arm64: ftrace: minimize ifdeffery

Now that we no longer refer to mod->arch.ftrace_trampolines in the body
of ftrace_make_call(), we can use IS_ENABLED() rather than ifdeffery,
and make the code easier to follow. Likewise in ftrace_make_nop().

Let's do so.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Torsten Duwe <duwe@suse.de>
Tested-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Tested-by: Torsten Duwe <duwe@suse.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>

diff --git a/arch/arm64/kernel/ftrace.c b/arch/arm64/kernel/ftrace.c
index aea652c33a38c323e6c0bef3bdc5a38254a000f3..8618faa82e6d23a0893dedb2e1230ebb1707b6b3 100644 (file)
--- a/arch/arm64/kernel/ftrace.c
+++ b/arch/arm64/kernel/ftrace.c
@@ -62,18 +62,18 @@ int ftrace_update_ftrace_func(ftrace_func_t func)
        return ftrace_modify_code(pc, 0, new, false);
 }
 
-#ifdef CONFIG_ARM64_MODULE_PLTS
 static struct plt_entry *get_ftrace_plt(struct module *mod, unsigned long addr)
 {
+#ifdef CONFIG_ARM64_MODULE_PLTS
        struct plt_entry *plt = mod->arch.ftrace_trampolines;
 
        if (addr == FTRACE_ADDR)
                return &plt[FTRACE_PLT_IDX];
        if (addr == FTRACE_REGS_ADDR && IS_ENABLED(CONFIG_FTRACE_WITH_REGS))
                return &plt[FTRACE_REGS_PLT_IDX];
+#endif
        return NULL;
 }
-#endif
 
 /*
  * Turn on the call to ftrace_caller() in instrumented function
@@ -85,10 +85,12 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
        long offset = (long)pc - (long)addr;
 
        if (offset < -SZ_128M || offset >= SZ_128M) {
-#ifdef CONFIG_ARM64_MODULE_PLTS
                struct module *mod;
                struct plt_entry *plt;
 
+               if (!IS_ENABLED(CONFIG_ARM64_MODULE_PLTS))
+                       return -EINVAL;
+
                /*
                 * On kernels that support module PLTs, the offset between the
                 * branch instruction and its target may legally exceed the
@@ -113,9 +115,6 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
                }
 
                addr = (unsigned long)plt;
-#else /* CONFIG_ARM64_MODULE_PLTS */
-               return -EINVAL;
-#endif /* CONFIG_ARM64_MODULE_PLTS */
        }
 
        old = aarch64_insn_gen_nop();
@@ -185,9 +184,11 @@ int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec,
        long offset = (long)pc - (long)addr;
 
        if (offset < -SZ_128M || offset >= SZ_128M) {
-#ifdef CONFIG_ARM64_MODULE_PLTS
                u32 replaced;
 
+               if (!IS_ENABLED(CONFIG_ARM64_MODULE_PLTS))
+                       return -EINVAL;
+
                /*
                 * 'mod' is only set at module load time, but if we end up
                 * dealing with an out-of-range condition, we can assume it
@@ -218,9 +219,6 @@ int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec,
                        return -EINVAL;
 
                validate = false;
-#else /* CONFIG_ARM64_MODULE_PLTS */
-               return -EINVAL;
-#endif /* CONFIG_ARM64_MODULE_PLTS */
        } else {
                old = aarch64_insn_gen_branch_imm(pc, addr,
                                                  AARCH64_INSN_BRANCH_LINK);