From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 83105E77184 for ; Thu, 19 Dec 2024 18:26:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=GT0FbbsurS5S4ECv5z1enEwKrOdtiLXNJ+lQpQ2OqoQ=; b=xYgMSCmDUtfqRj c3WKQIEudjAo1wRGQBgilLSSwN/0zIcCmOtRLOkLOx2aQjleYNPL8OtyQaKXLCeEc12ISCVkt14bl +AYNP65ozcMNt2ndYXDwQXjxV7KdW3alzUMpohF3zXfqoK9JAY2szZSghd0+Hgwy/93CYrDEZQJMY qxkc/AYN3kPV3omSgjBYOQ3Z6do2fR7so/BOoYOXZToH7p/lj2xwlc5mX6VbIq2mcfF2KkFcvg3F+ K054MwEfwmX0TTMgVllTL/GpdSsJJB/j096Gksi9ajAiAIuyYiFaXVWVr7Mb2Cke8MszqSL9xKQDq GTXXYz8wBdlCNhUOSteA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tOLE7-00000002jmx-2biy; Thu, 19 Dec 2024 18:26:23 +0000 Received: from mail-pj1-x1033.google.com ([2607:f8b0:4864:20::1033]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tOLE4-00000002jmZ-3Xg4 for linux-riscv@lists.infradead.org; Thu, 19 Dec 2024 18:26:22 +0000 Received: by mail-pj1-x1033.google.com with SMTP id 98e67ed59e1d1-2ee786b3277so737009a91.1 for ; Thu, 19 Dec 2024 10:26:20 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rivosinc-com.20230601.gappssmtp.com; s=20230601; t=1734632779; x=1735237579; darn=lists.infradead.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=hMRnvozbssngVqbSknpjzbx2RK+JVnD39zwZDG+y2n8=; b=qQGm+Oe/J+dXhdQwhCUI6HuNC2wr+lcizByK0xLxecn2F7d3Vj/AIJalBwJpNg8nMc pnXFxhIlzTBO/WHYJ+Ilq/KndB1mr4csIune73PNfePJxlGhWL9RVyuHG84PcbHrs1Vc q1EfezyYHXWAPKobmibOspe3dWD9Imc8lLAGSMn3sFN7QsFN4kFuO90rnBxTIn9tlFwh I3iEAoBV4dysT6LS8qSaww2fZIQ3JpO5m2j0bbReTZ0nrlyLoMO6x9kH8e5saabiqYbU +pA9ku2yTlNxmPjxZKhb8cETetNkUVFSLoRyiwWWg+W7S4hnZh6JTzu5nveGS8AlSt/a +jTA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1734632779; x=1735237579; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=hMRnvozbssngVqbSknpjzbx2RK+JVnD39zwZDG+y2n8=; b=bTK2ax8nDBWlMAPp9XKf6Ut54XHEgmn3wF8e3Rap47XXSgb8d2OtNU23SW7lUhLxCN wQY+AUXCF9VvXFpjHC2LE+B+A1qC1/afcnk6IJ6JicfS+Y7IxkE+AyRoEEp+kSnPl2ym xZNsVr269aWw6AMg8YZtjGJbZUTzM5nFa+Wxy3b9YfCwWmVAOZrB9dKyaOdTV6Z9aeC7 2Nmbf0aoKIPfglBaQWnUVsNc2O33ydE3QuoWt0IDhYEwQ74iTFqt3kMbK2epGbi+ZLza 989UR7tGzxPTugUEhFDDR3BGySunxh609F7JmZSpn2j8XWRQucEHHl3iEpC4RNvsQrpV yDVg== X-Forwarded-Encrypted: i=1; AJvYcCU2FjuOcCdcEIYV4vRsbcSiz9Kc5Wmxk0OKD6f6RhVcqTSEm8RWdma3sV5IUkKmwhPEPu35+zAV+1+yNg==@lists.infradead.org X-Gm-Message-State: AOJu0YxsFbyZBQH6mtKyrlDZy1+loxDx/Dyug2FFpk/+y3tLyhNd6dsb BMZGdZkPvh8i+laZJyXS6/oQ1GmJMa5mHzZUzFlIA+GJ7gwnxnpfbpxjqzJxO6A= X-Gm-Gg: ASbGncvQdcFj+g8c/vSA/sK1eYml3NOP+vg3I4vYDCoCqVMqfO7OxUXNtG+F9TWb4gg DogJ5SMUtE36/e03+Xd9jlsKNuMQjY+ENbwj4Cz8octyJzr+NvSikTd8gJUVzgqHu2CmpQGa1gE uQyJD7SOWtY1y2Iq6+UcHb1jipwiPoYjEV6iDp/xBAdDLi0t/8KEhyEDAEuQKvFjPzil/zwSzB3 /b+hpnbPU8/XC5btITgeyP9cIsZ+BIc9ZuxiMJf2E3lE69x0bym X-Google-Smtp-Source: AGHT+IFsWgJOva12zvp6tp180q3OiFLZ0d0TjIkVYwvTLN5q8JRYcM/SHtSfXHGK+OHbcvE+dj549w== X-Received: by 2002:a17:90b:2c84:b0:2ee:bbe0:98c6 with SMTP id 98e67ed59e1d1-2f452dfcb28mr13994a91.8.1734632779465; Thu, 19 Dec 2024 10:26:19 -0800 (PST) Received: from ghost ([2601:647:6700:64d0:1e6a:6188:cfff:248e]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-2f447883b0csm1887523a91.42.2024.12.19.10.26.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 19 Dec 2024 10:26:18 -0800 (PST) Date: Thu, 19 Dec 2024 10:26:15 -0800 From: Charlie Jenkins To: Andrew Jones Cc: Celeste Liu , Oleg Nesterov , Paul Walmsley , Palmer Dabbelt , Albert Ou , Eric Biederman , Kees Cook , Shuah Khan , Alexandre Ghiti , "Dmitry V. Levin" , Andrea Bolognani , =?iso-8859-1?Q?Bj=F6rn_T=F6pel?= , Thomas Gleixner , Ron Economos , Quan Zhou , Felix Yan , Ruizhe Pan , Shiqi Zhang , Guo Ren , Yao Zi , Han Gao , linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, stable@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: Re: [PATCH v2 2/2] riscv: selftests: Add a ptrace test to verify syscall parameter modification Message-ID: References: <20241203-riscv-new-regset-v2-0-d37da8c0cba6@coelacanthus.name> <20241203-riscv-new-regset-v2-2-d37da8c0cba6@coelacanthus.name> <20241203-55c76715e16422ddaf8d7edf@orel> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20241203-55c76715e16422ddaf8d7edf@orel> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241219_102621_157439_460723B8 X-CRM114-Status: GOOD ( 37.40 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On Tue, Dec 03, 2024 at 01:55:07PM +0100, Andrew Jones wrote: > On Tue, Dec 03, 2024 at 05:30:05PM +0800, Celeste Liu wrote: > > From: Charlie Jenkins > > > > This test checks that orig_a0 allows a syscall argument to be modified, > > and that changing a0 does not change the syscall argument. > > > > Cc: stable@vger.kernel.org > > Co-developed-by: Quan Zhou > > Signed-off-by: Quan Zhou > > Co-developed-by: Celeste Liu > > Signed-off-by: Celeste Liu > > Signed-off-by: Charlie Jenkins > > --- > > tools/testing/selftests/riscv/abi/.gitignore | 1 + > > tools/testing/selftests/riscv/abi/Makefile | 5 +- > > tools/testing/selftests/riscv/abi/ptrace.c | 134 +++++++++++++++++++++++++++ > > 3 files changed, 139 insertions(+), 1 deletion(-) > > > > diff --git a/tools/testing/selftests/riscv/abi/.gitignore b/tools/testing/selftests/riscv/abi/.gitignore > > index b38358f91c4d2240ae64892871d9ca98bda1ae58..378c605919a3b3d58eec2701eb7af430cfe315d6 100644 > > --- a/tools/testing/selftests/riscv/abi/.gitignore > > +++ b/tools/testing/selftests/riscv/abi/.gitignore > > @@ -1 +1,2 @@ > > pointer_masking > > +ptrace > > diff --git a/tools/testing/selftests/riscv/abi/Makefile b/tools/testing/selftests/riscv/abi/Makefile > > index ed82ff9c664e7eb3f760cbab81fb957ff72579c5..3f74d059dfdcbce4d45d8ff618781ccea1419061 100644 > > --- a/tools/testing/selftests/riscv/abi/Makefile > > +++ b/tools/testing/selftests/riscv/abi/Makefile > > @@ -2,9 +2,12 @@ > > > > CFLAGS += -I$(top_srcdir)/tools/include > > > > -TEST_GEN_PROGS := pointer_masking > > +TEST_GEN_PROGS := pointer_masking ptrace > > > > include ../../lib.mk > > > > $(OUTPUT)/pointer_masking: pointer_masking.c > > $(CC) -static -o$@ $(CFLAGS) $(LDFLAGS) $^ > > + > > +$(OUTPUT)/ptrace: ptrace.c > > + $(CC) -static -o$@ $(CFLAGS) $(LDFLAGS) $^ > > diff --git a/tools/testing/selftests/riscv/abi/ptrace.c b/tools/testing/selftests/riscv/abi/ptrace.c > > new file mode 100644 > > index 0000000000000000000000000000000000000000..d192764b428d1f1c442f3957c6fedeb01a48d556 > > --- /dev/null > > +++ b/tools/testing/selftests/riscv/abi/ptrace.c > > @@ -0,0 +1,134 @@ > > +// SPDX-License-Identifier: GPL-2.0-only > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > + > > +#include "../../kselftest_harness.h" > > + > > +#define ORIG_A0_MODIFY 0x01 > > +#define A0_MODIFY 0x02 > > +#define A0_OLD 0x03 > > +#define A0_NEW 0x04 > > Shouldn't A0_OLD and A0_NEW set more bits, since 3 and 4 aren't very > unique (we could have those values by accident)? And should we include > setting bits over 31 for 64-bit targets? > > > + > > +#define perr_and_exit(fmt, ...) \ > > + ({ \ > > + char buf[256]; \ > > + snprintf(buf, sizeof(buf), "%s:%d:" fmt ": %m\n", \ > > + __func__, __LINE__, ##__VA_ARGS__); \ > > + perror(buf); \ > > + exit(-1); \ > > + }) > > Can we use e.g. ksft_exit_fail_perror() instead? I'd prefer we try to > consolidate testing/selftests/riscv/* tests on a common format for > errors and exit codes and we're already using other kselftest stuff. > > > + > > +static inline void resume_and_wait_tracee(pid_t pid, int flag) > > +{ > > + int status; > > + > > + if (ptrace(flag, pid, 0, 0)) > > + perr_and_exit("failed to resume the tracee %d\n", pid); > > + > > + if (waitpid(pid, &status, 0) != pid) > > + perr_and_exit("failed to wait for the tracee %d\n", pid); > > +} > > + > > +static void ptrace_test(int opt, int *result) > > +{ > > + int status; > > + pid_t pid; > > + struct user_regs_struct regs; > > + struct iovec iov = { > > + .iov_base = ®s, > > + .iov_len = sizeof(regs), > > + }; > > + > > + unsigned long orig_a0; > > + struct iovec a0_iov = { > > + .iov_base = &orig_a0, > > + .iov_len = sizeof(orig_a0), > > + }; > > + > > + pid = fork(); > > + if (pid == 0) { > > + /* Mark oneself being traced */ > > + long val = ptrace(PTRACE_TRACEME, 0, 0, 0); > > + > > + if (val) > > + perr_and_exit("failed to request for tracer to trace me: %ld\n", val); > > + > > + kill(getpid(), SIGSTOP); > > + > > + /* Perform exit syscall that will be intercepted */ > > + exit(A0_OLD); > > + } > > + > > + if (pid < 0) > > + exit(1); > > This unexpected error condition deserves a message, so I'd use > ksft_exit_fail_perror() here. > > > + > > + if (waitpid(pid, &status, 0) != pid) > > + perr_and_exit("failed to wait for the tracee %d\n", pid); > > + > > + /* Stop at the entry point of the syscall */ > > + resume_and_wait_tracee(pid, PTRACE_SYSCALL); > > + > > + /* Check tracee regs before the syscall */ > > + if (ptrace(PTRACE_GETREGSET, pid, NT_PRSTATUS, &iov)) > > + perr_and_exit("failed to get tracee registers\n"); > > + if (ptrace(PTRACE_GETREGSET, pid, NT_RISCV_ORIG_A0, &a0_iov)) > > + perr_and_exit("failed to get tracee registers\n"); > > + if (orig_a0 != A0_OLD) > > + perr_and_exit("unexpected orig_a0: 0x%lx\n", orig_a0); > > + > > + /* Modify a0/orig_a0 for the syscall */ > > + switch (opt) { > > + case A0_MODIFY: > > + regs.a0 = A0_NEW; > > + break; > > + case ORIG_A0_MODIFY: > > + orig_a0 = A0_NEW; > > + break; > > + } > > + > > + if (ptrace(PTRACE_SETREGSET, pid, NT_RISCV_ORIG_A0, &a0_iov)) > > + perr_and_exit("failed to set tracee registers\n"); > > + > > + /* Resume the tracee */ > > + ptrace(PTRACE_CONT, pid, 0, 0); > > + if (waitpid(pid, &status, 0) != pid) > > + perr_and_exit("failed to wait for the tracee\n"); > > + > > + *result = WEXITSTATUS(status); > > +} > > + > > +TEST(ptrace_modify_a0) > > +{ > > + int result; > > + > > + ptrace_test(A0_MODIFY, &result); > > + > > + /* The modification of a0 cannot affect the first argument of the syscall */ > > + EXPECT_EQ(A0_OLD, result); > > What about checking that we actually set regs.a0 to A0_NEW? We'd need > A0_NEW to be more unique than 4, though. > > > +} > > + > > +TEST(ptrace_modify_orig_a0) > > +{ > > + int result; > > + > > + ptrace_test(ORIG_A0_MODIFY, &result); > > + > > + /* Only modify orig_a0 to change the first argument of the syscall */ > > If we run ptrace_modify_a0 first then we've already set regs.a0 to A0_NEW > and can't check with this test that we don't set it to A0_NEW. We should > probably have two different test values, one for regs.a0 and one for > orig_a0 and ensure on both tests that we aren't writing both. > Celeste, do you want to fix this up or are you waiting for me to? - Charlie > > + EXPECT_EQ(A0_NEW, result); > > +} > > + > > +TEST_HARNESS_MAIN > > > > -- > > 2.47.0 > > > > Thanks, > drew _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv