Hi Ayan,
On 10/10/2024 15:03, Ayan Kumar Halder wrote:
If the BSS section is empty, then the function can just return.
This is more than "can", right? If we don't do it, we will end up to
zero outside of BSS. This could be critical data...
Also, I am tempted to suggest to add a Fixes tag because even if it is
unlikely BSS will be zero in the current Xen, it is also not unlikely.
The tag would be:
Fixes: dac84b66cc9a ("xen: arm64: initial build + config changes, start
of day code")
Signed-off-by: Ayan Kumar Halder <[email protected]>
I saw the discussion. I don't have a strong opinion on the exact
approach choosen for zeroing. With the commit message updated:
Acked-by: Julien Grall <[email protected]>
---
Changes from :-
v1..v2 - New patch introduced in v3.
xen/arch/arm/arm64/head.S | 2 ++
Don't we need a similar change on the arm32 code?
1 file changed, 2 insertions(+)
diff --git a/xen/arch/arm/arm64/head.S b/xen/arch/arm/arm64/head.S
index 14c3720d80..72c7b24498 100644
--- a/xen/arch/arm/arm64/head.S
+++ b/xen/arch/arm/arm64/head.S
@@ -346,6 +346,8 @@ FUNC_LOCAL(zero_bss)
PRINT("- Zero BSS -\r\n")
ldr x0, =__bss_start /* x0 := vaddr(__bss_start) */
ldr x1, =__bss_end /* x1 := vaddr(__bss_end) */
+ cmp x1, x0
+ beq skip_bss
1: str xzr, [x0], #8
cmp x0, x1
Cheers,
--
Julien Grall
