[PATCH 1/7] x86, asmlinkage, lguest: Pass in globals into assembler statement

From: Andi Kleen
Date: Tue Oct 22 2013 - 12:08:26 EST


From: Andi Kleen <ak@xxxxxxxxxxxxxxx>

Tell the compiler that the inline assembler statement
references lguest_entry.

This fixes compile problems with LTO where the variable
and the assembler code may end up in different files.

Cc: x86@xxxxxxxxxx
Cc: rusty@xxxxxxxxxxxxxxx
Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
---
drivers/lguest/x86/core.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/lguest/x86/core.c b/drivers/lguest/x86/core.c
index 5169239..922a1ac 100644
--- a/drivers/lguest/x86/core.c
+++ b/drivers/lguest/x86/core.c
@@ -157,7 +157,7 @@ static void run_guest_once(struct lg_cpu *cpu, struct lguest_pages *pages)
* stack, then the address of this call. This stack layout happens to
* exactly match the stack layout created by an interrupt...
*/
- asm volatile("pushf; lcall *lguest_entry"
+ asm volatile("pushf; lcall *%4"
/*
* This is how we tell GCC that %eax ("a") and %ebx ("b")
* are changed by this routine. The "=" means output.
@@ -169,7 +169,9 @@ static void run_guest_once(struct lg_cpu *cpu, struct lguest_pages *pages)
* physical address of the Guest's top-level page
* directory.
*/
- : "0"(pages), "1"(__pa(cpu->lg->pgdirs[cpu->cpu_pgd].pgdir))
+ : "0"(pages),
+ "1"(__pa(cpu->lg->pgdirs[cpu->cpu_pgd].pgdir)),
+ "m"(lguest_entry)
/*
* We tell gcc that all these registers could change,
* which means we don't have to save and restore them in
--
1.8.3.1

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