x86/mm: Remove set_kernel_text_r[ow]()

With the last and only user of these functions gone (ftrace) remove
them as well to avoid ever growing new users.

Tested-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20191111132457.819095320@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/include/asm/set_memory.h

@@ -81,8 +81,6 @@ int set_direct_map_invalid_noflush(struct page *page);
 int set_direct_map_default_noflush(struct page *page);
 
 extern int kernel_set_to_readonly;
-void set_kernel_text_rw(void);
-void set_kernel_text_ro(void);
 
 #ifdef CONFIG_X86_64
 static inline int set_mce_nospec(unsigned long pfn)

arch/x86/mm/init_32.c

@@ -874,34 +874,6 @@ void arch_remove_memory(int nid, u64 start, u64 size,
 
 int kernel_set_to_readonly __read_mostly;
 
-void set_kernel_text_rw(void)
-{
-	unsigned long start = PFN_ALIGN(_text);
-	unsigned long size = PFN_ALIGN(_etext) - start;
-
-	if (!kernel_set_to_readonly)
-		return;
-
-	pr_debug("Set kernel text: %lx - %lx for read write\n",
-		 start, start+size);
-
-	set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT);
-}
-
-void set_kernel_text_ro(void)
-{
-	unsigned long start = PFN_ALIGN(_text);
-	unsigned long size = PFN_ALIGN(_etext) - start;
-
-	if (!kernel_set_to_readonly)
-		return;
-
-	pr_debug("Set kernel text: %lx - %lx for read only\n",
-		 start, start+size);
-
-	set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
-}
-
 static void mark_nxdata_nx(void)
 {
 	/*

arch/x86/mm/init_64.c

@@ -1260,42 +1260,6 @@ void __init mem_init(void)
 
 int kernel_set_to_readonly;
 
-void set_kernel_text_rw(void)
-{
-	unsigned long start = PFN_ALIGN(_text);
-	unsigned long end = PFN_ALIGN(_etext);
-
-	if (!kernel_set_to_readonly)
-		return;
-
-	pr_debug("Set kernel text: %lx - %lx for read write\n",
-		 start, end);
-
-	/*
-	 * Make the kernel identity mapping for text RW. Kernel text
-	 * mapping will always be RO. Refer to the comment in
-	 * static_protections() in pageattr.c
-	 */
-	set_memory_rw(start, (end - start) >> PAGE_SHIFT);
-}
-
-void set_kernel_text_ro(void)
-{
-	unsigned long start = PFN_ALIGN(_text);
-	unsigned long end = PFN_ALIGN(_etext);
-
-	if (!kernel_set_to_readonly)
-		return;
-
-	pr_debug("Set kernel text: %lx - %lx for read only\n",
-		 start, end);
-
-	/*
-	 * Set the kernel identity mapping for text RO.
-	 */
-	set_memory_ro(start, (end - start) >> PAGE_SHIFT);
-}
-
 void mark_rodata_ro(void)
 {
 	unsigned long start = PFN_ALIGN(_text);