With the current ASM_FUNC() macro, there is no good way to declare an alignment constraint for a function. As ASM_FUNC() switches sections, declaring the constraint before the macro invocation applies it to the current location in the previous section. Declaring the constraint after the macro invocation lets the function label point to the location prior to alignment. Depending on toolchain behaviour, this may cause the label to point to alignment padding preceding the actual function definition.
To address these issues, introduce the ASM_FUNC_ALIGN() macro, which declares the alignment constraint right before the function label. Signed-off-by: Marvin Häuser <[email protected]> Cc: Leif Lindholm <[email protected]> Cc: Ard Biesheuvel <[email protected]> Cc: Sami Mujawar <[email protected]> Cc: Vitaly Cheptsov <[email protected]> --- ArmPkg/Include/AsmMacroIoLibV8.h | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-) diff --git a/ArmPkg/Include/AsmMacroIoLibV8.h b/ArmPkg/Include/AsmMacroIoLibV8.h index 135aaeca5d0b..919edc70384d 100644 --- a/ArmPkg/Include/AsmMacroIoLibV8.h +++ b/ArmPkg/Include/AsmMacroIoLibV8.h @@ -34,15 +34,29 @@ cbnz SAFE_XREG, 1f ;\ b . ;// We should never get here -#define _ASM_FUNC(Name, Section) \ - .global Name ; \ - .section #Section, "ax" ; \ - .type Name, %function ; \ +#define _ASM_FUNC_HDR(Name, Section) \ + .global Name ; \ + .section #Section, "ax" ; \ + .type Name, %function + +#define _ASM_FUNC_FTR(Name) \ Name: ; \ AARCH64_BTI(c) +#define _ASM_FUNC(Name, Section) \ + _ASM_FUNC_HDR(Name, Section) ; \ + _ASM_FUNC_FTR(Name) + +#define _ASM_FUNC_ALIGN(Name, Section, Align) \ + _ASM_FUNC_HDR(Name, Section) ; \ + .balign Align ; \ + _ASM_FUNC_FTR(Name) + #define ASM_FUNC(Name) _ASM_FUNC(ASM_PFX(Name), .text. ## Name) +#define ASM_FUNC_ALIGN(Name, Align) \ + _ASM_FUNC_ALIGN(ASM_PFX(Name), .text. ## Name, Align) + #define MOV32(Reg, Val) \ movz Reg, (Val) >> 16, lsl #16 ; \ movk Reg, (Val) & 0xffff -- 2.40.0 -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#103117): https://edk2.groups.io/g/devel/message/103117 Mute This Topic: https://groups.io/mt/98325898/21656 Group Owner: [email protected] Unsubscribe: https://edk2.groups.io/g/devel/unsub [[email protected]] -=-=-=-=-=-=-=-=-=-=-=-
