From 611e385087efc2cc3a7033aedd3f84ad0cf2a703 Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Tue, 28 Jun 2022 00:02:36 +1000 Subject: selftests/powerpc/ptrace: Do more of ptrace-gpr in asm The ptrace-gpr test includes some inline asm to load GPR and FPR registers. It then goes back to C to wait for the parent to trace it and then checks register contents. The split between inline asm and C is fragile, it relies on the compiler not using any non-volatile GPRs after the inline asm block. It also requires a very large and unwieldy inline asm block. So convert the logic to set registers, wait, and store registers to a single asm function, meaning there's no window for the compiler to intervene. Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220627140239.2464900-10-mpe@ellerman.id.au --- .../testing/selftests/powerpc/include/basic_asm.h | 8 ++++ tools/testing/selftests/powerpc/ptrace/Makefile | 1 + .../testing/selftests/powerpc/ptrace/ptrace-gpr.S | 52 ++++++++++++++++++++++ .../testing/selftests/powerpc/ptrace/ptrace-gpr.c | 29 +++++------- 4 files changed, 73 insertions(+), 17 deletions(-) create mode 100644 tools/testing/selftests/powerpc/ptrace/ptrace-gpr.S (limited to 'tools') diff --git a/tools/testing/selftests/powerpc/include/basic_asm.h b/tools/testing/selftests/powerpc/include/basic_asm.h index 2d7f6e592dd9..26cde8ea1f49 100644 --- a/tools/testing/selftests/powerpc/include/basic_asm.h +++ b/tools/testing/selftests/powerpc/include/basic_asm.h @@ -94,4 +94,12 @@ PPC_LL r0, STACK_FRAME_LR_POS(%r1); \ mtlr r0; +.macro OP_REGS op, reg_width, start_reg, end_reg, base_reg, base_reg_offset=0, skip=0 + .set i, \start_reg + .rept (\end_reg - \start_reg + 1) + \op i, (\reg_width * (i - \skip) + \base_reg_offset)(\base_reg) + .set i, i + 1 + .endr +.endm + #endif /* _SELFTESTS_POWERPC_BASIC_ASM_H */ diff --git a/tools/testing/selftests/powerpc/ptrace/Makefile b/tools/testing/selftests/powerpc/ptrace/Makefile index 3434a624ed77..2f02cb54224d 100644 --- a/tools/testing/selftests/powerpc/ptrace/Makefile +++ b/tools/testing/selftests/powerpc/ptrace/Makefile @@ -35,6 +35,7 @@ $(TM_TESTS): CFLAGS += -I../tm -mhtm CFLAGS += -I../../../../../usr/include -fno-pie +$(OUTPUT)/ptrace-gpr: ptrace-gpr.S $(OUTPUT)/ptrace-pkey $(OUTPUT)/core-pkey: LDLIBS += -pthread $(TEST_GEN_PROGS): ../harness.c ../utils.c ../lib/reg.S diff --git a/tools/testing/selftests/powerpc/ptrace/ptrace-gpr.S b/tools/testing/selftests/powerpc/ptrace/ptrace-gpr.S new file mode 100644 index 000000000000..070e8443e3cc --- /dev/null +++ b/tools/testing/selftests/powerpc/ptrace/ptrace-gpr.S @@ -0,0 +1,52 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * test helper assembly functions + * + * Copyright (C) 2016 Simon Guo, IBM Corporation. + * Copyright 2022 Michael Ellerman, IBM Corporation. + */ +#include "basic_asm.h" + +#define GPR_SIZE __SIZEOF_LONG__ +#define FIRST_GPR 14 +#define NUM_GPRS (32 - FIRST_GPR) +#define STACK_SIZE (NUM_GPRS * GPR_SIZE) + +// gpr_child_loop(int *read_flag, int *write_flag, +// unsigned long *gpr_buf, double *fpr_buf); +FUNC_START(gpr_child_loop) + // r3 = read_flag + // r4 = write_flag + // r5 = gpr_buf + // r6 = fpr_buf + PUSH_BASIC_STACK(STACK_SIZE) + + // Save non-volatile GPRs + OP_REGS PPC_STL, GPR_SIZE, FIRST_GPR, 31, %r1, STACK_FRAME_LOCAL(0, 0), FIRST_GPR + + // Load GPRs with expected values + OP_REGS PPC_LL, GPR_SIZE, FIRST_GPR, 31, r5, 0, FIRST_GPR + + // Load FPRs with expected values + OP_REGS lfd, 8, 0, 31, r6 + + // Signal to parent that we're ready + li r0, 1 + stw r0, 0(r4) + + // Wait for parent to finish +1: lwz r0, 0(r3) + cmpwi r0, 0 + beq 1b // Loop while flag is zero + + // Save GPRs back to caller buffer + OP_REGS PPC_STL, GPR_SIZE, FIRST_GPR, 31, r5, 0, FIRST_GPR + + // Save FPRs + OP_REGS stfd, 8, 0, 31, r6 + + // Reload non-volatile GPRs + OP_REGS PPC_LL, GPR_SIZE, FIRST_GPR, 31, %r1, STACK_FRAME_LOCAL(0, 0), FIRST_GPR + + POP_BASIC_STACK(STACK_SIZE) + blr diff --git a/tools/testing/selftests/powerpc/ptrace/ptrace-gpr.c b/tools/testing/selftests/powerpc/ptrace/ptrace-gpr.c index 1468e89c044b..4e7a7eb01e3a 100644 --- a/tools/testing/selftests/powerpc/ptrace/ptrace-gpr.c +++ b/tools/testing/selftests/powerpc/ptrace/ptrace-gpr.c @@ -16,32 +16,27 @@ double a = FPR_1; double b = FPR_2; double c = FPR_3; +extern void gpr_child_loop(int *read_flag, int *write_flag, + unsigned long *gpr_buf, double *fpr_buf); + void gpr(void) { - unsigned long gpr_buf[18]; + unsigned long gpr_buf[32]; double fpr_buf[32]; + int i; cptr = (int *)shmat(shm_id, NULL, 0); + memset(gpr_buf, 0, sizeof(gpr_buf)); + memset(fpr_buf, 0, sizeof(fpr_buf)); - asm __volatile__( - ASM_LOAD_GPR_IMMED(gpr_1) - ASM_LOAD_FPR(flt_1) - : - : [gpr_1]"i"(GPR_1), [flt_1] "b" (&a) - : "memory", "r6", "r7", "r8", "r9", "r10", - "r11", "r12", "r13", "r14", "r15", "r16", "r17", - "r18", "r19", "r20", "r21", "r22", "r23", "r24", - "r25", "r26", "r27", "r28", "r29", "r30", "r31" - ); - - cptr[1] = 1; + for (i = 0; i < 32; i++) { + gpr_buf[i] = GPR_1; + fpr_buf[i] = a; + } - while (!cptr[0]) - asm volatile("" : : : "memory"); + gpr_child_loop(&cptr[0], &cptr[1], gpr_buf, fpr_buf); shmdt((void *)cptr); - store_gpr(gpr_buf); - store_fpr(fpr_buf); if (validate_gpr(gpr_buf, GPR_3)) exit(1); -- cgit v1.2.3