diff options
| -rw-r--r-- | arch/arm/kernel/entry-ftrace.S | 16 | ||||
| -rw-r--r-- | arch/arm/kernel/ftrace.c | 23 |
2 files changed, 36 insertions, 3 deletions
diff --git a/arch/arm/kernel/entry-ftrace.S b/arch/arm/kernel/entry-ftrace.S index dca12a09322a..237d435e29aa 100644 --- a/arch/arm/kernel/entry-ftrace.S +++ b/arch/arm/kernel/entry-ftrace.S @@ -270,3 +270,19 @@ ENTRY(ftrace_stub) .Lftrace_stub: ret lr ENDPROC(ftrace_stub) + +#ifdef CONFIG_DYNAMIC_FTRACE + + __INIT + + .macro init_tramp, dst:req +ENTRY(\dst\()_from_init) + ldr pc, =\dst +ENDPROC(\dst\()_from_init) + .endm + + init_tramp ftrace_caller +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS + init_tramp ftrace_regs_caller +#endif +#endif diff --git a/arch/arm/kernel/ftrace.c b/arch/arm/kernel/ftrace.c index 811cadf7eefc..74d3913f5590 100644 --- a/arch/arm/kernel/ftrace.c +++ b/arch/arm/kernel/ftrace.c @@ -62,9 +62,20 @@ static unsigned long ftrace_nop_replace(struct dyn_ftrace *rec) return NOP; } -static unsigned long adjust_address(struct dyn_ftrace *rec, unsigned long addr) +void ftrace_caller_from_init(void); +void ftrace_regs_caller_from_init(void); + +static unsigned long __ref adjust_address(struct dyn_ftrace *rec, + unsigned long addr) { - return addr; + if (!IS_ENABLED(CONFIG_DYNAMIC_FTRACE) || + system_state >= SYSTEM_FREEING_INITMEM || + likely(!is_kernel_inittext(rec->ip))) + return addr; + if (!IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS) || + addr == (unsigned long)&ftrace_caller) + return (unsigned long)&ftrace_caller_from_init; + return (unsigned long)&ftrace_regs_caller_from_init; } int ftrace_arch_code_modify_prepare(void) @@ -200,7 +211,13 @@ int ftrace_make_nop(struct module *mod, #endif new = ftrace_nop_replace(rec); - ret = ftrace_modify_code(ip, old, new, true); + /* + * Locations in .init.text may call __gnu_mcount_mc via a linker + * emitted veneer if they are too far away from its implementation, and + * so validation may fail spuriously in such cases. Let's work around + * this by omitting those from validation. + */ + ret = ftrace_modify_code(ip, old, new, !is_kernel_inittext(ip)); return ret; } |