Thread (34 messages) 34 messages, 5 authors, 2018-03-15
STALE3030d
Revisions (3)
  1. v1 [diff vs current]
  2. v2 current
  3. v2 [diff vs current]

[PATCH v2 11/27] x86/power/64: Adapt assembly for PIE support

From: Thomas Garnier <hidden>
Date: 2018-03-13 20:59:29
Also in: kvm, linux-arch, linux-crypto, lkml, xen-devel
Subsystem: hibernation (aka software suspend, aka swsusp), the rest, x86 architecture (32-bit and 64-bit) · Maintainers: "Rafael J. Wysocki", Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen

Change the assembly code to use only relative references of symbols for the
kernel to be PIE compatible.

Position Independent Executable (PIE) support will allow to extended the
KASLR randomization range below the -2G memory limit.

Signed-off-by: Thomas Garnier <redacted>
---
 arch/x86/power/hibernate_asm_64.S | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/x86/power/hibernate_asm_64.S b/arch/x86/power/hibernate_asm_64.S
index ce8da3a0412c..6fdd7bbc3c33 100644
--- a/arch/x86/power/hibernate_asm_64.S
+++ b/arch/x86/power/hibernate_asm_64.S
@@ -24,7 +24,7 @@
 #include <asm/frame.h>
 
 ENTRY(swsusp_arch_suspend)
-	movq	$saved_context, %rax
+	leaq	saved_context(%rip), %rax
 	movq	%rsp, pt_regs_sp(%rax)
 	movq	%rbp, pt_regs_bp(%rax)
 	movq	%rsi, pt_regs_si(%rax)
@@ -115,7 +115,7 @@ ENTRY(restore_registers)
 	movq	%rax, %cr4;  # turn PGE back on
 
 	/* We don't restore %rax, it must be 0 anyway */
-	movq	$saved_context, %rax
+	leaq	saved_context(%rip), %rax
 	movq	pt_regs_sp(%rax), %rsp
 	movq	pt_regs_bp(%rax), %rbp
 	movq	pt_regs_si(%rax), %rsi
-- 
2.16.2.660.g709887971b-goog


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