Commit b5fa903b authored by Masami Hiramatsu (Google)'s avatar Masami Hiramatsu (Google) Committed by Steven Rostedt (Google)
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fprobe: Add fprobe_header encoding feature 



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: default avatarMasami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com> # s390
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Heiko Carstens <hca@linux.ibm.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: 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: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/173519005783.391279.5307910947400277525.stgit@devnote2


Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent 4346ba16

arch/arm64/include/asm/Kbuild

+1 −0
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ syscall-y += unistd_32.h 
syscall-y += unistd_compat_32.h



generic-y += early_ioremap.h

generic-y += fprobe.h

generic-y += mcs_spinlock.h

generic-y += mmzone.h

generic-y += qrwlock.h

arch/loongarch/include/asm/fprobe.h

0 → 100644
+12 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0 */

#ifndef _ASM_LOONGARCH_FPROBE_H

#define _ASM_LOONGARCH_FPROBE_H



/*

 * Explicitly undef ARCH_DEFINE_ENCODE_FPROBE_HEADER, because loongarch does not

 * have enough number of fixed MSBs of the address of kernel objects for

 * encoding the size of data in fprobe_header. Use 2-entries encoding instead.

 */

#undef ARCH_DEFINE_ENCODE_FPROBE_HEADER



#endif /* _ASM_LOONGARCH_FPROBE_H */

arch/riscv/include/asm/Kbuild

+1 −0
Original line number Diff line number Diff line
@@ -4,6 +4,7 @@ syscall-y += syscall_table_64.h 


generic-y += early_ioremap.h

generic-y += flat.h

generic-y += fprobe.h

generic-y += kvm_para.h

generic-y += mmzone.h

generic-y += mcs_spinlock.h

arch/s390/include/asm/fprobe.h

0 → 100644
+10 −0
Original line number Diff line number Diff line 
/* 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 */

arch/x86/include/asm/Kbuild

+1 −0
Original line number Diff line number Diff line
@@ -10,5 +10,6 @@ generated-y += unistd_64_x32.h 
generated-y += xen-hypercalls.h



generic-y += early_ioremap.h

generic-y += fprobe.h

generic-y += mcs_spinlock.h

generic-y += mmzone.h