2023-10-26 11:46:04

by Huang Pei

[permalink] [raw]
Subject: [PATCH 1/3] selftests/rseq: Add 64bit LoongArch support

Signed-off-by: Huang Pei <[email protected]>
---
tools/testing/selftests/rseq/param_test.c | 20 +
.../selftests/rseq/rseq-loongarch-bits.h | 463 ++++++++++++++++++
.../rseq/rseq-loongarch-thread-pointer.h | 22 +
tools/testing/selftests/rseq/rseq-loongarch.h | 140 ++++++
.../selftests/rseq/rseq-thread-pointer.h | 2 +
tools/testing/selftests/rseq/rseq.h | 2 +
6 files changed, 649 insertions(+)
create mode 100644 tools/testing/selftests/rseq/rseq-loongarch-bits.h
create mode 100644 tools/testing/selftests/rseq/rseq-loongarch-thread-pointer.h
create mode 100644 tools/testing/selftests/rseq/rseq-loongarch.h

diff --git a/tools/testing/selftests/rseq/param_test.c b/tools/testing/selftests/rseq/param_test.c
index bf951a490bb4..e930aa73c219 100644
--- a/tools/testing/selftests/rseq/param_test.c
+++ b/tools/testing/selftests/rseq/param_test.c
@@ -227,7 +227,27 @@ unsigned int yield_mod_cnt, nr_abort;
"bnez " INJECT_ASM_REG ", 222b\n\t" \
"333:\n\t"

+#elif defined(__loongarch__)
+#define RSEQ_INJECT_INPUT \
+ , [loop_cnt_1]"m"(loop_cnt[1]) \
+ , [loop_cnt_2]"m"(loop_cnt[2]) \
+ , [loop_cnt_3]"m"(loop_cnt[3]) \
+ , [loop_cnt_4]"m"(loop_cnt[4]) \
+ , [loop_cnt_5]"m"(loop_cnt[5]) \
+ , [loop_cnt_6]"m"(loop_cnt[6])
+
+#define INJECT_ASM_REG "$r12"
+
+#define RSEQ_INJECT_CLOBBER \
+ , INJECT_ASM_REG

+#define RSEQ_INJECT_ASM(n) \
+ "ld.w " INJECT_ASM_REG ", %[loop_cnt_" #n "]\n\t" \
+ "beqz " INJECT_ASM_REG ", 333f\n\t" \
+ "222:\n\t" \
+ "addi.w " INJECT_ASM_REG "," INJECT_ASM_REG ", -1\n\t" \
+ "bnez " INJECT_ASM_REG ", 222b\n\t" \
+ "333:\n\t"
#else
#error unsupported target
#endif
diff --git a/tools/testing/selftests/rseq/rseq-loongarch-bits.h b/tools/testing/selftests/rseq/rseq-loongarch-bits.h
new file mode 100644
index 000000000000..cf933c1a2100
--- /dev/null
+++ b/tools/testing/selftests/rseq/rseq-loongarch-bits.h
@@ -0,0 +1,463 @@
+/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
+/*
+ * Author: Huang Pei <[email protected]>
+ * (C) Copyright 2023 Loongson Technology Corporation Limited
+ * (C) Copyright 2016-2022 - Mathieu Desnoyers <[email protected]>
+ * (C) Copyright 2018 MIPS Tech LLC
+ * (C) Copyright 2018 - Paul Burton <[email protected]>
+ */
+#include "rseq-bits-template.h"
+
+#if defined(RSEQ_TEMPLATE_MO_RELAXED) && \
+ (defined(RSEQ_TEMPLATE_CPU_ID) || defined(RSEQ_TEMPLATE_MM_CID))
+
+static inline __attribute__((always_inline))
+int RSEQ_TEMPLATE_IDENTIFIER(rseq_cmpeqv_storev)(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
+{
+ RSEQ_INJECT_C(9)
+
+ __asm__ __volatile__ goto (
+ RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
+ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
+#ifdef RSEQ_COMPARE_TWICE
+ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
+ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
+#endif
+ /* Start rseq by storing table entry pointer into rseq_cs. */
+ RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs)
+ RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
+ RSEQ_INJECT_ASM(3)
+ LONG_L " $r4, %[v]\n\t"
+ "bne $r4, %[expect], %l[cmpfail]\n\t"
+ RSEQ_INJECT_ASM(4)
+#ifdef RSEQ_COMPARE_TWICE
+ RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1])
+ LONG_L " $r4, %[v]\n\t"
+ "bne $r4, %[expect], %l[error2]\n\t"
+#endif
+ /* final store */
+ LONG_S " %[newv], %[v]\n\t"
+ "2:\n\t"
+ RSEQ_INJECT_ASM(5)
+ "b 5f\n\t"
+ RSEQ_ASM_DEFINE_ABORT(3, 4, "", abort, 1b, 2b, 4f)
+ "5:\n\t"
+ : /* gcc asm goto does not allow outputs */
+ : [cpu_id] "r" (cpu),
+ [current_cpu_id] "m" (rseq_get_abi()->RSEQ_TEMPLATE_CPU_ID_FIELD),
+ [rseq_cs] "m" (rseq_get_abi()->rseq_cs.arch.ptr),
+ [v] "m" (*v),
+ [expect] "r" (expect),
+ [newv] "r" (newv)
+ RSEQ_INJECT_INPUT
+ : "$r4", "memory"
+ RSEQ_INJECT_CLOBBER
+ : abort, cmpfail
+#ifdef RSEQ_COMPARE_TWICE
+ , error1, error2
+#endif
+ );
+ return 0;
+abort:
+ RSEQ_INJECT_FAILED
+ return -1;
+cmpfail:
+ return 1;
+#ifdef RSEQ_COMPARE_TWICE
+error1:
+ rseq_bug("cpu_id comparison failed");
+error2:
+ rseq_bug("expected value comparison failed");
+#endif
+}
+
+static inline __attribute__((always_inline))
+int RSEQ_TEMPLATE_IDENTIFIER(rseq_cmpnev_storeoffp_load)(intptr_t *v, intptr_t expectnot,
+ long voffp, intptr_t *load, int cpu)
+{
+ RSEQ_INJECT_C(9)
+
+ __asm__ __volatile__ goto (
+ RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
+ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
+#ifdef RSEQ_COMPARE_TWICE
+ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
+ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
+#endif
+ /* Start rseq by storing table entry pointer into rseq_cs. */
+ RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs)
+ RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
+ RSEQ_INJECT_ASM(3)
+ LONG_L " $r4, %[v]\n\t"
+ "beq $r4, %[expectnot], %l[cmpfail]\n\t"
+ RSEQ_INJECT_ASM(4)
+#ifdef RSEQ_COMPARE_TWICE
+ RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1])
+ LONG_L " $r4, %[v]\n\t"
+ "beq $r4, %[expectnot], %l[error2]\n\t"
+#endif
+ LONG_S " $r4, %[load]\n\t"
+ LONG_ADDI " $r4, $r4, %[voffp]\n\t"
+ LONG_L " $r4, $r4, 0\n\t"
+ /* final store */
+ LONG_S " $r4, %[v]\n\t"
+ "2:\n\t"
+ RSEQ_INJECT_ASM(5)
+ "b 5f\n\t"
+ RSEQ_ASM_DEFINE_ABORT(3, 4, "", abort, 1b, 2b, 4f)
+ "5:\n\t"
+ : /* gcc asm goto does not allow outputs */
+ : [cpu_id] "r" (cpu),
+ [current_cpu_id] "m" (rseq_get_abi()->RSEQ_TEMPLATE_CPU_ID_FIELD),
+ [rseq_cs] "m" (rseq_get_abi()->rseq_cs.arch.ptr),
+ /* final store input */
+ [v] "m" (*v),
+ [expectnot] "r" (expectnot),
+ [voffp] "Ir" (voffp),
+ [load] "m" (*load)
+ RSEQ_INJECT_INPUT
+ : "$r4", "memory"
+ RSEQ_INJECT_CLOBBER
+ : abort, cmpfail
+#ifdef RSEQ_COMPARE_TWICE
+ , error1, error2
+#endif
+ );
+ return 0;
+abort:
+ RSEQ_INJECT_FAILED
+ return -1;
+cmpfail:
+ return 1;
+#ifdef RSEQ_COMPARE_TWICE
+error1:
+ rseq_bug("cpu_id comparison failed");
+error2:
+ rseq_bug("expected value comparison failed");
+#endif
+}
+
+static inline __attribute__((always_inline))
+int RSEQ_TEMPLATE_IDENTIFIER(rseq_addv)(intptr_t *v, intptr_t count, int cpu)
+{
+ RSEQ_INJECT_C(9)
+
+ __asm__ __volatile__ goto (
+ RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
+#ifdef RSEQ_COMPARE_TWICE
+ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
+#endif
+ /* Start rseq by storing table entry pointer into rseq_cs. */
+ RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs)
+ RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
+ RSEQ_INJECT_ASM(3)
+#ifdef RSEQ_COMPARE_TWICE
+ RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1])
+#endif
+ LONG_L " $r4, %[v]\n\t"
+ LONG_ADDI " $r4, $r4, %[count]\n\t"
+ /* final store */
+ LONG_S " $r4, %[v]\n\t"
+ "2:\n\t"
+ RSEQ_INJECT_ASM(4)
+ "b 5f\n\t"
+ RSEQ_ASM_DEFINE_ABORT(3, 4, "", abort, 1b, 2b, 4f)
+ "5:\n\t"
+ : /* gcc asm goto does not allow outputs */
+ : [cpu_id] "r" (cpu),
+ [current_cpu_id] "m" (rseq_get_abi()->RSEQ_TEMPLATE_CPU_ID_FIELD),
+ [rseq_cs] "m" (rseq_get_abi()->rseq_cs.arch.ptr),
+ [v] "m" (*v),
+ [count] "Ir" (count)
+ RSEQ_INJECT_INPUT
+ : "$r4", "memory"
+ RSEQ_INJECT_CLOBBER
+ : abort
+#ifdef RSEQ_COMPARE_TWICE
+ , error1
+#endif
+ );
+ return 0;
+abort:
+ RSEQ_INJECT_FAILED
+ return -1;
+#ifdef RSEQ_COMPARE_TWICE
+error1:
+ rseq_bug("cpu_id comparison failed");
+#endif
+}
+
+static inline __attribute__((always_inline))
+int RSEQ_TEMPLATE_IDENTIFIER(rseq_cmpeqv_cmpeqv_storev)(intptr_t *v, intptr_t expect,
+ intptr_t *v2, intptr_t expect2,
+ intptr_t newv, int cpu)
+{
+ RSEQ_INJECT_C(9)
+
+ __asm__ __volatile__ goto (
+ RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
+ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
+#ifdef RSEQ_COMPARE_TWICE
+ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
+ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
+ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error3])
+#endif
+ /* Start rseq by storing table entry pointer into rseq_cs. */
+ RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs)
+ RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
+ RSEQ_INJECT_ASM(3)
+ LONG_L " $r4, %[v]\n\t"
+ "bne $r4, %[expect], %l[cmpfail]\n\t"
+ RSEQ_INJECT_ASM(4)
+ LONG_L " $r4, %[v2]\n\t"
+ "bne $r4, %[expect2], %l[cmpfail]\n\t"
+ RSEQ_INJECT_ASM(5)
+#ifdef RSEQ_COMPARE_TWICE
+ RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1])
+ LONG_L " $r4, %[v]\n\t"
+ "bne $r4, %[expect], %l[error2]\n\t"
+ LONG_L " $r4, %[v2]\n\t"
+ "bne $r4, %[expect2], %l[error3]\n\t"
+#endif
+ /* final store */
+ LONG_S " %[newv], %[v]\n\t"
+ "2:\n\t"
+ RSEQ_INJECT_ASM(6)
+ "b 5f\n\t"
+ RSEQ_ASM_DEFINE_ABORT(3, 4, "", abort, 1b, 2b, 4f)
+ "5:\n\t"
+ : /* gcc asm goto does not allow outputs */
+ : [cpu_id] "r" (cpu),
+ [current_cpu_id] "m" (rseq_get_abi()->RSEQ_TEMPLATE_CPU_ID_FIELD),
+ [rseq_cs] "m" (rseq_get_abi()->rseq_cs.arch.ptr),
+ /* cmp2 input */
+ [v2] "m" (*v2),
+ [expect2] "r" (expect2),
+ /* final store input */
+ [v] "m" (*v),
+ [expect] "r" (expect),
+ [newv] "r" (newv)
+ RSEQ_INJECT_INPUT
+ : "$r4", "memory"
+ RSEQ_INJECT_CLOBBER
+ : abort, cmpfail
+#ifdef RSEQ_COMPARE_TWICE
+ , error1, error2, error3
+#endif
+ );
+ return 0;
+abort:
+ RSEQ_INJECT_FAILED
+ return -1;
+cmpfail:
+ return 1;
+#ifdef RSEQ_COMPARE_TWICE
+error1:
+ rseq_bug("cpu_id comparison failed");
+error2:
+ rseq_bug("1st expected value comparison failed");
+error3:
+ rseq_bug("2nd expected value comparison failed");
+#endif
+}
+
+#endif /* #if defined(RSEQ_TEMPLATE_MO_RELAXED) &&
+ (defined(RSEQ_TEMPLATE_CPU_ID) || defined(RSEQ_TEMPLATE_MM_CID)) */
+
+#if (defined(RSEQ_TEMPLATE_MO_RELAXED) || defined(RSEQ_TEMPLATE_MO_RELEASE)) && \
+ (defined(RSEQ_TEMPLATE_CPU_ID) || defined(RSEQ_TEMPLATE_MM_CID))
+
+static inline __attribute__((always_inline))
+int RSEQ_TEMPLATE_IDENTIFIER(rseq_cmpeqv_trystorev_storev)(intptr_t *v, intptr_t expect,
+ intptr_t *v2, intptr_t newv2,
+ intptr_t newv, int cpu)
+{
+ RSEQ_INJECT_C(9)
+
+ __asm__ __volatile__ goto (
+ RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
+ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
+#ifdef RSEQ_COMPARE_TWICE
+ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
+ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
+#endif
+ /* Start rseq by storing table entry pointer into rseq_cs. */
+ RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs)
+ RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
+ RSEQ_INJECT_ASM(3)
+ LONG_L " $r4, %[v]\n\t"
+ "bne $r4, %[expect], %l[cmpfail]\n\t"
+ RSEQ_INJECT_ASM(4)
+#ifdef RSEQ_COMPARE_TWICE
+ RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1])
+ LONG_L " $r4, %[v]\n\t"
+ "bne $r4, %[expect], %l[error2]\n\t"
+#endif
+ /* try store */
+ LONG_S " %[newv2], %[v2]\n\t"
+ RSEQ_INJECT_ASM(5)
+#ifdef RSEQ_TEMPLATE_MO_RELEASE
+ "dbar 0x12\n\t" /* store-release */
+#endif
+ /* final store */
+ LONG_S " %[newv], %[v]\n\t"
+ "2:\n\t"
+ RSEQ_INJECT_ASM(6)
+ "b 5f\n\t"
+ RSEQ_ASM_DEFINE_ABORT(3, 4, "", abort, 1b, 2b, 4f)
+ "5:\n\t"
+ : /* gcc asm goto does not allow outputs */
+ : [cpu_id] "r" (cpu),
+ [current_cpu_id] "m" (rseq_get_abi()->RSEQ_TEMPLATE_CPU_ID_FIELD),
+ [rseq_cs] "m" (rseq_get_abi()->rseq_cs.arch.ptr),
+ /* try store input */
+ [v2] "m" (*v2),
+ [newv2] "r" (newv2),
+ /* final store input */
+ [v] "m" (*v),
+ [expect] "r" (expect),
+ [newv] "r" (newv)
+ RSEQ_INJECT_INPUT
+ : "$r4", "memory"
+ RSEQ_INJECT_CLOBBER
+ : abort, cmpfail
+#ifdef RSEQ_COMPARE_TWICE
+ , error1, error2
+#endif
+ );
+ return 0;
+abort:
+ RSEQ_INJECT_FAILED
+ return -1;
+cmpfail:
+ return 1;
+#ifdef RSEQ_COMPARE_TWICE
+error1:
+ rseq_bug("cpu_id comparison failed");
+error2:
+ rseq_bug("expected value comparison failed");
+#endif
+}
+
+static inline __attribute__((always_inline))
+int RSEQ_TEMPLATE_IDENTIFIER(rseq_cmpeqv_trymemcpy_storev)(intptr_t *v, intptr_t expect,
+ void *dst, void *src, size_t len,
+ intptr_t newv, int cpu)
+{
+ uintptr_t rseq_scratch[3];
+
+ RSEQ_INJECT_C(9)
+
+ __asm__ __volatile__ goto (
+ RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
+ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
+#ifdef RSEQ_COMPARE_TWICE
+ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
+ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
+#endif
+ LONG_S " %[src], %[rseq_scratch0]\n\t"
+ LONG_S " %[dst], %[rseq_scratch1]\n\t"
+ LONG_S " %[len], %[rseq_scratch2]\n\t"
+ /* Start rseq by storing table entry pointer into rseq_cs. */
+ RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs)
+ RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
+ RSEQ_INJECT_ASM(3)
+ LONG_L " $r4, %[v]\n\t"
+ "bne $r4, %[expect], 5f\n\t"
+ RSEQ_INJECT_ASM(4)
+#ifdef RSEQ_COMPARE_TWICE
+ RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 6f)
+ LONG_L " $r4, %[v]\n\t"
+ "bne $r4, %[expect], 7f\n\t"
+#endif
+ /* try memcpy */
+ "beqz %[len], 333f\n\t" \
+ "222:\n\t" \
+ "ld.b $r4, %[src], 0\n\t" \
+ "st.b $r4, %[dst], 0\n\t" \
+ LONG_ADDI " %[src], %[src], 1\n\t" \
+ LONG_ADDI " %[dst], %[dst], 1\n\t" \
+ LONG_ADDI " %[len], %[len], -1\n\t" \
+ "bnez %[len], 222b\n\t" \
+ "333:\n\t" \
+ RSEQ_INJECT_ASM(5)
+#ifdef RSEQ_TEMPLATE_MO_RELEASE
+ "dbar 0x12\n\t" /* store-release */
+#endif
+ /* final store */
+ LONG_S " %[newv], %[v]\n\t"
+ "2:\n\t"
+ RSEQ_INJECT_ASM(6)
+ /* teardown */
+ LONG_L " %[len], %[rseq_scratch2]\n\t"
+ LONG_L " %[dst], %[rseq_scratch1]\n\t"
+ LONG_L " %[src], %[rseq_scratch0]\n\t"
+ "b 8f\n\t"
+ RSEQ_ASM_DEFINE_ABORT(3, 4,
+ /* teardown */
+ LONG_L " %[len], %[rseq_scratch2]\n\t"
+ LONG_L " %[dst], %[rseq_scratch1]\n\t"
+ LONG_L " %[src], %[rseq_scratch0]\n\t",
+ abort, 1b, 2b, 4f)
+ RSEQ_ASM_DEFINE_CMPFAIL(5,
+ /* teardown */
+ LONG_L " %[len], %[rseq_scratch2]\n\t"
+ LONG_L " %[dst], %[rseq_scratch1]\n\t"
+ LONG_L " %[src], %[rseq_scratch0]\n\t",
+ cmpfail)
+#ifdef RSEQ_COMPARE_TWICE
+ RSEQ_ASM_DEFINE_CMPFAIL(6,
+ /* teardown */
+ LONG_L " %[len], %[rseq_scratch2]\n\t"
+ LONG_L " %[dst], %[rseq_scratch1]\n\t"
+ LONG_L " %[src], %[rseq_scratch0]\n\t",
+ error1)
+ RSEQ_ASM_DEFINE_CMPFAIL(7,
+ /* teardown */
+ LONG_L " %[len], %[rseq_scratch2]\n\t"
+ LONG_L " %[dst], %[rseq_scratch1]\n\t"
+ LONG_L " %[src], %[rseq_scratch0]\n\t",
+ error2)
+#endif
+ "8:\n\t"
+ : /* gcc asm goto does not allow outputs */
+ : [cpu_id] "r" (cpu),
+ [current_cpu_id] "m" (rseq_get_abi()->RSEQ_TEMPLATE_CPU_ID_FIELD),
+ [rseq_cs] "m" (rseq_get_abi()->rseq_cs.arch.ptr),
+ /* final store input */
+ [v] "m" (*v),
+ [expect] "r" (expect),
+ [newv] "r" (newv),
+ /* try memcpy input */
+ [dst] "r" (dst),
+ [src] "r" (src),
+ [len] "r" (len),
+ [rseq_scratch0] "m" (rseq_scratch[0]),
+ [rseq_scratch1] "m" (rseq_scratch[1]),
+ [rseq_scratch2] "m" (rseq_scratch[2])
+ RSEQ_INJECT_INPUT
+ : "$r4", "memory"
+ RSEQ_INJECT_CLOBBER
+ : abort, cmpfail
+#ifdef RSEQ_COMPARE_TWICE
+ , error1, error2
+#endif
+ );
+ return 0;
+abort:
+ RSEQ_INJECT_FAILED
+ return -1;
+cmpfail:
+ return 1;
+#ifdef RSEQ_COMPARE_TWICE
+error1:
+ rseq_bug("cpu_id comparison failed");
+error2:
+ rseq_bug("expected value comparison failed");
+#endif
+}
+
+#endif /* #if (defined(RSEQ_TEMPLATE_MO_RELAXED) || defined(RSEQ_TEMPLATE_MO_RELEASE)) &&
+ (defined(RSEQ_TEMPLATE_CPU_ID) || defined(RSEQ_TEMPLATE_MM_CID)) */
+
+#include "rseq-bits-reset.h"
diff --git a/tools/testing/selftests/rseq/rseq-loongarch-thread-pointer.h b/tools/testing/selftests/rseq/rseq-loongarch-thread-pointer.h
new file mode 100644
index 000000000000..7dc990687982
--- /dev/null
+++ b/tools/testing/selftests/rseq/rseq-loongarch-thread-pointer.h
@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: MIT */
+/* SPDX-FileCopyrightText: 2023 Huang Pei <[email protected]> */
+
+#ifndef _RSEQ_LOONGARCH_THREAD_POINTER
+#define _RSEQ_LOONGARCH_THREAD_POINTER
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+static inline void *rseq_thread_pointer(void)
+{
+ register void *__result asm ("$2");
+ asm ("" : "=r" (__result));
+ return __result;
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/tools/testing/selftests/rseq/rseq-loongarch.h b/tools/testing/selftests/rseq/rseq-loongarch.h
new file mode 100644
index 000000000000..37aae463edde
--- /dev/null
+++ b/tools/testing/selftests/rseq/rseq-loongarch.h
@@ -0,0 +1,140 @@
+/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
+/*
+ * Author: Huang Pei <[email protected]>
+ * (C) Copyright 2023 Loongson Technology Corporation Limited
+ * (C) Copyright 2016-2022 - Mathieu Desnoyers <[email protected]>
+ * (C) Copyright 2018 MIPS Tech LLC
+ * (C) Copyright 2018 - Paul Burton <[email protected]>
+ */
+
+/*
+ * RSEQ_SIG use "break 0x10" instruction.
+ */
+
+# define RSEQ_SIG 0x002a0010
+
+
+
+#define rseq_smp_mb() __asm__ __volatile__ ("dbar 0x10" ::: "memory")
+#define rseq_smp_rmb() __asm__ __volatile__ ("dbar 0x15" ::: "memory")
+#define rseq_smp_wmb() __asm__ __volatile__ ("dbar 0x1a" ::: "memory")
+
+#define rseq_smp_load_acquire(p) \
+__extension__ ({ \
+ rseq_unqual_scalar_typeof(*(p)) ____p1 = RSEQ_READ_ONCE(*(p)); \
+ __asm__ __volatile__("dbar 0x14" ::: "memory"); \
+ ____p1; \
+})
+
+#define rseq_smp_acquire__after_ctrl_dep() rseq_smp_rmb()
+
+#define rseq_smp_store_release(p, v) \
+do { \
+ __asm__ __volatile__("dbar 0x12" ::: "memory"); \
+ RSEQ_WRITE_ONCE(*(p), v); \
+} while (0)
+
+# define LONG ".dword"
+# define LONG_LA "la.local"
+# define LONG_L "ld.d"
+# define LONG_S "st.d"
+# define LONG_ADDI "addi.d"
+# define U32_U64_PAD(x) x
+
+#define __RSEQ_ASM_DEFINE_TABLE(label, version, flags, start_ip, \
+ post_commit_offset, abort_ip) \
+ ".pushsection __rseq_cs, \"aw\"\n\t" \
+ ".balign 32\n\t" \
+ __rseq_str(label) ":\n\t" \
+ ".word " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \
+ LONG " " U32_U64_PAD(__rseq_str(start_ip)) "\n\t" \
+ LONG " " U32_U64_PAD(__rseq_str(post_commit_offset)) "\n\t" \
+ LONG " " U32_U64_PAD(__rseq_str(abort_ip)) "\n\t" \
+ ".popsection\n\t" \
+ ".pushsection __rseq_cs_ptr_array, \"aw\"\n\t" \
+ LONG " " U32_U64_PAD(__rseq_str(label) "b") "\n\t" \
+ ".popsection\n\t"
+
+#define RSEQ_ASM_DEFINE_TABLE(label, start_ip, post_commit_ip, abort_ip) \
+ __RSEQ_ASM_DEFINE_TABLE(label, 0x0, 0x0, start_ip, \
+ (post_commit_ip - start_ip), abort_ip)
+/*
+ * Exit points of a rseq critical section consist of all instructions outside
+ * of the critical section where a critical section can either branch to or
+ * reach through the normal course of its execution. The abort IP and the
+ * post-commit IP are already part of the __rseq_cs section and should not be
+ * explicitly defined as additional exit points. Knowing all exit points is
+ * useful to assist debuggers stepping over the critical section.
+ */
+#define RSEQ_ASM_DEFINE_EXIT_POINT(start_ip, exit_ip) \
+ ".pushsection __rseq_exit_point_array, \"aw\"\n\t" \
+ LONG " " U32_U64_PAD(__rseq_str(start_ip)) "\n\t" \
+ LONG " " U32_U64_PAD(__rseq_str(exit_ip)) "\n\t" \
+ ".popsection\n\t"
+
+#define RSEQ_ASM_STORE_RSEQ_CS(label, cs_label, rseq_cs) \
+ RSEQ_INJECT_ASM(1) \
+ LONG_LA " $r4, " __rseq_str(cs_label) "\n\t" \
+ LONG_S " $r4, %[" __rseq_str(rseq_cs) "]\n\t" \
+ __rseq_str(label) ":\n\t"
+
+#define RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, label) \
+ RSEQ_INJECT_ASM(2) \
+ "ld.w $r4, %[" __rseq_str(current_cpu_id) "]\n\t" \
+ "bne $r4, %[" __rseq_str(cpu_id) "], " __rseq_str(label) "\n\t"
+
+#define __RSEQ_ASM_DEFINE_ABORT(table_label, label, teardown, \
+ abort_label, version, flags, \
+ start_ip, post_commit_offset, abort_ip) \
+ ".balign 32\n\t" \
+ __rseq_str(table_label) ":\n\t" \
+ ".word " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \
+ LONG " " U32_U64_PAD(__rseq_str(start_ip)) "\n\t" \
+ LONG " " U32_U64_PAD(__rseq_str(post_commit_offset)) "\n\t" \
+ LONG " " U32_U64_PAD(__rseq_str(abort_ip)) "\n\t" \
+ ".word " __rseq_str(RSEQ_SIG) "\n\t" \
+ __rseq_str(label) ":\n\t" \
+ teardown \
+ "b %l[" __rseq_str(abort_label) "]\n\t"
+
+#define RSEQ_ASM_DEFINE_ABORT(table_label, label, teardown, abort_label, \
+ start_ip, post_commit_ip, abort_ip) \
+ __RSEQ_ASM_DEFINE_ABORT(table_label, label, teardown, \
+ abort_label, 0x0, 0x0, start_ip, \
+ (post_commit_ip - start_ip), abort_ip)
+
+#define RSEQ_ASM_DEFINE_CMPFAIL(label, teardown, cmpfail_label) \
+ __rseq_str(label) ":\n\t" \
+ teardown \
+ "b %l[" __rseq_str(cmpfail_label) "]\n\t"
+
+/* Per-cpu-id indexing. */
+#define RSEQ_TEMPLATE_CPU_ID
+#define RSEQ_TEMPLATE_MO_RELAXED
+#include "rseq-loongarch-bits.h"
+#undef RSEQ_TEMPLATE_MO_RELAXED
+
+#define RSEQ_TEMPLATE_MO_RELEASE
+#include "rseq-loongarch-bits.h"
+#undef RSEQ_TEMPLATE_MO_RELEASE
+#undef RSEQ_TEMPLATE_CPU_ID
+
+/* Per-mm-cid indexing. */
+
+#define RSEQ_TEMPLATE_MM_CID
+#define RSEQ_TEMPLATE_MO_RELAXED
+#include "rseq-loongarch-bits.h"
+#undef RSEQ_TEMPLATE_MO_RELAXED
+
+#define RSEQ_TEMPLATE_MO_RELEASE
+#include "rseq-loongarch-bits.h"
+#undef RSEQ_TEMPLATE_MO_RELEASE
+#undef RSEQ_TEMPLATE_MM_CID
+
+/* APIs which are not based on cpu ids. */
+
+#define RSEQ_TEMPLATE_CPU_ID_NONE
+#define RSEQ_TEMPLATE_MO_RELAXED
+#include "rseq-loongarch-bits.h"
+#undef RSEQ_TEMPLATE_MO_RELAXED
+#undef RSEQ_TEMPLATE_CPU_ID_NONE
diff --git a/tools/testing/selftests/rseq/rseq-thread-pointer.h b/tools/testing/selftests/rseq/rseq-thread-pointer.h
index 977c25d758b2..b9c8fe7c4683 100644
--- a/tools/testing/selftests/rseq/rseq-thread-pointer.h
+++ b/tools/testing/selftests/rseq/rseq-thread-pointer.h
@@ -12,6 +12,8 @@
#include "rseq-x86-thread-pointer.h"
#elif defined(__PPC__)
#include "rseq-ppc-thread-pointer.h"
+#elif defined(__loongarch__)
+#include "rseq-loongarch-thread-pointer.h"
#else
#include "rseq-generic-thread-pointer.h"
#endif
diff --git a/tools/testing/selftests/rseq/rseq.h b/tools/testing/selftests/rseq/rseq.h
index d7364ea4d201..75c4bbe013d3 100644
--- a/tools/testing/selftests/rseq/rseq.h
+++ b/tools/testing/selftests/rseq/rseq.h
@@ -128,6 +128,8 @@ static inline struct rseq_abi *rseq_get_abi(void)
#include <rseq-s390.h>
#elif defined(__riscv)
#include <rseq-riscv.h>
+#elif defined(__loongarch__)
+#include <rseq-loongarch.h>
#else
#error unsupported target
#endif
--
2.20.1


2023-10-26 11:46:16

by Huang Pei

[permalink] [raw]
Subject: [PATCH 2/3] LoongArch: Add RSEQ_SIG break code definition

Signed-off-by: Huang Pei <[email protected]>
---
arch/loongarch/include/uapi/asm/break.h | 2 ++
1 file changed, 2 insertions(+)

diff --git a/arch/loongarch/include/uapi/asm/break.h b/arch/loongarch/include/uapi/asm/break.h
index bb9b82ba59f2..e0fcfc304834 100644
--- a/arch/loongarch/include/uapi/asm/break.h
+++ b/arch/loongarch/include/uapi/asm/break.h
@@ -20,4 +20,6 @@
#define BRK_UPROBE_BP 12 /* See <asm/uprobes.h> */
#define BRK_UPROBE_XOLBP 13 /* See <asm/uprobes.h> */

+#define BRK_RSEQ_SIG 16 /* See rseq */
+
#endif /* __UAPI_ASM_BREAK_H */
--
2.20.1

2023-10-26 12:08:19

by Huacai Chen

[permalink] [raw]
Subject: Re: [PATCH 1/3] selftests/rseq: Add 64bit LoongArch support

Hi,

1, The two patches should be marked as [1/2] and [2/2], not [1/3] and [2/3].
2, It is better to exchange the two patches' order.
3, Please add some commit messages, don't leave empty.

Huacai

On Thu, Oct 26, 2023 at 7:45 PM Huang Pei <[email protected]> wrote:
>
> Signed-off-by: Huang Pei <[email protected]>
> ---
> tools/testing/selftests/rseq/param_test.c | 20 +
> .../selftests/rseq/rseq-loongarch-bits.h | 463 ++++++++++++++++++
> .../rseq/rseq-loongarch-thread-pointer.h | 22 +
> tools/testing/selftests/rseq/rseq-loongarch.h | 140 ++++++
> .../selftests/rseq/rseq-thread-pointer.h | 2 +
> tools/testing/selftests/rseq/rseq.h | 2 +
> 6 files changed, 649 insertions(+)
> create mode 100644 tools/testing/selftests/rseq/rseq-loongarch-bits.h
> create mode 100644 tools/testing/selftests/rseq/rseq-loongarch-thread-pointer.h
> create mode 100644 tools/testing/selftests/rseq/rseq-loongarch.h
>
> diff --git a/tools/testing/selftests/rseq/param_test.c b/tools/testing/selftests/rseq/param_test.c
> index bf951a490bb4..e930aa73c219 100644
> --- a/tools/testing/selftests/rseq/param_test.c
> +++ b/tools/testing/selftests/rseq/param_test.c
> @@ -227,7 +227,27 @@ unsigned int yield_mod_cnt, nr_abort;
> "bnez " INJECT_ASM_REG ", 222b\n\t" \
> "333:\n\t"
>
> +#elif defined(__loongarch__)
> +#define RSEQ_INJECT_INPUT \
> + , [loop_cnt_1]"m"(loop_cnt[1]) \
> + , [loop_cnt_2]"m"(loop_cnt[2]) \
> + , [loop_cnt_3]"m"(loop_cnt[3]) \
> + , [loop_cnt_4]"m"(loop_cnt[4]) \
> + , [loop_cnt_5]"m"(loop_cnt[5]) \
> + , [loop_cnt_6]"m"(loop_cnt[6])
> +
> +#define INJECT_ASM_REG "$r12"
> +
> +#define RSEQ_INJECT_CLOBBER \
> + , INJECT_ASM_REG
>
> +#define RSEQ_INJECT_ASM(n) \
> + "ld.w " INJECT_ASM_REG ", %[loop_cnt_" #n "]\n\t" \
> + "beqz " INJECT_ASM_REG ", 333f\n\t" \
> + "222:\n\t" \
> + "addi.w " INJECT_ASM_REG "," INJECT_ASM_REG ", -1\n\t" \
> + "bnez " INJECT_ASM_REG ", 222b\n\t" \
> + "333:\n\t"
> #else
> #error unsupported target
> #endif
> diff --git a/tools/testing/selftests/rseq/rseq-loongarch-bits.h b/tools/testing/selftests/rseq/rseq-loongarch-bits.h
> new file mode 100644
> index 000000000000..cf933c1a2100
> --- /dev/null
> +++ b/tools/testing/selftests/rseq/rseq-loongarch-bits.h
> @@ -0,0 +1,463 @@
> +/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
> +/*
> + * Author: Huang Pei <[email protected]>
> + * (C) Copyright 2023 Loongson Technology Corporation Limited
> + * (C) Copyright 2016-2022 - Mathieu Desnoyers <[email protected]>
> + * (C) Copyright 2018 MIPS Tech LLC
> + * (C) Copyright 2018 - Paul Burton <[email protected]>
> + */
> +#include "rseq-bits-template.h"
> +
> +#if defined(RSEQ_TEMPLATE_MO_RELAXED) && \
> + (defined(RSEQ_TEMPLATE_CPU_ID) || defined(RSEQ_TEMPLATE_MM_CID))
> +
> +static inline __attribute__((always_inline))
> +int RSEQ_TEMPLATE_IDENTIFIER(rseq_cmpeqv_storev)(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
> +{
> + RSEQ_INJECT_C(9)
> +
> + __asm__ __volatile__ goto (
> + RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
> + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
> +#ifdef RSEQ_COMPARE_TWICE
> + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
> + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
> +#endif
> + /* Start rseq by storing table entry pointer into rseq_cs. */
> + RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs)
> + RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
> + RSEQ_INJECT_ASM(3)
> + LONG_L " $r4, %[v]\n\t"
> + "bne $r4, %[expect], %l[cmpfail]\n\t"
> + RSEQ_INJECT_ASM(4)
> +#ifdef RSEQ_COMPARE_TWICE
> + RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1])
> + LONG_L " $r4, %[v]\n\t"
> + "bne $r4, %[expect], %l[error2]\n\t"
> +#endif
> + /* final store */
> + LONG_S " %[newv], %[v]\n\t"
> + "2:\n\t"
> + RSEQ_INJECT_ASM(5)
> + "b 5f\n\t"
> + RSEQ_ASM_DEFINE_ABORT(3, 4, "", abort, 1b, 2b, 4f)
> + "5:\n\t"
> + : /* gcc asm goto does not allow outputs */
> + : [cpu_id] "r" (cpu),
> + [current_cpu_id] "m" (rseq_get_abi()->RSEQ_TEMPLATE_CPU_ID_FIELD),
> + [rseq_cs] "m" (rseq_get_abi()->rseq_cs.arch.ptr),
> + [v] "m" (*v),
> + [expect] "r" (expect),
> + [newv] "r" (newv)
> + RSEQ_INJECT_INPUT
> + : "$r4", "memory"
> + RSEQ_INJECT_CLOBBER
> + : abort, cmpfail
> +#ifdef RSEQ_COMPARE_TWICE
> + , error1, error2
> +#endif
> + );
> + return 0;
> +abort:
> + RSEQ_INJECT_FAILED
> + return -1;
> +cmpfail:
> + return 1;
> +#ifdef RSEQ_COMPARE_TWICE
> +error1:
> + rseq_bug("cpu_id comparison failed");
> +error2:
> + rseq_bug("expected value comparison failed");
> +#endif
> +}
> +
> +static inline __attribute__((always_inline))
> +int RSEQ_TEMPLATE_IDENTIFIER(rseq_cmpnev_storeoffp_load)(intptr_t *v, intptr_t expectnot,
> + long voffp, intptr_t *load, int cpu)
> +{
> + RSEQ_INJECT_C(9)
> +
> + __asm__ __volatile__ goto (
> + RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
> + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
> +#ifdef RSEQ_COMPARE_TWICE
> + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
> + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
> +#endif
> + /* Start rseq by storing table entry pointer into rseq_cs. */
> + RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs)
> + RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
> + RSEQ_INJECT_ASM(3)
> + LONG_L " $r4, %[v]\n\t"
> + "beq $r4, %[expectnot], %l[cmpfail]\n\t"
> + RSEQ_INJECT_ASM(4)
> +#ifdef RSEQ_COMPARE_TWICE
> + RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1])
> + LONG_L " $r4, %[v]\n\t"
> + "beq $r4, %[expectnot], %l[error2]\n\t"
> +#endif
> + LONG_S " $r4, %[load]\n\t"
> + LONG_ADDI " $r4, $r4, %[voffp]\n\t"
> + LONG_L " $r4, $r4, 0\n\t"
> + /* final store */
> + LONG_S " $r4, %[v]\n\t"
> + "2:\n\t"
> + RSEQ_INJECT_ASM(5)
> + "b 5f\n\t"
> + RSEQ_ASM_DEFINE_ABORT(3, 4, "", abort, 1b, 2b, 4f)
> + "5:\n\t"
> + : /* gcc asm goto does not allow outputs */
> + : [cpu_id] "r" (cpu),
> + [current_cpu_id] "m" (rseq_get_abi()->RSEQ_TEMPLATE_CPU_ID_FIELD),
> + [rseq_cs] "m" (rseq_get_abi()->rseq_cs.arch.ptr),
> + /* final store input */
> + [v] "m" (*v),
> + [expectnot] "r" (expectnot),
> + [voffp] "Ir" (voffp),
> + [load] "m" (*load)
> + RSEQ_INJECT_INPUT
> + : "$r4", "memory"
> + RSEQ_INJECT_CLOBBER
> + : abort, cmpfail
> +#ifdef RSEQ_COMPARE_TWICE
> + , error1, error2
> +#endif
> + );
> + return 0;
> +abort:
> + RSEQ_INJECT_FAILED
> + return -1;
> +cmpfail:
> + return 1;
> +#ifdef RSEQ_COMPARE_TWICE
> +error1:
> + rseq_bug("cpu_id comparison failed");
> +error2:
> + rseq_bug("expected value comparison failed");
> +#endif
> +}
> +
> +static inline __attribute__((always_inline))
> +int RSEQ_TEMPLATE_IDENTIFIER(rseq_addv)(intptr_t *v, intptr_t count, int cpu)
> +{
> + RSEQ_INJECT_C(9)
> +
> + __asm__ __volatile__ goto (
> + RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
> +#ifdef RSEQ_COMPARE_TWICE
> + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
> +#endif
> + /* Start rseq by storing table entry pointer into rseq_cs. */
> + RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs)
> + RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
> + RSEQ_INJECT_ASM(3)
> +#ifdef RSEQ_COMPARE_TWICE
> + RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1])
> +#endif
> + LONG_L " $r4, %[v]\n\t"
> + LONG_ADDI " $r4, $r4, %[count]\n\t"
> + /* final store */
> + LONG_S " $r4, %[v]\n\t"
> + "2:\n\t"
> + RSEQ_INJECT_ASM(4)
> + "b 5f\n\t"
> + RSEQ_ASM_DEFINE_ABORT(3, 4, "", abort, 1b, 2b, 4f)
> + "5:\n\t"
> + : /* gcc asm goto does not allow outputs */
> + : [cpu_id] "r" (cpu),
> + [current_cpu_id] "m" (rseq_get_abi()->RSEQ_TEMPLATE_CPU_ID_FIELD),
> + [rseq_cs] "m" (rseq_get_abi()->rseq_cs.arch.ptr),
> + [v] "m" (*v),
> + [count] "Ir" (count)
> + RSEQ_INJECT_INPUT
> + : "$r4", "memory"
> + RSEQ_INJECT_CLOBBER
> + : abort
> +#ifdef RSEQ_COMPARE_TWICE
> + , error1
> +#endif
> + );
> + return 0;
> +abort:
> + RSEQ_INJECT_FAILED
> + return -1;
> +#ifdef RSEQ_COMPARE_TWICE
> +error1:
> + rseq_bug("cpu_id comparison failed");
> +#endif
> +}
> +
> +static inline __attribute__((always_inline))
> +int RSEQ_TEMPLATE_IDENTIFIER(rseq_cmpeqv_cmpeqv_storev)(intptr_t *v, intptr_t expect,
> + intptr_t *v2, intptr_t expect2,
> + intptr_t newv, int cpu)
> +{
> + RSEQ_INJECT_C(9)
> +
> + __asm__ __volatile__ goto (
> + RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
> + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
> +#ifdef RSEQ_COMPARE_TWICE
> + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
> + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
> + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error3])
> +#endif
> + /* Start rseq by storing table entry pointer into rseq_cs. */
> + RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs)
> + RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
> + RSEQ_INJECT_ASM(3)
> + LONG_L " $r4, %[v]\n\t"
> + "bne $r4, %[expect], %l[cmpfail]\n\t"
> + RSEQ_INJECT_ASM(4)
> + LONG_L " $r4, %[v2]\n\t"
> + "bne $r4, %[expect2], %l[cmpfail]\n\t"
> + RSEQ_INJECT_ASM(5)
> +#ifdef RSEQ_COMPARE_TWICE
> + RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1])
> + LONG_L " $r4, %[v]\n\t"
> + "bne $r4, %[expect], %l[error2]\n\t"
> + LONG_L " $r4, %[v2]\n\t"
> + "bne $r4, %[expect2], %l[error3]\n\t"
> +#endif
> + /* final store */
> + LONG_S " %[newv], %[v]\n\t"
> + "2:\n\t"
> + RSEQ_INJECT_ASM(6)
> + "b 5f\n\t"
> + RSEQ_ASM_DEFINE_ABORT(3, 4, "", abort, 1b, 2b, 4f)
> + "5:\n\t"
> + : /* gcc asm goto does not allow outputs */
> + : [cpu_id] "r" (cpu),
> + [current_cpu_id] "m" (rseq_get_abi()->RSEQ_TEMPLATE_CPU_ID_FIELD),
> + [rseq_cs] "m" (rseq_get_abi()->rseq_cs.arch.ptr),
> + /* cmp2 input */
> + [v2] "m" (*v2),
> + [expect2] "r" (expect2),
> + /* final store input */
> + [v] "m" (*v),
> + [expect] "r" (expect),
> + [newv] "r" (newv)
> + RSEQ_INJECT_INPUT
> + : "$r4", "memory"
> + RSEQ_INJECT_CLOBBER
> + : abort, cmpfail
> +#ifdef RSEQ_COMPARE_TWICE
> + , error1, error2, error3
> +#endif
> + );
> + return 0;
> +abort:
> + RSEQ_INJECT_FAILED
> + return -1;
> +cmpfail:
> + return 1;
> +#ifdef RSEQ_COMPARE_TWICE
> +error1:
> + rseq_bug("cpu_id comparison failed");
> +error2:
> + rseq_bug("1st expected value comparison failed");
> +error3:
> + rseq_bug("2nd expected value comparison failed");
> +#endif
> +}
> +
> +#endif /* #if defined(RSEQ_TEMPLATE_MO_RELAXED) &&
> + (defined(RSEQ_TEMPLATE_CPU_ID) || defined(RSEQ_TEMPLATE_MM_CID)) */
> +
> +#if (defined(RSEQ_TEMPLATE_MO_RELAXED) || defined(RSEQ_TEMPLATE_MO_RELEASE)) && \
> + (defined(RSEQ_TEMPLATE_CPU_ID) || defined(RSEQ_TEMPLATE_MM_CID))
> +
> +static inline __attribute__((always_inline))
> +int RSEQ_TEMPLATE_IDENTIFIER(rseq_cmpeqv_trystorev_storev)(intptr_t *v, intptr_t expect,
> + intptr_t *v2, intptr_t newv2,
> + intptr_t newv, int cpu)
> +{
> + RSEQ_INJECT_C(9)
> +
> + __asm__ __volatile__ goto (
> + RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
> + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
> +#ifdef RSEQ_COMPARE_TWICE
> + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
> + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
> +#endif
> + /* Start rseq by storing table entry pointer into rseq_cs. */
> + RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs)
> + RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
> + RSEQ_INJECT_ASM(3)
> + LONG_L " $r4, %[v]\n\t"
> + "bne $r4, %[expect], %l[cmpfail]\n\t"
> + RSEQ_INJECT_ASM(4)
> +#ifdef RSEQ_COMPARE_TWICE
> + RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1])
> + LONG_L " $r4, %[v]\n\t"
> + "bne $r4, %[expect], %l[error2]\n\t"
> +#endif
> + /* try store */
> + LONG_S " %[newv2], %[v2]\n\t"
> + RSEQ_INJECT_ASM(5)
> +#ifdef RSEQ_TEMPLATE_MO_RELEASE
> + "dbar 0x12\n\t" /* store-release */
> +#endif
> + /* final store */
> + LONG_S " %[newv], %[v]\n\t"
> + "2:\n\t"
> + RSEQ_INJECT_ASM(6)
> + "b 5f\n\t"
> + RSEQ_ASM_DEFINE_ABORT(3, 4, "", abort, 1b, 2b, 4f)
> + "5:\n\t"
> + : /* gcc asm goto does not allow outputs */
> + : [cpu_id] "r" (cpu),
> + [current_cpu_id] "m" (rseq_get_abi()->RSEQ_TEMPLATE_CPU_ID_FIELD),
> + [rseq_cs] "m" (rseq_get_abi()->rseq_cs.arch.ptr),
> + /* try store input */
> + [v2] "m" (*v2),
> + [newv2] "r" (newv2),
> + /* final store input */
> + [v] "m" (*v),
> + [expect] "r" (expect),
> + [newv] "r" (newv)
> + RSEQ_INJECT_INPUT
> + : "$r4", "memory"
> + RSEQ_INJECT_CLOBBER
> + : abort, cmpfail
> +#ifdef RSEQ_COMPARE_TWICE
> + , error1, error2
> +#endif
> + );
> + return 0;
> +abort:
> + RSEQ_INJECT_FAILED
> + return -1;
> +cmpfail:
> + return 1;
> +#ifdef RSEQ_COMPARE_TWICE
> +error1:
> + rseq_bug("cpu_id comparison failed");
> +error2:
> + rseq_bug("expected value comparison failed");
> +#endif
> +}
> +
> +static inline __attribute__((always_inline))
> +int RSEQ_TEMPLATE_IDENTIFIER(rseq_cmpeqv_trymemcpy_storev)(intptr_t *v, intptr_t expect,
> + void *dst, void *src, size_t len,
> + intptr_t newv, int cpu)
> +{
> + uintptr_t rseq_scratch[3];
> +
> + RSEQ_INJECT_C(9)
> +
> + __asm__ __volatile__ goto (
> + RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
> + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
> +#ifdef RSEQ_COMPARE_TWICE
> + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
> + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
> +#endif
> + LONG_S " %[src], %[rseq_scratch0]\n\t"
> + LONG_S " %[dst], %[rseq_scratch1]\n\t"
> + LONG_S " %[len], %[rseq_scratch2]\n\t"
> + /* Start rseq by storing table entry pointer into rseq_cs. */
> + RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs)
> + RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
> + RSEQ_INJECT_ASM(3)
> + LONG_L " $r4, %[v]\n\t"
> + "bne $r4, %[expect], 5f\n\t"
> + RSEQ_INJECT_ASM(4)
> +#ifdef RSEQ_COMPARE_TWICE
> + RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 6f)
> + LONG_L " $r4, %[v]\n\t"
> + "bne $r4, %[expect], 7f\n\t"
> +#endif
> + /* try memcpy */
> + "beqz %[len], 333f\n\t" \
> + "222:\n\t" \
> + "ld.b $r4, %[src], 0\n\t" \
> + "st.b $r4, %[dst], 0\n\t" \
> + LONG_ADDI " %[src], %[src], 1\n\t" \
> + LONG_ADDI " %[dst], %[dst], 1\n\t" \
> + LONG_ADDI " %[len], %[len], -1\n\t" \
> + "bnez %[len], 222b\n\t" \
> + "333:\n\t" \
> + RSEQ_INJECT_ASM(5)
> +#ifdef RSEQ_TEMPLATE_MO_RELEASE
> + "dbar 0x12\n\t" /* store-release */
> +#endif
> + /* final store */
> + LONG_S " %[newv], %[v]\n\t"
> + "2:\n\t"
> + RSEQ_INJECT_ASM(6)
> + /* teardown */
> + LONG_L " %[len], %[rseq_scratch2]\n\t"
> + LONG_L " %[dst], %[rseq_scratch1]\n\t"
> + LONG_L " %[src], %[rseq_scratch0]\n\t"
> + "b 8f\n\t"
> + RSEQ_ASM_DEFINE_ABORT(3, 4,
> + /* teardown */
> + LONG_L " %[len], %[rseq_scratch2]\n\t"
> + LONG_L " %[dst], %[rseq_scratch1]\n\t"
> + LONG_L " %[src], %[rseq_scratch0]\n\t",
> + abort, 1b, 2b, 4f)
> + RSEQ_ASM_DEFINE_CMPFAIL(5,
> + /* teardown */
> + LONG_L " %[len], %[rseq_scratch2]\n\t"
> + LONG_L " %[dst], %[rseq_scratch1]\n\t"
> + LONG_L " %[src], %[rseq_scratch0]\n\t",
> + cmpfail)
> +#ifdef RSEQ_COMPARE_TWICE
> + RSEQ_ASM_DEFINE_CMPFAIL(6,
> + /* teardown */
> + LONG_L " %[len], %[rseq_scratch2]\n\t"
> + LONG_L " %[dst], %[rseq_scratch1]\n\t"
> + LONG_L " %[src], %[rseq_scratch0]\n\t",
> + error1)
> + RSEQ_ASM_DEFINE_CMPFAIL(7,
> + /* teardown */
> + LONG_L " %[len], %[rseq_scratch2]\n\t"
> + LONG_L " %[dst], %[rseq_scratch1]\n\t"
> + LONG_L " %[src], %[rseq_scratch0]\n\t",
> + error2)
> +#endif
> + "8:\n\t"
> + : /* gcc asm goto does not allow outputs */
> + : [cpu_id] "r" (cpu),
> + [current_cpu_id] "m" (rseq_get_abi()->RSEQ_TEMPLATE_CPU_ID_FIELD),
> + [rseq_cs] "m" (rseq_get_abi()->rseq_cs.arch.ptr),
> + /* final store input */
> + [v] "m" (*v),
> + [expect] "r" (expect),
> + [newv] "r" (newv),
> + /* try memcpy input */
> + [dst] "r" (dst),
> + [src] "r" (src),
> + [len] "r" (len),
> + [rseq_scratch0] "m" (rseq_scratch[0]),
> + [rseq_scratch1] "m" (rseq_scratch[1]),
> + [rseq_scratch2] "m" (rseq_scratch[2])
> + RSEQ_INJECT_INPUT
> + : "$r4", "memory"
> + RSEQ_INJECT_CLOBBER
> + : abort, cmpfail
> +#ifdef RSEQ_COMPARE_TWICE
> + , error1, error2
> +#endif
> + );
> + return 0;
> +abort:
> + RSEQ_INJECT_FAILED
> + return -1;
> +cmpfail:
> + return 1;
> +#ifdef RSEQ_COMPARE_TWICE
> +error1:
> + rseq_bug("cpu_id comparison failed");
> +error2:
> + rseq_bug("expected value comparison failed");
> +#endif
> +}
> +
> +#endif /* #if (defined(RSEQ_TEMPLATE_MO_RELAXED) || defined(RSEQ_TEMPLATE_MO_RELEASE)) &&
> + (defined(RSEQ_TEMPLATE_CPU_ID) || defined(RSEQ_TEMPLATE_MM_CID)) */
> +
> +#include "rseq-bits-reset.h"
> diff --git a/tools/testing/selftests/rseq/rseq-loongarch-thread-pointer.h b/tools/testing/selftests/rseq/rseq-loongarch-thread-pointer.h
> new file mode 100644
> index 000000000000..7dc990687982
> --- /dev/null
> +++ b/tools/testing/selftests/rseq/rseq-loongarch-thread-pointer.h
> @@ -0,0 +1,22 @@
> +/* SPDX-License-Identifier: MIT */
> +/* SPDX-FileCopyrightText: 2023 Huang Pei <[email protected]> */
> +
> +#ifndef _RSEQ_LOONGARCH_THREAD_POINTER
> +#define _RSEQ_LOONGARCH_THREAD_POINTER
> +
> +#ifdef __cplusplus
> +extern "C" {
> +#endif
> +
> +static inline void *rseq_thread_pointer(void)
> +{
> + register void *__result asm ("$2");
> + asm ("" : "=r" (__result));
> + return __result;
> +}
> +
> +#ifdef __cplusplus
> +}
> +#endif
> +
> +#endif
> diff --git a/tools/testing/selftests/rseq/rseq-loongarch.h b/tools/testing/selftests/rseq/rseq-loongarch.h
> new file mode 100644
> index 000000000000..37aae463edde
> --- /dev/null
> +++ b/tools/testing/selftests/rseq/rseq-loongarch.h
> @@ -0,0 +1,140 @@
> +/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
> +/*
> + * Author: Huang Pei <[email protected]>
> + * (C) Copyright 2023 Loongson Technology Corporation Limited
> + * (C) Copyright 2016-2022 - Mathieu Desnoyers <[email protected]>
> + * (C) Copyright 2018 MIPS Tech LLC
> + * (C) Copyright 2018 - Paul Burton <[email protected]>
> + */
> +
> +/*
> + * RSEQ_SIG use "break 0x10" instruction.
> + */
> +
> +# define RSEQ_SIG 0x002a0010
> +
> +
> +
> +#define rseq_smp_mb() __asm__ __volatile__ ("dbar 0x10" ::: "memory")
> +#define rseq_smp_rmb() __asm__ __volatile__ ("dbar 0x15" ::: "memory")
> +#define rseq_smp_wmb() __asm__ __volatile__ ("dbar 0x1a" ::: "memory")
> +
> +#define rseq_smp_load_acquire(p) \
> +__extension__ ({ \
> + rseq_unqual_scalar_typeof(*(p)) ____p1 = RSEQ_READ_ONCE(*(p)); \
> + __asm__ __volatile__("dbar 0x14" ::: "memory"); \
> + ____p1; \
> +})
> +
> +#define rseq_smp_acquire__after_ctrl_dep() rseq_smp_rmb()
> +
> +#define rseq_smp_store_release(p, v) \
> +do { \
> + __asm__ __volatile__("dbar 0x12" ::: "memory"); \
> + RSEQ_WRITE_ONCE(*(p), v); \
> +} while (0)
> +
> +# define LONG ".dword"
> +# define LONG_LA "la.local"
> +# define LONG_L "ld.d"
> +# define LONG_S "st.d"
> +# define LONG_ADDI "addi.d"
> +# define U32_U64_PAD(x) x
> +
> +#define __RSEQ_ASM_DEFINE_TABLE(label, version, flags, start_ip, \
> + post_commit_offset, abort_ip) \
> + ".pushsection __rseq_cs, \"aw\"\n\t" \
> + ".balign 32\n\t" \
> + __rseq_str(label) ":\n\t" \
> + ".word " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \
> + LONG " " U32_U64_PAD(__rseq_str(start_ip)) "\n\t" \
> + LONG " " U32_U64_PAD(__rseq_str(post_commit_offset)) "\n\t" \
> + LONG " " U32_U64_PAD(__rseq_str(abort_ip)) "\n\t" \
> + ".popsection\n\t" \
> + ".pushsection __rseq_cs_ptr_array, \"aw\"\n\t" \
> + LONG " " U32_U64_PAD(__rseq_str(label) "b") "\n\t" \
> + ".popsection\n\t"
> +
> +#define RSEQ_ASM_DEFINE_TABLE(label, start_ip, post_commit_ip, abort_ip) \
> + __RSEQ_ASM_DEFINE_TABLE(label, 0x0, 0x0, start_ip, \
> + (post_commit_ip - start_ip), abort_ip)
> +/*
> + * Exit points of a rseq critical section consist of all instructions outside
> + * of the critical section where a critical section can either branch to or
> + * reach through the normal course of its execution. The abort IP and the
> + * post-commit IP are already part of the __rseq_cs section and should not be
> + * explicitly defined as additional exit points. Knowing all exit points is
> + * useful to assist debuggers stepping over the critical section.
> + */
> +#define RSEQ_ASM_DEFINE_EXIT_POINT(start_ip, exit_ip) \
> + ".pushsection __rseq_exit_point_array, \"aw\"\n\t" \
> + LONG " " U32_U64_PAD(__rseq_str(start_ip)) "\n\t" \
> + LONG " " U32_U64_PAD(__rseq_str(exit_ip)) "\n\t" \
> + ".popsection\n\t"
> +
> +#define RSEQ_ASM_STORE_RSEQ_CS(label, cs_label, rseq_cs) \
> + RSEQ_INJECT_ASM(1) \
> + LONG_LA " $r4, " __rseq_str(cs_label) "\n\t" \
> + LONG_S " $r4, %[" __rseq_str(rseq_cs) "]\n\t" \
> + __rseq_str(label) ":\n\t"
> +
> +#define RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, label) \
> + RSEQ_INJECT_ASM(2) \
> + "ld.w $r4, %[" __rseq_str(current_cpu_id) "]\n\t" \
> + "bne $r4, %[" __rseq_str(cpu_id) "], " __rseq_str(label) "\n\t"
> +
> +#define __RSEQ_ASM_DEFINE_ABORT(table_label, label, teardown, \
> + abort_label, version, flags, \
> + start_ip, post_commit_offset, abort_ip) \
> + ".balign 32\n\t" \
> + __rseq_str(table_label) ":\n\t" \
> + ".word " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \
> + LONG " " U32_U64_PAD(__rseq_str(start_ip)) "\n\t" \
> + LONG " " U32_U64_PAD(__rseq_str(post_commit_offset)) "\n\t" \
> + LONG " " U32_U64_PAD(__rseq_str(abort_ip)) "\n\t" \
> + ".word " __rseq_str(RSEQ_SIG) "\n\t" \
> + __rseq_str(label) ":\n\t" \
> + teardown \
> + "b %l[" __rseq_str(abort_label) "]\n\t"
> +
> +#define RSEQ_ASM_DEFINE_ABORT(table_label, label, teardown, abort_label, \
> + start_ip, post_commit_ip, abort_ip) \
> + __RSEQ_ASM_DEFINE_ABORT(table_label, label, teardown, \
> + abort_label, 0x0, 0x0, start_ip, \
> + (post_commit_ip - start_ip), abort_ip)
> +
> +#define RSEQ_ASM_DEFINE_CMPFAIL(label, teardown, cmpfail_label) \
> + __rseq_str(label) ":\n\t" \
> + teardown \
> + "b %l[" __rseq_str(cmpfail_label) "]\n\t"
> +
> +/* Per-cpu-id indexing. */
> +#define RSEQ_TEMPLATE_CPU_ID
> +#define RSEQ_TEMPLATE_MO_RELAXED
> +#include "rseq-loongarch-bits.h"
> +#undef RSEQ_TEMPLATE_MO_RELAXED
> +
> +#define RSEQ_TEMPLATE_MO_RELEASE
> +#include "rseq-loongarch-bits.h"
> +#undef RSEQ_TEMPLATE_MO_RELEASE
> +#undef RSEQ_TEMPLATE_CPU_ID
> +
> +/* Per-mm-cid indexing. */
> +
> +#define RSEQ_TEMPLATE_MM_CID
> +#define RSEQ_TEMPLATE_MO_RELAXED
> +#include "rseq-loongarch-bits.h"
> +#undef RSEQ_TEMPLATE_MO_RELAXED
> +
> +#define RSEQ_TEMPLATE_MO_RELEASE
> +#include "rseq-loongarch-bits.h"
> +#undef RSEQ_TEMPLATE_MO_RELEASE
> +#undef RSEQ_TEMPLATE_MM_CID
> +
> +/* APIs which are not based on cpu ids. */
> +
> +#define RSEQ_TEMPLATE_CPU_ID_NONE
> +#define RSEQ_TEMPLATE_MO_RELAXED
> +#include "rseq-loongarch-bits.h"
> +#undef RSEQ_TEMPLATE_MO_RELAXED
> +#undef RSEQ_TEMPLATE_CPU_ID_NONE
> diff --git a/tools/testing/selftests/rseq/rseq-thread-pointer.h b/tools/testing/selftests/rseq/rseq-thread-pointer.h
> index 977c25d758b2..b9c8fe7c4683 100644
> --- a/tools/testing/selftests/rseq/rseq-thread-pointer.h
> +++ b/tools/testing/selftests/rseq/rseq-thread-pointer.h
> @@ -12,6 +12,8 @@
> #include "rseq-x86-thread-pointer.h"
> #elif defined(__PPC__)
> #include "rseq-ppc-thread-pointer.h"
> +#elif defined(__loongarch__)
> +#include "rseq-loongarch-thread-pointer.h"
> #else
> #include "rseq-generic-thread-pointer.h"
> #endif
> diff --git a/tools/testing/selftests/rseq/rseq.h b/tools/testing/selftests/rseq/rseq.h
> index d7364ea4d201..75c4bbe013d3 100644
> --- a/tools/testing/selftests/rseq/rseq.h
> +++ b/tools/testing/selftests/rseq/rseq.h
> @@ -128,6 +128,8 @@ static inline struct rseq_abi *rseq_get_abi(void)
> #include <rseq-s390.h>
> #elif defined(__riscv)
> #include <rseq-riscv.h>
> +#elif defined(__loongarch__)
> +#include <rseq-loongarch.h>
> #else
> #error unsupported target
> #endif
> --
> 2.20.1
>
>

2023-10-26 18:07:32

by Mathieu Desnoyers

[permalink] [raw]
Subject: Re: [PATCH 2/3] LoongArch: Add RSEQ_SIG break code definition

On 2023-10-26 07:44, Huang Pei wrote:
> Signed-off-by: Huang Pei <[email protected]>
> ---
> arch/loongarch/include/uapi/asm/break.h | 2 ++

Why is this part of the uapi ? None of the other architecture has this
as part of uapi. It's only defined in the rseq selftest arch-specific
header file.

Thanks,

Mathieu

> 1 file changed, 2 insertions(+)
>
> diff --git a/arch/loongarch/include/uapi/asm/break.h b/arch/loongarch/include/uapi/asm/break.h
> index bb9b82ba59f2..e0fcfc304834 100644
> --- a/arch/loongarch/include/uapi/asm/break.h
> +++ b/arch/loongarch/include/uapi/asm/break.h
> @@ -20,4 +20,6 @@
> #define BRK_UPROBE_BP 12 /* See <asm/uprobes.h> */
> #define BRK_UPROBE_XOLBP 13 /* See <asm/uprobes.h> */
>
> +#define BRK_RSEQ_SIG 16 /* See rseq */
> +
> #endif /* __UAPI_ASM_BREAK_H */

--
Mathieu Desnoyers
EfficiOS Inc.
https://www.efficios.com

2023-10-27 01:41:49

by Huacai Chen

[permalink] [raw]
Subject: Re: [PATCH 2/3] LoongArch: Add RSEQ_SIG break code definition

Hi, Mathieu,

On Fri, Oct 27, 2023 at 2:16 AM Mathieu Desnoyers
<[email protected]> wrote:
>
> On 2023-10-26 07:44, Huang Pei wrote:
> > Signed-off-by: Huang Pei <[email protected]>
> > ---
> > arch/loongarch/include/uapi/asm/break.h | 2 ++
>
> Why is this part of the uapi ? None of the other architecture has this
> as part of uapi. It's only defined in the rseq selftest arch-specific
> header file.
From my point of view, it makes sense to list the dedicated break code
in UAPI. It is harmless and can avoid potential conflict in future.

Huacai

>
> Thanks,
>
> Mathieu
>
> > 1 file changed, 2 insertions(+)
> >
> > diff --git a/arch/loongarch/include/uapi/asm/break.h b/arch/loongarch/include/uapi/asm/break.h
> > index bb9b82ba59f2..e0fcfc304834 100644
> > --- a/arch/loongarch/include/uapi/asm/break.h
> > +++ b/arch/loongarch/include/uapi/asm/break.h
> > @@ -20,4 +20,6 @@
> > #define BRK_UPROBE_BP 12 /* See <asm/uprobes.h> */
> > #define BRK_UPROBE_XOLBP 13 /* See <asm/uprobes.h> */
> >
> > +#define BRK_RSEQ_SIG 16 /* See rseq */
> > +
> > #endif /* __UAPI_ASM_BREAK_H */
>
> --
> Mathieu Desnoyers
> EfficiOS Inc.
> https://www.efficios.com
>
>