lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Wed, 6 Apr 2022 19:50:59 -0700 From: Ira Weiny <ira.weiny@...el.com> To: Dave Hansen <dave.hansen@...ux.intel.com>, "H. Peter Anvin" <hpa@...or.com>, Dan Williams <dan.j.williams@...el.com> Cc: Fenghua Yu <fenghua.yu@...el.com>, Rick Edgecombe <rick.p.edgecombe@...el.com>, "Shankar, Ravi V" <ravi.v.shankar@...el.com>, linux-kernel@...r.kernel.org Subject: Re: [PATCH V9 24/45] entry: Split up irqentry_exit_cond_resched() On Thu, Mar 10, 2022 at 09:19:58AM -0800, Ira wrote: > From: Ira Weiny <ira.weiny@...el.com> > > Auxiliary pt_regs space needs to be manipulated by the generic > entry/exit code. Because of fix to the irqentry_exit_cond_resched() code[1] this patch needed rework upon rebasing to 5.18-rc1 This basic design of this patch remains but the code is different. The irqentry_exit_cond_resched() still needs to have pt_regs passed into it. However, this could be safely ignored for this review cycle as well. As soon as I have a series based on 5.18 I'll resend the full series. Thanks for understanding, Ira [1] 4624a14f4daa ("sched/preempt: Simplify irqentry_exit_cond_resched() callers") > > Normally irqentry_exit() would take care of handling any auxiliary > pt_regs on exit. Unfortunately, the call to > irqentry_exit_cond_resched() from xen_pv_evtchn_do_upcall() bypasses the > normal irqentry_exit() call. Because of this bypass > irqentry_exit_cond_resched() will be required to handle any auxiliary > pt_regs exit handling. However, this prevents irqentry_exit() from > being able to call irqentry_exit_cond_resched() and while maintaining > control of the auxiliary pt_regs. > > Separate out the common functionality of irqentry_exit_cond_resched() so > that functionality can be used by irqentry_exit(). Add a pt_regs > parameter in anticipation of having irqentry_exit_cond_resched() handle > the auxiliary pt_regs separately from irqentry_exit(). > > Signed-off-by: Ira Weiny <ira.weiny@...el.com> > > --- > Changes for V9 > Update commit message > > Changes for V8 > New Patch > --- > arch/x86/entry/common.c | 2 +- > include/linux/entry-common.h | 3 ++- > kernel/entry/common.c | 9 +++++++-- > 3 files changed, 10 insertions(+), 4 deletions(-) > > diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c > index 6c2826417b33..f1ba770d035d 100644 > --- a/arch/x86/entry/common.c > +++ b/arch/x86/entry/common.c > @@ -309,7 +309,7 @@ __visible noinstr void xen_pv_evtchn_do_upcall(struct pt_regs *regs) > > inhcall = get_and_clear_inhcall(); > if (inhcall && !WARN_ON_ONCE(state.exit_rcu)) { > - irqentry_exit_cond_resched(); > + irqentry_exit_cond_resched(regs); > instrumentation_end(); > restore_inhcall(inhcall); > } else { > diff --git a/include/linux/entry-common.h b/include/linux/entry-common.h > index ddaffc983e62..14fd329847e7 100644 > --- a/include/linux/entry-common.h > +++ b/include/linux/entry-common.h > @@ -451,10 +451,11 @@ irqentry_state_t noinstr irqentry_enter(struct pt_regs *regs); > > /** > * irqentry_exit_cond_resched - Conditionally reschedule on return from interrupt > + * @regs: Pointer to pt_regs of interrupted context > * > * Conditional reschedule with additional sanity checks. > */ > -void irqentry_exit_cond_resched(void); > +void irqentry_exit_cond_resched(struct pt_regs *regs); > > void __irqentry_exit_cond_resched(void); > #ifdef CONFIG_PREEMPT_DYNAMIC > diff --git a/kernel/entry/common.c b/kernel/entry/common.c > index 490442a48332..f4210a7fc84d 100644 > --- a/kernel/entry/common.c > +++ b/kernel/entry/common.c > @@ -395,7 +395,7 @@ void __irqentry_exit_cond_resched(void) > DEFINE_STATIC_CALL(__irqentry_exit_cond_resched, __irqentry_exit_cond_resched); > #endif > > -void irqentry_exit_cond_resched(void) > +static void exit_cond_resched(void) > { > if (IS_ENABLED(CONFIG_PREEMPTION)) { > #ifdef CONFIG_PREEMPT_DYNAMIC > @@ -406,6 +406,11 @@ void irqentry_exit_cond_resched(void) > } > } > > +void irqentry_exit_cond_resched(struct pt_regs *regs) > +{ > + exit_cond_resched(); > +} > + > noinstr void irqentry_exit(struct pt_regs *regs, irqentry_state_t state) > { > lockdep_assert_irqs_disabled(); > @@ -431,7 +436,7 @@ noinstr void irqentry_exit(struct pt_regs *regs, irqentry_state_t state) > } > > instrumentation_begin(); > - irqentry_exit_cond_resched(); > + exit_cond_resched(); > /* Covers both tracing and lockdep */ > trace_hardirqs_on(); > instrumentation_end(); > -- > 2.35.1 >
Powered by blists - more mailing lists