arm64: ftrace: Simplify get_ftrace_plt

JIRA: https://issues.redhat.com/browse/RHEL-101598

commit 0f59dca
Author: Florent Revest <[email protected]>
Date:   Wed Apr 5 20:02:47 2023 +0200

    arm64: ftrace: Simplify get_ftrace_plt

    Following recent refactorings, the get_ftrace_plt function only ever
    gets called with addr = FTRACE_ADDR so its code can be simplified to
    always return the ftrace trampoline plt.

    Signed-off-by: Florent Revest <[email protected]>
    Acked-by: Mark Rutland <[email protected]>
    Link: https://lore.kernel.org/r/[email protected]
    Signed-off-by: Will Deacon <[email protected]>

Conflicts:
- Context change from already backported commit
ea3752b ("arm64: module: mandate MODULE_PLTS")

Signed-off-by: Jerome Marchand <[email protected]>

Author: jeromemarchand

arch/arm64/kernel/ftrace.c

@@ -195,15 +195,15 @@ int ftrace_update_ftrace_func(ftrace_func_t func)
 	return ftrace_modify_code(pc, 0, new, false);
 }
 
-static struct plt_entry *get_ftrace_plt(struct module *mod, unsigned long addr)
+static struct plt_entry *get_ftrace_plt(struct module *mod)
 {
 #ifdef CONFIG_MODULES
 	struct plt_entry *plt = mod->arch.ftrace_trampolines;
 
-	if (addr == FTRACE_ADDR)
-		return &plt[FTRACE_PLT_IDX];
-#endif
+	return &plt[FTRACE_PLT_IDX];
+#else
 	return NULL;
+#endif
 }
 
 static bool reachable_by_bl(unsigned long addr, unsigned long pc)
@@ -270,7 +270,7 @@ static bool ftrace_find_callable_addr(struct dyn_ftrace *rec,
 	if (WARN_ON(!mod))
 		return false;
 
-	plt = get_ftrace_plt(mod, *addr);
+	plt = get_ftrace_plt(mod);
 	if (!plt) {
 		pr_err("ftrace: no module PLT for %ps\n", (void *)*addr);
 		return false;