linux-kernel - Re: [PATCH v18 12/17] fprobe: Add fprobe

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: <20241110001054.b0a5afb2d7bb1c09b4bd6b0b@kernel.org>
Date: Sun, 10 Nov 2024 00:10:54 +0900
From: Masami Hiramatsu (Google) <mhiramat@...nel.org>
To: Steven Rostedt <rostedt@...dmis.org>
Cc: Alexei Starovoitov <alexei.starovoitov@...il.com>, Florent Revest
 <revest@...omium.org>, linux-trace-kernel@...r.kernel.org, LKML
 <linux-kernel@...r.kernel.org>, Martin KaFai Lau <martin.lau@...ux.dev>,
 bpf <bpf@...r.kernel.org>, Alexei Starovoitov <ast@...nel.org>, Jiri Olsa
 <jolsa@...nel.org>, Alan Maguire <alan.maguire@...cle.com>, Mark Rutland
 <mark.rutland@....com>, linux-arch@...r.kernel.org, Catalin Marinas
 <catalin.marinas@....com>, Will Deacon <will@...nel.org>, Huacai Chen
 <chenhuacai@...nel.org>, WANG Xuerui <kernel@...0n.name>, Paul Walmsley
 <paul.walmsley@...ive.com>, Palmer Dabbelt <palmer@...belt.com>, Albert Ou
 <aou@...s.berkeley.edu>, 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>, Ingo Molnar
 <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>, Dave Hansen
 <dave.hansen@...ux.intel.com>, x86@...nel.org, "H. Peter Anvin"
 <hpa@...or.com>, Arnd Bergmann <arnd@...db.de>, Mathieu Desnoyers
 <mathieu.desnoyers@...icios.com>
Subject: Re: [PATCH v18 12/17] fprobe: Add fprobe_header encoding feature

On Fri, 1 Nov 2024 10:22:12 -0400
Steven Rostedt <rostedt@...dmis.org> wrote:

> On Sat, 26 Oct 2024 13:37:59 +0900
> "Masami Hiramatsu (Google)" <mhiramat@...nel.org> wrote:
> 
> > From: Masami Hiramatsu (Google) <mhiramat@...nel.org>
> > 
> > Fprobe store its data structure address and size on the fgraph return stack
> > by __fprobe_header. But most 64bit architecture can combine those to
> > one unsigned long value because 4 MSB in the kernel address are the same.
> > With this encoding, fprobe can consume less space on ret_stack.
> > 
> > This introduces asm/fprobe.h to define arch dependent encode/decode
> > macros. Note that since fprobe depends on CONFIG_HAVE_FUNCTION_GRAPH_FREGS,
> > currently only arm64, loongarch, riscv, s390 and x86 are supported.
> > 
> > Signed-off-by: Masami Hiramatsu (Google) <mhiramat@...nel.org>
> > Cc: Catalin Marinas <catalin.marinas@....com>
> > Cc: Will Deacon <will@...nel.org>
> > Cc: Huacai Chen <chenhuacai@...nel.org>
> > Cc: WANG Xuerui <kernel@...0n.name>
> > Cc: Paul Walmsley <paul.walmsley@...ive.com>
> > Cc: Palmer Dabbelt <palmer@...belt.com>
> > Cc: Albert Ou <aou@...s.berkeley.edu>
> > Cc: Heiko Carstens <hca@...ux.ibm.com>
> > Cc: Vasily Gorbik <gor@...ux.ibm.com>
> > Cc: Alexander Gordeev <agordeev@...ux.ibm.com>
> > Cc: Christian Borntraeger <borntraeger@...ux.ibm.com>
> > Cc: Sven Schnelle <svens@...ux.ibm.com>
> > Cc: Thomas Gleixner <tglx@...utronix.de>
> > Cc: Ingo Molnar <mingo@...hat.com>
> > Cc: Borislav Petkov <bp@...en8.de>
> > Cc: Dave Hansen <dave.hansen@...ux.intel.com>
> > Cc: x86@...nel.org
> > Cc: "H. Peter Anvin" <hpa@...or.com>
> > Cc: Arnd Bergmann <arnd@...db.de>
> > Cc: Steven Rostedt <rostedt@...dmis.org>
> > Cc: Masami Hiramatsu <mhiramat@...nel.org>
> > Cc: Mathieu Desnoyers <mathieu.desnoyers@...icios.com>
> > ---
> >  arch/arm64/include/asm/fprobe.h     |    7 +++++++
> >  arch/loongarch/include/asm/fprobe.h |    5 +++++
> >  arch/riscv/include/asm/fprobe.h     |    9 +++++++++
> >  arch/s390/include/asm/fprobe.h      |   10 ++++++++++
> >  arch/x86/include/asm/fprobe.h       |    9 +++++++++
> >  include/asm-generic/fprobe.h        |   33 +++++++++++++++++++++++++++++++++
> >  kernel/trace/fprobe.c               |   29 +++++++++++++++++++++++++++++
> >  7 files changed, 102 insertions(+)
> >  create mode 100644 arch/arm64/include/asm/fprobe.h
> >  create mode 100644 arch/loongarch/include/asm/fprobe.h
> >  create mode 100644 arch/riscv/include/asm/fprobe.h
> >  create mode 100644 arch/s390/include/asm/fprobe.h
> >  create mode 100644 arch/x86/include/asm/fprobe.h
> >  create mode 100644 include/asm-generic/fprobe.h
> > 
> > diff --git a/arch/arm64/include/asm/fprobe.h b/arch/arm64/include/asm/fprobe.h
> > new file mode 100644
> > index 000000000000..bbf254db878d
> > --- /dev/null
> > +++ b/arch/arm64/include/asm/fprobe.h
> > @@ -0,0 +1,7 @@
> > +/* SPDX-License-Identifier: GPL-2.0 */
> > +#ifndef _ASM_ARM64_FPROBE_H
> > +#define _ASM_ARM64_FPROBE_H
> > +
> > +#include <asm-generic/fprobe.h>
> > +
> > +#endif /* _ASM_ARM64_FPROBE_H */
> > \ No newline at end of file
> 
> This isn't the way to add asm-generic code to architectures. It needs to be
> in the Kbuild file. Like this:
> 
> diff --git a/arch/arm64/include/asm/Kbuild b/arch/arm64/include/asm/Kbuild
> index 4e350df9a02d..0d0a638d41a8 100644
> --- a/arch/arm64/include/asm/Kbuild
> +++ b/arch/arm64/include/asm/Kbuild
> @@ -14,6 +14,7 @@ generic-y += qrwlock.h
>  generic-y += qspinlock.h
>  generic-y += parport.h
>  generic-y += user.h
> +generic-y += fprobe.h
>  
>  generated-y += cpucap-defs.h
>  generated-y += sysreg-defs.h

OK.

> 
> 
> > diff --git a/arch/loongarch/include/asm/fprobe.h b/arch/loongarch/include/asm/fprobe.h
> > new file mode 100644
> > index 000000000000..68156a66873c
> > --- /dev/null
> > +++ b/arch/loongarch/include/asm/fprobe.h
> > @@ -0,0 +1,5 @@
> > +/* SPDX-License-Identifier: GPL-2.0 */
> > +#ifndef _ASM_LOONGARCH_FPROBE_H
> > +#define _ASM_LOONGARCH_FPROBE_H
> > +
> > +#endif /* _ASM_LOONGARCH_FPROBE_H */
> > \ No newline at end of file
> > diff --git a/arch/riscv/include/asm/fprobe.h b/arch/riscv/include/asm/fprobe.h
> > new file mode 100644
> > index 000000000000..51fc2ef3eda1
> > --- /dev/null
> > +++ b/arch/riscv/include/asm/fprobe.h
> > @@ -0,0 +1,9 @@
> > +/* SPDX-License-Identifier: GPL-2.0 */
> > +#ifndef _ASM_RISCV_FPROBE_H
> > +#define _ASM_RISCV_FPROBE_H
> > +
> > +#ifdef CONFIG_64BIT
> > +#include <asm-generic/fprobe.h>
> > +#endif
> > +
> > +#endif /* _ASM_RISCV_FPROBE_H */
> > \ No newline at end of file
> > diff --git a/arch/s390/include/asm/fprobe.h b/arch/s390/include/asm/fprobe.h
> > new file mode 100644
> > index 000000000000..84b94ba6e3a4
> > --- /dev/null
> > +++ b/arch/s390/include/asm/fprobe.h
> > @@ -0,0 +1,10 @@
> > +/* SPDX-License-Identifier: GPL-2.0 */
> > +#ifndef _ASM_S390_FPROBE_H
> > +#define _ASM_S390_FPROBE_H
> > +
> > +#include <asm-generic/fprobe.h>
> > +
> > +#undef FPROBE_HEADER_MSB_PATTERN
> > +#define FPROBE_HEADER_MSB_PATTERN 0
> > +
> > +#endif /* _ASM_S390_FPROBE_H */
> > \ No newline at end of file
> > diff --git a/arch/x86/include/asm/fprobe.h b/arch/x86/include/asm/fprobe.h
> > new file mode 100644
> > index 000000000000..c863518bef90
> > --- /dev/null
> > +++ b/arch/x86/include/asm/fprobe.h
> > @@ -0,0 +1,9 @@
> > +/* SPDX-License-Identifier: GPL-2.0 */
> > +#ifndef _ASM_X86_FPROBE_H
> > +#define _ASM_X86_FPROBE_H
> > +
> > +#ifdef CONFIG_64BIT
> > +#include <asm-generic/fprobe.h>
> > +#endif
> > +
> > +#endif /* _ASM_X86_FPROBE_H */
> > \ No newline at end of file
> 
> Same for the above.

OK, but x86 and riscv, we need this default template on 64bit only.
So those may keep it, right?

Thank you,

> 
> -- Steve


-- 
Masami Hiramatsu (Google) <mhiramat@...nel.org>