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| author | Ard Biesheuvel <ard.biesheuvel@linaro.org> | 2016-03-17 09:07:28 +0100 |
|---|---|---|
| committer | Ard Biesheuvel <ard.biesheuvel@linaro.org> | 2016-03-22 14:39:01 +0100 |
| commit | a34608ca9670e07d8a4b6de2914b2960132d4b16 (patch) | |
| tree | 2f6e00f8792682634ae704c7f22e6ccf6dc40d90 /ArmPkg/Include/AsmMacroIoLibV8.h | |
| parent | 725cdb8fbfb034cd73574ed9c356b0dca14ff843 (diff) | |
| download | edk2-a34608ca9670e07d8a4b6de2914b2960132d4b16.tar.gz edk2-a34608ca9670e07d8a4b6de2914b2960132d4b16.tar.bz2 edk2-a34608ca9670e07d8a4b6de2914b2960132d4b16.zip | |
ArmPkg/AsmMacroIoLibV8: remove undocumented assumption from ELx macros
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 <ard.biesheuvel@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
Reviewed-by: Eugene Cohen <eugene@hp.com>
Diffstat (limited to 'ArmPkg/Include/AsmMacroIoLibV8.h')
| -rw-r--r-- | ArmPkg/Include/AsmMacroIoLibV8.h | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/ArmPkg/Include/AsmMacroIoLibV8.h b/ArmPkg/Include/AsmMacroIoLibV8.h index a9f8491bc9..37fa255f84 100644 --- a/ArmPkg/Include/AsmMacroIoLibV8.h +++ b/ArmPkg/Include/AsmMacroIoLibV8.h @@ -24,23 +24,23 @@ #define EL1_OR_EL2(SAFE_XREG) \
mrs SAFE_XREG, CurrentEL ;\
cmp SAFE_XREG, #0x8 ;\
+ b.gt . ;\
b.eq 2f ;\
- cmp SAFE_XREG, #0x4 ;\
- b.ne . ;// We should never get here
-// EL1 code starts here
+ cbnz SAFE_XREG, 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.
// Provide the Macro with a safe temp xreg to use.
#define EL1_OR_EL2_OR_EL3(SAFE_XREG) \
mrs SAFE_XREG, CurrentEL ;\
- cmp SAFE_XREG, #0xC ;\
- b.eq 3f ;\
cmp SAFE_XREG, #0x8 ;\
+ b.gt 3f ;\
b.eq 2f ;\
- cmp SAFE_XREG, #0x4 ;\
- b.ne . ;// We should never get here
-// EL1 code starts here
+ cbnz SAFE_XREG, 1f ;\
+ b . ;// We should never get here
+
#if defined(__clang__)
// load x0 with _Data
|