigned long ip)
{
fregs->regs.psw.addr = ip;
}
#define ftrace_regs_get_argument(fregs, n) \
regs_get_kernel_argument(&(fregs)->regs, n)
#define ftrace_regs_get_stack_pointer(fregs) \
kernel_stack_pointer(&(fregs)->regs)
#define ftrace_regs_return_value(fregs) \
regs_return_value(&(fregs)->regs)
#define ftrace_regs_set_return_value(fregs, ret) \
regs_set_return_value(&(fregs)->regs, ret)
#define ftrace_override_function_with_return(fregs) \
override_function_with_return(&(fregs)->regs)
#define ftrace_regs_query_register_offset(name) \
regs_query_register_offset(name)
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
/*
* When an ftrace registered caller is tracing a function that is
* also set by a register_ftrace_direct() call, it needs to be
* differentiated in the ftrace_caller trampoline. To do this,
* place the direct caller in the ORIG_GPR2 part of pt_regs. This
* tells the ftrace_caller that there's a direct caller.
*/
static inline void arch_ftrace_set_direct_caller(struct ftrace_regs *fregs, unsigned long addr)
{
struct pt_regs *regs = &fregs->regs;
regs->orig_gpr2 = addr;
}
#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
/*
* Even though the system call numbers are identical for s390/s390x a
* different system call table is used for compat tasks. This may lead
* to e.g. incorrect or missing trace event sysfs files.
* Therefore simply do not trace compat system calls at all.
* See kernel/trace/trace_syscalls.c.
*/
#define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS
static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs)
{
return is_compat_task();
}
#define ARCH_HAS_SYSCALL_MATCH_SYM_NAME
static inline bool arch_syscall_match_sym_name(const char *sym,
const char *name)
{
/*
* Skip __s390_ and __s390x_ prefix - due to compat wrappers
* and aliasing some symbols of 64 bit system call functions
* may get the __s390_ prefix instead of the __s390x_ prefix.
*/
return !strcmp(sym + 7, name) || !strcmp(sym + 8, name);
}
#endif /* __ASSEMBLY__ */
#ifdef CONFIG_FUNCTION_TRACER
#define FTRACE_NOP_INSN .word 0xc004, 0x0000, 0x0000 /* brcl 0,0 */
#ifndef CC_USING_HOTPATCH
#define FTRACE_GEN_MCOUNT_RECORD(name) \
.section __mcount_loc, "a", @progbits; \
.quad name; \
.previous;
#else /* !CC_USING_HOTPATCH */
#define FTRACE_GEN_MCOUNT_RECORD(name)
#endif /* !CC_USING_HOTPATCH */
#define FTRACE_GEN_NOP_ASM(name) \
FTRACE_GEN_MCOUNT_RECORD(name) \
FTRACE_NOP_INSN
#else /* CONFIG_FUNCTION_TRACER */
#define FTRACE_GEN_NOP_ASM(name)
#endif /* CONFIG_FUNCTION_TRACER */
#endif /* _ASM_S390_FTRACE_H */