From nobody Sun May 19 08:26:16 2024 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 6B9BD13CF83; Tue, 23 Apr 2024 16:23:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713889427; cv=none; b=KSNfte7kqObAcCkFL7t60c2KqXZJjOybRuvEyX1Y1+n5Ml79DfONCqdNen0DvoKl14GBVlNgj274sGpgNfzgibrAhxwmi2tB6jwCPrV3Pq0csDUihGLEhArtECtGNUKd1aDYy3zurqNvY7/hIYYTRvHL8oq3nFDG2IbsmQc9DdE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713889427; c=relaxed/simple; bh=fKYVuUYF5edyTftSCxz7zqctoDERM/BF//4XAvd9R4g=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=on9NWCqwRA9XrEF0mzXCGASByURT9QEnp/UvaRB4E5gmCiSfB5FT+RuFI5Yvbie1CvPhzhX6KCv0JCJVfQMMZsrfRYnBgjKpbu9a0S/Hr1FvwrmQFp876TTSRq79fq8mDGfsc7f6IR+zFCCzeuUp8d0H7a2wyObkdF5LIRztxfY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=sBFlWpa0; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="sBFlWpa0" Received: from localhost.localdomain (unknown [4.155.48.122]) by linux.microsoft.com (Postfix) with ESMTPSA id 0A92020FFC2A; Tue, 23 Apr 2024 09:23:44 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 0A92020FFC2A DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1713889424; bh=771h4bXVshWzVkVXlBvpLqIM/IohUjbVJYAEkUl/tJs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sBFlWpa0ejJOLc1xqCRwBdC4HduVSIpzO98wIKIjBklTG7X4WTfvKn5dSpyn2G7qR JjuwElkEXl627fAWqnWEGgGCXEQBCo7xlTfDFP4FZrOabq5oNL0BGi+6k+ISD/hp5k V3ZjSDawaM5czwOedMuV+soTG6+bxy02KRrIbJzI= From: Beau Belgrave To: rostedt@goodmis.org, mhiramat@kernel.org, mathieu.desnoyers@efficios.com Cc: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, dcook@linux.microsoft.com Subject: [PATCH v2 1/2] tracing/user_events: Fix non-spaced field matching Date: Tue, 23 Apr 2024 16:23:37 +0000 Message-Id: <20240423162338.292-2-beaub@linux.microsoft.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240423162338.292-1-beaub@linux.microsoft.com> References: <20240423162338.292-1-beaub@linux.microsoft.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" When the ABI was updated to prevent same name w/different args, it missed an important corner case when fields don't end with a space. Typically, space is used for fields to help separate them, like "u8 field1; u8 field2". If no spaces are used, like "u8 field1;u8 field2", then the parsing works for the first time. However, the match check fails on a subsequent register, leading to confusion. This is because the match check uses argv_split() and assumes that all fields will be split upon the space. When spaces are used, we get back { "u8", "field1;" }, without spaces we get back { "u8", "field1;u8" }. This causes a mismatch, and the user program gets back -EADDRINUSE. Add a method to detect this case before calling argv_split(). If found force a space after the field separator character ';'. This ensures all cases work properly for matching. With this fix, the following are all treated as matching: u8 field1;u8 field2 u8 field1; u8 field2 u8 field1;\tu8 field2 u8 field1;\nu8 field2 Fixes: ba470eebc2f6 ("tracing/user_events: Prevent same name but different = args event") Signed-off-by: Beau Belgrave --- kernel/trace/trace_events_user.c | 76 +++++++++++++++++++++++++++++++- 1 file changed, 75 insertions(+), 1 deletion(-) diff --git a/kernel/trace/trace_events_user.c b/kernel/trace/trace_events_u= ser.c index 70d428c394b6..82b191f33a28 100644 --- a/kernel/trace/trace_events_user.c +++ b/kernel/trace/trace_events_user.c @@ -1989,6 +1989,80 @@ static int user_event_set_tp_name(struct user_event = *user) return 0; } =20 +/* + * Counts how many ';' without a trailing space are in the args. + */ +static int count_semis_no_space(char *args) +{ + int count =3D 0; + + while ((args =3D strchr(args, ';'))) { + args++; + + if (!isspace(*args)) + count++; + } + + return count; +} + +/* + * Copies the arguments while ensuring all ';' have a trailing space. + */ +static char *insert_space_after_semis(char *args, int count) +{ + char *fixed, *pos; + int len; + + len =3D strlen(args) + count; + fixed =3D kmalloc(len + 1, GFP_KERNEL); + + if (!fixed) + return NULL; + + pos =3D fixed; + + /* Insert a space after ';' if there is no trailing space. */ + while (*args) { + *pos =3D *args++; + + if (*pos++ =3D=3D ';' && !isspace(*args)) + *pos++ =3D ' '; + } + + *pos =3D '\0'; + + return fixed; +} + +static char **user_event_argv_split(char *args, int *argc) +{ + char **split; + char *fixed; + int count; + + /* Count how many ';' without a trailing space */ + count =3D count_semis_no_space(args); + + /* No fixup is required */ + if (!count) + return argv_split(GFP_KERNEL, args, argc); + + /* We must fixup 'field;field' to 'field; field' */ + fixed =3D insert_space_after_semis(args, count); + + if (!fixed) + return NULL; + + /* We do a normal split afterwards */ + split =3D argv_split(GFP_KERNEL, fixed, argc); + + /* We can free since argv_split makes a copy */ + kfree(fixed); + + return split; +} + /* * Parses the event name, arguments and flags then registers if successful. * The name buffer lifetime is owned by this method for success cases only. @@ -2012,7 +2086,7 @@ static int user_event_parse(struct user_event_group *= group, char *name, return -EPERM; =20 if (args) { - argv =3D argv_split(GFP_KERNEL, args, &argc); + argv =3D user_event_argv_split(args, &argc); =20 if (!argv) return -ENOMEM; --=20 2.34.1 From nobody Sun May 19 08:26:16 2024 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 7CEA513D256; Tue, 23 Apr 2024 16:23:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713889425; cv=none; b=FYn4ntL9zmmP9PEXFmLcbfDsD6RDWk6cNPfAYENKCbAQR7e6Kd4C7yr6mM6G5UpCa07RqJHl16mBMhRMHV6FqXrhR8VY//thnzM33/oPQ2b+PvMHPfggIDEEXR2py2mnDzxjUZZCvFlN/7os7/LsbWk4qJQmQkp6IYffg9AjV3E= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713889425; c=relaxed/simple; bh=y1wrF17AgEHKJmFGNE7yGIyl4eKYJ5YVmr3GJsXkZys=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=MGbyE60cot2eVRKYFNYInn/utDW3KQoOWDWcl+NNpZ4U+0TwwSrGXDoADOZ6aSDzTZPonp+Eh9RmePbK0tQEGK6+sw9wwn2aYDANB7njGj8wRK9kzTt1WKMsLPO8azRlC3PEQQ5Y9HkXHB4CWXkhY8lgXDJ8DKTYqn15deRRfss= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=e1zf0Nfk; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="e1zf0Nfk" Received: from localhost.localdomain (unknown [4.155.48.122]) by linux.microsoft.com (Postfix) with ESMTPSA id 2834520FFC2F; Tue, 23 Apr 2024 09:23:44 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 2834520FFC2F DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1713889424; bh=Qzj7PgGGTTDfdmHHRJjNMrG5XlDt+SDkey8oIImgtmw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=e1zf0NfkDoYjqyhjBzT9TbLcXh96wfsbb0UBqW7ipUZ+M/pOHo6MYkru3SUgtQKSl Wxp+ZeX9EDU6gm87rxdsMZ5vRn3pImcExlWv0rIZo/EUkHQY+Mryhj1QilAtPTyev1 KwplJaEzgDNoBjit99PyBEYYCs4jEaTOdWjrYdNE= From: Beau Belgrave To: rostedt@goodmis.org, mhiramat@kernel.org, mathieu.desnoyers@efficios.com Cc: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, dcook@linux.microsoft.com Subject: [PATCH v2 2/2] selftests/user_events: Add non-spacing separator check Date: Tue, 23 Apr 2024 16:23:38 +0000 Message-Id: <20240423162338.292-3-beaub@linux.microsoft.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240423162338.292-1-beaub@linux.microsoft.com> References: <20240423162338.292-1-beaub@linux.microsoft.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The ABI documentation indicates that field separators do not need a space between them, only a ';'. When no spacing is used, the register must work. Any subsequent register, with or without spaces, must match and not return -EADDRINUSE. Add a non-spacing separator case to our self-test register case to ensure it works going forward. Signed-off-by: Beau Belgrave --- tools/testing/selftests/user_events/ftrace_test.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/tools/testing/selftests/user_events/ftrace_test.c b/tools/test= ing/selftests/user_events/ftrace_test.c index dcd7509fe2e0..0bb46793dcd4 100644 --- a/tools/testing/selftests/user_events/ftrace_test.c +++ b/tools/testing/selftests/user_events/ftrace_test.c @@ -261,6 +261,12 @@ TEST_F(user, register_events) { ASSERT_EQ(0, ioctl(self->data_fd, DIAG_IOCSREG, ®)); ASSERT_EQ(0, reg.write_index); =20 + /* Register without separator spacing should still match */ + reg.enable_bit =3D 29; + reg.name_args =3D (__u64)"__test_event u32 field1;u32 field2"; + ASSERT_EQ(0, ioctl(self->data_fd, DIAG_IOCSREG, ®)); + ASSERT_EQ(0, reg.write_index); + /* Multiple registers to same name but different args should fail */ reg.enable_bit =3D 29; reg.name_args =3D (__u64)"__test_event u32 field1;"; @@ -288,6 +294,8 @@ TEST_F(user, register_events) { ASSERT_EQ(0, ioctl(self->data_fd, DIAG_IOCSUNREG, &unreg)); unreg.disable_bit =3D 30; ASSERT_EQ(0, ioctl(self->data_fd, DIAG_IOCSUNREG, &unreg)); + unreg.disable_bit =3D 29; + ASSERT_EQ(0, ioctl(self->data_fd, DIAG_IOCSUNREG, &unreg)); =20 /* Delete should have been auto-done after close and unregister */ close(self->data_fd); --=20 2.34.1