Select the HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS to provide the
register_ftrace_direct[_multi] interfaces allowing users to register
the customed trampoline (direct_caller) as the mcount for one or more
target functions. And modify_ftrace_direct[_multi] are also provided
for modifying direct_caller.
There are a few cases to distinguish:
- If a direct call ops is the only one tracing a function AND the direct
called trampoline is within the reach of a 'bl' instruction
-> the ftrace patchsite jumps to the trampoline
- Else
-> the ftrace patchsite jumps to the ftrace_regs_caller trampoline points
to ftrace_list_ops so it iterates over all registered ftrace ops,
including the direct call ops and calls its call_direct_funcs handler
which stores the direct called trampoline's address in the ftrace_regs
and the ftrace_regs_caller trampoline will return to that address
instead of returning to the traced function
Signed-off-by: Qing Zhang <zhangqing@loongson.cn>
Signed-off-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
select HAVE_DMA_CONTIGUOUS
select HAVE_DYNAMIC_FTRACE
select HAVE_DYNAMIC_FTRACE_WITH_ARGS
select HAVE_DMA_CONTIGUOUS
select HAVE_DYNAMIC_FTRACE
select HAVE_DYNAMIC_FTRACE_WITH_ARGS
+ select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
select HAVE_DYNAMIC_FTRACE_WITH_REGS
select HAVE_EBPF_JIT
select HAVE_EFFICIENT_UNALIGNED_ACCESS if !ARCH_STRICT_ALIGN
select HAVE_DYNAMIC_FTRACE_WITH_REGS
select HAVE_EBPF_JIT
select HAVE_EFFICIENT_UNALIGNED_ACCESS if !ARCH_STRICT_ALIGN
#define ftrace_graph_func ftrace_graph_func
void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *op, struct ftrace_regs *fregs);
#define ftrace_graph_func ftrace_graph_func
void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *op, struct ftrace_regs *fregs);
+
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
+static inline void
+__arch_ftrace_set_direct_caller(struct pt_regs *regs, unsigned long addr)
+{
+ regs->regs[13] = addr; /* t1 */
+}
+
+#define arch_ftrace_set_direct_caller(fregs, addr) \
+ __arch_ftrace_set_direct_caller(&(fregs)->regs, addr)
+#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
+
#endif
#endif /* __ASSEMBLY__ */
#endif
#endif /* __ASSEMBLY__ */
unsigned long pc = rec->ip + LOONGARCH_INSN_SIZE;
struct plt_entry *plt;
unsigned long pc = rec->ip + LOONGARCH_INSN_SIZE;
struct plt_entry *plt;
+ /*
+ * If a custom trampoline is unreachable, rely on the ftrace_regs_caller
+ * trampoline which knows how to indirectly reach that trampoline through
+ * ops->direct_call.
+ */
+ if (*addr != FTRACE_ADDR && *addr != FTRACE_REGS_ADDR && !reachable_by_bl(*addr, pc))
+ *addr = FTRACE_REGS_ADDR;
+
/*
* When the target is within range of the 'bl' instruction, use 'addr'
* as-is and branch to that directly.
/*
* When the target is within range of the 'bl' instruction, use 'addr'
* as-is and branch to that directly.
.if \allregs
PTR_S tp, sp, PT_R2
PTR_S t0, sp, PT_R12
.if \allregs
PTR_S tp, sp, PT_R2
PTR_S t0, sp, PT_R12
PTR_S t2, sp, PT_R14
PTR_S t3, sp, PT_R15
PTR_S t4, sp, PT_R16
PTR_S t2, sp, PT_R14
PTR_S t3, sp, PT_R15
PTR_S t4, sp, PT_R16
PTR_S zero, sp, PT_R0
.endif
PTR_S ra, sp, PT_ERA /* Save trace function ra at PT_ERA */
PTR_S zero, sp, PT_R0
.endif
PTR_S ra, sp, PT_ERA /* Save trace function ra at PT_ERA */
+ move t1, zero
+ PTR_S t1, sp, PT_R13
PTR_ADDI t8, sp, PT_SIZE
PTR_S t8, sp, PT_R3
.endm
PTR_ADDI t8, sp, PT_SIZE
PTR_S t8, sp, PT_R3
.endm
PTR_L a7, sp, PT_R11
PTR_L fp, sp, PT_R22
PTR_L t0, sp, PT_ERA
PTR_L a7, sp, PT_R11
PTR_L fp, sp, PT_R22
PTR_L t0, sp, PT_ERA
SYM_CODE_END(ftrace_common)
SYM_CODE_START(ftrace_caller)
SYM_CODE_END(ftrace_common)
SYM_CODE_START(ftrace_caller)
jr ra
SYM_CODE_END(return_to_handler)
#endif
jr ra
SYM_CODE_END(return_to_handler)
#endif
+
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
+SYM_CODE_START(ftrace_stub_direct_tramp)
+ jr t0
+SYM_CODE_END(ftrace_stub_direct_tramp)
+#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */