linux-kernel - Re: [PATCH v7 4/5] x86: perf: Refactor misc flag assignments

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

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <393bbcf0-aebd-450c-ad0b-e6140f1272b4@linux.intel.com>
Date: Thu, 7 Nov 2024 14:40:50 -0500
From: "Liang, Kan" <kan.liang@...ux.intel.com>
To: Colton Lewis <coltonlewis@...gle.com>, kvm@...r.kernel.org
Cc: Oliver Upton <oliver.upton@...ux.dev>,
 Sean Christopherson <seanjc@...gle.com>,
 Peter Zijlstra <peterz@...radead.org>, Ingo Molnar <mingo@...hat.com>,
 Arnaldo Carvalho de Melo <acme@...nel.org>,
 Namhyung Kim <namhyung@...nel.org>, Mark Rutland <mark.rutland@....com>,
 Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
 Jiri Olsa <jolsa@...nel.org>, Ian Rogers <irogers@...gle.com>,
 Adrian Hunter <adrian.hunter@...el.com>, Will Deacon <will@...nel.org>,
 Russell King <linux@...linux.org.uk>,
 Catalin Marinas <catalin.marinas@....com>,
 Michael Ellerman <mpe@...erman.id.au>, Nicholas Piggin <npiggin@...il.com>,
 Christophe Leroy <christophe.leroy@...roup.eu>,
 Naveen N Rao <naveen@...nel.org>, Heiko Carstens <hca@...ux.ibm.com>,
 Vasily Gorbik <gor@...ux.ibm.com>, Alexander Gordeev
 <agordeev@...ux.ibm.com>, Christian Borntraeger <borntraeger@...ux.ibm.com>,
 Sven Schnelle <svens@...ux.ibm.com>, Thomas Gleixner <tglx@...utronix.de>,
 Borislav Petkov <bp@...en8.de>, Dave Hansen <dave.hansen@...ux.intel.com>,
 x86@...nel.org, "H . Peter Anvin" <hpa@...or.com>,
 linux-perf-users@...r.kernel.org, linux-kernel@...r.kernel.org,
 linux-arm-kernel@...ts.infradead.org, linuxppc-dev@...ts.ozlabs.org,
 linux-s390@...r.kernel.org
Subject: Re: [PATCH v7 4/5] x86: perf: Refactor misc flag assignments

On 2024-11-07 2:03 p.m., Colton Lewis wrote:
> Break the assignment logic for misc flags into their own respective
> functions to reduce the complexity of the nested logic.
> 
> Signed-off-by: Colton Lewis <coltonlewis@...gle.com>
> Reviewed-by: Oliver Upton <oliver.upton@...ux.dev>
> ---

Acked-by: Kan Liang <kan.liang@...ux.intel.com>

Thanks,
Kan
>  arch/x86/events/core.c            | 32 +++++++++++++++++++++++--------
>  arch/x86/include/asm/perf_event.h |  2 ++
>  2 files changed, 26 insertions(+), 8 deletions(-)
> 
> diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
> index d19e939f3998..9fdc5fa22c66 100644
> --- a/arch/x86/events/core.c
> +++ b/arch/x86/events/core.c
> @@ -3011,16 +3011,35 @@ unsigned long perf_arch_instruction_pointer(struct pt_regs *regs)
>  	return regs->ip + code_segment_base(regs);
>  }
>  
> +static unsigned long common_misc_flags(struct pt_regs *regs)
> +{
> +	if (regs->flags & PERF_EFLAGS_EXACT)
> +		return PERF_RECORD_MISC_EXACT_IP;
> +
> +	return 0;
> +}
> +
> +unsigned long perf_arch_guest_misc_flags(struct pt_regs *regs)
> +{
> +	unsigned long guest_state = perf_guest_state();
> +	unsigned long flags = common_misc_flags(regs);
> +
> +	if (!(guest_state & PERF_GUEST_ACTIVE))
> +		return flags;
> +
> +	if (guest_state & PERF_GUEST_USER)
> +		return flags & PERF_RECORD_MISC_GUEST_USER;
> +	else
> +		return flags & PERF_RECORD_MISC_GUEST_KERNEL;
> +}
> +
>  unsigned long perf_arch_misc_flags(struct pt_regs *regs)
>  {
>  	unsigned int guest_state = perf_guest_state();
> -	int misc = 0;
> +	unsigned long misc = common_misc_flags(regs);
>  
>  	if (guest_state) {
> -		if (guest_state & PERF_GUEST_USER)
> -			misc |= PERF_RECORD_MISC_GUEST_USER;
> -		else
> -			misc |= PERF_RECORD_MISC_GUEST_KERNEL;
> +		misc |= perf_arch_guest_misc_flags(regs);
>  	} else {
>  		if (user_mode(regs))
>  			misc |= PERF_RECORD_MISC_USER;
> @@ -3028,9 +3047,6 @@ unsigned long perf_arch_misc_flags(struct pt_regs *regs)
>  			misc |= PERF_RECORD_MISC_KERNEL;
>  	}
>  
> -	if (regs->flags & PERF_EFLAGS_EXACT)
> -		misc |= PERF_RECORD_MISC_EXACT_IP;
> -
>  	return misc;
>  }
>  
> diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h
> index feb87bf3d2e9..d95f902acc52 100644
> --- a/arch/x86/include/asm/perf_event.h
> +++ b/arch/x86/include/asm/perf_event.h
> @@ -538,7 +538,9 @@ struct x86_perf_regs {
>  
>  extern unsigned long perf_arch_instruction_pointer(struct pt_regs *regs);
>  extern unsigned long perf_arch_misc_flags(struct pt_regs *regs);
> +extern unsigned long perf_arch_guest_misc_flags(struct pt_regs *regs);
>  #define perf_arch_misc_flags(regs)	perf_arch_misc_flags(regs)
> +#define perf_arch_guest_misc_flags(regs)	perf_arch_guest_misc_flags(regs)
>  
>  #include <asm/stacktrace.h>
>