xen/arch/x86/boot/head.S | 2 +- xen/arch/x86/boot/trampoline.S | 15 ++++++++------- xen/arch/x86/x86_64/kexec_reloc.S | 4 ++-- 3 files changed, 11 insertions(+), 10 deletions(-)
gdt_boot_descr and gdt_48 disagree on how long trampoline_gdt is.
Introduce an end label and have the linker calculate the size, rather than
hard coding it.
Also, just as with c/s af292b41e9, there is no point forcing the CPU to set
Access bits. Fix all remaining GDTs in Xen.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
---
CC: Jan Beulich <JBeulich@suse.com>
CC: Wei Liu <wl@xen.org>
CC: Roger Pau Monné <roger.pau@citrix.com>
The trampoline GDT access bits were actually noticed when trying to clean up
our boot time pagetables and map the trampoline read-only.
---
xen/arch/x86/boot/head.S | 2 +-
xen/arch/x86/boot/trampoline.S | 15 ++++++++-------
xen/arch/x86/x86_64/kexec_reloc.S | 4 ++--
3 files changed, 11 insertions(+), 10 deletions(-)
diff --git a/xen/arch/x86/boot/head.S b/xen/arch/x86/boot/head.S
index 26b680521d..9fdb9b3954 100644
--- a/xen/arch/x86/boot/head.S
+++ b/xen/arch/x86/boot/head.S
@@ -129,7 +129,7 @@ multiboot2_header:
.word 0
gdt_boot_descr:
- .word 7*8-1
+ .word .Ltramopline_gdt_end - trampoline_gdt - 1
gdt_boot_base:
.long sym_offs(trampoline_gdt)
.long 0 /* Needed for 64-bit lgdt */
diff --git a/xen/arch/x86/boot/trampoline.S b/xen/arch/x86/boot/trampoline.S
index 7c6a2328d2..1761fc1213 100644
--- a/xen/arch/x86/boot/trampoline.S
+++ b/xen/arch/x86/boot/trampoline.S
@@ -63,22 +63,23 @@ trampoline_gdt:
/* 0x0000: unused */
.quad 0x0000000000000000
/* 0x0008: ring 0 code, 32-bit mode */
- .quad 0x00cf9a000000ffff
+ .quad 0x00cf9b000000ffff
/* 0x0010: ring 0 code, 64-bit mode */
- .quad 0x00af9a000000ffff
+ .quad 0x00af9b000000ffff
/* 0x0018: ring 0 data */
- .quad 0x00cf92000000ffff
+ .quad 0x00cf93000000ffff
/* 0x0020: real-mode code @ BOOT_TRAMPOLINE */
.long 0x0000ffff
- .long 0x00009a00
+ .long 0x00009b00
/* 0x0028: real-mode data @ BOOT_TRAMPOLINE */
.long 0x0000ffff
- .long 0x00009200
+ .long 0x00009300
/*
* 0x0030: ring 0 Xen data, 16 MiB size, base
* address is computed at runtime.
*/
- .quad 0x00c0920000000fff
+ .quad 0x00c0930000000fff
+.Ltramopline_gdt_end:
.pushsection .trampoline_rel, "a"
.long trampoline_gdt + BOOT_PSEUDORM_CS + 2 - .
@@ -182,7 +183,7 @@ start64:
.word 0
idt_48: .word 0, 0, 0 # base = limit = 0
.word 0
-gdt_48: .word 6*8-1
+gdt_48: .word .Ltramopline_gdt_end - trampoline_gdt - 1
.long bootsym_rel(trampoline_gdt,4)
/* The first page of trampoline is permanent, the rest boot-time only. */
diff --git a/xen/arch/x86/x86_64/kexec_reloc.S b/xen/arch/x86/x86_64/kexec_reloc.S
index 5bf61d5c2d..9e5b7a6ba1 100644
--- a/xen/arch/x86/x86_64/kexec_reloc.S
+++ b/xen/arch/x86/x86_64/kexec_reloc.S
@@ -182,8 +182,8 @@ compat_mode_gdt_desc:
.align 8
compat_mode_gdt:
.quad 0x0000000000000000 /* null */
- .quad 0x00cf92000000ffff /* 0x0008 ring 0 data */
- .quad 0x00cf9a000000ffff /* 0x0010 ring 0 code, compatibility */
+ .quad 0x00cf93000000ffff /* 0x0008 ring 0 data */
+ .quad 0x00cf9b000000ffff /* 0x0010 ring 0 code, compatibility */
compat_mode_idt:
.word 0 /* limit */
--
2.11.0
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Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-develOn 19.08.2019 15:42, Andrew Cooper wrote: > gdt_boot_descr and gdt_48 disagree on how long trampoline_gdt is. > > Introduce an end label and have the linker calculate the size, rather than > hard coding it. > > Also, just as with c/s af292b41e9, there is no point forcing the CPU to set > Access bits. Fix all remaining GDTs in Xen. > > Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> > --- > CC: Jan Beulich <JBeulich@suse.com> > CC: Wei Liu <wl@xen.org> > CC: Roger Pau Monné <roger.pau@citrix.com> > > The trampoline GDT access bits were actually noticed when trying to clean up > our boot time pagetables and map the trampoline read-only. > --- > xen/arch/x86/boot/head.S | 2 +- > xen/arch/x86/boot/trampoline.S | 15 ++++++++------- > xen/arch/x86/x86_64/kexec_reloc.S | 4 ++-- > 3 files changed, 11 insertions(+), 10 deletions(-) > > diff --git a/xen/arch/x86/boot/head.S b/xen/arch/x86/boot/head.S > index 26b680521d..9fdb9b3954 100644 > --- a/xen/arch/x86/boot/head.S > +++ b/xen/arch/x86/boot/head.S > @@ -129,7 +129,7 @@ multiboot2_header: > > .word 0 > gdt_boot_descr: > - .word 7*8-1 > + .word .Ltramopline_gdt_end - trampoline_gdt - 1 > gdt_boot_base: > .long sym_offs(trampoline_gdt) > .long 0 /* Needed for 64-bit lgdt */ > diff --git a/xen/arch/x86/boot/trampoline.S b/xen/arch/x86/boot/trampoline.S > index 7c6a2328d2..1761fc1213 100644 > --- a/xen/arch/x86/boot/trampoline.S > +++ b/xen/arch/x86/boot/trampoline.S > @@ -63,22 +63,23 @@ trampoline_gdt: > /* 0x0000: unused */ > .quad 0x0000000000000000 > /* 0x0008: ring 0 code, 32-bit mode */ > - .quad 0x00cf9a000000ffff > + .quad 0x00cf9b000000ffff > /* 0x0010: ring 0 code, 64-bit mode */ > - .quad 0x00af9a000000ffff > + .quad 0x00af9b000000ffff > /* 0x0018: ring 0 data */ > - .quad 0x00cf92000000ffff > + .quad 0x00cf93000000ffff > /* 0x0020: real-mode code @ BOOT_TRAMPOLINE */ > .long 0x0000ffff > - .long 0x00009a00 > + .long 0x00009b00 > /* 0x0028: real-mode data @ BOOT_TRAMPOLINE */ > .long 0x0000ffff > - .long 0x00009200 > + .long 0x00009300 > /* > * 0x0030: ring 0 Xen data, 16 MiB size, base > * address is computed at runtime. > */ > - .quad 0x00c0920000000fff > + .quad 0x00c0930000000fff > +.Ltramopline_gdt_end: With the typo here fixed Reviewed-by: Jan Beulich <jbeulich@suse.com> But may I talk you into ... > --- a/xen/arch/x86/x86_64/kexec_reloc.S > +++ b/xen/arch/x86/x86_64/kexec_reloc.S > @@ -182,8 +182,8 @@ compat_mode_gdt_desc: > .align 8 > compat_mode_gdt: > .quad 0x0000000000000000 /* null */ > - .quad 0x00cf92000000ffff /* 0x0008 ring 0 data */ > - .quad 0x00cf9a000000ffff /* 0x0010 ring 0 code, compatibility */ > + .quad 0x00cf93000000ffff /* 0x0008 ring 0 data */ > + .quad 0x00cf9b000000ffff /* 0x0010 ring 0 code, compatibility */ ... introducing a similar "end" label here and using it at compat_mode_gdt_desc (the R-b above stands with that change)? Jan _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
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