lguest: Fix guest crash when CONFIG_X86_USE_3DNOW=y (c413fecc) · Commits · 戴 / test

One of the very first things lguest_init() does is a memcpy. On Athlon/Duron/K7 or CyrixIII/VIA-C3 or Geode GX/LX, this tries to use MMX. memcpy -> _mmx_memcpy -> kernel_fpu_begin -> clts -> paravirt_ops.clts But we haven't set paravirt_ops.clts yet, so we do the native version and crash. The simplest solution is to use __memcpy. Thanks to Michael Rasenberger for the bug report. Signed-off-by:

Rusty Russell <rusty@rustcorp.com.au> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

drivers/lguest/lguest.c

+4 −3

Original line number	Diff line number	Diff line
		@@ -964,11 +964,12 @@ __init void lguest_init(void *boot)
		{
		/* Copy boot parameters first: the Launcher put the physical location
		* in %esi, and head.S converted that to a virtual address and handed
		* it to us. */
		memcpy(&boot_params, boot, PARAM_SIZE);
		* it to us. We use "__memcpy" because "memcpy" sometimes tries to do
		* tricky things to go faster, and we're not ready for that. */
		__memcpy(&boot_params, boot, PARAM_SIZE);
		/* The boot parameters also tell us where the command-line is: save
		* that, too. */
		memcpy(boot_command_line, __va(boot_params.hdr.cmd_line_ptr),
		__memcpy(boot_command_line, __va(boot_params.hdr.cmd_line_ptr),
		COMMAND_LINE_SIZE);

		/* We're under lguest, paravirt is enabled, and we're running at

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