arm64: Add FIX_HOLE to permanent fixed addresses
PATCH 1/1 arm64: Add FIX_HOLE to permanent fixed addresses
Every other architecture with permanent fixed addresses has FIX_HOLE as the first entry. This seems to be designed as a debugging aid but there are a couple of side effects of not having FIX_HOLE:
- If the first fixed address is 0, fix_to_virt -> virt_to_fix triggers a BUG_ON for the virtual address being equal to FIXADDR_TOP
- fix_to_virt may return a value outside of FIXADDR_START and FIXADDR_TOP which may look like a bug to a developer.
Match up with other architectures and make everything clearer by adding FIX_HOLE.
--- arch/arm64/include/asm/fixmap.h | 1 + 1 file changed, 1 insertion(+)
arch/arm64/include/asm/fixmap.h +1 -0
@@ -31,6 +31,7 @@* */ enum fixed_addresses { +FIX_HOLE ,FIX_EARLYCON_MEM_BASE , __end_of_permanent_fixed_addresses,
Signature · 2 lines
Qualcomm Innovation Center, Inc. Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project
PATCH 1/1 arm64: Add FIX_HOLE to permanent fixed addresses
Quoted 24 lines · Laura Abbott
Every other architecture with permanent fixed addresses has
FIX_HOLEas the first entry. This seems to be designed as a debugging aid but there are a couple of side effects of not havingFIX_HOLE:- If the first fixed address is 0,
fix_to_virt->virt_to_fixtriggers aBUG_ONfor the virtual address being equal toFIXADDR_TOP
-fix_to_virtmay return a value outside ofFIXADDR_STARTandFIXADDR_TOPwhich may look like a bug to a developer.Match up with other architectures and make everything clearer by adding
FIX_HOLE.Signed-off-by Laura Abbott <[email protected]>--- arch/arm64/include/asm/fixmap.h | 1 + 1 file changed, 1 insertion(+)arch/arm64/include/asm/fixmap.h +0
-0
arch/arm64/include/asm/fixmap.h line 36
Quoted 6 lines
arch/arm64/include/asm/fixmap.h +1
-0@@ -31,6 +31,7 @@* */ enum fixed_addresses { +FIX_HOLE ,FIX_EARLYCON_MEM_BASE , __end_of_permanent_fixed_addresses,
Looks sensible to me, thanks.
Will