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authorGiacomo Travaglini <giacomo.travaglini@arm.com>2018-06-07 17:17:16 +0100
committerGiacomo Travaglini <giacomo.travaglini@arm.com>2018-06-22 10:52:55 +0000
commitfc278fffb78512ff3d62a906804d6b285edd00c7 (patch)
tree5c8f488763041f6774ebada7609b86d6a3a865bd /src/arch/arm/isa/formats
parent3ed0c3c0bef2eefddcf2033e6ab9d22cf45c486d (diff)
downloadgem5-fc278fffb78512ff3d62a906804d6b285edd00c7.tar.xz
arch-arm: BadMode checking if corresponding EL is implemented
The old utility function called badMode was only checking if the mode passed as an argument was a recognized mode. It was not checking if the corresponding mode/EL was implemented. That function has been renamed to unknownMode and a new badMode has been introduced. This is used by the cpsrWriteByInstruction function. In this way any try to change the execution mode won't succeed if the mode hasn't been implemented. Change-Id: Ibfe385c5465b904acc0d2eb9647710891d72c9df Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com> Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com> Reviewed-on: https://gem5-review.googlesource.com/11196 Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Diffstat (limited to 'src/arch/arm/isa/formats')
-rw-r--r--src/arch/arm/isa/formats/mem.isa7
-rw-r--r--src/arch/arm/isa/formats/uncond.isa7
2 files changed, 12 insertions, 2 deletions
diff --git a/src/arch/arm/isa/formats/mem.isa b/src/arch/arm/isa/formats/mem.isa
index 1a30fbb9d..50e3e358f 100644
--- a/src/arch/arm/isa/formats/mem.isa
+++ b/src/arch/arm/isa/formats/mem.isa
@@ -282,7 +282,12 @@ def format Thumb32SrsRfe() {{
}
} else {
const uint32_t mode = bits(machInst, 4, 0);
- if (badMode32((OperatingMode)mode))
+ // We check at decode stage if the mode exists even
+ // if the checking is re-done by Srs::execute.
+ // This is done because we will otherwise panic if
+ // trying to read the banked stack pointer of an
+ // unrecognized mode.
+ if (unknownMode32((OperatingMode)mode))
return new Unknown(machInst);
if (!add && !wb) {
return new %(srs)s(machInst, mode,
diff --git a/src/arch/arm/isa/formats/uncond.isa b/src/arch/arm/isa/formats/uncond.isa
index c376cd9ce..e0b07ab5a 100644
--- a/src/arch/arm/isa/formats/uncond.isa
+++ b/src/arch/arm/isa/formats/uncond.isa
@@ -166,7 +166,12 @@ def format ArmUnconditional() {{
const uint32_t val = ((machInst >> 20) & 0x5);
if (val == 0x4) {
const uint32_t mode = bits(machInst, 4, 0);
- if (badMode32((OperatingMode)mode))
+ // We check at decode stage if the mode exists even
+ // if the checking is re-done by Srs::execute.
+ // This is done because we will otherwise panic if
+ // trying to read the banked stack pointer of an
+ // unrecognized mode.
+ if (unknownMode32((OperatingMode)mode))
return new Unknown(machInst);
switch (bits(machInst, 24, 21)) {
case 0x2: