From 0bd1e94bf3da386510186cb2acd3e91f0ea59bc6 Mon Sep 17 00:00:00 2001 From: Helge Deller Date: Tue, 3 Feb 2015 21:52:47 +0100 Subject: parisc: Add error checks when building up signal trampoline handler Add checks if the userspace trampoline code was correctly generated by the signal trampoline generation code. In addition only flush caches as needed and fix the old flushing code which didn't flushed all generated instructions. Signed-off-by: Helge Deller --- arch/parisc/kernel/signal.c | 29 +++++++++++++++-------------- 1 file changed, 15 insertions(+), 14 deletions(-) (limited to 'arch') diff --git a/arch/parisc/kernel/signal.c b/arch/parisc/kernel/signal.c index 9b910a0251b8..1fd300c00a80 100644 --- a/arch/parisc/kernel/signal.c +++ b/arch/parisc/kernel/signal.c @@ -476,6 +476,9 @@ insert_restart_trampoline(struct pt_regs *regs) case -ERESTART_RESTARTBLOCK: { /* Restart the system call - no handlers present */ unsigned int *usp = (unsigned int *)regs->gr[30]; + unsigned long start = (unsigned long) &usp[2]; + unsigned long end = (unsigned long) &usp[5]; + long err = 0; /* Setup a trampoline to restart the syscall * with __NR_restart_syscall @@ -487,23 +490,21 @@ insert_restart_trampoline(struct pt_regs *regs) * 16: ldi __NR_restart_syscall, %r20 */ #ifdef CONFIG_64BIT - put_user(regs->gr[31] >> 32, &usp[0]); - put_user(regs->gr[31] & 0xffffffff, &usp[1]); - put_user(0x0fc010df, &usp[2]); + err |= put_user(regs->gr[31] >> 32, &usp[0]); + err |= put_user(regs->gr[31] & 0xffffffff, &usp[1]); + err |= put_user(0x0fc010df, &usp[2]); #else - put_user(regs->gr[31], &usp[0]); - put_user(0x0fc0109f, &usp[2]); + err |= put_user(regs->gr[31], &usp[0]); + err |= put_user(0x0fc0109f, &usp[2]); #endif - put_user(0xe0008200, &usp[3]); - put_user(0x34140000, &usp[4]); + err |= put_user(0xe0008200, &usp[3]); + err |= put_user(0x34140000, &usp[4]); - /* Stack is 64-byte aligned, and we only need - * to flush 1 cache line. - * Flushing one cacheline is cheap. - * "sync" on bigger (> 4 way) boxes is not. - */ - flush_user_dcache_range(regs->gr[30], regs->gr[30] + 4); - flush_user_icache_range(regs->gr[30], regs->gr[30] + 4); + WARN_ON(err); + + /* flush data/instruction cache for new insns */ + flush_user_dcache_range(start, end); + flush_user_icache_range(start, end); regs->gr[31] = regs->gr[30] + 8; return; -- cgit v1.2.3