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 v7 07/10] vsprintf: Consolidate handling of unknown pointer specifiers
Date: Wed, 17 Apr 2019 13:53:47 +0200 [thread overview]
Message-ID: <20190417115350.20479-8-pmladek@suse.com> (raw)
In-Reply-To: <20190417115350.20479-1-pmladek@suse.com>
There are few printk formats that make sense only with two or more
specifiers. Also some specifiers make sense only when a kernel feature
is enabled.
The handling of unknown specifiers is inconsistent and not helpful.
Using WARN() looks like an overkill for this type of error. pr_warn()
is not good either. It would by handled via printk_safe buffer and
it might be hard to match it with the problematic string.
A reasonable compromise seems to be writing the unknown format specifier
into the original string with a question mark, for example (%pC?).
It should be self-explaining enough. Note that it is in brackets
to follow the (null) style.
Note that it introduces a warning about that test_hashed() function
is unused. It is going to be used again by a later patch.
Signed-off-by: Petr Mladek <pmladek@suse.com>
---
lib/test_printf.c | 3 +--
lib/vsprintf.c | 28 +++++++++++++++++-----------
2 files changed, 18 insertions(+), 13 deletions(-)
diff --git a/lib/test_printf.c b/lib/test_printf.c
index 659b6cc0d483..250ee864b8b8 100644
--- a/lib/test_printf.c
+++ b/lib/test_printf.c
@@ -462,8 +462,7 @@ struct_rtc_time(void)
.tm_year = 118,
};
- test_hashed("%pt", &tm);
-
+ test("(%ptR?)", "%pt", &tm);
test("2018-11-26T05:35:43", "%ptR", &tm);
test("0118-10-26T05:35:43", "%ptRr", &tm);
test("05:35:43|2018-11-26", "%ptRt|%ptRd", &tm, &tm);
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 9817d171f608..f471a658422f 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -1435,6 +1435,8 @@ 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);
@@ -1457,7 +1459,8 @@ char *ip_addr_string(char *buf, char *end, const void *ptr,
}}
}
- return ptr_to_id(buf, end, ptr, spec);
+ err_fmt_msg = fmt[0] == 'i' ? "(%pi?)" : "(%pI?)";
+ return string_nocheck(buf, end, err_fmt_msg, spec);
}
static noinline_for_stack
@@ -1585,7 +1588,7 @@ char *netdev_bits(char *buf, char *end, const void *addr,
size = sizeof(netdev_features_t);
break;
default:
- return ptr_to_id(buf, end, addr, spec);
+ return string_nocheck(buf, end, "(%pN?)", spec);
}
return special_hex_number(buf, end, num, size);
@@ -1689,7 +1692,7 @@ char *time_and_date(char *buf, char *end, void *ptr, struct printf_spec spec,
case 'R':
return rtc_str(buf, end, (const struct rtc_time *)ptr, fmt);
default:
- return ptr_to_id(buf, end, ptr, spec);
+ return string_nocheck(buf, end, "(%ptR?)", spec);
}
}
@@ -1697,7 +1700,10 @@ static noinline_for_stack
char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,
const char *fmt)
{
- if (!IS_ENABLED(CONFIG_HAVE_CLK) || !clk)
+ if (!IS_ENABLED(CONFIG_HAVE_CLK))
+ return string_nocheck(buf, end, "(%pC?)", spec);
+
+ if (!clk)
return string(buf, end, NULL, spec);
switch (fmt[1]) {
@@ -1706,7 +1712,7 @@ char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,
#ifdef CONFIG_COMMON_CLK
return string(buf, end, __clk_get_name(clk), spec);
#else
- return ptr_to_id(buf, end, clk, spec);
+ return string_nocheck(buf, end, "(%pC?)", spec);
#endif
}
}
@@ -1739,7 +1745,8 @@ char *format_flags(char *buf, char *end, unsigned long flags,
}
static noinline_for_stack
-char *flags_string(char *buf, char *end, void *flags_ptr, const char *fmt)
+char *flags_string(char *buf, char *end, void *flags_ptr,
+ struct printf_spec spec, const char *fmt)
{
unsigned long flags;
const struct trace_print_flags *names;
@@ -1760,8 +1767,7 @@ char *flags_string(char *buf, char *end, void *flags_ptr, const char *fmt)
names = gfpflag_names;
break;
default:
- WARN_ONCE(1, "Unsupported flags modifier: %c\n", fmt[1]);
- return buf;
+ return string_nocheck(buf, end, "(%pG?)", spec);
}
return format_flags(buf, end, flags, names);
@@ -1817,7 +1823,7 @@ char *device_node_string(char *buf, char *end, struct device_node *dn,
str_spec.field_width = -1;
if (!IS_ENABLED(CONFIG_OF))
- return string_nocheck(buf, end, "(!OF)", spec);
+ return string_nocheck(buf, end, "(%pOF?)", spec);
if ((unsigned long)dn < PAGE_SIZE)
return string_nocheck(buf, end, "(null)", spec);
@@ -1896,7 +1902,7 @@ static char *kobject_string(char *buf, char *end, void *ptr,
return device_node_string(buf, end, ptr, spec, fmt + 1);
}
- return ptr_to_id(buf, end, ptr, spec);
+ return string_nocheck(buf, end, "(%pO?)", spec);
}
/*
@@ -2091,7 +2097,7 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr,
#endif
case 'G':
- return flags_string(buf, end, ptr, fmt);
+ return flags_string(buf, end, ptr, spec, fmt);
case 'O':
return kobject_string(buf, end, ptr, spec, fmt);
case 'x':
--
2.16.4
next prev parent reply other threads:[~2019-04-17 11:54 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-17 11:53 [PATCH v7 00/10] vsprintf: Prevent silent crashes and consolidate error handling Petr Mladek
2019-04-17 11:53 ` [PATCH v7 01/10] vsprintf: Shuffle restricted_pointer() Petr Mladek
2019-04-17 11:53 ` [PATCH v7 02/10] vsprintf: Consistent %pK handling for kptr_restrict == 0 Petr Mladek
2019-04-17 13:44 ` Steven Rostedt
2019-04-17 11:53 ` [PATCH v7 03/10] vsprintf: Do not check address of well-known strings Petr Mladek
2019-04-17 11:53 ` [PATCH v7 04/10] vsprintf: Factor out %p[iI] handler as ip_addr_string() Petr Mladek
2019-04-17 11:53 ` [PATCH v7 05/10] vsprintf: Factor out %pV handler as va_format() Petr Mladek
2019-04-17 11:53 ` [PATCH v7 06/10] vsprintf: Factor out %pO handler as kobject_string() Petr Mladek
2019-04-17 11:53 ` Petr Mladek [this message]
2019-04-18 14:34 ` [PATCH v7 07/10] vsprintf: Consolidate handling of unknown pointer specifiers Sergey Senozhatsky
2019-04-18 14:43 ` Sergey Senozhatsky
2019-04-18 14:50 ` Sergey Senozhatsky
2019-06-25 10:59 ` Geert Uytterhoeven
2019-06-26 10:46 ` Petr Mladek
2019-06-26 11:16 ` Geert Uytterhoeven
2019-04-17 11:53 ` [PATCH v7 08/10] vsprintf: Prevent crash when dereferencing invalid pointers Petr Mladek
2019-04-17 11:53 ` [PATCH v7 09/10] vsprintf: Avoid confusion between invalid address and value Petr Mladek
2019-04-17 11:53 ` [PATCH v7 10/10] vsprintf: Limit the length of inlined error messages Petr Mladek
2019-04-19 1:51 ` [PATCH v7 00/10] vsprintf: Prevent silent crashes and consolidate error handling Sergey Senozhatsky
2019-04-24 13:53 ` Petr Mladek
2019-04-26 13:02 ` Andy Shevchenko
2019-04-26 14:27 ` Petr Mladek
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