From c604b40728c28ba4d831832c7f03805aba11a8e2 Mon Sep 17 00:00:00 2001
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Date: Fri, 16 Feb 2018 23:07:03 +0200
Subject: [PATCH 1/9] lib/test_printf: Mark big constant with UL
Sparse complains that constant is so big for unsigned long on 64-bit
architecture.
lib/test_printf.c:217:54: warning: constant 0xffff0123456789ab is so big it is unsigned long
lib/test_printf.c:246:54: warning: constant 0xffff0123456789ab is so big it is unsigned long
To satisfy everyone, mark the constant with UL.
Link: http://lkml.kernel.org/r/20180216210711.79901-1-andriy.shevchenko@linux.intel.com
To: "Tobin C . Harding" <me@tobin.cc>
To: linux@rasmusvillemoes.dk
To: Joe Perches <joe@perches.com>
To: linux-kernel@vger.kernel.org
To: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
[pmladek@suse.com: Changed from ULL to UL as suggested by Luc Van Oostenryck <luc.vanoostenryck@gmail.com>]
Signed-off-by: Petr Mladek <pmladek@suse.com>
---
lib/test_printf.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/lib/test_printf.c b/lib/test_printf.c
index 71ebfa43ad05f..cea592f402ed0 100644
--- a/lib/test_printf.c
+++ b/lib/test_printf.c
@@ -204,7 +204,7 @@ test_string(void)
#if BITS_PER_LONG == 64
#define PTR_WIDTH 16
-#define PTR ((void *)0xffff0123456789ab)
+#define PTR ((void *)0xffff0123456789abUL)
#define PTR_STR "ffff0123456789ab"
#define ZEROS "00000000" /* hex 32 zero bits */
From ce0b4910bdf8c515fe8be49a6c582ee8b206ca0a Mon Sep 17 00:00:00 2001
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Date: Fri, 16 Feb 2018 23:07:04 +0200
Subject: [PATCH 2/9] lib/vsprintf: Make dec_spec global
There are places where default specification to print decimal numbers
is in use.
Make it global and convert existing users.
Link: http://lkml.kernel.org/r/20180216210711.79901-2-andriy.shevchenko@linux.intel.com
To: "Tobin C . Harding" <me@tobin.cc>
To: linux@rasmusvillemoes.dk
To: Joe Perches <joe@perches.com>
To: linux-kernel@vger.kernel.org
To: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
---
lib/vsprintf.c | 21 +++++++++------------
1 file changed, 9 insertions(+), 12 deletions(-)
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index d7a708f82559c..8f29af063d8a5 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -693,6 +693,11 @@ char *symbol_string(char *buf, char *end, void *ptr,
#endif
}
+static const struct printf_spec default_dec_spec = {
+ .base = 10,
+ .precision = -1,
+};
+
static noinline_for_stack
char *resource_string(char *buf, char *end, struct resource *res,
struct printf_spec spec, const char *fmt)
@@ -722,11 +727,6 @@ char *resource_string(char *buf, char *end, struct resource *res,
.precision = -1,
.flags = SMALL | ZEROPAD,
};
- static const struct printf_spec dec_spec = {
- .base = 10,
- .precision = -1,
- .flags = 0,
- };
static const struct printf_spec str_spec = {
.field_width = -1,
.precision = 10,
@@ -760,10 +760,10 @@ char *resource_string(char *buf, char *end, struct resource *res,
specp = &mem_spec;
} else if (res->flags & IORESOURCE_IRQ) {
p = string(p, pend, "irq ", str_spec);
- specp = &dec_spec;
+ specp = &default_dec_spec;
} else if (res->flags & IORESOURCE_DMA) {
p = string(p, pend, "dma ", str_spec);
- specp = &dec_spec;
+ specp = &default_dec_spec;
} else if (res->flags & IORESOURCE_BUS) {
p = string(p, pend, "bus ", str_spec);
specp = &bus_spec;
@@ -903,9 +903,6 @@ char *bitmap_list_string(char *buf, char *end, unsigned long *bitmap,
int cur, rbot, rtop;
bool first = true;
- /* reused to print numbers */
- spec = (struct printf_spec){ .base = 10 };
-
rbot = cur = find_first_bit(bitmap, nr_bits);
while (cur < nr_bits) {
rtop = cur;
@@ -920,13 +917,13 @@ char *bitmap_list_string(char *buf, char *end, unsigned long *bitmap,
}
first = false;
- buf = number(buf, end, rbot, spec);
+ buf = number(buf, end, rbot, default_dec_spec);
if (rbot < rtop) {
if (buf < end)
*buf = '-';
buf++;
- buf = number(buf, end, rtop, spec);
+ buf = number(buf, end, rtop, default_dec_spec);
}
rbot = cur;
From abd4fe6276fa1111453f96cefa7145b6d15868ca Mon Sep 17 00:00:00 2001
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Date: Fri, 16 Feb 2018 23:07:05 +0200
Subject: [PATCH 3/9] lib/vsprintf: Make strspec global
There are places where default specification to print strings
is in use.
Make it global and convert existing users.
Link: http://lkml.kernel.org/r/20180216210711.79901-3-andriy.shevchenko@linux.intel.com
To: "Tobin C . Harding" <me@tobin.cc>
To: linux@rasmusvillemoes.dk
To: Joe Perches <joe@perches.com>
To: linux-kernel@vger.kernel.org
To: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
---
lib/vsprintf.c | 21 +++++++++------------
1 file changed, 9 insertions(+), 12 deletions(-)
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 8f29af063d8a5..0c23b006b4958 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -693,6 +693,11 @@ char *symbol_string(char *buf, char *end, void *ptr,
#endif
}
+static const struct printf_spec default_str_spec = {
+ .field_width = -1,
+ .precision = -1,
+};
+
static const struct printf_spec default_dec_spec = {
.base = 10,
.precision = -1,
@@ -1461,10 +1466,6 @@ char *format_flags(char *buf, char *end, unsigned long flags,
const struct trace_print_flags *names)
{
unsigned long mask;
- const struct printf_spec strspec = {
- .field_width = -1,
- .precision = -1,
- };
const struct printf_spec numspec = {
.flags = SPECIAL|SMALL,
.field_width = -1,
@@ -1477,7 +1478,7 @@ char *format_flags(char *buf, char *end, unsigned long flags,
if ((flags & mask) != mask)
continue;
- buf = string(buf, end, names->name, strspec);
+ buf = string(buf, end, names->name, default_str_spec);
flags &= ~mask;
if (flags) {
@@ -1535,22 +1536,18 @@ char *device_node_gen_full_name(const struct device_node *np, char *buf, char *e
{
int depth;
const struct device_node *parent = np->parent;
- static const struct printf_spec strspec = {
- .field_width = -1,
- .precision = -1,
- };
/* special case for root node */
if (!parent)
- return string(buf, end, "/", strspec);
+ return string(buf, end, "/", default_str_spec);
for (depth = 0; parent->parent; depth++)
parent = parent->parent;
for ( ; depth >= 0; depth--) {
- buf = string(buf, end, "/", strspec);
+ buf = string(buf, end, "/", default_str_spec);
buf = string(buf, end, device_node_name_for_depth(np, depth),
- strspec);
+ default_str_spec);
}
return buf;
}
From 544339730844674058e772084948cfcc9e62a3c5 Mon Sep 17 00:00:00 2001
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Date: Fri, 16 Feb 2018 23:07:06 +0200
Subject: [PATCH 4/9] lib/vsprintf: Make flag_spec global
There are places where default specification to print flags as number
is in use.
Make it global and convert existing users.
Link: http://lkml.kernel.org/r/20180216210711.79901-4-andriy.shevchenko@linux.intel.com
To: "Tobin C . Harding" <me@tobin.cc>
To: linux@rasmusvillemoes.dk
To: Joe Perches <joe@perches.com>
To: linux-kernel@vger.kernel.org
To: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
---
lib/vsprintf.c | 21 ++++++++-------------
1 file changed, 8 insertions(+), 13 deletions(-)
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 0c23b006b4958..c789d265311b0 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -698,6 +698,12 @@ static const struct printf_spec default_str_spec = {
.precision = -1,
};
+static const struct printf_spec default_flag_spec = {
+ .base = 16,
+ .precision = -1,
+ .flags = SPECIAL | SMALL,
+};
+
static const struct printf_spec default_dec_spec = {
.base = 10,
.precision = -1,
@@ -737,11 +743,6 @@ char *resource_string(char *buf, char *end, struct resource *res,
.precision = 10,
.flags = LEFT,
};
- static const struct printf_spec flag_spec = {
- .base = 16,
- .precision = -1,
- .flags = SPECIAL | SMALL,
- };
/* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
* 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
@@ -798,7 +799,7 @@ char *resource_string(char *buf, char *end, struct resource *res,
p = string(p, pend, " disabled", str_spec);
} else {
p = string(p, pend, " flags ", str_spec);
- p = number(p, pend, res->flags, flag_spec);
+ p = number(p, pend, res->flags, default_flag_spec);
}
*p++ = ']';
*p = '\0';
@@ -1466,12 +1467,6 @@ char *format_flags(char *buf, char *end, unsigned long flags,
const struct trace_print_flags *names)
{
unsigned long mask;
- const struct printf_spec numspec = {
- .flags = SPECIAL|SMALL,
- .field_width = -1,
- .precision = -1,
- .base = 16,
- };
for ( ; flags && names->name; names++) {
mask = names->mask;
@@ -1489,7 +1484,7 @@ char *format_flags(char *buf, char *end, unsigned long flags,
}
if (flags)
- buf = number(buf, end, flags, numspec);
+ buf = number(buf, end, flags, default_flag_spec);
return buf;
}
From 558594f3c2a5cd65f18b976faf68143c502b73b2 Mon Sep 17 00:00:00 2001
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Date: Fri, 16 Feb 2018 23:07:07 +0200
Subject: [PATCH 5/9] lib/vsprintf: Move pointer_string() upper
As preparatory patch to further clean up.
No functional change.
Link: http://lkml.kernel.org/r/20180216210711.79901-5-andriy.shevchenko@linux.intel.com
To: "Tobin C . Harding" <me@tobin.cc>
To: linux@rasmusvillemoes.dk
To: Joe Perches <joe@perches.com>
To: linux-kernel@vger.kernel.org
To: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
---
lib/vsprintf.c | 28 ++++++++++++++--------------
1 file changed, 14 insertions(+), 14 deletions(-)
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index c789d265311b0..87dbced51b1af 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -1347,6 +1347,20 @@ char *uuid_string(char *buf, char *end, const u8 *addr,
return string(buf, end, uuid, 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);
+}
+
int kptr_restrict __read_mostly;
static noinline_for_stack
@@ -1634,20 +1648,6 @@ char *device_node_string(char *buf, char *end, struct device_node *dn,
return widen_string(buf, buf - buf_start, end, 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;
From 496a9a5f3806d58b14ae06b390d5b1ffa26e9f9a Mon Sep 17 00:00:00 2001
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Date: Fri, 16 Feb 2018 23:07:08 +0200
Subject: [PATCH 6/9] lib/vsprintf: Deduplicate pointer_string()
There is an exact code at the end of ptr_to_id().
Replace it by calling pointer_string() directly.
This is followup to the commit ad67b74d2469 ("printk: hash addresses
printed with %p").
Cc: Tobin C. Harding <me@tobin.cc>
Link: http://lkml.kernel.org/r/20180216210711.79901-6-andriy.shevchenko@linux.intel.com
To: "Tobin C . Harding" <me@tobin.cc>
To: linux@rasmusvillemoes.dk
To: Joe Perches <joe@perches.com>
To: linux-kernel@vger.kernel.org
To: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
---
lib/vsprintf.c | 27 +++++++--------------------
1 file changed, 7 insertions(+), 20 deletions(-)
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 87dbced51b1af..9004bbb3d84d9 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -1367,13 +1367,6 @@ static noinline_for_stack
char *restricted_pointer(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;
- }
-
switch (kptr_restrict) {
case 0:
/* Always print %pK values */
@@ -1385,8 +1378,11 @@ char *restricted_pointer(char *buf, char *end, const void *ptr,
* 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 (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
@@ -1411,7 +1407,7 @@ char *restricted_pointer(char *buf, char *end, const void *ptr,
break;
}
- return number(buf, end, (unsigned long)ptr, spec);
+ return pointer_string(buf, end, ptr, spec);
}
static noinline_for_stack
@@ -1686,10 +1682,9 @@ early_initcall(initialize_ptr_random);
static char *ptr_to_id(char *buf, char *end, void *ptr, struct printf_spec spec)
{
unsigned long hashval;
- const int default_width = 2 * sizeof(ptr);
if (unlikely(!have_filled_random_ptr_key)) {
- spec.field_width = default_width;
+ spec.field_width = 2 * sizeof(ptr);
/* string length must be less than default_width */
return string(buf, end, "(ptrval)", spec);
}
@@ -1704,15 +1699,7 @@ static char *ptr_to_id(char *buf, char *end, void *ptr, struct printf_spec spec)
#else
hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key);
#endif
-
- spec.flags |= SMALL;
- if (spec.field_width == -1) {
- spec.field_width = default_width;
- spec.flags |= ZEROPAD;
- }
- spec.base = 16;
-
- return number(buf, end, hashval, spec);
+ return pointer_string(buf, end, (const void *)hashval, spec);
}
/*
From 91efafb1dd8f471177a3dddb4841d75d3df1cc46 Mon Sep 17 00:00:00 2001
From: Shunyong Yang <shunyong.yang@hxt-semitech.com>
Date: Fri, 16 Feb 2018 23:07:09 +0200
Subject: [PATCH 7/9] lib/vsprintf: Replace space with '_' before crng is ready
Before crng is ready, output of "%p" composes of "(ptrval)" and
left padding spaces for alignment as no random address can be
generated. This seems a little strange when default string width
is larger than strlen("(ptrval)").
For example, when irq domain names are built with "%p", the nodes
under /sys/kernel/debug/irq/domains like this on AArch64 system,
[root@y irq]# ls domains/
default irqchip@ (ptrval)-2
irqchip@ (ptrval)-4 \_SB_.TCS0.QIC1 \_SB_.TCS0.QIC3
irqchip@ (ptrval) irqchip@ (ptrval)-3
\_SB_.TCS0.QIC0 \_SB_.TCS0.QIC2
The name "irqchip@ (ptrval)-2" is not so readable in console
output.
This patch replaces space with readable "_" when output needs padding.
Following is the output after applying the patch,
[root@y domains]# ls
default irqchip@(____ptrval____)-2
irqchip@(____ptrval____)-4 \_SB_.TCS0.QIC1 \_SB_.TCS0.QIC3
irqchip@(____ptrval____) irqchip@(____ptrval____)-3 \_SB_.TCS0.QIC0
\_SB_.TCS0.QIC2
There is same problem in some subsystem's dmesg output. Moreover,
someone may call "%p" in a similar case. In addition, the timing of
crng initialization done may vary on different system. So, the change
is made in vsprintf.c.
Suggested-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Link: http://lkml.kernel.org/r/20180216210711.79901-7-andriy.shevchenko@linux.intel.com
To: "Tobin C . Harding" <me@tobin.cc>
To: linux@rasmusvillemoes.dk
To: Joe Perches <joe@perches.com>
To: linux-kernel@vger.kernel.org
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Joey Zheng <yu.zheng@hxt-semitech.com>
Signed-off-by: Shunyong Yang <shunyong.yang@hxt-semitech.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
---
lib/vsprintf.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 9004bbb3d84d9..97be2d07297a7 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -1681,12 +1681,13 @@ 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, "(ptrval)", spec);
+ return string(buf, end, str, spec);
}
#ifdef CONFIG_64BIT
From 7e6bd6f3dcf913460a0a0ae7f260a8280001dd80 Mon Sep 17 00:00:00 2001
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Date: Fri, 16 Feb 2018 23:07:11 +0200
Subject: [PATCH 8/9] lib/vsprintf: Mark expected switch fall-through
In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.
Link: http://lkml.kernel.org/r/20180216210711.79901-9-andriy.shevchenko@linux.intel.com
To: "Tobin C . Harding" <me@tobin.cc>
To: linux@rasmusvillemoes.dk
To: Joe Perches <joe@perches.com>
To: linux-kernel@vger.kernel.org
To: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
---
lib/vsprintf.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 97be2d07297a7..38a71df48d489 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -2092,6 +2092,7 @@ int format_decode(const char *fmt, struct printf_spec *spec)
case 'x':
spec->flags |= SMALL;
+ /* fall through */
case 'X':
spec->base = 16;
@@ -3046,8 +3047,10 @@ int vsscanf(const char *buf, const char *fmt, va_list args)
break;
case 'i':
base = 0;
+ /* fall through */
case 'd':
is_sign = true;
+ /* fall through */
case 'u':
break;
case '%':
From cdb7e52d960a59f30de853f5dd85574432d6bb50 Mon Sep 17 00:00:00 2001
From: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Date: Sat, 14 Apr 2018 12:00:05 +0900
Subject: [PATCH 9/9] vsprintf: Tweak pF/pf comment
Reflect changes that have happened to pf/pF (deprecation)
specifiers in pointer() comment section.
Link: http://lkml.kernel.org/r/20180414030005.25831-1-sergey.senozhatsky@gmail.com
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Joe Perches <joe@perches.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
---
lib/vsprintf.c | 12 ++++--------
1 file changed, 4 insertions(+), 8 deletions(-)
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 38a71df48d489..7649ef4ed7d0b 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -1713,10 +1713,10 @@ static char *ptr_to_id(char *buf, char *end, void *ptr, struct printf_spec spec)
*
* Right now we handle:
*
- * - 'F' For symbolic function descriptor pointers with offset
- * - 'f' For simple symbolic function names without offset
- * - 'S' For symbolic direct pointers with offset
- * - 's' For symbolic direct pointers without offset
+ * - 'S' For symbolic direct pointers (or function descriptors) with offset
+ * - 's' For symbolic direct pointers (or function descriptors) without offset
+ * - 'F' Same as 'S'
+ * - 'f' Same as 's'
* - '[FfSs]R' as above with __builtin_extract_return_addr() translation
* - 'B' For backtraced symbolic direct pointers with offset
* - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
@@ -1813,10 +1813,6 @@ static char *ptr_to_id(char *buf, char *end, void *ptr, struct printf_spec spec)
* ** When making changes please also update:
* Documentation/core-api/printk-formats.rst
*
- * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
- * function pointers are really function descriptors, which contain a
- * pointer to the real address.
- *
* Note: The default behaviour (unadorned %p) is to hash the address,
* rendering it useful as a unique identifier.
*/