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| author | Giacomo Travaglini <giacomo.travaglini@arm.com> | 2017-12-19 10:18:13 +0000 |
|---|---|---|
| committer | Giacomo Travaglini <giacomo.travaglini@arm.com> | 2018-02-08 09:48:02 +0000 |
| commit | ad36e61ce400deaddfb07e71b13aea8a74b52550 (patch) | |
| tree | 5268efd73e5369b1f98bdf492125424199bc1922 | |
| parent | b885dc68a26e0c7a401ca4b338d997ac577847a8 (diff) | |
| download | gem5-ad36e61ce400deaddfb07e71b13aea8a74b52550.tar.xz | |
arch-arm: Don't change PSTATE in Illegal Exception return
This patch fixes the Illegal Exception return handler. According to the
armarm documentation, when PSTATE.IL is set to one because of an illegal
exception return, PSTATE.{EL, nRW, SP} are unchanged. This means the
Exception level, Execution state, and stack pointer selection do not
change as a result of the return.
Change-Id: I35f2fe68fb2822a54fc4a21930871eab7a1aaab4
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/8021
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
| -rw-r--r-- | src/arch/arm/insts/static_inst.cc | 10 | ||||
| -rw-r--r-- | src/arch/arm/isa.cc | 2 |
2 files changed, 11 insertions, 1 deletions
diff --git a/src/arch/arm/insts/static_inst.cc b/src/arch/arm/insts/static_inst.cc index aace1de2b..a7ba91e03 100644 --- a/src/arch/arm/insts/static_inst.cc +++ b/src/arch/arm/insts/static_inst.cc @@ -1018,7 +1018,17 @@ ArmStaticInst::getPSTATEFromPSR(ThreadContext *tc, CPSR cpsr, CPSR spsr) const new_cpsr.ss = 0; if (illegalExceptionReturn(tc, cpsr, spsr)) { + // If the SPSR specifies an illegal exception return, + // then PSTATE.{M, nRW, EL, SP} are unchanged and PSTATE.IL + // is set to 1. new_cpsr.il = 1; + if (cpsr.width) { + new_cpsr.mode = cpsr.mode; + } else { + new_cpsr.width = cpsr.width; + new_cpsr.el = cpsr.el; + new_cpsr.sp = cpsr.sp; + } } else { new_cpsr.il = spsr.il; if (spsr.width && badMode32((OperatingMode)(uint8_t)spsr.mode)) { diff --git a/src/arch/arm/isa.cc b/src/arch/arm/isa.cc index c917abacf..5d34e188a 100644 --- a/src/arch/arm/isa.cc +++ b/src/arch/arm/isa.cc @@ -726,7 +726,7 @@ ISA::setMiscReg(int misc_reg, const MiscReg &val, ThreadContext *tc) CPSR old_cpsr = miscRegs[MISCREG_CPSR]; int old_mode = old_cpsr.mode; CPSR cpsr = val; - if (old_mode != cpsr.mode) { + if (old_mode != cpsr.mode || cpsr.il != old_cpsr.il) { getITBPtr(tc)->invalidateMiscReg(); getDTBPtr(tc)->invalidateMiscReg(); } |