[RFC PATCH v2 02/45] arm64: debug: don't mask DAIF for mdscr_write()
Vladimir Murzin
vladimir.murzin at arm.com
Mon Jul 27 09:34:10 PDT 2026
From: Ada Couprie Diaz <ada.coupriediaz at arm.com>
Masking DAIF around the write to MDSCR_EL1 doesn't do anything: we can
write to sysregs with interrupts unmasked, and writing to PSTATE is
not a context synchronization event so it does not synchronize it.
This is done in the context of a general interrupt handling cleanup,
so it does not address the missing context synchronization for the
MDSCR_EL1 write, staying consistent with the current state. This
should be addressed in a future patch.
Signed-off-by: Ada Couprie Diaz <ada.coupriediaz at arm.com>
Signed-off-by: Vladimir Murzin <vladimir.murzin at arm.com>
---
arch/arm64/kernel/debug-monitors.c | 3 ---
1 file changed, 3 deletions(-)
diff --git a/arch/arm64/kernel/debug-monitors.c b/arch/arm64/kernel/debug-monitors.c
index 29307642f4c9..e271fbac5f82 100644
--- a/arch/arm64/kernel/debug-monitors.c
+++ b/arch/arm64/kernel/debug-monitors.c
@@ -40,10 +40,7 @@ u8 debug_monitors_arch(void)
*/
static void mdscr_write(u64 mdscr)
{
- unsigned long flags;
- flags = local_daif_save();
write_sysreg(mdscr, mdscr_el1);
- local_daif_restore(flags);
}
NOKPROBE_SYMBOL(mdscr_write);
--
2.34.1
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