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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 01/11] vsprintf: Shuffle misc pointer to string functions
Date: Wed, 25 Apr 2018 13:12:41 +0200	[thread overview]
Message-ID: <20180425111251.13246-2-pmladek@suse.com> (raw)
In-Reply-To: <20180425111251.13246-1-pmladek@suse.com>

This is just a preparation step for further changes.

The patch does not change the code.

Signed-off-by: Petr Mladek <pmladek@suse.com>
---
 lib/vsprintf.c | 244 ++++++++++++++++++++++++++++-----------------------------
 1 file changed, 122 insertions(+), 122 deletions(-)

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index b82f0c6c2aec..19fdfe621b40 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -613,6 +613,128 @@ char *string(char *buf, char *end, const char *s, struct printf_spec spec)
 }
 
 static noinline_for_stack
+char *pointer_string(char *buf, char *end, const void *ptr,
+		     struct printf_spec spec)
+{
+	spec.base = 16;
+	spec.flags |= SMALL;
+	if (spec.field_width == -1) {
+		spec.field_width = 2 * sizeof(ptr);
+		spec.flags |= ZEROPAD;
+	}
+
+	return number(buf, end, (unsigned long int)ptr, spec);
+}
+
+static bool have_filled_random_ptr_key __read_mostly;
+static siphash_key_t ptr_key __read_mostly;
+
+static void fill_random_ptr_key(struct random_ready_callback *unused)
+{
+	get_random_bytes(&ptr_key, sizeof(ptr_key));
+	/*
+	 * have_filled_random_ptr_key==true is dependent on get_random_bytes().
+	 * ptr_to_id() needs to see have_filled_random_ptr_key==true
+	 * after get_random_bytes() returns.
+	 */
+	smp_mb();
+	WRITE_ONCE(have_filled_random_ptr_key, true);
+}
+
+static struct random_ready_callback random_ready = {
+	.func = fill_random_ptr_key
+};
+
+static int __init initialize_ptr_random(void)
+{
+	int ret = add_random_ready_callback(&random_ready);
+
+	if (!ret) {
+		return 0;
+	} else if (ret == -EALREADY) {
+		fill_random_ptr_key(&random_ready);
+		return 0;
+	}
+
+	return ret;
+}
+early_initcall(initialize_ptr_random);
+
+/* Maps a pointer to a 32 bit unique identifier. */
+static char *ptr_to_id(char *buf, char *end, void *ptr, struct printf_spec spec)
+{
+	const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)";
+	unsigned long hashval;
+
+	if (unlikely(!have_filled_random_ptr_key)) {
+		spec.field_width = 2 * sizeof(ptr);
+		/* string length must be less than default_width */
+		return string(buf, end, str, spec);
+	}
+
+#ifdef CONFIG_64BIT
+	hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
+	/*
+	 * Mask off the first 32 bits, this makes explicit that we have
+	 * modified the address (and 32 bits is plenty for a unique ID).
+	 */
+	hashval = hashval & 0xffffffff;
+#else
+	hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key);
+#endif
+	return pointer_string(buf, end, (const void *)hashval, spec);
+}
+
+int kptr_restrict __read_mostly;
+
+static noinline_for_stack
+char *restricted_pointer(char *buf, char *end, const void *ptr,
+			 struct printf_spec spec)
+{
+	switch (kptr_restrict) {
+	case 0:
+		/* Always print %pK values */
+		break;
+	case 1: {
+		const struct cred *cred;
+
+		/*
+		 * kptr_restrict==1 cannot be used in IRQ context
+		 * because its test for CAP_SYSLOG would be meaningless.
+		 */
+		if (in_irq() || in_serving_softirq() || in_nmi()) {
+			if (spec.field_width == -1)
+				spec.field_width = 2 * sizeof(ptr);
+			return string(buf, end, "pK-error", spec);
+		}
+
+		/*
+		 * Only print the real pointer value if the current
+		 * process has CAP_SYSLOG and is running with the
+		 * same credentials it started with. This is because
+		 * access to files is checked at open() time, but %pK
+		 * checks permission at read() time. We don't want to
+		 * leak pointer values if a binary opens a file using
+		 * %pK and then elevates privileges before reading it.
+		 */
+		cred = current_cred();
+		if (!has_capability_noaudit(current, CAP_SYSLOG) ||
+		    !uid_eq(cred->euid, cred->uid) ||
+		    !gid_eq(cred->egid, cred->gid))
+			ptr = NULL;
+		break;
+	}
+	case 2:
+	default:
+		/* Always print 0's for %pK */
+		ptr = NULL;
+		break;
+	}
+
+	return pointer_string(buf, end, ptr, spec);
+}
+
+static noinline_for_stack
 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
 		  const char *fmt)
 {
@@ -1358,69 +1480,6 @@ char *uuid_string(char *buf, char *end, const u8 *addr,
 }
 
 static noinline_for_stack
-char *pointer_string(char *buf, char *end, const void *ptr,
-		     struct printf_spec spec)
-{
-	spec.base = 16;
-	spec.flags |= SMALL;
-	if (spec.field_width == -1) {
-		spec.field_width = 2 * sizeof(ptr);
-		spec.flags |= ZEROPAD;
-	}
-
-	return number(buf, end, (unsigned long int)ptr, spec);
-}
-
-int kptr_restrict __read_mostly;
-
-static noinline_for_stack
-char *restricted_pointer(char *buf, char *end, const void *ptr,
-			 struct printf_spec spec)
-{
-	switch (kptr_restrict) {
-	case 0:
-		/* Always print %pK values */
-		break;
-	case 1: {
-		const struct cred *cred;
-
-		/*
-		 * kptr_restrict==1 cannot be used in IRQ context
-		 * because its test for CAP_SYSLOG would be meaningless.
-		 */
-		if (in_irq() || in_serving_softirq() || in_nmi()) {
-			if (spec.field_width == -1)
-				spec.field_width = 2 * sizeof(ptr);
-			return string(buf, end, "pK-error", spec);
-		}
-
-		/*
-		 * Only print the real pointer value if the current
-		 * process has CAP_SYSLOG and is running with the
-		 * same credentials it started with. This is because
-		 * access to files is checked at open() time, but %pK
-		 * checks permission at read() time. We don't want to
-		 * leak pointer values if a binary opens a file using
-		 * %pK and then elevates privileges before reading it.
-		 */
-		cred = current_cred();
-		if (!has_capability_noaudit(current, CAP_SYSLOG) ||
-		    !uid_eq(cred->euid, cred->uid) ||
-		    !gid_eq(cred->egid, cred->gid))
-			ptr = NULL;
-		break;
-	}
-	case 2:
-	default:
-		/* Always print 0's for %pK */
-		ptr = NULL;
-		break;
-	}
-
-	return pointer_string(buf, end, ptr, spec);
-}
-
-static noinline_for_stack
 char *netdev_bits(char *buf, char *end, const void *addr, const char *fmt)
 {
 	unsigned long long num;
@@ -1654,65 +1713,6 @@ char *device_node_string(char *buf, char *end, struct device_node *dn,
 	return widen_string(buf, buf - buf_start, end, spec);
 }
 
-static bool have_filled_random_ptr_key __read_mostly;
-static siphash_key_t ptr_key __read_mostly;
-
-static void fill_random_ptr_key(struct random_ready_callback *unused)
-{
-	get_random_bytes(&ptr_key, sizeof(ptr_key));
-	/*
-	 * have_filled_random_ptr_key==true is dependent on get_random_bytes().
-	 * ptr_to_id() needs to see have_filled_random_ptr_key==true
-	 * after get_random_bytes() returns.
-	 */
-	smp_mb();
-	WRITE_ONCE(have_filled_random_ptr_key, true);
-}
-
-static struct random_ready_callback random_ready = {
-	.func = fill_random_ptr_key
-};
-
-static int __init initialize_ptr_random(void)
-{
-	int ret = add_random_ready_callback(&random_ready);
-
-	if (!ret) {
-		return 0;
-	} else if (ret == -EALREADY) {
-		fill_random_ptr_key(&random_ready);
-		return 0;
-	}
-
-	return ret;
-}
-early_initcall(initialize_ptr_random);
-
-/* Maps a pointer to a 32 bit unique identifier. */
-static char *ptr_to_id(char *buf, char *end, void *ptr, struct printf_spec spec)
-{
-	const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)";
-	unsigned long hashval;
-
-	if (unlikely(!have_filled_random_ptr_key)) {
-		spec.field_width = 2 * sizeof(ptr);
-		/* string length must be less than default_width */
-		return string(buf, end, str, spec);
-	}
-
-#ifdef CONFIG_64BIT
-	hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
-	/*
-	 * Mask off the first 32 bits, this makes explicit that we have
-	 * modified the address (and 32 bits is plenty for a unique ID).
-	 */
-	hashval = hashval & 0xffffffff;
-#else
-	hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key);
-#endif
-	return pointer_string(buf, end, (const void *)hashval, spec);
-}
-
 /*
  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
  * by an extra set of alphanumeric characters that are extended format
-- 
2.13.6

  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 ` Petr Mladek [this message]
2018-04-25 14:57   ` [PATCH v5 01/11] vsprintf: Shuffle misc pointer to string functions 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 ` [PATCH v5 06/11] vsprintf: Factor out %p[iI] handler as ip_addr_string() Petr Mladek
2018-04-25 13:11   ` 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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