[Xen-changelog] [xen stable-4.8] x86/layout: Correct Xen's idea of its own memory layout

[patchbot@xxxxxxx]

commit 8c2da8f4649bf5e29b6f3338132e36369e8f5700
Author:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
AuthorDate: Tue Mar 14 12:41:21 2017 +0100
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Tue Mar 14 12:41:21 2017 +0100

    x86/layout: Correct Xen's idea of its own memory layout
    
    c/s b4cd59fe "x86: reorder .data and .init when linking" had an unintended
    side effect, where xen_in_range() and the tboot S3 MAC were no longer 
correct.
    
    In practice, it means that Xen's .data section is excluded from 
consideration,
    which means:
     1) Default IOMMU construction for the hardware domain could create 
mappings.
     2) .data isn't included in the tboot MAC checked on resume from S3.
    
    Adjust the comments and virtual address anchors used to define the regions.
    
    Reported-by: Jan Beulich <jbeulich@xxxxxxxx>
    Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
    master commit: c9a4a1c419cebac83a8fb60c4532ad8ccc973dc4
    master date: 2017-02-28 16:18:38 +0000
---
 xen/arch/x86/setup.c | 14 +++++++-------
 xen/arch/x86/tboot.c | 12 +++++++-----
 2 files changed, 14 insertions(+), 12 deletions(-)

diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
index b130671..8dbf36c 100644
--- a/xen/arch/x86/setup.c
+++ b/xen/arch/x86/setup.c
@@ -1672,7 +1672,7 @@ int __hwdom_init xen_in_range(unsigned long mfn)
     paddr_t start, end;
     int i;
 
-    enum { region_s3, region_text, region_bss, nr_regions };
+    enum { region_s3, region_ro, region_rw, nr_regions };
     static struct {
         paddr_t s, e;
     } xen_regions[nr_regions] __hwdom_initdata;
@@ -1683,12 +1683,12 @@ int __hwdom_init xen_in_range(unsigned long mfn)
         /* S3 resume code (and other real mode trampoline code) */
         xen_regions[region_s3].s = bootsym_phys(trampoline_start);
         xen_regions[region_s3].e = bootsym_phys(trampoline_end);
-        /* hypervisor code + data */
-        xen_regions[region_text].s =__pa(&_stext);
-        xen_regions[region_text].e = __pa(&__init_begin);
-        /* bss */
-        xen_regions[region_bss].s = __pa(&__bss_start);
-        xen_regions[region_bss].e = __pa(&__bss_end);
+        /* hypervisor .text + .rodata */
+        xen_regions[region_ro].s = __pa(&_stext);
+        xen_regions[region_ro].e = __pa(&__2M_rodata_end);
+        /* hypervisor .data + .bss */
+        xen_regions[region_rw].s = __pa(&__2M_rwdata_start);
+        xen_regions[region_rw].e = __pa(&__2M_rwdata_end);
     }
 
     start = (paddr_t)mfn << PAGE_SHIFT;
diff --git a/xen/arch/x86/tboot.c b/xen/arch/x86/tboot.c
index e5d7c42..3c00cfc 100644
--- a/xen/arch/x86/tboot.c
+++ b/xen/arch/x86/tboot.c
@@ -12,6 +12,7 @@
 #include <asm/processor.h>
 #include <asm/e820.h>
 #include <asm/tboot.h>
+#include <asm/setup.h>
 #include <crypto/vmac.h>
 
 /* tboot=<physical address of shared page> */
@@ -370,13 +371,14 @@ void tboot_shutdown(uint32_t shutdown_type)
         g_tboot_shared->mac_regions[0].start = bootsym_phys(trampoline_start);
         g_tboot_shared->mac_regions[0].size = bootsym_phys(trampoline_end) -
                                               bootsym_phys(trampoline_start);
-        /* hypervisor code + data */
+        /* hypervisor .text + .rodata */
         g_tboot_shared->mac_regions[1].start = (uint64_t)__pa(&_stext);
-        g_tboot_shared->mac_regions[1].size = __pa(&__init_begin) -
+        g_tboot_shared->mac_regions[1].size = __pa(&__2M_rodata_end) -
                                               __pa(&_stext);
-        /* bss */
-        g_tboot_shared->mac_regions[2].start = (uint64_t)__pa(&__bss_start);
-        g_tboot_shared->mac_regions[2].size = __pa(&__bss_end) - 
__pa(&__bss_start);
+        /* hypervisor .data + .bss */
+        g_tboot_shared->mac_regions[2].start = 
(uint64_t)__pa(&__2M_rwdata_start);
+        g_tboot_shared->mac_regions[2].size = __pa(&__2M_rwdata_end) -
+                                              __pa(&__2M_rwdata_start);
 
         /*
          * MAC domains and other Xen memory
--
generated by git-patchbot for /home/xen/git/xen.git#stable-4.8

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