1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
|
From 8f38106de8d023be8b3b28955df3615637c65dd9 Mon Sep 17 00:00:00 2001
From: Luke Shumaker <lukeshu@parabola.nu>
Date: Thu, 28 Dec 2017 06:42:12 -0500
Subject: [PATCH 08/10] linux-user: init_guest_space: Don't try to align if
we'll reject it
If the ensure-alignment code gets triggered, then the
"if (host_start && real_start != current_start)" check will always trigger,
so save 2 syscalls and put that check first.
Note that we can't just switch to using MAP_FIXED for that check, because
then we couldn't differentiate between a failure because "there isn't
enough space" and "there isn't enough space *here*".
Signed-off-by: Luke Shumaker <lukeshu@parabola.nu>
---
linux-user/elfload.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index 5c0ad65611..1b7583d659 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -1871,6 +1871,11 @@ unsigned long init_guest_space(unsigned long host_start,
return (unsigned long)-1;
}
+ /* Check to see if the address is valid. */
+ if (host_start && real_start != current_start) {
+ goto try_again;
+ }
+
/* Ensure the address is properly aligned. */
if (real_start & ~qemu_host_page_mask) {
/* Ideally, we adjust like
@@ -1905,11 +1910,6 @@ unsigned long init_guest_space(unsigned long host_start,
aligned_start = real_start;
}
- /* Check to see if the address is valid. */
- if (host_start && aligned_start != current_start) {
- goto try_again;
- }
-
#if defined(TARGET_ARM) && !defined(TARGET_AARCH64)
/* On 32-bit ARM, we need to also be able to map the commpage. */
int valid = init_guest_commpage(aligned_start - guest_start,
--
2.15.1
|
