From: Martin Lucina <martin@lucina.net>
To: "Roger Pau Monné" <roger.pau@citrix.com>,
"Jürgen Groß" <jgross@suse.com>,
anil@recoil.org, "Andrew Cooper" <andrew.cooper3@citrix.com>,
mirageos-devel@lists.xenproject.org, dave@recoil.org,
xen-devel@lists.xenproject.org
Subject: Re: Xen PVH domU start-of-day VCPU state
Date: Tue, 26 May 2020 17:42:24 +0200 [thread overview]
Message-ID: <20200526154224.GC25283@nodbug.lucina.net> (raw)
In-Reply-To: <20200526101203.GE5942@nodbug.lucina.net>
Oh! I think I've found a solution, even though I don't entirely understand the
problem/root cause:
On Tuesday, 26.05.2020 at 12:12, Martin Lucina wrote:
> > On Tue, May 26, 2020 at 11:34:21AM +0200, Roger Pau Monné wrote:
> > Forgot to ask, but can you also add the output of readelf -lW
> > <kernel>?
>
> Elf file type is EXEC (Executable file)
> Entry point 0x1001e0
> There are 7 program headers, starting at offset 64
>
> Program Headers:
> Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align
> INTERP 0x001000 0x0000000000100000 0x0000000000100000 0x000018 0x000018 R 0x8
> [Requesting program interpreter: /nonexistent/solo5/]
> LOAD 0x001000 0x0000000000100000 0x0000000000100000 0x00626c 0x00626c R E 0x1000
> LOAD 0x008000 0x0000000000107000 0x0000000000107000 0x007120 0x00ed48 RW 0x1000
> NOTE 0x0080ac 0x00000000001070ac 0x00000000001070ac 0x000018 0x000018 R 0x4
> NOTE 0x00f120 0x00000000001070c4 0x00000000001070c4 0x000014 0x000000 R 0x4
^^^^^^^^
I should have picked up on the above, but thought it wasn't relevant.
> NOTE 0x008088 0x0000000000107088 0x0000000000107088 0x000024 0x000024 R 0x4
> NOTE 0x008000 0x0000000000107000 0x0000000000107000 0x000088 0x000088 R 0x4
>
> Section to Segment mapping:
> Segment Sections...
> 00 .interp
> 01 .interp .text .rodata .eh_frame
> 02 .note.solo5.manifest .note.solo5.abi .note.solo5.not-openbsd .data .bss
And also the missing .note.solo5.xen above.
> 03 .note.solo5.not-openbsd
> 04 .note.solo5.xen
> 05 .note.solo5.abi
> 06 .note.solo5.manifest
Turns out that the .note.solo5.xen section as defined in boot.S was not
marked allocatable, and that was doing <something> that was confusing our
linker script[1] (?).
If I make this simple change:
--- a/bindings/xen/boot.S
+++ b/bindings/xen/boot.S
@@ -32,7 +32,7 @@
#define ENTRY(x) .text; .globl x; .type x,%function; x:
#define END(x) .size x, . - x
-.section .note.solo5.xen
+.section .note.solo5.xen, "a", @note
.align 4
.long 4
then I get the expected output from readelf -lW, and I can get as far as
the C _start() with no issues!
FWIW, here's the diff of readelf -lW before/after:
--- before 2020-05-26 17:36:46.117885855 +0200
+++ after 2020-05-26 17:38:07.090508322 +0200
@@ -8,9 +8,9 @@
INTERP 0x001000 0x0000000000100000 0x0000000000100000 0x000018 0x000018 R 0x8
[Requesting program interpreter: /nonexistent/solo5/]
LOAD 0x001000 0x0000000000100000 0x0000000000100000 0x00615c 0x00615c R E 0x1000
- LOAD 0x008000 0x0000000000107000 0x0000000000107000 0x007120 0x00ed28 RW 0x1000
+ LOAD 0x008000 0x0000000000107000 0x0000000000107000 0x006120 0x00dd28 RW 0x1000
NOTE 0x0080ac 0x00000000001070ac 0x00000000001070ac 0x000018 0x000018 R 0x4
- NOTE 0x00f120 0x00000000001070c4 0x00000000001070c4 0x000014 0x000000 R 0x4
+ NOTE 0x0080c4 0x00000000001070c4 0x00000000001070c4 0x000014 0x000014 R 0x4
NOTE 0x008088 0x0000000000107088 0x0000000000107088 0x000024 0x000024 R 0x4
NOTE 0x008000 0x0000000000107000 0x0000000000107000 0x000088 0x000088 R 0x4
@@ -18,7 +18,7 @@
Segment Sections...
00 .interp
01 .interp .text .rodata .eh_frame
- 02 .note.solo5.manifest .note.solo5.abi .note.solo5.not-openbsd .data .bss
+ 02 .note.solo5.manifest .note.solo5.abi .note.solo5.not-openbsd .note.solo5.xen .data .bss
03 .note.solo5.not-openbsd
04 .note.solo5.xen
05 .note.solo5.abi
-mato
[1] https://github.com/mato/solo5/blob/xen/bindings/xen/solo5_xen.lds
next prev parent reply other threads:[~2020-05-26 15:42 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-25 16:04 Xen PVH domU start-of-day VCPU state Martin Lucina
2020-05-25 16:42 ` Jürgen Groß
2020-05-25 16:59 ` Andrew Cooper
2020-05-26 8:52 ` Martin Lucina
2020-05-26 9:34 ` Roger Pau Monné
2020-05-26 10:03 ` Roger Pau Monné
2020-05-26 10:12 ` Martin Lucina
2020-05-26 10:32 ` Roger Pau Monné
2020-05-26 15:42 ` Martin Lucina [this message]
2020-05-26 16:30 ` Roger Pau Monné
2020-05-27 8:00 ` Martin Lucina
2020-05-27 14:41 ` Roger Pau Monné
2020-05-27 14:57 ` Martin Lucina
2020-05-27 15:05 ` Roger Pau Monné
2020-05-26 10:08 ` Martin Lucina
2020-05-26 10:58 ` Andrew Cooper
2020-05-26 11:54 ` Mail-Followup-To (was Re: Xen PVH domU start-of-day VCPU state) Martin Lucina
2020-05-26 11:58 ` Andrew Cooper
2020-05-26 12:41 ` Martin Lucina
2020-05-26 12:42 ` Andrew Cooper
2020-05-26 12:44 ` Martin Lucina
2020-05-25 17:41 ` Xen PVH domU start-of-day VCPU state Andrew Cooper
2020-05-26 8:27 ` Martin Lucina
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