Commit c89f1bf1 authored by Evan Hunt's avatar Evan Hunt

[master] turn off memory fill by default

4768.	[func]		By default, memory is no longer filled with tag values
			when it is allocated or freed; this improves
			performance but makes debugging of certain memory
			issues more difficult. "named -M fill" turns memory
			filling back on. (Building "configure
			--enable-developer", turns memory fill on by
			default again; it can then be disabled with
			"named -M nofill".) [RT #45123]
parent 6cdff948
4768. [func] By default, memory is no longer filled with tag values
when it is allocated or freed; this improves
performance but makes debugging of certain memory
issues more difficult. "named -M fill" turns memory
filling back on. (Building "configure
--enable-developer", turns memory fill on by
default again; it can then be disabled with
"named -M nofill".) [RT #45123]
4767. [func] Add a new function, isc_buffer_printf(), which can be
used to append a formatted string to the used region of
a buffer. [RT #46201]
......
......@@ -5,9 +5,9 @@ defined in configure.
Some of these settings are:
Setting Description
Don't ovewrite memory when allocating or freeing
-DISC_MEM_FILL=0 it; this improves performance but makes
debugging more difficult.
Overwrite memory with tag values when allocating
-DISC_MEM_DEFAULTFILL=1 or freeing it; this impairs performance but
makes debugging of memory problems easier.
Don't track memory allocations by file and line
-DISC_MEM_TRACKLINES=0 number; this improves performance but makes
debugging more difficult.
......
......@@ -13,7 +13,7 @@ Some of these settings are:
|Setting |Description |
|-----------------------------------|----------------------------------------|
|`-DISC_MEM_FILL=0`|Don't ovewrite memory when allocating or freeing it; this improves performance but makes debugging more difficult.|
|`-DISC_MEM_DEFAULTFILL=1`|Overwrite memory with tag values when allocating or freeing it; this impairs performance but makes debugging of memory problems easier.|
|`-DISC_MEM_TRACKLINES=0`|Don't track memory allocations by file and line number; this improves performance but makes debugging more difficult.|
|<nobr>`-DISC_FACILITY=LOG_LOCAL0`</nobr>|Change the default syslog facility for `named`|
|`-DNS_CLIENT_DROPPORT=0`|Disable dropping queries from particular well-known ports:|
......
......@@ -390,14 +390,20 @@ parse_int(char *arg, const char *desc) {
static struct flag_def {
const char *name;
unsigned int value;
isc_boolean_t negate;
} mem_debug_flags[] = {
{ "none", 0},
{ "trace", ISC_MEM_DEBUGTRACE },
{ "record", ISC_MEM_DEBUGRECORD },
{ "usage", ISC_MEM_DEBUGUSAGE },
{ "size", ISC_MEM_DEBUGSIZE },
{ "mctx", ISC_MEM_DEBUGCTX },
{ NULL, 0 }
{ "none", 0, ISC_FALSE },
{ "trace", ISC_MEM_DEBUGTRACE, ISC_FALSE },
{ "record", ISC_MEM_DEBUGRECORD, ISC_FALSE },
{ "usage", ISC_MEM_DEBUGUSAGE, ISC_FALSE },
{ "size", ISC_MEM_DEBUGSIZE, ISC_FALSE },
{ "mctx", ISC_MEM_DEBUGCTX, ISC_FALSE },
{ NULL, 0, ISC_FALSE }
}, mem_context_flags[] = {
{ "external", ISC_MEMFLAG_INTERNAL, ISC_TRUE },
{ "fill", ISC_MEMFLAG_FILL, ISC_FALSE },
{ "nofill", ISC_MEMFLAG_FILL, ISC_TRUE },
{ NULL, 0, ISC_FALSE }
};
static void
......@@ -416,7 +422,10 @@ set_flags(const char *arg, struct flag_def *defs, unsigned int *ret) {
memcmp(arg, def->name, arglen) == 0) {
if (def->value == 0)
clear = ISC_TRUE;
*ret |= def->value;
if (def->negate)
*ret &= ~(def->value);
else
*ret |= def->value;
goto found;
}
}
......@@ -519,8 +528,8 @@ parse_command_line(int argc, char *argv[]) {
named_g_logfile = isc_commandline_argument;
break;
case 'M':
if (strcmp(isc_commandline_argument, "external") == 0)
isc_mem_defaultflags = 0;
set_flags(isc_commandline_argument, mem_context_flags,
&isc_mem_defaultflags);
break;
case 'm':
set_flags(isc_commandline_argument, mem_debug_flags,
......@@ -1382,6 +1391,15 @@ main(int argc, char *argv[]) {
pk11_result_register();
#endif
#if !ISC_MEM_DEFAULTFILL
/*
* Update the default flags to remove ISC_MEMFLAG_FILL
* before we parse the command line. If disabled here,
* it can be turned back on with -M fill.
*/
isc_mem_defaultflags &= ~ISC_MEMFLAG_FILL;
#endif
parse_command_line(argc, argv);
#ifdef ENABLE_AFL
......
......@@ -212,11 +212,17 @@
<term>-M <replaceable class="parameter">option</replaceable></term>
<listitem>
<para>
Sets the default memory context options. Currently
the only supported option is
Sets the default memory context options. If set to
<replaceable class="parameter">external</replaceable>,
which causes the internal memory manager to be bypassed
this causes the internal memory manager to be bypassed
in favor of system-provided memory allocation functions.
If set to <replaceable class="parameter">fill</replaceable>,
blocks of memory will be filled with tag values when allocated
or freed, to assist debugging of memory problems.
(<replaceable class="parameter">nofill</replaceable>
disables this behavior, and is the default unless
<command>named</command> has been compiled with developer
options.)
</para>
</listitem>
</varlistentry>
......
......@@ -11466,7 +11466,7 @@ fi
XTARGETS=
case "$enable_developer" in
yes)
STD_CDEFINES="$STD_CDEFINES -DISC_LIST_CHECKINIT=1"
STD_CDEFINES="$STD_CDEFINES -DISC_MEM_DEFAULTFILL=1 -DISC_LIST_CHECKINIT=1"
test "${enable_fixed_rrset+set}" = set || enable_fixed_rrset=yes
test "${enable_querytrace+set}" = set || enable_querytrace=yes
test "${with_atf+set}" = set || with_atf=yes
......
......@@ -62,7 +62,7 @@ AC_ARG_ENABLE(developer, [ --enable-developer enable developer build setti
XTARGETS=
case "$enable_developer" in
yes)
STD_CDEFINES="$STD_CDEFINES -DISC_LIST_CHECKINIT=1"
STD_CDEFINES="$STD_CDEFINES -DISC_MEM_DEFAULTFILL=1 -DISC_LIST_CHECKINIT=1"
test "${enable_fixed_rrset+set}" = set || enable_fixed_rrset=yes
test "${enable_querytrace+set}" = set || enable_querytrace=yes
test "${with_atf+set}" = set || with_atf=yes
......
......@@ -129,6 +129,18 @@
case restoration, hashing, and buffers.
</para>
</listitem>
<listitem>
<para>
When built with default <command>configure</command> options,
<command>named</command> no longer fills memory with tag
values when allocating or freeing it. This improves performance,
but makes it more difficult to debug certain memory-related
errors. The default is reversed if building with developer
options. <command>named -M fill</command> or
<command>named -M nofill</command> will set the behavior
accordingly regardless of build options.
</para>
</listitem>
</itemizedlist>
</listitem>
<listitem>
......
......@@ -52,23 +52,6 @@ typedef void (*isc_memfree_t)(void *, void *);
#define ISC_MEM_CHECKOVERRUN 1
#endif
/*%
* Define ISC_MEM_FILL=1 to fill each block of memory returned to the system
* with the byte string '0xbe'. This helps track down uninitialized pointers
* and the like. On freeing memory, the space is filled with '0xde' for
* the same reasons.
*
* If we are performing a Coverity static analysis then ISC_MEM_FILL
* can hide bugs that would otherwise discovered so force to zero.
*/
#ifdef __COVERITY__
#undef ISC_MEM_FILL
#define ISC_MEM_FILL 0
#endif
#ifndef ISC_MEM_FILL
#define ISC_MEM_FILL 1
#endif
/*%
* Define ISC_MEMPOOL_NAMES=1 to make memory pools store a symbolic
* name so that the leaking pool can be more readily identified in
......@@ -142,10 +125,12 @@ LIBISC_EXTERNAL_DATA extern unsigned int isc_mem_defaultflags;
*/
#define ISC_MEMFLAG_NOLOCK 0x00000001 /* no lock is necessary */
#define ISC_MEMFLAG_INTERNAL 0x00000002 /* use internal malloc */
#if ISC_MEM_USE_INTERNAL_MALLOC
#define ISC_MEMFLAG_DEFAULT ISC_MEMFLAG_INTERNAL
#else
#define ISC_MEMFLAG_FILL 0x00000004 /* fill with pattern after alloc and frees */
#if !ISC_MEM_USE_INTERNAL_MALLOC
#define ISC_MEMFLAG_DEFAULT 0
#else
#define ISC_MEMFLAG_DEFAULT ISC_MEMFLAG_INTERNAL|ISC_MEMFLAG_FILL
#endif
......
......@@ -657,8 +657,8 @@ mem_getunlocked(isc__mem_t *ctx, size_t size) {
ctx->maxmalloced = ctx->malloced;
/*
* If we don't set new_size to size, then the
* ISC_MEM_FILL code might write over bytes we
* don't own.
* ISC_MEMFLAG_FILL code might write over bytes we don't
* own.
*/
new_size = size;
goto done;
......@@ -691,16 +691,14 @@ mem_getunlocked(isc__mem_t *ctx, size_t size) {
ctx->inuse += new_size;
done:
#if ISC_MEM_FILL
if (ret != NULL)
if (ISC_UNLIKELY((ctx->flags & ISC_MEMFLAG_FILL) != 0) &&
ISC_LIKELY(ret != NULL))
memset(ret, 0xbe, new_size); /* Mnemonic for "beef". */
#endif
return (ret);
}
#if ISC_MEM_FILL && ISC_MEM_CHECKOVERRUN
#if ISC_MEM_CHECKOVERRUN
static inline void
check_overrun(void *mem, size_t size, size_t new_size) {
unsigned char *cp;
......@@ -724,9 +722,9 @@ mem_putunlocked(isc__mem_t *ctx, void *mem, size_t size) {
/*
* memput() called on something beyond our upper limit.
*/
#if ISC_MEM_FILL
memset(mem, 0xde, size); /* Mnemonic for "dead". */
#endif
if (ISC_UNLIKELY((ctx->flags & ISC_MEMFLAG_FILL) != 0))
memset(mem, 0xde, size); /* Mnemonic for "dead". */
(ctx->memfree)(ctx->arg, mem);
INSIST(ctx->stats[ctx->max_size].gets != 0U);
ctx->stats[ctx->max_size].gets--;
......@@ -736,12 +734,12 @@ mem_putunlocked(isc__mem_t *ctx, void *mem, size_t size) {
return;
}
#if ISC_MEM_FILL
if (ISC_UNLIKELY((ctx->flags & ISC_MEMFLAG_FILL) != 0)) {
#if ISC_MEM_CHECKOVERRUN
check_overrun(mem, size, new_size);
#endif
memset(mem, 0xde, new_size); /* Mnemonic for "dead". */
check_overrun(mem, size, new_size);
#endif
memset(mem, 0xde, new_size); /* Mnemonic for "dead". */
}
/*
* The free list uses the "rounded-up" size "new_size".
......@@ -771,19 +769,18 @@ mem_get(isc__mem_t *ctx, size_t size) {
#if ISC_MEM_CHECKOVERRUN
size += 1;
#endif
ret = (ctx->memalloc)(ctx->arg, size);
if (ret == NULL)
ctx->memalloc_failures++;
#if ISC_MEM_FILL
if (ret != NULL)
memset(ret, 0xbe, size); /* Mnemonic for "beef". */
#else
# if ISC_MEM_CHECKOVERRUN
if (ret != NULL)
ret[size-1] = 0xbe;
# endif
if (ISC_UNLIKELY((ctx->flags & ISC_MEMFLAG_FILL) != 0)) {
if (ISC_LIKELY(ret != NULL))
memset(ret, 0xbe, size); /* Mnemonic for "beef". */
} else {
#if ISC_MEM_CHECKOVERRUN
if (ISC_LIKELY(ret != NULL))
ret[size-1] = 0xbe;
}
#endif
return (ret);
......@@ -799,9 +796,8 @@ mem_put(isc__mem_t *ctx, void *mem, size_t size) {
INSIST(((unsigned char *)mem)[size] == 0xbe);
size += 1;
#endif
#if ISC_MEM_FILL
memset(mem, 0xde, size); /* Mnemonic for "dead". */
#endif
if (ISC_UNLIKELY((ctx->flags & ISC_MEMFLAG_FILL) != 0))
memset(mem, 0xde, size); /* Mnemonic for "dead". */
(ctx->memfree)(ctx->arg, mem);
}
......
......@@ -66,7 +66,7 @@ cd $builddir || exit 1
# Test a libtool / separate object dir / threadless build.
CFLAGS="-g -DISC_CHECK_NONE -DISC_MEM_FILL=0 -DISC_LIST_CHECKINIT" \
CFLAGS="-g -DISC_CHECK_NONE -DISC_LIST_CHECKINIT" \
sh $srcdir/bind-*/configure --with-libtool \
--disable-threads --with-openssl --prefix=$instdir
gmake clean
......@@ -77,7 +77,7 @@ gmake install
# works, then run it.
cd $srcdir/bind-* || exit 1
CFLAGS="-g -DISC_CHECK_NONE -DISC_MEM_FILL=0 -DISC_LIST_CHECKINIT" \
CFLAGS="-g -DISC_CHECK_NONE -DISC_LIST_CHECKINIT" \
sh configure --with-libtool --disable-threads --prefix=$instdir
make
make install
......
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