From patchwork Fri Apr 5 08:35:11 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nicholas Piggin X-Patchwork-Id: 1920097 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20230601 header.b=UgtMW+og; dkim-atps=neutral Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.ozlabs.org (client-ip=112.213.38.117; helo=lists.ozlabs.org; envelope-from=linuxppc-dev-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org; receiver=patchwork.ozlabs.org) Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (secp384r1) server-digest SHA384) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4V9sT84jcSz1yYf for ; Fri, 5 Apr 2024 19:43:24 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20230601 header.b=UgtMW+og; dkim-atps=neutral Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4V9sT770CPz3vrL for ; Fri, 5 Apr 2024 19:43:23 +1100 (AEDT) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20230601 header.b=UgtMW+og; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=gmail.com (client-ip=2607:f8b0:4864:20::42b; helo=mail-pf1-x42b.google.com; envelope-from=npiggin@gmail.com; receiver=lists.ozlabs.org) Received: from mail-pf1-x42b.google.com (mail-pf1-x42b.google.com [IPv6:2607:f8b0:4864:20::42b]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4V9sKB2p0kz3vZH for ; Fri, 5 Apr 2024 19:36:30 +1100 (AEDT) Received: by mail-pf1-x42b.google.com with SMTP id d2e1a72fcca58-6ecf9898408so734880b3a.1 for ; Fri, 05 Apr 2024 01:36:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1712306188; x=1712910988; darn=lists.ozlabs.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=ojc5Jzo7lufTrgoyK+GArsWzgBJsqMRvJtb4QkYd9p0=; b=UgtMW+ogv1DZreosxi1kay2OXRskZGfl/z41yxTJtdw37cRRDSFaRTJ2kPmNkf+mpX Xeyh5LyFAKPKVcHX9ot0s006bRhcuxOkcYcoAgk9v4NORBV3e5J/QY59iPt8GA/wdzne 4p24pujsIVP6gotLkvi0ceJK6lR7gBfvBNz7hgJ985Q/ejSyj5Hg8gtjgW9Zs5ubttYI MzRfeAZMMKi4zk/upJO7uE/48Yhg0eFzH0dpYPom9MV4/rHThuXjmxvz7hZGqSouRbrf R3VNF8qHNq4EP+OLpRTtRIdYcYFVyx+3wx0UozKbw9dAxqkbz6Zh5NPLGwRB2rNhi4ZN H0Ag== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1712306188; x=1712910988; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=ojc5Jzo7lufTrgoyK+GArsWzgBJsqMRvJtb4QkYd9p0=; b=mR2qaba6aAMrcdI74YQpI4VlxI2yCKa2LeeXUv9uOcfD1YZO2ghmB2v39wRyQONxHA 1tE9A8qru3n77AqpFuHxKTZMbW2sYAmTTLN2FrJYOf3UrjKnvy2FurAJ+GQCRvPxK8Nz fJnXExPuUjy3ly2O0xl7p9wlP9+rbrbpw6AalhWPCL/b8COkm1FHzmxVdFRB5V7O3HHK 919g1Baiv+Tog65o+t8XzDWHzDqZDo1vYRzWp1EkcelJQadLYCGQG3/p+IAYDchd5fqd 5eOTY/daey8PTS7zfb9LHApOk21t+fjTQycrrBEaqdF9m8PxOUt2YST/ryY8O8lKSCyL egOg== X-Forwarded-Encrypted: i=1; AJvYcCXd2/1lawFaPHuhbWdAkV32ECYKfIpNvYlbkGE+8SEAXWE+uURp5Xuhsz4YYwzkD6i43nHlhRNVW7kD8YOqUyC1ypCCHHeXUUtqJpp9dA== X-Gm-Message-State: AOJu0Yz1vaY89touZbjq+bYF24yyesCKQkAXLZQunDaSbnJjERfsEFCE jH7szRyq4zqGOui8f0GE2IT8GwaV+g9xXKq6+zUe841diHnLkh6O X-Google-Smtp-Source: AGHT+IHhkgehUTWXHc9Epdp8neXLEfg0Xxtzigufux5Yi09dT9q7r3Cj5bfLmMhAMIPs13Ja1RKsAA== X-Received: by 2002:a05:6a21:7888:b0:1a3:a821:f297 with SMTP id bf8-20020a056a21788800b001a3a821f297mr1328214pzc.2.1712306187838; Fri, 05 Apr 2024 01:36:27 -0700 (PDT) Received: from wheely.local0.net (124-169-104-130.tpgi.com.au. [124.169.104.130]) by smtp.gmail.com with ESMTPSA id y7-20020a63de47000000b005e838b99c96sm808638pgi.80.2024.04.05.01.36.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 05 Apr 2024 01:36:27 -0700 (PDT) From: Nicholas Piggin To: Thomas Huth Subject: [kvm-unit-tests PATCH v8 10/35] powerpc: interrupt stack backtracing Date: Fri, 5 Apr 2024 18:35:11 +1000 Message-ID: <20240405083539.374995-11-npiggin@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240405083539.374995-1-npiggin@gmail.com> References: <20240405083539.374995-1-npiggin@gmail.com> MIME-Version: 1.0 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Laurent Vivier , kvm@vger.kernel.org, Nicholas Piggin , Andrew Jones , Paolo Bonzini , linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" Add support for backtracing across interrupt stacks, and add interrupt frame backtrace for unhandled interrupts. This requires a back-chain created from initial interrupt stack frame to the r1 value of the interrupted context. A label is added at the return location of the exception handler call, so the unwinder can recognize the initial interrupt frame. The additional cstart entry-frame is no longer required because the unwinder now looks for frame == 0 as well as address == 0. Signed-off-by: Nicholas Piggin Acked-by: Thomas Huth --- lib/powerpc/processor.c | 4 +++- lib/ppc64/asm/stack.h | 3 +++ lib/ppc64/stack.c | 53 +++++++++++++++++++++++++++++++++++++++++ powerpc/Makefile.ppc64 | 1 + powerpc/cstart64.S | 15 +++--------- 5 files changed, 63 insertions(+), 13 deletions(-) create mode 100644 lib/ppc64/stack.c diff --git a/lib/powerpc/processor.c b/lib/powerpc/processor.c index ad0d95666..114584024 100644 --- a/lib/powerpc/processor.c +++ b/lib/powerpc/processor.c @@ -51,7 +51,9 @@ void do_handle_exception(struct pt_regs *regs) return; } - printf("unhandled cpu exception %#lx at NIA:0x%016lx MSR:0x%016lx\n", regs->trap, regs->nip, regs->msr); + printf("Unhandled cpu exception %#lx at NIA:0x%016lx MSR:0x%016lx\n", + regs->trap, regs->nip, regs->msr); + dump_frame_stack((void *)regs->nip, (void *)regs->gpr[1]); abort(); } diff --git a/lib/ppc64/asm/stack.h b/lib/ppc64/asm/stack.h index 9734bbb8f..94fd1021c 100644 --- a/lib/ppc64/asm/stack.h +++ b/lib/ppc64/asm/stack.h @@ -5,4 +5,7 @@ #error Do not directly include . Just use . #endif +#define HAVE_ARCH_BACKTRACE +#define HAVE_ARCH_BACKTRACE_FRAME + #endif diff --git a/lib/ppc64/stack.c b/lib/ppc64/stack.c new file mode 100644 index 000000000..e6f259de7 --- /dev/null +++ b/lib/ppc64/stack.c @@ -0,0 +1,53 @@ +#include +#include +#include + +extern char do_handle_exception_return[]; + +int arch_backtrace_frame(const void *frame, const void **return_addrs, + int max_depth, bool current_frame) +{ + static int walking; + int depth = 0; + const unsigned long *bp = (unsigned long *)frame; + void *return_addr; + + asm volatile("" ::: "lr"); /* Force it to save LR */ + + if (walking) { + printf("RECURSIVE STACK WALK!!!\n"); + return 0; + } + walking = 1; + + if (current_frame) + bp = __builtin_frame_address(0); + + bp = (unsigned long *)bp[0]; + return_addr = (void *)bp[2]; + + for (depth = 0; bp && depth < max_depth; depth++) { + return_addrs[depth] = return_addr; + if (return_addrs[depth] == 0) + break; + if (return_addrs[depth] == do_handle_exception_return) { + struct pt_regs *regs; + + regs = (void *)bp + STACK_FRAME_OVERHEAD; + bp = (unsigned long *)bp[0]; + /* Represent interrupt frame with vector number */ + return_addr = (void *)regs->trap; + if (depth + 1 < max_depth) { + depth++; + return_addrs[depth] = return_addr; + return_addr = (void *)regs->nip; + } + } else { + bp = (unsigned long *)bp[0]; + return_addr = (void *)bp[2]; + } + } + + walking = 0; + return depth; +} diff --git a/powerpc/Makefile.ppc64 b/powerpc/Makefile.ppc64 index b0ed2b104..eb682c226 100644 --- a/powerpc/Makefile.ppc64 +++ b/powerpc/Makefile.ppc64 @@ -17,6 +17,7 @@ cstart.o = $(TEST_DIR)/cstart64.o reloc.o = $(TEST_DIR)/reloc64.o OBJDIRS += lib/ppc64 +cflatobjs += lib/ppc64/stack.o # ppc64 specific tests tests = $(TEST_DIR)/spapr_vpa.elf diff --git a/powerpc/cstart64.S b/powerpc/cstart64.S index 80baabe8f..07d297f61 100644 --- a/powerpc/cstart64.S +++ b/powerpc/cstart64.S @@ -51,16 +51,6 @@ start: std r0,0(r1) std r0,16(r1) - /* - * Create entry frame of 64-bytes, same as the initial frame. A callee - * may use the caller frame to store LR, and backtrace() termination - * looks for return address == NULL, so the initial stack frame can't - * be used to call C or else it could overwrite the zeroed LR save slot - * and break backtrace termination. This frame would be unnecessary if - * backtrace looked for a zeroed frame address. - */ - stdu r1,-64(r1) - /* save DTB pointer */ std r3, 56(r1) @@ -195,6 +185,7 @@ call_handler: .endr mfsprg1 r0 std r0,GPR1(r1) + std r0,0(r1) /* Backchain from interrupt stack to regular stack */ /* lr, xer, ccr */ @@ -213,12 +204,12 @@ call_handler: subi r31, r31, 0b - start_text ld r2, (p_toc_text - start_text)(r31) - /* FIXME: build stack frame */ - /* call generic handler */ addi r3,r1,STACK_FRAME_OVERHEAD bl do_handle_exception + .global do_handle_exception_return +do_handle_exception_return: /* restore context */