| Message ID | 79eb2f12e521f96a53dd166eb7db485bb3d9d067.1718962824.git.nicola.vetrini@bugseng.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [RFC,XEN] x86/mctelem: address violations of MISRA C: 2012 Rule 5.3 | expand |
On 21.06.2024 11:50, Nicola Vetrini wrote: > From: Alessandro Zucchelli <alessandro.zucchelli@bugseng.com> > > This addresses violations of MISRA C:2012 Rule 5.3 which states as > following: An identifier declared in an inner scope shall not hide an > identifier declared in an outer scope. In this case the shadowing is between > local variables "mctctl" and the file-scope static struct variable with the > same name. > > No functional change. > > Signed-off-by: Alessandro Zucchelli <alessandro.zucchelli@bugseng.com> > Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com> > --- > RFC because I'm not 100% sure the semantics of the code is preserved. > I think so, and it passes gitlab pipelines [1], but there may be some missing > information. Details as to your concerns would help. I see no issue, not even a concern. > --- a/xen/arch/x86/cpu/mcheck/mctelem.c > +++ b/xen/arch/x86/cpu/mcheck/mctelem.c > @@ -168,14 +168,14 @@ static void mctelem_xchg_head(struct mctelem_ent **headp, > void mctelem_defer(mctelem_cookie_t cookie, bool lmce) > { > struct mctelem_ent *tep = COOKIE2MCTE(cookie); > - struct mc_telem_cpu_ctl *mctctl = &this_cpu(mctctl); > + struct mc_telem_cpu_ctl *mctctl_cpu = &this_cpu(mctctl); When possible (i.e. without loss of meaning) I'd generally prefer names to be shortened. Wouldn't just "ctl" work here? > - ASSERT(mctctl->pending == NULL || mctctl->lmce_pending == NULL); > + ASSERT(mctctl_cpu->pending == NULL || mctctl_cpu->lmce_pending == NULL); > > - if (mctctl->pending) > - mctelem_xchg_head(&mctctl->pending, &tep->mcte_next, tep); > + if (mctctl_cpu->pending) > + mctelem_xchg_head(&mctctl_cpu->pending, &tep->mcte_next, tep); > else if (lmce) > - mctelem_xchg_head(&mctctl->lmce_pending, &tep->mcte_next, tep); > + mctelem_xchg_head(&mctctl_cpu->lmce_pending, &tep->mcte_next, tep); > else { > /* > * LMCE is supported on Skylake-server and later CPUs, on > @@ -186,10 +186,10 @@ void mctelem_defer(mctelem_cookie_t cookie, bool lmce) > * moment. As a result, the following two exchanges together > * can be treated as atomic. > */ In the middle of this comment the variable is also mentioned, and hence also wants adjusting (twice). > - if (mctctl->lmce_pending) > - mctelem_xchg_head(&mctctl->lmce_pending, > - &mctctl->pending, NULL); > - mctelem_xchg_head(&mctctl->pending, &tep->mcte_next, tep); > + if (mctctl_cpu->lmce_pending) > + mctelem_xchg_head(&mctctl_cpu->lmce_pending, > + &mctctl_cpu->pending, NULL); > + mctelem_xchg_head(&mctctl_cpu->pending, &tep->mcte_next, tep); > } > } > > @@ -213,7 +213,7 @@ void mctelem_process_deferred(unsigned int cpu, > { > struct mctelem_ent *tep; > struct mctelem_ent *head, *prev; > - struct mc_telem_cpu_ctl *mctctl = &per_cpu(mctctl, cpu); > + struct mc_telem_cpu_ctl *mctctl_cpu = &per_cpu(mctctl, cpu); > int ret; > > /* > @@ -232,7 +232,7 @@ void mctelem_process_deferred(unsigned int cpu, > * Any MC# occurring after the following atomic exchange will be > * handled by another round of MCE softirq. > */ > - mctelem_xchg_head(lmce ? &mctctl->lmce_pending : &mctctl->pending, > + mctelem_xchg_head(lmce ? &mctctl_cpu->lmce_pending : &mctctl_cpu->pending, > &this_cpu(mctctl.processing), NULL); By shortening the variable name here you'd also avoid going past line length limits. Jan
On 2024-06-24 11:00, Jan Beulich wrote: > On 21.06.2024 11:50, Nicola Vetrini wrote: >> From: Alessandro Zucchelli <alessandro.zucchelli@bugseng.com> >> >> This addresses violations of MISRA C:2012 Rule 5.3 which states as >> following: An identifier declared in an inner scope shall not hide an >> identifier declared in an outer scope. In this case the shadowing is >> between >> local variables "mctctl" and the file-scope static struct variable >> with the >> same name. >> >> No functional change. >> >> Signed-off-by: Alessandro Zucchelli <alessandro.zucchelli@bugseng.com> >> Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com> >> --- >> RFC because I'm not 100% sure the semantics of the code is preserved. >> I think so, and it passes gitlab pipelines [1], but there may be some >> missing >> information. > > Details as to your concerns would help. I see no issue, not even a > concern. > That's reassuring. My main concern was that somehow the global (trough perhaps some macro expansion) would be updated instead of the local (or viceversa). >> --- a/xen/arch/x86/cpu/mcheck/mctelem.c >> +++ b/xen/arch/x86/cpu/mcheck/mctelem.c >> @@ -168,14 +168,14 @@ static void mctelem_xchg_head(struct mctelem_ent >> **headp, >> void mctelem_defer(mctelem_cookie_t cookie, bool lmce) >> { >> struct mctelem_ent *tep = COOKIE2MCTE(cookie); >> - struct mc_telem_cpu_ctl *mctctl = &this_cpu(mctctl); >> + struct mc_telem_cpu_ctl *mctctl_cpu = &this_cpu(mctctl); > > When possible (i.e. without loss of meaning) I'd generally prefer names > to > be shortened. Wouldn't just "ctl" work here? I can try. I do not expect shadowing with "ctl", but it may happen. I'll try and let you know. > >> - ASSERT(mctctl->pending == NULL || mctctl->lmce_pending == NULL); >> + ASSERT(mctctl_cpu->pending == NULL || mctctl_cpu->lmce_pending == >> NULL); >> >> - if (mctctl->pending) >> - mctelem_xchg_head(&mctctl->pending, &tep->mcte_next, tep); >> + if (mctctl_cpu->pending) >> + mctelem_xchg_head(&mctctl_cpu->pending, &tep->mcte_next, tep); >> else if (lmce) >> - mctelem_xchg_head(&mctctl->lmce_pending, &tep->mcte_next, tep); >> + mctelem_xchg_head(&mctctl_cpu->lmce_pending, &tep->mcte_next, tep); >> else { >> /* >> * LMCE is supported on Skylake-server and later CPUs, on >> @@ -186,10 +186,10 @@ void mctelem_defer(mctelem_cookie_t cookie, bool >> lmce) >> * moment. As a result, the following two exchanges together >> * can be treated as atomic. >> */ > > In the middle of this comment the variable is also mentioned, and hence > also wants adjusting (twice). Ok, will update. > >> - if (mctctl->lmce_pending) >> - mctelem_xchg_head(&mctctl->lmce_pending, >> - &mctctl->pending, NULL); >> - mctelem_xchg_head(&mctctl->pending, &tep->mcte_next, tep); >> + if (mctctl_cpu->lmce_pending) >> + mctelem_xchg_head(&mctctl_cpu->lmce_pending, >> + &mctctl_cpu->pending, NULL); >> + mctelem_xchg_head(&mctctl_cpu->pending, &tep->mcte_next, tep); >> } >> } >> >> @@ -213,7 +213,7 @@ void mctelem_process_deferred(unsigned int cpu, >> { >> struct mctelem_ent *tep; >> struct mctelem_ent *head, *prev; >> - struct mc_telem_cpu_ctl *mctctl = &per_cpu(mctctl, cpu); >> + struct mc_telem_cpu_ctl *mctctl_cpu = &per_cpu(mctctl, cpu); >> int ret; >> >> /* >> @@ -232,7 +232,7 @@ void mctelem_process_deferred(unsigned int cpu, >> * Any MC# occurring after the following atomic exchange will be >> * handled by another round of MCE softirq. >> */ >> - mctelem_xchg_head(lmce ? &mctctl->lmce_pending : &mctctl->pending, >> + mctelem_xchg_head(lmce ? &mctctl_cpu->lmce_pending : >> &mctctl_cpu->pending, >> &this_cpu(mctctl.processing), NULL); > > By shortening the variable name here you'd also avoid going past line > length limits. > Ok.
diff --git a/xen/arch/x86/cpu/mcheck/mctelem.c b/xen/arch/x86/cpu/mcheck/mctelem.c index b8d0368a7d37..df1a31bffb61 100644 --- a/xen/arch/x86/cpu/mcheck/mctelem.c +++ b/xen/arch/x86/cpu/mcheck/mctelem.c @@ -168,14 +168,14 @@ static void mctelem_xchg_head(struct mctelem_ent **headp, void mctelem_defer(mctelem_cookie_t cookie, bool lmce) { struct mctelem_ent *tep = COOKIE2MCTE(cookie); - struct mc_telem_cpu_ctl *mctctl = &this_cpu(mctctl); + struct mc_telem_cpu_ctl *mctctl_cpu = &this_cpu(mctctl); - ASSERT(mctctl->pending == NULL || mctctl->lmce_pending == NULL); + ASSERT(mctctl_cpu->pending == NULL || mctctl_cpu->lmce_pending == NULL); - if (mctctl->pending) - mctelem_xchg_head(&mctctl->pending, &tep->mcte_next, tep); + if (mctctl_cpu->pending) + mctelem_xchg_head(&mctctl_cpu->pending, &tep->mcte_next, tep); else if (lmce) - mctelem_xchg_head(&mctctl->lmce_pending, &tep->mcte_next, tep); + mctelem_xchg_head(&mctctl_cpu->lmce_pending, &tep->mcte_next, tep); else { /* * LMCE is supported on Skylake-server and later CPUs, on @@ -186,10 +186,10 @@ void mctelem_defer(mctelem_cookie_t cookie, bool lmce) * moment. As a result, the following two exchanges together * can be treated as atomic. */ - if (mctctl->lmce_pending) - mctelem_xchg_head(&mctctl->lmce_pending, - &mctctl->pending, NULL); - mctelem_xchg_head(&mctctl->pending, &tep->mcte_next, tep); + if (mctctl_cpu->lmce_pending) + mctelem_xchg_head(&mctctl_cpu->lmce_pending, + &mctctl_cpu->pending, NULL); + mctelem_xchg_head(&mctctl_cpu->pending, &tep->mcte_next, tep); } } @@ -213,7 +213,7 @@ void mctelem_process_deferred(unsigned int cpu, { struct mctelem_ent *tep; struct mctelem_ent *head, *prev; - struct mc_telem_cpu_ctl *mctctl = &per_cpu(mctctl, cpu); + struct mc_telem_cpu_ctl *mctctl_cpu = &per_cpu(mctctl, cpu); int ret; /* @@ -232,7 +232,7 @@ void mctelem_process_deferred(unsigned int cpu, * Any MC# occurring after the following atomic exchange will be * handled by another round of MCE softirq. */ - mctelem_xchg_head(lmce ? &mctctl->lmce_pending : &mctctl->pending, + mctelem_xchg_head(lmce ? &mctctl_cpu->lmce_pending : &mctctl_cpu->pending, &this_cpu(mctctl.processing), NULL); head = this_cpu(mctctl.processing);