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[Qemu-devel] [PULL 16/18] linux-user: init_guest_space: Clean up control
From: |
Laurent Vivier |
Subject: |
[Qemu-devel] [PULL 16/18] linux-user: init_guest_space: Clean up control flow a bit |
Date: |
Tue, 13 Mar 2018 18:33:53 +0100 |
From: Luke Shumaker <address@hidden>
Instead of doing
if (check1) {
if (check2) {
success;
}
}
retry;
Do a clearer
if (!check1) {
goto try_again;
}
if (!check2) {
goto try_again;
}
success;
try_again:
retry;
Besides being clearer, this makes it easier to insert more checks that
need to trigger a retry on check failure, or rearrange them, or anything
like that.
Because some indentation is changing, "ignore space change" may be useful
for viewing this patch.
Signed-off-by: Luke Shumaker <address@hidden>
Message-Id: <address@hidden>
Reviewed-by: Peter Maydell <address@hidden>
[lv: modified to try again fi valid == 0, not valid == -1 (error case)]
Signed-off-by: Laurent Vivier <address@hidden>
---
linux-user/elfload.c | 34 +++++++++++++++++++---------------
1 file changed, 19 insertions(+), 15 deletions(-)
diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index 8699f430b1..c6491a8d35 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -1880,24 +1880,28 @@ unsigned long init_guest_space(unsigned long host_start,
}
/* Check to see if the address is valid. */
- if (!host_start || aligned_start == current_start) {
+ 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,
- aligned_size + guest_start);
- if (valid == 1) {
- break;
- } else if (valid == -1) {
- munmap((void *)real_start, real_size);
- return (unsigned long)-1;
- }
- /* valid == 0, so try again. */
-#else
- /* On other architectures, whatever we have here is fine. */
- break;
-#endif
+ /* On 32-bit ARM, we need to also be able to map the commpage. */
+ int valid = init_guest_commpage(aligned_start - guest_start,
+ aligned_size + guest_start);
+ if (valid == -1) {
+ munmap((void *)real_start, real_size);
+ return (unsigned long)-1;
+ } else if (valid == 0) {
+ goto try_again;
}
+#endif
+
+ /* If nothing has said `return -1` or `goto try_again` yet,
+ * then the address we have is good.
+ */
+ break;
+ try_again:
/* That address didn't work. Unmap and try a different one.
* The address the host picked because is typically right at
* the top of the host address space and leaves the guest with
--
2.14.3
- [Qemu-devel] [PULL 04/18] linux-user: Support f_flags in statfs when available., (continued)
- [Qemu-devel] [PULL 04/18] linux-user: Support f_flags in statfs when available., Laurent Vivier, 2018/03/13
- [Qemu-devel] [PULL 09/18] qemu-binfmt-conf.sh: add qemu-xtensa, Laurent Vivier, 2018/03/13
- [Qemu-devel] [PULL 02/18] linux-user: Remove the unused "not implemented" signal handling stubs, Laurent Vivier, 2018/03/13
- [Qemu-devel] [PULL 08/18] linux-user: drop unused target_msync function, Laurent Vivier, 2018/03/13
- [Qemu-devel] [PULL 01/18] linux-user: Drop unicore32 code, Laurent Vivier, 2018/03/13
- [Qemu-devel] [PULL 10/18] linux-user: Use #if to only call validate_guest_space for 32-bit ARM target, Laurent Vivier, 2018/03/13
- [Qemu-devel] [PULL 12/18] linux-user: init_guest_space: Clean up if we can't initialize the commpage, Laurent Vivier, 2018/03/13
- [Qemu-devel] [PULL 17/18] linux-user: init_guest_space: Don't try to align if we'll reject it, Laurent Vivier, 2018/03/13
- [Qemu-devel] [PULL 14/18] linux-user: init_guest_space: Clarify page alignment logic, Laurent Vivier, 2018/03/13
- [Qemu-devel] [PULL 11/18] linux-user: Rename validate_guest_space => init_guest_commpage, Laurent Vivier, 2018/03/13
- [Qemu-devel] [PULL 16/18] linux-user: init_guest_space: Clean up control flow a bit,
Laurent Vivier <=
- [Qemu-devel] [PULL 15/18] linux-user: init_guest_commpage: Add a comment about size check, Laurent Vivier, 2018/03/13
- [Qemu-devel] [PULL 18/18] linux-user: init_guest_space: Add a comment about search strategy, Laurent Vivier, 2018/03/13
- [Qemu-devel] [PULL 13/18] linux-user: init_guest_space: Correctly handle guest_start in commpage initialization, Laurent Vivier, 2018/03/13
- Re: [Qemu-devel] [PULL 00/18] Linux user for 2.12 patches, no-reply, 2018/03/14
- Re: [Qemu-devel] [PULL 00/18] Linux user for 2.12 patches, Peter Maydell, 2018/03/15