m68k: Use get_kernel_nofault() in show_registers() (c75e59e4) · Commits · 戴 / test

Use the proper get_kernel_nofault() helper to access an unsafe kernel pointer without faulting instead of playing with set_fs() and get_user(). Signed-off-by:

Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20200720114314.196686-1-hch@lst.de Signed-off-by:

Geert Uytterhoeven <geert@linux-m68k.org>

arch/m68k/kernel/traps.c

+1 −4

Original line number	Diff line number	Diff line
		@@ -845,7 +845,6 @@ static void show_trace(unsigned long stack, const char loglvl)
		void show_registers(struct pt_regs *regs)
		{
		struct frame fp = (struct frame )regs;
		mm_segment_t old_fs = get_fs();
		u16 c, *cp;
		unsigned long addr;
		int i;
		@@ -918,10 +917,9 @@ void show_registers(struct pt_regs *regs)
		show_stack(NULL, (unsigned long *)addr, KERN_INFO);

		pr_info("Code:");
		set_fs(KERNEL_DS);
		cp = (u16 *)regs->pc;
		for (i = -8; i < 16; i++) {
		if (get_user(c, cp + i) && i >= 0) {
		if (get_kernel_nofault(c, cp + i) && i >= 0) {
		pr_cont(" Bad PC value.");
		break;
		}
		@@ -930,7 +928,6 @@ void show_registers(struct pt_regs *regs)
		else
		pr_cont(" <%04x>", c);
		}
		set_fs(old_fs);
		pr_cont("\n");
		}

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