[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20240322165233.71698-5-brgerst@gmail.com>
Date: Fri, 22 Mar 2024 12:52:21 -0400
From: Brian Gerst <brgerst@...il.com>
To: linux-kernel@...r.kernel.org,
x86@...nel.org
Cc: Ingo Molnar <mingo@...nel.org>,
Thomas Gleixner <tglx@...utronix.de>,
Borislav Petkov <bp@...en8.de>,
"H . Peter Anvin" <hpa@...or.com>,
Uros Bizjak <ubizjak@...il.com>,
David.Laight@...lab.com,
Brian Gerst <brgerst@...il.com>
Subject: [PATCH v4 04/16] x86/pvh: Use fixed_percpu_data for early boot GSBASE
Instead of having a private area for the stack canary, use
fixed_percpu_data for GSBASE like the native kernel.
Signed-off-by: Brian Gerst <brgerst@...il.com>
---
arch/x86/platform/pvh/head.S | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/arch/x86/platform/pvh/head.S b/arch/x86/platform/pvh/head.S
index f7235ef87bc3..1f1c3230b27b 100644
--- a/arch/x86/platform/pvh/head.S
+++ b/arch/x86/platform/pvh/head.S
@@ -95,10 +95,15 @@ SYM_CODE_START_LOCAL(pvh_start_xen)
/* 64-bit entry point. */
.code64
1:
- /* Set base address in stack canary descriptor. */
+ /*
+ * Set up GSBASE.
+ * Note that, on SMP, the boot cpu uses init data section until
+ * the per cpu areas are set up.
+ */
mov $MSR_GS_BASE,%ecx
- mov $_pa(canary), %eax
- xor %edx, %edx
+ lea INIT_PER_CPU_VAR(fixed_percpu_data)(%rip), %rdx
+ mov %edx, %eax
+ shr $32, %rdx
wrmsr
call xen_prepare_pvh
@@ -157,8 +162,6 @@ SYM_DATA_START_LOCAL(gdt_start)
SYM_DATA_END_LABEL(gdt_start, SYM_L_LOCAL, gdt_end)
.balign 16
-SYM_DATA_LOCAL(canary, .fill 48, 1, 0)
-
SYM_DATA_START_LOCAL(early_stack)
.fill BOOT_STACK_SIZE, 1, 0
SYM_DATA_END_LABEL(early_stack, SYM_L_LOCAL, early_stack_end)
--
2.44.0
Powered by blists - more mailing lists