• A
    arm64: KVM: regmap: Fix unexpected switch fall-through · 3d584a3c
    Anders Roxell 提交于
    When fall-through warnings was enabled by default, commit d93512ef0f0e
    ("Makefile: Globally enable fall-through warning"), the following
    warnings was starting to show up:
    
    In file included from ../arch/arm64/include/asm/kvm_emulate.h:19,
                     from ../arch/arm64/kvm/regmap.c:13:
    ../arch/arm64/kvm/regmap.c: In function ‘vcpu_write_spsr32’:
    ../arch/arm64/include/asm/kvm_hyp.h:31:3: warning: this statement may fall
     through [-Wimplicit-fallthrough=]
       asm volatile(ALTERNATIVE(__msr_s(r##nvh, "%x0"), \
       ^~~
    ../arch/arm64/include/asm/kvm_hyp.h:46:31: note: in expansion of macro ‘write_sysreg_elx’
     #define write_sysreg_el1(v,r) write_sysreg_elx(v, r, _EL1, _EL12)
                                   ^~~~~~~~~~~~~~~~
    ../arch/arm64/kvm/regmap.c:180:3: note: in expansion of macro ‘write_sysreg_el1’
       write_sysreg_el1(v, SYS_SPSR);
       ^~~~~~~~~~~~~~~~
    ../arch/arm64/kvm/regmap.c:181:2: note: here
      case KVM_SPSR_ABT:
      ^~~~
    In file included from ../arch/arm64/include/asm/cputype.h:132,
                     from ../arch/arm64/include/asm/cache.h:8,
                     from ../include/linux/cache.h:6,
                     from ../include/linux/printk.h:9,
                     from ../include/linux/kernel.h:15,
                     from ../include/asm-generic/bug.h:18,
                     from ../arch/arm64/include/asm/bug.h:26,
                     from ../include/linux/bug.h:5,
                     from ../include/linux/mmdebug.h:5,
                     from ../include/linux/mm.h:9,
                     from ../arch/arm64/kvm/regmap.c:11:
    ../arch/arm64/include/asm/sysreg.h:837:2: warning: this statement may fall
     through [-Wimplicit-fallthrough=]
      asm volatile("msr " __stringify(r) ", %x0"  \
      ^~~
    ../arch/arm64/kvm/regmap.c:182:3: note: in expansion of macro ‘write_sysreg’
       write_sysreg(v, spsr_abt);
       ^~~~~~~~~~~~
    ../arch/arm64/kvm/regmap.c:183:2: note: here
      case KVM_SPSR_UND:
      ^~~~
    
    Rework to add a 'break;' in the swich-case since it didn't have that,
    leading to an interresting set of bugs.
    
    Cc: stable@vger.kernel.org # v4.17+
    Fixes: a8928195 ("KVM: arm64: Prepare to handle deferred save/restore of 32-bit registers")
    Signed-off-by: NAnders Roxell <anders.roxell@linaro.org>
    [maz: reworked commit message, fixed stable range]
    Signed-off-by: NMarc Zyngier <maz@kernel.org>
    3d584a3c
regmap.c 5.0 KB