Re: [PATCH] [POWERPC] Check that the syscall table matches the syscall
From: Milton Miller <hidden>
Date: 2008-01-03 07:32:03
Hmmm, in-reply-to on the web archive is broken again, sfr alerted. On Thu Jan 3 16:41:41 EST 2008, Stephen Rothwell wrote:
Hopefully this will catch any out of order additions to the table in the future.
#ifdef CONFIG_PPC64 -#define SYSCALL(func) .llong .sys_##func,.sys_##func -#define COMPAT_SYS(func) .llong .sys_##func,.compat_sys_##func -#define PPC_SYS(func) .llong .ppc_##func,.ppc_##func +#define CHECK_SYS(n) .org .sys_call_table + n * 16 + +#define SYSCALL(func) CHECK_SYS(__NR_##func); \ + .llong .sys_##func,.sys_##func +#define COMPAT_SYS(func) CHECK_SYS(__NR_##func); \ + .llong .sys_##func,.compat_sys_##func
While it may detect misordered additions, it does nothing to check for holes. Actually, it would hide holes: presently, if you leave a hole the entry you add at the end of the table will not work / crash the kernel. After this patch, the hole will crash the kernel but the new syscall will work. I'm still thinking this through, but perhaps instead of checking the numbers by org in asm, we can define another way to include the systable.h, possibly as a build-only check target. Something compareing the line number to __NR_##func perhaps cpp into a simple awk script ... later, milton