The macros EL1_OR_EL2() and EL1_OR_EL2_OR_EL3() allow conditional execution of assembly sequences based on the current exception level, by jumping to caller supplied labels 1f, 2f or 3f. However, the jump to 1f is actually a fallthrough, which means the EL1 code needs to follow right after the macro invocation, and the 1f label is ignored.
So let's fix this by making all jumps explicit. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Ard Biesheuvel <[email protected]> --- ArmPkg/Include/AsmMacroIoLibV8.h | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) diff --git a/ArmPkg/Include/AsmMacroIoLibV8.h b/ArmPkg/Include/AsmMacroIoLibV8.h index a9f8491bc922..efc47d3bbbc7 100644 --- a/ArmPkg/Include/AsmMacroIoLibV8.h +++ b/ArmPkg/Include/AsmMacroIoLibV8.h @@ -25,9 +25,9 @@ mrs SAFE_XREG, CurrentEL ;\ cmp SAFE_XREG, #0x8 ;\ b.eq 2f ;\ - cmp SAFE_XREG, #0x4 ;\ - b.ne . ;// We should never get here -// EL1 code starts here + tbnz SAFE_XREG, #2, 1f ;\ + b . ;// We should never get here + // CurrentEL : 0xC = EL3; 8 = EL2; 4 = EL1 // This only selects between EL1 and EL2 and EL3, else we die. @@ -36,11 +36,10 @@ mrs SAFE_XREG, CurrentEL ;\ cmp SAFE_XREG, #0xC ;\ b.eq 3f ;\ - cmp SAFE_XREG, #0x8 ;\ - b.eq 2f ;\ - cmp SAFE_XREG, #0x4 ;\ - b.ne . ;// We should never get here -// EL1 code starts here + tbnz SAFE_XREG, #3, 2f ;\ + tbnz SAFE_XREG, #2, 1f ;\ + b . ;// We should never get here + #if defined(__clang__) // load x0 with _Data -- 2.5.0 _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
