| Message ID | 20240422113523.4070414-2-mark.rutland@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: cleanup DAIF.D manipulation | expand |
On Mon, Apr 22, 2024 at 12:35:22PM +0100, Mark Rutland wrote: > A comment in the disable_step_tsk macro refers to synchronising with > enable_dbg, as historically the entry used enable_dbg to unmask debug > exceptions after disabling single-stepping. Reviewed-by: Mark Brown <broonie@kernel.org>
diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h index ab8b396428da8..b27dac4a9c0f4 100644 --- a/arch/arm64/include/asm/assembler.h +++ b/arch/arm64/include/asm/assembler.h @@ -59,7 +59,7 @@ mrs \tmp, mdscr_el1 bic \tmp, \tmp, #DBG_MDSCR_SS msr mdscr_el1, \tmp - isb // Synchronise with enable_dbg + isb // Take effect before a subsequent clear of DAIF.D 9990: .endm
A comment in the disable_step_tsk macro refers to synchronising with enable_dbg, as historically the entry used enable_dbg to unmask debug exceptions after disabling single-stepping. These days the unmasking happens in entry-common.c via local_daif_restore() or local_daif_inherit(), so the comment is stale. This logic is likely to chang in future, so it would be best to avoid referring to those macros specifically. Update the comment to take this into account, and describe it in terms of clearing DAIF.D so that it doesn't macro where this logic lives nor what it is called. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Mark Brown <broonie@kernel.org> Cc: Will Deacon <will@kernel.org> --- arch/arm64/include/asm/assembler.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)