[PATCH] x86/x86_64: mark rodata section read-only: make some datastructures const

Mark some key kernel datastructures readonly.  This patch was previously
posted on Jun 28th but was back then not merged because nothing was enforcing
rodata anyway..  well that changed now :)

Patch by Christoph Lameter <christoph@lameter.com> and Dave Jones
<davej@redhat.com>

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/arch/i386/kernel/entry.S b/arch/i386/kernel/entry.S
index e50b93155249b79732378ccbc6d4bc41c2d74207..607c0600750894e21f2beeb423101ab2e56f5952 100644 (file)
--- a/arch/i386/kernel/entry.S
+++ b/arch/i386/kernel/entry.S
@@ -657,6 +657,7 @@ ENTRY(spurious_interrupt_bug)
        pushl $do_spurious_interrupt_bug
        jmp error_code
 
+.section .rodata,"a"
 #include "syscall_table.S"
 
 syscall_table_size=(.-sys_call_table)

diff --git a/arch/i386/kernel/syscall_table.S b/arch/i386/kernel/syscall_table.S
index 9b21a31d4f4ec1b32b4d6c438d236c6332a19759..f7ba4acc20ec3d7049d77b8d417e95e49e94787a 100644 (file)
--- a/arch/i386/kernel/syscall_table.S
+++ b/arch/i386/kernel/syscall_table.S
@@ -1,4 +1,3 @@
-.data
 ENTRY(sys_call_table)
        .long sys_restart_syscall       /* 0 - old "setup()" system call, used for restarting */
        .long sys_exit

diff --git a/arch/x86_64/ia32/ia32entry.S b/arch/x86_64/ia32/ia32entry.S
index e0eb0c712fe91fbddfc74beb9048eace392e1566..df0773c9bdbe70337e236bd6c267e91bedcaf465 100644 (file)
--- a/arch/x86_64/ia32/ia32entry.S
+++ b/arch/x86_64/ia32/ia32entry.S
@@ -341,7 +341,7 @@ ENTRY(ia32_ptregs_common)
        jmp  ia32_sysret        /* misbalances the return cache */
        CFI_ENDPROC
 
-       .data
+       .section .rodata,"a"
        .align 8
        .globl ia32_sys_call_table
 ia32_sys_call_table:

diff --git a/arch/x86_64/kernel/syscall.c b/arch/x86_64/kernel/syscall.c
index e263685f864cac46228a7585d2ef9f3a9584a01e..7c176b3edde00daab10dfaed6d954d7412d9541d 100644 (file)
--- a/arch/x86_64/kernel/syscall.c
+++ b/arch/x86_64/kernel/syscall.c
@@ -19,7 +19,7 @@ typedef void (*sys_call_ptr_t)(void);
 
 extern void sys_ni_syscall(void);
 
-sys_call_ptr_t sys_call_table[__NR_syscall_max+1] __cacheline_aligned = { 
+const sys_call_ptr_t sys_call_table[__NR_syscall_max+1] = {
        /* Smells like a like a compiler bug -- it doesn't work when the & below is removed. */ 
        [0 ... __NR_syscall_max] = &sys_ni_syscall,
 #include <asm-x86_64/unistd.h>