linux-kernel - [PATCH V7 1/2] riscv: Add support for perf registers sampling

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]

Date:   Thu,  5 Sep 2019 11:46:35 +0800
From:   Mao Han <han_mao@...ky.com>
To:     linux-riscv@...ts.infradead.org
Cc:     linux-kernel@...r.kernel.org, linux-csky@...r.kernel.org,
        Mao Han <han_mao@...ky.com>,
        Paul Walmsley <paul.walmsley@...ive.com>,
        Greentime Hu <green.hu@...il.com>,
        Palmer Dabbelt <palmer@...ive.com>,
        Christoph Hellwig <hch@....de>, Guo Ren <guoren@...nel.org>
Subject: [PATCH V7 1/2] riscv: Add support for perf registers sampling

This patch implements the perf registers sampling and validation API
for riscv arch. The valid registers and their register ID are defined in
perf_regs.h. Perf tool can backtrace in userspace with unwind library
and the registers/user stack dump support.

Signed-off-by: Mao Han <han_mao@...ky.com>
Cc: Paul Walmsley <paul.walmsley@...ive.com>
Cc: Greentime Hu <green.hu@...il.com>
Cc: Palmer Dabbelt <palmer@...ive.com>
Cc: linux-riscv <linux-riscv@...ts.infradead.org>
Cc: Christoph Hellwig <hch@....de>
Cc: Guo Ren <guoren@...nel.org>
---
 arch/riscv/Kconfig                      |  2 ++
 arch/riscv/include/uapi/asm/perf_regs.h | 42 +++++++++++++++++++++++++++++++
 arch/riscv/kernel/Makefile              |  1 +
 arch/riscv/kernel/perf_regs.c           | 44 +++++++++++++++++++++++++++++++++
 4 files changed, 89 insertions(+)
 create mode 100644 arch/riscv/include/uapi/asm/perf_regs.h
 create mode 100644 arch/riscv/kernel/perf_regs.c

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 59a4727..4bc976d 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -35,6 +35,8 @@ config RISCV
 	select HAVE_DMA_CONTIGUOUS
 	select HAVE_FUTEX_CMPXCHG if FUTEX
 	select HAVE_PERF_EVENTS
+	select HAVE_PERF_REGS
+	select HAVE_PERF_USER_STACK_DUMP
 	select HAVE_SYSCALL_TRACEPOINTS
 	select IRQ_DOMAIN
 	select SPARSE_IRQ
diff --git a/arch/riscv/include/uapi/asm/perf_regs.h b/arch/riscv/include/uapi/asm/perf_regs.h
new file mode 100644
index 0000000..196f964
--- /dev/null
+++ b/arch/riscv/include/uapi/asm/perf_regs.h
@@ -0,0 +1,42 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/* Copyright (C) 2019 Hangzhou C-SKY Microsystems co.,ltd. */
+
+#ifndef _ASM_RISCV_PERF_REGS_H
+#define _ASM_RISCV_PERF_REGS_H
+
+enum perf_event_riscv_regs {
+	PERF_REG_RISCV_PC,
+	PERF_REG_RISCV_RA,
+	PERF_REG_RISCV_SP,
+	PERF_REG_RISCV_GP,
+	PERF_REG_RISCV_TP,
+	PERF_REG_RISCV_T0,
+	PERF_REG_RISCV_T1,
+	PERF_REG_RISCV_T2,
+	PERF_REG_RISCV_S0,
+	PERF_REG_RISCV_S1,
+	PERF_REG_RISCV_A0,
+	PERF_REG_RISCV_A1,
+	PERF_REG_RISCV_A2,
+	PERF_REG_RISCV_A3,
+	PERF_REG_RISCV_A4,
+	PERF_REG_RISCV_A5,
+	PERF_REG_RISCV_A6,
+	PERF_REG_RISCV_A7,
+	PERF_REG_RISCV_S2,
+	PERF_REG_RISCV_S3,
+	PERF_REG_RISCV_S4,
+	PERF_REG_RISCV_S5,
+	PERF_REG_RISCV_S6,
+	PERF_REG_RISCV_S7,
+	PERF_REG_RISCV_S8,
+	PERF_REG_RISCV_S9,
+	PERF_REG_RISCV_S10,
+	PERF_REG_RISCV_S11,
+	PERF_REG_RISCV_T3,
+	PERF_REG_RISCV_T4,
+	PERF_REG_RISCV_T5,
+	PERF_REG_RISCV_T6,
+	PERF_REG_RISCV_MAX,
+};
+#endif /* _ASM_RISCV_PERF_REGS_H */
diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
index b1bea89..696020f 100644
--- a/arch/riscv/kernel/Makefile
+++ b/arch/riscv/kernel/Makefile
@@ -40,5 +40,6 @@ obj-$(CONFIG_DYNAMIC_FTRACE)	+= mcount-dyn.o
 
 obj-$(CONFIG_PERF_EVENTS)	+= perf_event.o
 obj-$(CONFIG_PERF_EVENTS)	+= perf_callchain.o
+obj-$(CONFIG_HAVE_PERF_REGS)	+= perf_regs.o
 
 clean:
diff --git a/arch/riscv/kernel/perf_regs.c b/arch/riscv/kernel/perf_regs.c
new file mode 100644
index 0000000..04a38fb
--- /dev/null
+++ b/arch/riscv/kernel/perf_regs.c
@@ -0,0 +1,44 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2019 Hangzhou C-SKY Microsystems co.,ltd. */
+
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/perf_event.h>
+#include <linux/bug.h>
+#include <asm/perf_regs.h>
+#include <asm/ptrace.h>
+
+u64 perf_reg_value(struct pt_regs *regs, int idx)
+{
+	if (WARN_ON_ONCE((u32)idx >= PERF_REG_RISCV_MAX))
+		return 0;
+
+	return ((unsigned long *)regs)[idx];
+}
+
+#define REG_RESERVED (~((1ULL << PERF_REG_RISCV_MAX) - 1))
+
+int perf_reg_validate(u64 mask)
+{
+	if (!mask || mask & REG_RESERVED)
+		return -EINVAL;
+
+	return 0;
+}
+
+u64 perf_reg_abi(struct task_struct *task)
+{
+#if __riscv_xlen == 64
+	return PERF_SAMPLE_REGS_ABI_64;
+#else
+	return PERF_SAMPLE_REGS_ABI_32;
+#endif
+}
+
+void perf_get_regs_user(struct perf_regs *regs_user,
+			struct pt_regs *regs,
+			struct pt_regs *regs_user_copy)
+{
+	regs_user->regs = task_pt_regs(current);
+	regs_user->abi = perf_reg_abi(current);
+}
-- 
2.7.4