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lguest: Fix guest crash when CONFIG_X86_USE_3DNOW=y

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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>
This commit is contained in:
Rusty Russell 2007-09-11 17:06:37 +10:00 committed by Linus Torvalds
parent 9863b78a1a
commit c413fecc76
1 changed files with 4 additions and 3 deletions
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7
drivers/lguest/lguest.c
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@ -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