[PATCH v2 01/16] xen/riscv: initialize bitmap to zero in riscv_fill_hwcap_from_isa_string()

[Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>]

The this_isa bitmap should be explicitly initialized to zero to avoid
false positives when detecting supported ISA extensions. Without proper
zero-initialization, the bitmap may retain non-zero values from
uninitialized memory, causing Xen to incorrectly assume that certain
extensions are supported.

This change ensures reliable detection of ISA capabilities.

Fixes: 0c2f717eae ("xen/riscv: identify specific ISA supported by cpu")
Signed-off-by: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>
---
Changes in V2:
 - new patch.
---
 xen/arch/riscv/cpufeature.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/xen/arch/riscv/cpufeature.c b/xen/arch/riscv/cpufeature.c
index 5aafab0f49..3246a03624 100644
--- a/xen/arch/riscv/cpufeature.c
+++ b/xen/arch/riscv/cpufeature.c
@@ -405,6 +405,8 @@ static void __init riscv_fill_hwcap_from_isa_string(void)
         const char *isa;
         unsigned long cpuid;
 
+        bitmap_zero(this_isa, RISCV_ISA_EXT_MAX);
+
         if ( !dt_device_type_is_equal(cpu, "cpu") )
             continue;
 
-- 
2.49.0