1. Patchew
  2. linux
  3. [PATCH v18 00/17] tracing: fprobe: function_graph: Multi-function graph and fprobe on fgraph
  4. View patch

[PATCH v18 12/17] fprobe: Add fprobe_header encoding feature

Masami Hiramatsu (Google) posted 17 patches 1 month ago
There is a newer version of this series
[PATCH v18 12/17] fprobe: Add fprobe_header encoding feature
Posted by Masami Hiramatsu (Google) 1 month ago 
From: Masami Hiramatsu (Google) <mhiramat@kernel.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@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: x86@kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.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
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
diff --git a/include/asm-generic/fprobe.h b/include/asm-generic/fprobe.h
new file mode 100644
index 000000000000..00f480748a1d
--- /dev/null
+++ b/include/asm-generic/fprobe.h
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * linux/include/asm-generic/fprobe.h
+ */
+#ifndef __ASM_GENERIC_FPROBE_H__
+#define __ASM_GENERIC_FPROBE_H__
+
+#include <linux/bits.h>
+
+#define ARCH_HAVE_ENCODE_FPROBE_HEADER
+
+#define FPROBE_HEADER_MSB_SIZE_SHIFT (BITS_PER_LONG - FPROBE_DATA_SIZE_BITS)
+#define FPROBE_HEADER_MSB_MASK					\
+	GENMASK(FPROBE_HEADER_MSB_SIZE_SHIFT - 1, 0)
+#define FPROBE_HEADER_MSB_PATTERN				\
+	GENMASK(BITS_PER_LONG - 1, FPROBE_HEADER_MSB_SIZE_SHIFT)
+
+#define arch_fprobe_header_encodable(fp)			\
+	(((unsigned long)(fp) & ~FPROBE_HEADER_MSB_MASK) ==	\
+	 FPROBE_HEADER_MSB_PATTERN)
+
+#define arch_encode_fprobe_header(fp, size) 			\
+	((unsigned long)(fp) & FPROBE_HEADER_MSB_MASK) | 	\
+	((unsigned long)(size) << FPROBE_HEADER_MSB_SIZE_SHIFT)
+
+#define arch_decode_fprobe_header_size(val) 			\
+	((unsigned long)(val) >> FPROBE_HEADER_MSB_SIZE_SHIFT)
+
+#define arch_decode_fprobe_header_fp(val) 					\
+	(struct fprobe *)(((unsigned long)(val) & FPROBE_HEADER_MSB_MASK) |	\
+			  FPROBE_HEADER_MSB_PATTERN)
+
+#endif /* __ASM_GENERIC_FPROBE_H__ */
\ No newline at end of file
diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c
index ed9c1d79426a..949963f1f17a 100644
--- a/kernel/trace/fprobe.c
+++ b/kernel/trace/fprobe.c
@@ -13,6 +13,8 @@
 #include <linux/slab.h>
 #include <linux/sort.h>
 
+#include <asm/fprobe.h>
+
 #include "trace.h"
 
 #define FPROBE_IP_HASH_BITS 8
@@ -143,6 +145,31 @@ static int del_fprobe_hash(struct fprobe *fp)
 	return 0;
 }
 
+#ifdef ARCH_HAVE_ENCODE_FPROBE_HEADER
+
+/* The arch should encode fprobe_header info into one unsigned long */
+#define FPROBE_HEADER_SIZE_IN_LONG	1
+
+static inline bool write_fprobe_header(unsigned long *stack,
+					struct fprobe *fp, unsigned int size_words)
+{
+	if (WARN_ON_ONCE(size_words > MAX_FPROBE_DATA_SIZE_WORD ||
+			 !arch_fprobe_header_encodable(fp)))
+		return false;
+
+	*stack = arch_encode_fprobe_header(fp, size_words);
+	return true;
+}
+
+static inline void read_fprobe_header(unsigned long *stack,
+					struct fprobe **fp, unsigned int *size_words)
+{
+	*fp = arch_decode_fprobe_header_fp(*stack);
+	*size_words = arch_decode_fprobe_header_size(*stack);
+}
+
+#else
+
 /* Generic fprobe_header */
 struct __fprobe_header {
 	struct fprobe *fp;
@@ -173,6 +200,8 @@ static inline void read_fprobe_header(unsigned long *stack,
 	*size_words = fph->size_words;
 }
 
+#endif
+
 /*
  * fprobe shadow stack management:
  * Since fprobe shares a single fgraph_ops, it needs to share the stack entry
Re: [PATCH v18 12/17] fprobe: Add fprobe_header encoding feature
Posted by Steven Rostedt 3 weeks, 2 days ago 
On Sat, 26 Oct 2024 13:37:59 +0900
"Masami Hiramatsu (Google)" <mhiramat@kernel.org> wrote:

> From: Masami Hiramatsu (Google) <mhiramat@kernel.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@kernel.org>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Will Deacon <will@kernel.org>
> Cc: Huacai Chen <chenhuacai@kernel.org>
> Cc: WANG Xuerui <kernel@xen0n.name>
> Cc: Paul Walmsley <paul.walmsley@sifive.com>
> Cc: Palmer Dabbelt <palmer@dabbelt.com>
> Cc: Albert Ou <aou@eecs.berkeley.edu>
> Cc: Heiko Carstens <hca@linux.ibm.com>
> Cc: Vasily Gorbik <gor@linux.ibm.com>
> Cc: Alexander Gordeev <agordeev@linux.ibm.com>
> Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
> Cc: Sven Schnelle <svens@linux.ibm.com>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: Borislav Petkov <bp@alien8.de>
> Cc: Dave Hansen <dave.hansen@linux.intel.com>
> Cc: x86@kernel.org
> Cc: "H. Peter Anvin" <hpa@zytor.com>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Steven Rostedt <rostedt@goodmis.org>
> Cc: Masami Hiramatsu <mhiramat@kernel.org>
> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.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


> 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.

-- Steve
Re: [PATCH v18 12/17] fprobe: Add fprobe_header encoding feature
Posted by Masami Hiramatsu (Google) 2 weeks, 1 day ago 
On Fri, 1 Nov 2024 10:22:12 -0400
Steven Rostedt <rostedt@goodmis.org> wrote:

> On Sat, 26 Oct 2024 13:37:59 +0900
> "Masami Hiramatsu (Google)" <mhiramat@kernel.org> wrote:
> 
> > From: Masami Hiramatsu (Google) <mhiramat@kernel.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@kernel.org>
> > Cc: Catalin Marinas <catalin.marinas@arm.com>
> > Cc: Will Deacon <will@kernel.org>
> > Cc: Huacai Chen <chenhuacai@kernel.org>
> > Cc: WANG Xuerui <kernel@xen0n.name>
> > Cc: Paul Walmsley <paul.walmsley@sifive.com>
> > Cc: Palmer Dabbelt <palmer@dabbelt.com>
> > Cc: Albert Ou <aou@eecs.berkeley.edu>
> > Cc: Heiko Carstens <hca@linux.ibm.com>
> > Cc: Vasily Gorbik <gor@linux.ibm.com>
> > Cc: Alexander Gordeev <agordeev@linux.ibm.com>
> > Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
> > Cc: Sven Schnelle <svens@linux.ibm.com>
> > Cc: Thomas Gleixner <tglx@linutronix.de>
> > Cc: Ingo Molnar <mingo@redhat.com>
> > Cc: Borislav Petkov <bp@alien8.de>
> > Cc: Dave Hansen <dave.hansen@linux.intel.com>
> > Cc: x86@kernel.org
> > Cc: "H. Peter Anvin" <hpa@zytor.com>
> > Cc: Arnd Bergmann <arnd@arndb.de>
> > Cc: Steven Rostedt <rostedt@goodmis.org>
> > Cc: Masami Hiramatsu <mhiramat@kernel.org>
> > Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.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@kernel.org>
Re: [PATCH v18 12/17] fprobe: Add fprobe_header encoding feature
Posted by Steven Rostedt 1 week, 5 days ago 
On Sun, 10 Nov 2024 00:10:54 +0900
Masami Hiramatsu (Google) <mhiramat@kernel.org> wrote:

> > > +++ 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?

Hmm, I wonder if we could just add:

  generic-$(CONFIG_X86_32)

But since I don't see that used anywhere, we may need this for archs that
partially have it.

-- Steve
Re: [PATCH v18 12/17] fprobe: Add fprobe_header encoding feature
Posted by Masami Hiramatsu (Google) 1 week, 5 days ago 
On Tue, 12 Nov 2024 09:44:37 -0500
Steven Rostedt <rostedt@goodmis.org> wrote:

> On Sun, 10 Nov 2024 00:10:54 +0900
> Masami Hiramatsu (Google) <mhiramat@kernel.org> wrote:
> 
> > > > +++ 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?
> 
> Hmm, I wonder if we could just add:
> 
>   generic-$(CONFIG_X86_32)
> 
> But since I don't see that used anywhere, we may need this for archs that
> partially have it.

Since this mask is not available on 32bit (since 32-4 = 28bit is 256MB,
which is too small for kernel space), I checked CONFIG_64BIT in 
asm-generic header in v19. So now I can use generic-y for most
architecture.

Thank you,

> 
> -- Steve


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

Patchew 2.1-devel-b67e4c2

© 2016 - 2024 Red Hat, Inc.