Re: [ovs-dev] [PATCH ovn] logical-fields: fix memory leak while initializing ovnfield_by_name
On Wed, Aug 7, 2019 at 12:50 PM Damijan Skvarc wrote:
>
> ovnfield_by_name is a hash table, intended to quicky find ovn_field by
> name from a list of supported ovn_fields. This hash table is initialized
> in ovn_init_symtab() function based on ovn_fields const array. In case
> ovn_init_symtab() function is called multiple times then hash table is
> reinitialized multiple times without deallocating previously allocated
> memory. This is actually what happens in ovn_controller by initializing
> lflow.symtab and ofctrl.symtab tables.
>
> Since ovnfield_by_name is initialized twice with same values I have
> introduced a flag indicating ovnfield_by_name is already initialized
> or not and based on this flag hash table is prevented to be initialized
> multiple times.
>
> Note that currently ovn_fields array is constituted from one single
> entry and thus searching a list of one entry by using helper hash table
> is somehow useless. Memory leak could be solved by simply removing
> ovnfield_by_name table and do a linear search through a list of single
> entry. However I want to keep previous functionality in case ovn_fields
> array will be extended somewhen in the future.
>
> Signed-off-by: Damijan Skvarc
> ---
> lib/logical-fields.c | 25 +++--
> 1 file changed, 19 insertions(+), 6 deletions(-)
>
> diff --git a/lib/logical-fields.c b/lib/logical-fields.c
> index 4ad5bf4..62b9a71 100644
> --- a/lib/logical-fields.c
> +++ b/lib/logical-fields.c
> @@ -57,6 +57,23 @@ add_ct_bit(const char *name, int index, struct shash
> *symtab)
> free(expansion);
> }
>
> +
> +static void
> +init_ovnfield_by_name()
> +{
This should actually be init_ovnfield_by_name(void)
> +static bool initialized = 0;
> +
> +if (0 == initialized) {
> +shash_init(_by_name);
> +for (int i = 0; i < OVN_FIELD_N_IDS; i++) {
> +const struct ovn_field *of = _fields[i];
> +ovs_assert(of->id == i); /* Fields must be in the enum order. */
> +shash_add_once(_by_name, of->name, of);
> +}
> +initialized=1;
I'd use "initialized = true/false" and if "(!initialized)" instead of
using 0 and 1.
> +}
> +}
Instead of adding this check here isn't it cleaner to just make sure
that we call init_ovnfield_by_name only once? I see there's
OVS_CONSTRUCTOR which should allow exactly what you're trying to do
with the check.
Thanks,
Dumitru
> +
> void
> ovn_init_symtab(struct shash *symtab)
> {
> @@ -218,12 +235,8 @@ ovn_init_symtab(struct shash *symtab)
> expr_symtab_add_field(symtab, "sctp.src", MFF_SCTP_SRC, "sctp", false);
> expr_symtab_add_field(symtab, "sctp.dst", MFF_SCTP_DST, "sctp", false);
>
> -shash_init(_by_name);
> -for (int i = 0; i < OVN_FIELD_N_IDS; i++) {
> -const struct ovn_field *of = _fields[i];
> -ovs_assert(of->id == i); /* Fields must be in the enum order. */
> -shash_add_once(_by_name, of->name, of);
> -}
> +init_ovnfield_by_name();
> +
> expr_symtab_add_ovn_field(symtab, "icmp4.frag_mtu", OVN_ICMP4_FRAG_MTU);
> }
>
> --
> 2.7.4
>
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Re: [ovs-dev] [PATCH ovn] logical-fields: fix memory leak while initializing ovnfield_by_name
Bleep bloop. Greetings Damijan Skvarc, I am a robot and I have tried out your patch. Thanks for your contribution. I encountered some error that I wasn't expecting. See the details below. checkpatch: WARNING: Line lacks whitespace around operator WARNING: Line lacks whitespace around operator #52 FILE: lib/logical-fields.c:73: initialized=1; Lines checked: 76, Warnings: 2, Errors: 0 build: mv -f $depbase.Tpo $depbase.Plo libtool: compile: gcc -std=gnu99 -DHAVE_CONFIG_H -I. -I ./include -I ./ovs/include -I ./ovs/include -I ./ovs/lib -I ./ovs/lib -I ./ovs -I ./ovs -I ./lib -I ./lib -Wstrict-prototypes -Wall -Wextra -Wno-sign-compare -Wpointer-arith -Wformat -Wformat-security -Wswitch-enum -Wunused-parameter -Wbad-function-cast -Wcast-align -Wstrict-prototypes -Wold-style-definition -Wmissing-prototypes -Wmissing-field-initializers -fno-strict-aliasing -Wshadow -Werror -Werror -g -O2 -MT lib/mcast-group-index.lo -MD -MP -MF lib/.deps/mcast-group-index.Tpo -c lib/mcast-group-index.c -o lib/mcast-group-index.o depbase=`echo lib/lex.lo | sed 's|[^/]*$|.deps/&|;s|\.lo$||'`;\ /bin/sh ./libtool --tag=CC --mode=compile gcc -std=gnu99 -DHAVE_CONFIG_H -I. -I ./include -I ./ovs/include -I ./ovs/include -I ./ovs/lib -I ./ovs/lib -I ./ovs -I ./ovs -I ./lib -I ./lib-Wstrict-prototypes -Wall -Wextra -Wno-sign-compare -Wpointer-arith -Wformat -Wformat-security -Wswitch-enum -Wunused-parameter -Wbad-function-cast -Wcast-align -Wstrict-prototypes -Wold-style-definition -Wmissing-prototypes -Wmissing-field-initializers -fno-strict-aliasing -Wshadow -Werror -Werror -g -O2 -MT lib/lex.lo -MD -MP -MF $depbase.Tpo -c -o lib/lex.lo lib/lex.c &&\ mv -f $depbase.Tpo $depbase.Plo libtool: compile: gcc -std=gnu99 -DHAVE_CONFIG_H -I. -I ./include -I ./ovs/include -I ./ovs/include -I ./ovs/lib -I ./ovs/lib -I ./ovs -I ./ovs -I ./lib -I ./lib -Wstrict-prototypes -Wall -Wextra -Wno-sign-compare -Wpointer-arith -Wformat -Wformat-security -Wswitch-enum -Wunused-parameter -Wbad-function-cast -Wcast-align -Wstrict-prototypes -Wold-style-definition -Wmissing-prototypes -Wmissing-field-initializers -fno-strict-aliasing -Wshadow -Werror -Werror -g -O2 -MT lib/lex.lo -MD -MP -MF lib/.deps/lex.Tpo -c lib/lex.c -o lib/lex.o depbase=`echo lib/ovn-util.lo | sed 's|[^/]*$|.deps/&|;s|\.lo$||'`;\ /bin/sh ./libtool --tag=CC --mode=compile gcc -std=gnu99 -DHAVE_CONFIG_H -I. -I ./include -I ./ovs/include -I ./ovs/include -I ./ovs/lib -I ./ovs/lib -I ./ovs -I ./ovs -I ./lib -I ./lib-Wstrict-prototypes -Wall -Wextra -Wno-sign-compare -Wpointer-arith -Wformat -Wformat-security -Wswitch-enum -Wunused-parameter -Wbad-function-cast -Wcast-align -Wstrict-prototypes -Wold-style-definition -Wmissing-prototypes -Wmissing-field-initializers -fno-strict-aliasing -Wshadow -Werror -Werror -g -O2 -MT lib/ovn-util.lo -MD -MP -MF $depbase.Tpo -c -o lib/ovn-util.lo lib/ovn-util.c &&\ mv -f $depbase.Tpo $depbase.Plo libtool: compile: gcc -std=gnu99 -DHAVE_CONFIG_H -I. -I ./include -I ./ovs/include -I ./ovs/include -I ./ovs/lib -I ./ovs/lib -I ./ovs -I ./ovs -I ./lib -I ./lib -Wstrict-prototypes -Wall -Wextra -Wno-sign-compare -Wpointer-arith -Wformat -Wformat-security -Wswitch-enum -Wunused-parameter -Wbad-function-cast -Wcast-align -Wstrict-prototypes -Wold-style-definition -Wmissing-prototypes -Wmissing-field-initializers -fno-strict-aliasing -Wshadow -Werror -Werror -g -O2 -MT lib/ovn-util.lo -MD -MP -MF lib/.deps/ovn-util.Tpo -c lib/ovn-util.c -o lib/ovn-util.o depbase=`echo lib/logical-fields.lo | sed 's|[^/]*$|.deps/&|;s|\.lo$||'`;\ /bin/sh ./libtool --tag=CC --mode=compile gcc -std=gnu99 -DHAVE_CONFIG_H -I. -I ./include -I ./ovs/include -I ./ovs/include -I ./ovs/lib -I ./ovs/lib -I ./ovs -I ./ovs -I ./lib -I ./lib-Wstrict-prototypes -Wall -Wextra -Wno-sign-compare -Wpointer-arith -Wformat -Wformat-security -Wswitch-enum -Wunused-parameter -Wbad-function-cast -Wcast-align -Wstrict-prototypes -Wold-style-definition -Wmissing-prototypes -Wmissing-field-initializers -fno-strict-aliasing -Wshadow -Werror -Werror -g -O2 -MT lib/logical-fields.lo -MD -MP -MF $depbase.Tpo -c -o lib/logical-fields.lo lib/logical-fields.c &&\ mv -f $depbase.Tpo $depbase.Plo libtool: compile: gcc -std=gnu99 -DHAVE_CONFIG_H -I. -I ./include -I ./ovs/include -I ./ovs/include -I ./ovs/lib -I ./ovs/lib -I ./ovs -I ./ovs -I ./lib -I ./lib -Wstrict-prototypes -Wall -Wextra -Wno-sign-compare -Wpointer-arith -Wformat -Wformat-security -Wswitch-enum -Wunused-parameter -Wbad-function-cast -Wcast-align -Wstrict-prototypes -Wold-style-definition -Wmissing-prototypes -Wmissing-field-initializers -fno-strict-aliasing -Wshadow -Werror -Werror -g -O2 -MT lib/logical-fields.lo -MD -MP -MF lib/.deps/logical-fields.Tpo -c lib/logical-fields.c -o lib/logical-fields.o lib/logical-fields.c:62:1: error: function declaration isn't a prototype [-Werror=strict-prototypes] init_ovnfield_by_name() ^
[ovs-dev] [PATCH ovn] logical-fields: fix memory leak while initializing ovnfield_by_name
ovnfield_by_name is a hash table, intended to quicky find ovn_field by
name from a list of supported ovn_fields. This hash table is initialized
in ovn_init_symtab() function based on ovn_fields const array. In case
ovn_init_symtab() function is called multiple times then hash table is
reinitialized multiple times without deallocating previously allocated
memory. This is actually what happens in ovn_controller by initializing
lflow.symtab and ofctrl.symtab tables.
Since ovnfield_by_name is initialized twice with same values I have
introduced a flag indicating ovnfield_by_name is already initialized
or not and based on this flag hash table is prevented to be initialized
multiple times.
Note that currently ovn_fields array is constituted from one single
entry and thus searching a list of one entry by using helper hash table
is somehow useless. Memory leak could be solved by simply removing
ovnfield_by_name table and do a linear search through a list of single
entry. However I want to keep previous functionality in case ovn_fields
array will be extended somewhen in the future.
Signed-off-by: Damijan Skvarc
---
lib/logical-fields.c | 25 +++--
1 file changed, 19 insertions(+), 6 deletions(-)
diff --git a/lib/logical-fields.c b/lib/logical-fields.c
index 4ad5bf4..62b9a71 100644
--- a/lib/logical-fields.c
+++ b/lib/logical-fields.c
@@ -57,6 +57,23 @@ add_ct_bit(const char *name, int index, struct shash *symtab)
free(expansion);
}
+
+static void
+init_ovnfield_by_name()
+{
+static bool initialized = 0;
+
+if (0 == initialized) {
+shash_init(_by_name);
+for (int i = 0; i < OVN_FIELD_N_IDS; i++) {
+const struct ovn_field *of = _fields[i];
+ovs_assert(of->id == i); /* Fields must be in the enum order. */
+shash_add_once(_by_name, of->name, of);
+}
+initialized=1;
+}
+}
+
void
ovn_init_symtab(struct shash *symtab)
{
@@ -218,12 +235,8 @@ ovn_init_symtab(struct shash *symtab)
expr_symtab_add_field(symtab, "sctp.src", MFF_SCTP_SRC, "sctp", false);
expr_symtab_add_field(symtab, "sctp.dst", MFF_SCTP_DST, "sctp", false);
-shash_init(_by_name);
-for (int i = 0; i < OVN_FIELD_N_IDS; i++) {
-const struct ovn_field *of = _fields[i];
-ovs_assert(of->id == i); /* Fields must be in the enum order. */
-shash_add_once(_by_name, of->name, of);
-}
+init_ovnfield_by_name();
+
expr_symtab_add_ovn_field(symtab, "icmp4.frag_mtu", OVN_ICMP4_FRAG_MTU);
}
--
2.7.4
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