Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
lguest: fix 'unhandled trap 13' with CONFIG_CC_STACKPROTECTOR
We don't set up the canary; let's disable stack protector on boot.c so
we can get into lguest_init, then set it up. As a side effect,
switch_to_new_gdt() sets up %fs for us properly too.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
authored by
Rusty Russell
and committed by
Linus Torvalds
2cb7878a
9fa7eb28
+14
-4
+1
arch/x86/lguest/Makefile
+1
arch/x86/lguest/Makefile
+13
-4
arch/x86/lguest/boot.c
+13
-4
arch/x86/lguest/boot.c
···
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#include <asm/mce.h>
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#include <asm/io.h>
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#include <asm/i387.h>
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+
#include <asm/stackprotector.h>
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#include <asm/reboot.h> /* for struct machine_ops */
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/*G:010 Welcome to the Guest!
···
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* lguest_init() where the rest of the fairly chaotic boot setup
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* occurs. */
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/* The stack protector is a weird thing where gcc places a canary
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* value on the stack and then checks it on return. This file is
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* compiled with -fno-stack-protector it, so we got this far without
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* problems. The value of the canary is kept at offset 20 from the
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* %gs register, so we need to set that up before calling C functions
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* in other files. */
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setup_stack_canary_segment(0);
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/* We could just call load_stack_canary_segment(), but we might as
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* call switch_to_new_gdt() which loads the whole table and sets up
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* the per-cpu segment descriptor register %fs as well. */
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switch_to_new_gdt(0);
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/* As described in head_32.S, we map the first 128M of memory. */
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max_pfn_mapped = (128*1024*1024) >> PAGE_SHIFT;
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/* Load the %fs segment register (the per-cpu segment register) with
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* the normal data segment to get through booting. */
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asm volatile ("mov %0, %%fs" : : "r" (__KERNEL_DS) : "memory");
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/* The Host<->Guest Switcher lives at the top of our address space, and
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* the Host told us how big it is when we made LGUEST_INIT hypercall: