As the ASM_FUNC() macro performs a section switch, the preceding .balign directive applies the alignment constraint to the current location in the previous section. As the linker may not merge the sections in-order, ArmReplaceLiveTranslationEntry() may be left unaligned.
Replace the explicit invocation of .balign with the ASM_FUNC_ALIGN() macro, which guarantees the alignment constraint is applied correctly. To make sure related issues are reliably caught in the future, align the end of the function before checking the total occupied size. This ensures crossing a 0x200 boundary will cause a compilation error. Reviewed-by: Leif Lindholm <quic_llind...@quicinc.com> Signed-off-by: Marvin Häuser <mhaeu...@posteo.de> Cc: Leif Lindholm <quic_llind...@quicinc.com> Cc: Ard Biesheuvel <ardb+tianoc...@kernel.org> Cc: Sami Mujawar <sami.muja...@arm.com> Cc: Vitaly Cheptsov <vit9...@protonmail.com> --- .../ArmMmuLib/AArch64/ArmMmuLibReplaceEntry.S | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibReplaceEntry.S b/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibReplaceEntry.S index e936a5be4e11..887439bc042f 100644 --- a/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibReplaceEntry.S +++ b/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibReplaceEntry.S @@ -69,17 +69,16 @@ .L2_\@: .endm - // Align this routine to a log2 upper bound of its size, so that it is - // guaranteed not to cross a page or block boundary. - .balign 0x200 - //VOID //ArmReplaceLiveTranslationEntry ( // IN UINT64 *Entry, // IN UINT64 Value, // IN UINT64 Address // ) -ASM_FUNC(ArmReplaceLiveTranslationEntry) +// +// Align this routine to a log2 upper bound of its size, so that it is +// guaranteed not to cross a page or block boundary. +ASM_FUNC_ALIGN(ArmReplaceLiveTranslationEntry, 0x200) // disable interrupts mrs x4, daif @@ -101,5 +100,8 @@ ASM_GLOBAL ASM_PFX(ArmReplaceLiveTranslationEntrySize) ASM_PFX(ArmReplaceLiveTranslationEntrySize): .long . - ArmReplaceLiveTranslationEntry - // Double check that we did not overrun the assumed maximum size + // Double check that we did not overrun the assumed maximum size or cross a + // 0x200 boundary (and thus implicitly not any larger power of two, including + // the page size). + .balign 0x200 .org ArmReplaceLiveTranslationEntry + 0x200 -- 2.40.0 -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#103312): https://edk2.groups.io/g/devel/message/103312 Mute This Topic: https://groups.io/mt/98391309/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
