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-rw-r--r--drivers/lguest/interrupts_and_traps.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/drivers/lguest/interrupts_and_traps.c b/drivers/lguest/interrupts_and_traps.c
index 49aa55577d0..39731232d82 100644
--- a/drivers/lguest/interrupts_and_traps.c
+++ b/drivers/lguest/interrupts_and_traps.c
@@ -270,8 +270,11 @@ void pin_stack_pages(struct lguest *lg)
/* Depending on the CONFIG_4KSTACKS option, the Guest can have one or
* two pages of stack space. */
for (i = 0; i < lg->stack_pages; i++)
- /* The stack grows *upwards*, hence the subtraction */
- pin_page(lg, lg->esp1 - i * PAGE_SIZE);
+ /* The stack grows *upwards*, so the address we're given is the
+ * start of the page after the kernel stack. Subtract one to
+ * get back onto the first stack page, and keep subtracting to
+ * get to the rest of the stack pages. */
+ pin_page(lg, lg->esp1 - 1 - i * PAGE_SIZE);
}
/* Direct traps also mean that we need to know whenever the Guest wants to use