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authorTiezhu Yang <yangtiezhu@loongson.cn>2021-02-04 11:35:22 +0800
committerThomas Bogendoerfer <tsbogend@alpha.franken.de>2021-02-04 21:55:45 +0100
commit1ddc96bd42daeeb58f66c9515e506f245ccb00c6 (patch)
treeb3f0028730f0feb0f47e209d84f53739baa16a1a /arch/mips
parentc87bc737220adc4627f191a5e4ed5068aabc24a1 (diff)
downloadlinux-1ddc96bd42daeeb58f66c9515e506f245ccb00c6.tar.bz2
MIPS: kernel: Support extracting off-line stack traces from user-space with perf
Add perf_event_mips_regs/perf_reg_value/perf_reg_validate to support features HAVE_PERF_REGS/HAVE_PERF_USER_STACK_DUMP in kernel. [ayan@wavecomp.com: Repick this patch for unwinding userstack backtrace by perf and libunwind on MIPS based CPU.] [ralf@linux-mips.org: Add perf_get_regs_user() which is required after 'commit 88a7c26af8da ("perf: Move task_pt_regs sampling into arch code")'.] [yangtiezhu@loongson.cn: Fix build error about perf_get_regs_user() after commit 76a4efa80900 ("perf/arch: Remove perf_sample_data::regs_user_copy"), and also separate the original patches into two parts (MIPS kernel and perf tools) to merge easily.] The original patches: https://lore.kernel.org/patchwork/patch/1126521/ https://lore.kernel.org/patchwork/patch/1126520/ Signed-off-by: David Daney <david.daney@cavium.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Archer Yan <ayan@wavecomp.com> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Diffstat (limited to 'arch/mips')
-rw-r--r--arch/mips/Kconfig2
-rw-r--r--arch/mips/include/uapi/asm/perf_regs.h40
-rw-r--r--arch/mips/kernel/Makefile2
-rw-r--r--arch/mips/kernel/perf_regs.c68
4 files changed, 111 insertions, 1 deletions
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 71df230d9c54..57b06798706c 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -77,6 +77,8 @@ config MIPS
select HAVE_NMI
select HAVE_OPROFILE
select HAVE_PERF_EVENTS
+ select HAVE_PERF_REGS
+ select HAVE_PERF_USER_STACK_DUMP
select HAVE_REGS_AND_STACK_ACCESS_API
select HAVE_RSEQ
select HAVE_SPARSE_SYSCALL_NR
diff --git a/arch/mips/include/uapi/asm/perf_regs.h b/arch/mips/include/uapi/asm/perf_regs.h
new file mode 100644
index 000000000000..d0f4ecd616cf
--- /dev/null
+++ b/arch/mips/include/uapi/asm/perf_regs.h
@@ -0,0 +1,40 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef _ASM_MIPS_PERF_REGS_H
+#define _ASM_MIPS_PERF_REGS_H
+
+enum perf_event_mips_regs {
+ PERF_REG_MIPS_PC,
+ PERF_REG_MIPS_R1,
+ PERF_REG_MIPS_R2,
+ PERF_REG_MIPS_R3,
+ PERF_REG_MIPS_R4,
+ PERF_REG_MIPS_R5,
+ PERF_REG_MIPS_R6,
+ PERF_REG_MIPS_R7,
+ PERF_REG_MIPS_R8,
+ PERF_REG_MIPS_R9,
+ PERF_REG_MIPS_R10,
+ PERF_REG_MIPS_R11,
+ PERF_REG_MIPS_R12,
+ PERF_REG_MIPS_R13,
+ PERF_REG_MIPS_R14,
+ PERF_REG_MIPS_R15,
+ PERF_REG_MIPS_R16,
+ PERF_REG_MIPS_R17,
+ PERF_REG_MIPS_R18,
+ PERF_REG_MIPS_R19,
+ PERF_REG_MIPS_R20,
+ PERF_REG_MIPS_R21,
+ PERF_REG_MIPS_R22,
+ PERF_REG_MIPS_R23,
+ PERF_REG_MIPS_R24,
+ PERF_REG_MIPS_R25,
+ PERF_REG_MIPS_R26,
+ PERF_REG_MIPS_R27,
+ PERF_REG_MIPS_R28,
+ PERF_REG_MIPS_R29,
+ PERF_REG_MIPS_R30,
+ PERF_REG_MIPS_R31,
+ PERF_REG_MIPS_MAX = PERF_REG_MIPS_R31 + 1,
+};
+#endif /* _ASM_MIPS_PERF_REGS_H */
diff --git a/arch/mips/kernel/Makefile b/arch/mips/kernel/Makefile
index 2303a5868c14..a893ea041ef5 100644
--- a/arch/mips/kernel/Makefile
+++ b/arch/mips/kernel/Makefile
@@ -103,7 +103,7 @@ obj-$(CONFIG_MIPSR2_TO_R6_EMULATOR) += mips-r2-to-r6-emul.o
CFLAGS_cpu-bugs64.o = $(shell if $(CC) $(KBUILD_CFLAGS) -Wa,-mdaddi -c -o /dev/null -x c /dev/null >/dev/null 2>&1; then echo "-DHAVE_AS_SET_DADDI"; fi)
-obj-$(CONFIG_PERF_EVENTS) += perf_event.o
+obj-$(CONFIG_PERF_EVENTS) += perf_event.o perf_regs.o
obj-$(CONFIG_HW_PERF_EVENTS) += perf_event_mipsxx.o
obj-$(CONFIG_JUMP_LABEL) += jump_label.o
diff --git a/arch/mips/kernel/perf_regs.c b/arch/mips/kernel/perf_regs.c
new file mode 100644
index 000000000000..e686780d1647
--- /dev/null
+++ b/arch/mips/kernel/perf_regs.c
@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Some parts derived from x86 version of this file.
+ *
+ * Copyright (C) 2013 Cavium, Inc.
+ */
+
+#include <linux/perf_event.h>
+
+#include <asm/ptrace.h>
+
+#ifdef CONFIG_32BIT
+u64 perf_reg_abi(struct task_struct *tsk)
+{
+ return PERF_SAMPLE_REGS_ABI_32;
+}
+#else /* Must be CONFIG_64BIT */
+u64 perf_reg_abi(struct task_struct *tsk)
+{
+ if (test_tsk_thread_flag(tsk, TIF_32BIT_REGS))
+ return PERF_SAMPLE_REGS_ABI_32;
+ else
+ return PERF_SAMPLE_REGS_ABI_64;
+}
+#endif /* CONFIG_32BIT */
+
+int perf_reg_validate(u64 mask)
+{
+ if (!mask)
+ return -EINVAL;
+ if (mask & ~((1ull << PERF_REG_MIPS_MAX) - 1))
+ return -EINVAL;
+ return 0;
+}
+
+u64 perf_reg_value(struct pt_regs *regs, int idx)
+{
+ long v;
+
+ switch (idx) {
+ case PERF_REG_MIPS_PC:
+ v = regs->cp0_epc;
+ break;
+ case PERF_REG_MIPS_R1 ... PERF_REG_MIPS_R25:
+ v = regs->regs[idx - PERF_REG_MIPS_R1 + 1];
+ break;
+ case PERF_REG_MIPS_R28 ... PERF_REG_MIPS_R31:
+ v = regs->regs[idx - PERF_REG_MIPS_R28 + 28];
+ break;
+
+ default:
+ WARN_ON_ONCE(1);
+ return 0;
+ }
+
+ return (s64)v; /* Sign extend if 32-bit. */
+}
+
+void perf_get_regs_user(struct perf_regs *regs_user,
+ struct pt_regs *regs)
+{
+ regs_user->regs = task_pt_regs(current);
+ regs_user->abi = perf_reg_abi(current);
+}