| Message ID | 20190726112705.19000-1-anders.roxell@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | [1/2] arm64: KVM: regmap: Mark expected switch fall-through | expand |
Hi Anders, On Fri, 26 Jul 2019 12:27:05 +0100, Anders Roxell <anders.roxell@linaro.org> wrote: > > 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. > That also made the compiler happy and didn't warn about fall-through. > > Cc: stable@vger.kernel.org # v3.16+ Erm... Are you sure about that? Here's what I have: $ git describe --contains a892819560c4 kvm-arm-for-v4.17~44 $ git describe --contains --match='v*' a892819560c4 v4.17-rc1~72^2~36^2~44 > Fixes: a892819560c4 ("KVM: arm64: Prepare to handle deferred save/restore of 32-bit registers") > Signed-off-by: Anders Roxell <anders.roxell@linaro.org> > --- > arch/arm64/kvm/regmap.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/arch/arm64/kvm/regmap.c b/arch/arm64/kvm/regmap.c > index 0d60e4f0af66..a900181e3867 100644 > --- a/arch/arm64/kvm/regmap.c > +++ b/arch/arm64/kvm/regmap.c > @@ -178,13 +178,18 @@ void vcpu_write_spsr32(struct kvm_vcpu *vcpu, unsigned long v) > switch (spsr_idx) { > case KVM_SPSR_SVC: > write_sysreg_el1(v, SYS_SPSR); > + break; > case KVM_SPSR_ABT: > write_sysreg(v, spsr_abt); > + break; > case KVM_SPSR_UND: > write_sysreg(v, spsr_und); > + break; > case KVM_SPSR_IRQ: > write_sysreg(v, spsr_irq); > + break; > case KVM_SPSR_FIQ: > write_sysreg(v, spsr_fiq); > + break; > } > } Otherwise looks like the right fix to me. Let me know what you think about the Fixes: tag (no need to resend for that). Thanks, M. -- Jazz is not dead, it just smells funny.
On Fri, 26 Jul 2019 at 14:30, Marc Zyngier <marc.zyngier@arm.com> wrote: > > Hi Anders, > > On Fri, 26 Jul 2019 12:27:05 +0100, > Anders Roxell <anders.roxell@linaro.org> wrote: > > > > 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. > > That also made the compiler happy and didn't warn about fall-through. > > > > Cc: stable@vger.kernel.org # v3.16+ > > Erm... Are you sure about that? I made two mistakes. 1. saying 3.x instead of 4.x 2. I said the same kernel that 'git describe' showed and not the later one. I did not know about '--match='. > Here's what I have: > > $ git describe --contains a892819560c4 > kvm-arm-for-v4.17~44 > $ git describe --contains --match='v*' a892819560c4 > v4.17-rc1~72^2~36^2~44 That's correct. > > > > Fixes: a892819560c4 ("KVM: arm64: Prepare to handle deferred save/restore of 32-bit registers") > > Signed-off-by: Anders Roxell <anders.roxell@linaro.org> > > --- > > arch/arm64/kvm/regmap.c | 5 +++++ > > 1 file changed, 5 insertions(+) > > > > diff --git a/arch/arm64/kvm/regmap.c b/arch/arm64/kvm/regmap.c > > index 0d60e4f0af66..a900181e3867 100644 > > --- a/arch/arm64/kvm/regmap.c > > +++ b/arch/arm64/kvm/regmap.c > > @@ -178,13 +178,18 @@ void vcpu_write_spsr32(struct kvm_vcpu *vcpu, unsigned long v) > > switch (spsr_idx) { > > case KVM_SPSR_SVC: > > write_sysreg_el1(v, SYS_SPSR); > > + break; > > case KVM_SPSR_ABT: > > write_sysreg(v, spsr_abt); > > + break; > > case KVM_SPSR_UND: > > write_sysreg(v, spsr_und); > > + break; > > case KVM_SPSR_IRQ: > > write_sysreg(v, spsr_irq); > > + break; > > case KVM_SPSR_FIQ: > > write_sysreg(v, spsr_fiq); > > + break; > > } > > } > > Otherwise looks like the right fix to me. Let me know what you think > about the Fixes: tag (no need to resend for that). It should be v4.17+. Cheers, Anders
diff --git a/arch/arm64/kvm/regmap.c b/arch/arm64/kvm/regmap.c index 0d60e4f0af66..a900181e3867 100644 --- a/arch/arm64/kvm/regmap.c +++ b/arch/arm64/kvm/regmap.c @@ -178,13 +178,18 @@ void vcpu_write_spsr32(struct kvm_vcpu *vcpu, unsigned long v) switch (spsr_idx) { case KVM_SPSR_SVC: write_sysreg_el1(v, SYS_SPSR); + break; case KVM_SPSR_ABT: write_sysreg(v, spsr_abt); + break; case KVM_SPSR_UND: write_sysreg(v, spsr_und); + break; case KVM_SPSR_IRQ: write_sysreg(v, spsr_irq); + break; case KVM_SPSR_FIQ: write_sysreg(v, spsr_fiq); + break; } }
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. That also made the compiler happy and didn't warn about fall-through. Cc: stable@vger.kernel.org # v3.16+ Fixes: a892819560c4 ("KVM: arm64: Prepare to handle deferred save/restore of 32-bit registers") Signed-off-by: Anders Roxell <anders.roxell@linaro.org> --- arch/arm64/kvm/regmap.c | 5 +++++ 1 file changed, 5 insertions(+) -- 2.20.1