commit d882b172512758703ff8d9efb96505eaaee48d2e
author Heiko Carstens <heiko.carstens@de.ibm.com> Sat Jul 01 04:36:31 2006 -0700
committer Linus Torvalds <torvalds@g5.osdl.org> Sat Jul 01 09:56:04 2006 -0700
tree 64b61d69b4af1395b80446fbc61f0488fbaeedb3
parent a581c2a4697ee264699b364399b73477af408e00

[PATCH] s390: put sys_call_table into .rodata section and write protect it

Put s390's syscall tables into .rodata section and write protect this
section to prevent misuse of it.  Suggested by Arjan van de Ven
<arjan@infradead.org>.

Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/s390/kernel/entry.S

diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index 1a434a7..d8948c3 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -228,8 +228,9 @@
 sysc_nr_ok:
 	mvc	SP_ARGS(4,%r15),SP_R7(%r15)
 sysc_do_restart:
+	l	%r8,BASED(.Lsysc_table)
 	tm	__TI_flags+3(%r9),(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT)
-        l       %r8,sys_call_table-system_call(%r7,%r13) # get system call addr.
+	l	%r8,0(%r7,%r8)	  # get system call addr.
         bnz     BASED(sysc_tracesys)
         basr    %r14,%r8          # call sys_xxxx
         st      %r2,SP_R2(%r15)   # store return value (change R2 on stack)
@@ -330,9 +331,10 @@
 	basr	%r14,%r1
 	clc	SP_R2(4,%r15),BASED(.Lnr_syscalls)
 	bnl	BASED(sysc_tracenogo)
+	l	%r8,BASED(.Lsysc_table)
 	l	%r7,SP_R2(%r15)        # strace might have changed the 
 	sll	%r7,2                  #  system call
-	l	%r8,sys_call_table-system_call(%r7,%r13)
+	l	%r8,0(%r7,%r8)
 sysc_tracego:
 	lm	%r3,%r6,SP_R3(%r15)
 	l	%r2,SP_ORIG_R2(%r15)
@@ -1009,6 +1011,7 @@
 .Ltrace:       .long  syscall_trace
 .Lvfork:       .long  sys_vfork
 .Lschedtail:   .long  schedule_tail
+.Lsysc_table:  .long  sys_call_table
 
 .Lcritical_start:
                .long  __critical_start + 0x80000000
@@ -1017,8 +1020,8 @@
 .Lcleanup_critical:
                .long  cleanup_critical
 
+	       .section .rodata, "a"
 #define SYSCALL(esa,esame,emu)	.long esa
 sys_call_table:
 #include "syscalls.S"
 #undef SYSCALL
-

arch/s390/kernel/entry64.S

diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S
index edad607..1ca499f 100644
--- a/arch/s390/kernel/entry64.S
+++ b/arch/s390/kernel/entry64.S
@@ -991,6 +991,7 @@
 .Lcritical_end:
                .quad  __critical_end
 
+	       .section .rodata, "a"
 #define SYSCALL(esa,esame,emu)	.long esame
 sys_call_table:
 #include "syscalls.S"