From fc3f61e1bcd5f88bfb7241bf509a3f63bab49ea8 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Mon, 14 Sep 2020 13:15:15 +0200 Subject: [PATCH] s390/dis: get rid of set_fs() usage Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik --- arch/s390/kernel/dis.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-) diff --git a/arch/s390/kernel/dis.c b/arch/s390/kernel/dis.c index f304802ecf7b..a7eab7be4db0 100644 --- a/arch/s390/kernel/dis.c +++ b/arch/s390/kernel/dis.c @@ -482,31 +482,37 @@ static int print_insn(char *buffer, unsigned char *code, unsigned long addr) return (int) (ptr - buffer); } +static int copy_from_regs(struct pt_regs *regs, void *dst, void *src, int len) +{ + if (user_mode(regs)) { + if (copy_from_user(dst, (char __user *)src, len)) + return -EFAULT; + } else { + if (copy_from_kernel_nofault(dst, src, len)) + return -EFAULT; + } + return 0; +} + void show_code(struct pt_regs *regs) { char *mode = user_mode(regs) ? "User" : "Krnl"; unsigned char code[64]; char buffer[128], *ptr; - mm_segment_t old_fs; unsigned long addr; int start, end, opsize, hops, i; /* Get a snapshot of the 64 bytes surrounding the fault address. */ - old_fs = get_fs(); - set_fs(user_mode(regs) ? USER_DS : KERNEL_DS); for (start = 32; start && regs->psw.addr >= 34 - start; start -= 2) { addr = regs->psw.addr - 34 + start; - if (__copy_from_user(code + start - 2, - (char __user *) addr, 2)) + if (copy_from_regs(regs, code + start - 2, (void *)addr, 2)) break; } for (end = 32; end < 64; end += 2) { addr = regs->psw.addr + end - 32; - if (__copy_from_user(code + end, - (char __user *) addr, 2)) + if (copy_from_regs(regs, code + end, (void *)addr, 2)) break; } - set_fs(old_fs); /* Code snapshot useable ? */ if ((regs->psw.addr & 1) || start >= end) { printk("%s Code: Bad PSW.\n", mode);