| Message ID | 20201028041620.2168707-1-kuhn.chenqun@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | target/ppc/excp_helper: Add a missing break for POWERPC_EXCP_HISI | expand |
On Wed, Oct 28, 2020 at 12:16:20PM +0800, Chen Qun wrote: > When using -Wimplicit-fallthrough in our CFLAGS, the compiler showed warning: > ../target/ppc/excp_helper.c: In function ‘powerpc_excp’: > ../target/ppc/excp_helper.c:529:13: warning: this statement may fall through [-Wimplicit-fallthrough=] > 529 | msr |= env->error_code; > | ~~~~^~~~~~~~~~~~~~~~~~ > ../target/ppc/excp_helper.c:530:5: note: here > 530 | case POWERPC_EXCP_HDECR: /* Hypervisor decrementer exception */ > | ^~~~ > > A break statement may be required to enter this exception. > > Reported-by: Euler Robot <euler.robot@huawei.com> > Signed-off-by: Chen Qun <kuhn.chenqun@huawei.com> This change is incorrect. We definitely need the fallthrough to set srr[01] properly. So the correct fix is to annotate the fallthrough, not remove it. > > --- > I guess there's a break missing in 'POWERPC_EXCP_HISI' branch, > just like the 'POWERPC_EXCP_ISI' branch. > --- > target/ppc/excp_helper.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/target/ppc/excp_helper.c b/target/ppc/excp_helper.c > index a988ba15f4..5e69ac1b33 100644 > --- a/target/ppc/excp_helper.c > +++ b/target/ppc/excp_helper.c > @@ -527,6 +527,7 @@ static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp) > break; > case POWERPC_EXCP_HISI: /* Hypervisor instruction storage exception */ > msr |= env->error_code; > + break; > case POWERPC_EXCP_HDECR: /* Hypervisor decrementer exception */ > case POWERPC_EXCP_HDSI: /* Hypervisor data storage exception */ > case POWERPC_EXCP_HDSEG: /* Hypervisor data segment exception */
> -----Original Message----- > From: David Gibson [mailto:david@gibson.dropbear.id.au] > Sent: Wednesday, October 28, 2020 12:28 PM > To: Chenqun (kuhn) <kuhn.chenqun@huawei.com> > Cc: qemu-devel@nongnu.org; qemu-trivial@nongnu.org; clg@kaod.org; > Zhanghailiang <zhang.zhanghailiang@huawei.com>; ganqixin > <ganqixin@huawei.com>; Euler Robot <euler.robot@huawei.com> > Subject: Re: [PATCH] target/ppc/excp_helper: Add a missing break for > POWERPC_EXCP_HISI > > On Wed, Oct 28, 2020 at 12:16:20PM +0800, Chen Qun wrote: > > When using -Wimplicit-fallthrough in our CFLAGS, the compiler showed > warning: > > ../target/ppc/excp_helper.c: In function ‘powerpc_excp’: > > ../target/ppc/excp_helper.c:529:13: warning: this statement may fall through > [-Wimplicit-fallthrough=] > > 529 | msr |= env->error_code; > > | ~~~~^~~~~~~~~~~~~~~~~~ > > ../target/ppc/excp_helper.c:530:5: note: here > > 530 | case POWERPC_EXCP_HDECR: /* Hypervisor > decrementer exception */ > > | ^~~~ > > > > A break statement may be required to enter this exception. > > > > Reported-by: Euler Robot <euler.robot@huawei.com> > > Signed-off-by: Chen Qun <kuhn.chenqun@huawei.com> > > This change is incorrect. We definitely need the fallthrough to set srr[01] > properly. So the correct fix is to annotate the fallthrough, not remove it. > OK, I'll modify it later. ' Thanks, Chen Qun > > > > --- > > I guess there's a break missing in 'POWERPC_EXCP_HISI' branch, just > > like the 'POWERPC_EXCP_ISI' branch. > > --- > > target/ppc/excp_helper.c | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/target/ppc/excp_helper.c b/target/ppc/excp_helper.c index > > a988ba15f4..5e69ac1b33 100644 > > --- a/target/ppc/excp_helper.c > > +++ b/target/ppc/excp_helper.c > > @@ -527,6 +527,7 @@ static inline void powerpc_excp(PowerPCCPU *cpu, > int excp_model, int excp) > > break; > > case POWERPC_EXCP_HISI: /* Hypervisor instruction storage > exception */ > > msr |= env->error_code; > > + break; > > case POWERPC_EXCP_HDECR: /* Hypervisor decrementer > exception */ > > case POWERPC_EXCP_HDSI: /* Hypervisor data storage > exception */ > > case POWERPC_EXCP_HDSEG: /* Hypervisor data segment > exception */ > > -- > David Gibson | I'll have my music baroque, and my code > david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ > _other_ > | _way_ _around_! > http://www.ozlabs.org/~dgibson
diff --git a/target/ppc/excp_helper.c b/target/ppc/excp_helper.c index a988ba15f4..5e69ac1b33 100644 --- a/target/ppc/excp_helper.c +++ b/target/ppc/excp_helper.c @@ -527,6 +527,7 @@ static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp) break; case POWERPC_EXCP_HISI: /* Hypervisor instruction storage exception */ msr |= env->error_code; + break; case POWERPC_EXCP_HDECR: /* Hypervisor decrementer exception */ case POWERPC_EXCP_HDSI: /* Hypervisor data storage exception */ case POWERPC_EXCP_HDSEG: /* Hypervisor data segment exception */
When using -Wimplicit-fallthrough in our CFLAGS, the compiler showed warning: ../target/ppc/excp_helper.c: In function ‘powerpc_excp’: ../target/ppc/excp_helper.c:529:13: warning: this statement may fall through [-Wimplicit-fallthrough=] 529 | msr |= env->error_code; | ~~~~^~~~~~~~~~~~~~~~~~ ../target/ppc/excp_helper.c:530:5: note: here 530 | case POWERPC_EXCP_HDECR: /* Hypervisor decrementer exception */ | ^~~~ A break statement may be required to enter this exception. Reported-by: Euler Robot <euler.robot@huawei.com> Signed-off-by: Chen Qun <kuhn.chenqun@huawei.com> --- I guess there's a break missing in 'POWERPC_EXCP_HISI' branch, just like the 'POWERPC_EXCP_ISI' branch. --- target/ppc/excp_helper.c | 1 + 1 file changed, 1 insertion(+)