linux-kernel - [PATCH v4 06/16] x86/mm: Remove set_kernel_text

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20191018074634.285927442@infradead.org>
Date:   Fri, 18 Oct 2019 09:35:31 +0200
From:   Peter Zijlstra <peterz@...radead.org>
To:     x86@...nel.org
Cc:     peterz@...radead.org, linux-kernel@...r.kernel.org,
        rostedt@...dmis.org, mhiramat@...nel.org, bristot@...hat.com,
        jbaron@...mai.com, torvalds@...ux-foundation.org,
        tglx@...utronix.de, mingo@...nel.org, namit@...are.com,
        hpa@...or.com, luto@...nel.org, ard.biesheuvel@...aro.org,
        jpoimboe@...hat.com, jeyu@...nel.org
Subject: [PATCH v4 06/16] 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.

Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
---
 arch/x86/include/asm/set_memory.h |    2 --
 arch/x86/mm/init_32.c             |   28 ----------------------------
 arch/x86/mm/init_64.c             |   36 ------------------------------------
 3 files changed, 66 deletions(-)

--- a/arch/x86/include/asm/set_memory.h
+++ b/arch/x86/include/asm/set_memory.h
@@ -80,8 +80,6 @@ int set_direct_map_invalid_noflush(struc
 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)
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -874,34 +874,6 @@ void arch_remove_memory(int nid, u64 sta
 
 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)
 {
 	/*
--- a/arch/x86/mm/init_64.c
+++ b/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(__stop___ex_table);
-
-	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(__stop___ex_table);
-
-	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);