Re: [PATCH v4 09/20] powerpc: Enable compile-time check for syscall handlers

"Nicholas Piggin" [off-list ref] writes:

On Wed Aug 24, 2022 at 12:05 PM AEST, Rohan McLure wrote:

...

quoted

diff --git a/arch/powerpc/kernel/systbl.S b/arch/powerpc/kernel/systbl.c
similarity index 59%
rename from arch/powerpc/kernel/systbl.S
rename to arch/powerpc/kernel/systbl.c
index cb3358886203..99ffdfef6b9c 100644
--- a/arch/powerpc/kernel/systbl.S
+++ b/arch/powerpc/kernel/systbl.c

@@ -10,31 +10,32 @@
  * PPC64 updates by Dave Engebretsen (engebret@us.ibm.com) 
  */
 
-#include <asm/ppc_asm.h>
+#include <linux/syscalls.h>
+#include <linux/compat.h>
+#include <asm/unistd.h>
+#include <asm/syscalls.h>
 
-.section .rodata,"a"
+#define __SYSCALL_WITH_COMPAT(nr, entry, compat) __SYSCALL(nr, entry)
 
-#ifdef CONFIG_PPC64
-	.p2align	3
-#define __SYSCALL(nr, entry)	.8byte entry
+#ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER
+#define __SYSCALL(nr, entry) [nr] = __powerpc_##entry,
+#define __powerpc_sys_ni_syscall	sys_ni_syscall
 #else
-#define __SYSCALL(nr, entry)	.long entry
+#define __SYSCALL(nr, entry) [nr] = entry,
 #endif
 
-#define __SYSCALL_WITH_COMPAT(nr, native, compat)	__SYSCALL(nr, native)
-.globl sys_call_table
-sys_call_table:
+void *sys_call_table[] = {

Humour me, the asm version had this in rodata, does this change that or
does it somehow get put back in there? Should this be const?

Even with const I still see it not landing in rodata for some reason.

$ grep -e start_rodata -e end_rodata -e sys_call_table .build/System.map
c000000000f90000 D __start_rodata
c0000000012b0000 R __end_rodata
c0000000027d51b0 D sys_call_table

vs before the series:

c000000000f80000 D __start_rodata
c000000000f805f0 D sys_call_table
c0000000012a0000 R __end_rodata


cheers