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From: Petr Mladek <pmladek@suse.com>
To: Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
	"Tobin C . Harding" <me@tobin.cc>, Joe Perches <joe@perches.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Michal Hocko <mhocko@suse.cz>,
	Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
	linux-kernel@vger.kernel.org, Petr Mladek <pmladek@suse.com>
Subject: [PATCH v5 06/11] vsprintf: Factor out %p[iI] handler as ip_addr_string()
Date: Wed, 25 Apr 2018 13:12:46 +0200	[thread overview]
Message-ID: <20180425111251.13246-7-pmladek@suse.com> (raw)
In-Reply-To: <20180425111251.13246-1-pmladek@suse.com>

Move the non-trivial code from the long pointer() function. We are going
to add a check for the access to the address that will make it even more
complicated.

Also it is better to warn about unknown specifier instead of falling
back to the %p behavior. It will help people to understand what is
going wrong. They expect the IP address and not a pointer anyway
in this situation.

Signed-off-by: Petr Mladek <pmladek@suse.com>
---
 lib/vsprintf.c | 57 ++++++++++++++++++++++++++++++++++-----------------------
 1 file changed, 34 insertions(+), 23 deletions(-)

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 587175a528b7..92793060bb1f 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -1387,6 +1387,39 @@ char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
 }
 
 static noinline_for_stack
+char *ip_addr_string(char *buf, char *end, const void *ptr,
+		     struct printf_spec spec, const char *fmt)
+{
+	char *err_fmt_msg;
+
+	switch (fmt[1]) {
+	case '6':
+		return ip6_addr_string(buf, end, ptr, spec, fmt);
+	case '4':
+		return ip4_addr_string(buf, end, ptr, spec, fmt);
+	case 'S': {
+		const union {
+			struct sockaddr		raw;
+			struct sockaddr_in	v4;
+			struct sockaddr_in6	v6;
+		} *sa = ptr;
+
+		switch (sa->raw.sa_family) {
+		case AF_INET:
+			return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
+		case AF_INET6:
+			return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
+		default:
+			return valid_string(buf, end, "(invalid address)",
+					    spec);
+		}}
+	}
+
+	err_fmt_msg = fmt[0] == 'i' ? "(%pi?)" : "(%pI?)";
+	return valid_string(buf, end, err_fmt_msg, spec);
+}
+
+static noinline_for_stack
 char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
 		     const char *fmt)
 {
@@ -1888,29 +1921,7 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr,
 					 * 4:	001.002.003.004
 					 * 6:   000102...0f
 					 */
-		switch (fmt[1]) {
-		case '6':
-			return ip6_addr_string(buf, end, ptr, spec, fmt);
-		case '4':
-			return ip4_addr_string(buf, end, ptr, spec, fmt);
-		case 'S': {
-			const union {
-				struct sockaddr		raw;
-				struct sockaddr_in	v4;
-				struct sockaddr_in6	v6;
-			} *sa = ptr;
-
-			switch (sa->raw.sa_family) {
-			case AF_INET:
-				return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
-			case AF_INET6:
-				return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
-			default:
-				return valid_string(buf, end,
-						    "(invalid address)", spec);
-			}}
-		}
-		break;
+		return ip_addr_string(buf, end, ptr, spec, fmt);
 	case 'E':
 		return escaped_string(buf, end, ptr, spec, fmt);
 	case 'U':
-- 
2.13.6

  parent reply	other threads:[~2018-04-25 11:13 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-25 11:12 [PATCH v5 00/11] vsprintf: Prevent silent crashes and consolidate error handling Petr Mladek
2018-04-25 11:12 ` [PATCH v5 01/11] vsprintf: Shuffle misc pointer to string functions Petr Mladek
2018-04-25 14:57   ` Andy Shevchenko
2018-04-25 11:12 ` [PATCH v5 02/11] vsprintf: Add missing const ptr qualifier to prt_to_id() Petr Mladek
2018-04-25 14:57   ` Andy Shevchenko
2018-04-25 11:12 ` [PATCH v5 03/11] vsprintf: Consistent %pK handling for kptr_restrict == 0 Petr Mladek
2018-04-25 14:58   ` Andy Shevchenko
2018-04-25 11:12 ` [PATCH v5 04/11] vsprintf: Do not check address of well-known strings Petr Mladek
2018-04-25 11:44   ` Andy Shevchenko
2018-04-25 11:12 ` [PATCH v5 05/11] vsprintf: Consolidate handling of unknown pointer specifiers Petr Mladek
2018-04-25 13:08   ` Andy Shevchenko
2018-04-25 11:12 ` Petr Mladek [this message]
2018-04-25 13:11   ` [PATCH v5 06/11] vsprintf: Factor out %p[iI] handler as ip_addr_string() Andy Shevchenko
2018-04-25 11:12 ` [PATCH v5 07/11] vsprintf: Factor out %pV handler as va_format() Petr Mladek
2018-04-25 14:56   ` Andy Shevchenko
2018-04-25 11:12 ` [PATCH v5 08/11] vsprintf: Factor out %pO handler as kobject_string() Petr Mladek
2018-04-25 15:01   ` Andy Shevchenko
2018-04-25 11:12 ` [PATCH v5 09/11] vsprintf: Prevent crash when dereferencing invalid pointers Petr Mladek
2018-04-25 15:10   ` Andy Shevchenko
2018-04-25 15:32     ` Andy Shevchenko
2018-04-27 12:47     ` Petr Mladek
2018-05-03 11:55       ` Andy Shevchenko
2018-04-26 21:46   ` kbuild test robot
2018-04-25 11:12 ` [PATCH v5 10/11] vsprintf: WARN() on invalid pointer access Petr Mladek
2018-04-25 12:43   ` Rasmus Villemoes
2018-04-26  1:28   ` Sergey Senozhatsky
2018-04-27 12:37     ` Petr Mladek
2018-04-25 11:12 ` [PATCH v5 11/11] vsprintf: Avoid confusion between invalid address and value Petr Mladek
2018-04-27 14:10 ` [PATCH v5 00/11] vsprintf: Prevent silent crashes and consolidate error handling Petr Mladek

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