From: Phillip Wood <phillip.wood123@gmail.com>
To: "Ævar Arnfjörð Bjarmason" <avarab@gmail.com>, git@vger.kernel.org
Cc: "Junio C Hamano" <gitster@pobox.com>, "Jeff King" <peff@peff.net>,
"Nguyễn Thái Ngọc Duy" <pclouds@gmail.com>,
"Elijah Newren" <newren@gmail.com>, "Eric Wong" <e@80x24.org>
Subject: Re: [PATCH v2] checkout: fix "branch info" memory leaks
Date: Sun, 24 Oct 2021 19:30:47 +0100 [thread overview]
Message-ID: <5ea4bf80-6dfb-5124-3082-c54844e11832@gmail.com> (raw)
In-Reply-To: <patch-v2-1.1-e2a166a9733-20211021T201541Z-avarab@gmail.com>
Hi Ævar
On 21/10/2021 21:16, Ævar Arnfjörð Bjarmason wrote:
> The "checkout" command is one of the main sources of leaks in the test
> suite, let's fix the common ones by not leaking from the "struct
> branch_info".
>
> Doing this is rather straightforward, albeit verbose, we need to
> xstrdup() constant strings going into the struct, and free() the ones
> we clobber as we go along.
>
> This also means that we can delete previous partial leak fixes in this
> area, i.e. the "path_to_free" accounting added by 96ec7b1e708 (Convert
> resolve_ref+xstrdup to new resolve_refdup function, 2011-12-13).
>
> There was some discussion about whether "we should retain the "const
> char *" here and cast at free() time, or have it be a "char *". Since
> this is not a public API with any sort of API boundary let's use
> "char *", as is already being done for the "refname" member of the
> same struct.
I think it makes sense to consistently use "char *", the range diff
looks good to me
Best Wishes
Phillip
> Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
> ---
> Range-diff against v1:
> 1: 9b17170b794 ! 1: e2a166a9733 checkout: fix "branch info" memory leaks
> @@ Commit message
> area, i.e. the "path_to_free" accounting added by 96ec7b1e708 (Convert
> resolve_ref+xstrdup to new resolve_refdup function, 2011-12-13).
>
> + There was some discussion about whether "we should retain the "const
> + char *" here and cast at free() time, or have it be a "char *". Since
> + this is not a public API with any sort of API boundary let's use
> + "char *", as is already being done for the "refname" member of the
> + same struct.
> +
> Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
>
> ## builtin/checkout.c ##
> +@@ builtin/checkout.c: struct checkout_opts {
> + };
> +
> + struct branch_info {
> +- const char *name; /* The short name used */
> +- const char *path; /* The full name of a real branch */
> ++ char *name; /* The short name used */
> ++ char *path; /* The full name of a real branch */
> + struct commit *commit; /* The named commit */
> + char *refname; /* The full name of the ref being checked out. */
> + struct object_id oid; /* The object ID of the commit being checked out. */
> @@ builtin/checkout.c: struct branch_info {
> char *checkout;
> };
> @@ builtin/checkout.c: struct branch_info {
> +{
> + if (!info)
> + return;
> -+ free((char *)info->name);
> -+ free((char *)info->path);
> ++ free(info->name);
> ++ free(info->path);
> + free(info->refname);
> + free(info->checkout);
> +}
> @@ builtin/checkout.c: static void setup_branch_path(struct branch_info *branch)
> strbuf_branchname(&buf, branch->name, INTERPRET_BRANCH_LOCAL);
> - if (strcmp(buf.buf, branch->name))
> + if (strcmp(buf.buf, branch->name)) {
> -+ free((char *)branch->name);
> ++ free(branch->name);
> branch->name = xstrdup(buf.buf);
> + }
> strbuf_splice(&buf, 0, 0, "refs/heads/", 11);
> @@ builtin/checkout.c: static void update_refs_for_switch(const struct checkout_opt
> opts->quiet,
> opts->track);
> - new_branch_info->name = opts->new_branch;
> -+ free((char *)new_branch_info->name);
> ++ free(new_branch_info->name);
> + free(new_branch_info->refname);
> + new_branch_info->name = xstrdup(opts->new_branch);
> setup_branch_path(new_branch_info);
> @@ builtin/checkout.c: static int switch_branches(const struct checkout_opts *opts,
> old_branch_info.commit = lookup_commit_reference_gently(the_repository, &rev, 1);
> - if (!(flag & REF_ISSYMREF))
> + if (!(flag & REF_ISSYMREF)) {
> -+ free((char *)old_branch_info.path);
> ++ free(old_branch_info.path);
> old_branch_info.path = NULL;
> + }
>
> @@ builtin/checkout.c: static void setup_new_branch_info_and_source_tree(
> setup_branch_path(new_branch_info);
>
> if (!check_refname_format(new_branch_info->path, 0) &&
> + !read_ref(new_branch_info->path, &branch_rev))
> + oidcpy(rev, &branch_rev);
> + else {
> +- free((char *)new_branch_info->path);
> ++ free(new_branch_info->path);
> + new_branch_info->path = NULL; /* not an existing branch */
> + }
> +
> @@ builtin/checkout.c: static char cb_option = 'b';
>
> static int checkout_main(int argc, const char **argv, const char *prefix,
>
> builtin/checkout.c | 82 ++++++++++++++++++++-----------
> t/t1005-read-tree-reset.sh | 1 +
> t/t1406-submodule-ref-store.sh | 1 +
> t/t2008-checkout-subdir.sh | 1 +
> t/t2014-checkout-switch.sh | 2 +
> t/t2026-checkout-pathspec-file.sh | 1 +
> t/t9102-git-svn-deep-rmdir.sh | 2 +
> 7 files changed, 62 insertions(+), 28 deletions(-)
>
> diff --git a/builtin/checkout.c b/builtin/checkout.c
> index cbf73b8c9f6..96a02d223a2 100644
> --- a/builtin/checkout.c
> +++ b/builtin/checkout.c
> @@ -91,8 +91,8 @@ struct checkout_opts {
> };
>
> struct branch_info {
> - const char *name; /* The short name used */
> - const char *path; /* The full name of a real branch */
> + char *name; /* The short name used */
> + char *path; /* The full name of a real branch */
> struct commit *commit; /* The named commit */
> char *refname; /* The full name of the ref being checked out. */
> struct object_id oid; /* The object ID of the commit being checked out. */
> @@ -103,6 +103,16 @@ struct branch_info {
> char *checkout;
> };
>
> +static void branch_info_release(struct branch_info *info)
> +{
> + if (!info)
> + return;
> + free(info->name);
> + free(info->path);
> + free(info->refname);
> + free(info->checkout);
> +}
> +
> static int post_checkout_hook(struct commit *old_commit, struct commit *new_commit,
> int changed)
> {
> @@ -688,8 +698,10 @@ static void setup_branch_path(struct branch_info *branch)
> repo_get_oid_committish(the_repository, branch->name, &branch->oid);
>
> strbuf_branchname(&buf, branch->name, INTERPRET_BRANCH_LOCAL);
> - if (strcmp(buf.buf, branch->name))
> + if (strcmp(buf.buf, branch->name)) {
> + free(branch->name);
> branch->name = xstrdup(buf.buf);
> + }
> strbuf_splice(&buf, 0, 0, "refs/heads/", 11);
> branch->path = strbuf_detach(&buf, NULL);
> }
> @@ -894,7 +906,9 @@ static void update_refs_for_switch(const struct checkout_opts *opts,
> opts->new_branch_log,
> opts->quiet,
> opts->track);
> - new_branch_info->name = opts->new_branch;
> + free(new_branch_info->name);
> + free(new_branch_info->refname);
> + new_branch_info->name = xstrdup(opts->new_branch);
> setup_branch_path(new_branch_info);
> }
>
> @@ -1062,8 +1076,7 @@ static int switch_branches(const struct checkout_opts *opts,
> struct branch_info *new_branch_info)
> {
> int ret = 0;
> - struct branch_info old_branch_info;
> - void *path_to_free;
> + struct branch_info old_branch_info = { 0 };
> struct object_id rev;
> int flag, writeout_error = 0;
> int do_merge = 1;
> @@ -1071,25 +1084,32 @@ static int switch_branches(const struct checkout_opts *opts,
> trace2_cmd_mode("branch");
>
> memset(&old_branch_info, 0, sizeof(old_branch_info));
> - old_branch_info.path = path_to_free = resolve_refdup("HEAD", 0, &rev, &flag);
> + old_branch_info.path = resolve_refdup("HEAD", 0, &rev, &flag);
> if (old_branch_info.path)
> old_branch_info.commit = lookup_commit_reference_gently(the_repository, &rev, 1);
> - if (!(flag & REF_ISSYMREF))
> + if (!(flag & REF_ISSYMREF)) {
> + free(old_branch_info.path);
> old_branch_info.path = NULL;
> + }
>
> - if (old_branch_info.path)
> - skip_prefix(old_branch_info.path, "refs/heads/", &old_branch_info.name);
> + if (old_branch_info.path) {
> + const char *p;
> + if (skip_prefix(old_branch_info.path, "refs/heads/", &p))
> + old_branch_info.name = xstrdup(p);
> + else
> + BUG("Should be able to skip with %s!", old_branch_info.path);
> + }
>
> if (opts->new_orphan_branch && opts->orphan_from_empty_tree) {
> if (new_branch_info->name)
> BUG("'switch --orphan' should never accept a commit as starting point");
> new_branch_info->commit = NULL;
> - new_branch_info->name = "(empty)";
> + new_branch_info->name = xstrdup("(empty)");
> do_merge = 1;
> }
>
> if (!new_branch_info->name) {
> - new_branch_info->name = "HEAD";
> + new_branch_info->name = xstrdup("HEAD");
> new_branch_info->commit = old_branch_info.commit;
> if (!new_branch_info->commit)
> die(_("You are on a branch yet to be born"));
> @@ -1102,7 +1122,7 @@ static int switch_branches(const struct checkout_opts *opts,
> if (do_merge) {
> ret = merge_working_tree(opts, &old_branch_info, new_branch_info, &writeout_error);
> if (ret) {
> - free(path_to_free);
> + branch_info_release(&old_branch_info);
> return ret;
> }
> }
> @@ -1113,7 +1133,8 @@ static int switch_branches(const struct checkout_opts *opts,
> update_refs_for_switch(opts, &old_branch_info, new_branch_info);
>
> ret = post_checkout_hook(old_branch_info.commit, new_branch_info->commit, 1);
> - free(path_to_free);
> + branch_info_release(&old_branch_info);
> +
> return ret || writeout_error;
> }
>
> @@ -1145,14 +1166,14 @@ static void setup_new_branch_info_and_source_tree(
> struct tree **source_tree = &opts->source_tree;
> struct object_id branch_rev;
>
> - new_branch_info->name = arg;
> + new_branch_info->name = xstrdup(arg);
> setup_branch_path(new_branch_info);
>
> if (!check_refname_format(new_branch_info->path, 0) &&
> !read_ref(new_branch_info->path, &branch_rev))
> oidcpy(rev, &branch_rev);
> else {
> - free((char *)new_branch_info->path);
> + free(new_branch_info->path);
> new_branch_info->path = NULL; /* not an existing branch */
> }
>
> @@ -1574,12 +1595,11 @@ static char cb_option = 'b';
>
> static int checkout_main(int argc, const char **argv, const char *prefix,
> struct checkout_opts *opts, struct option *options,
> - const char * const usagestr[])
> + const char * const usagestr[],
> + struct branch_info *new_branch_info)
> {
> - struct branch_info new_branch_info;
> int parseopt_flags = 0;
>
> - memset(&new_branch_info, 0, sizeof(new_branch_info));
> opts->overwrite_ignore = 1;
> opts->prefix = prefix;
> opts->show_progress = -1;
> @@ -1688,7 +1708,7 @@ static int checkout_main(int argc, const char **argv, const char *prefix,
> opts->track == BRANCH_TRACK_UNSPECIFIED &&
> !opts->new_branch;
> int n = parse_branchname_arg(argc, argv, dwim_ok,
> - &new_branch_info, opts, &rev);
> + new_branch_info, opts, &rev);
> argv += n;
> argc -= n;
> } else if (!opts->accept_ref && opts->from_treeish) {
> @@ -1697,7 +1717,7 @@ static int checkout_main(int argc, const char **argv, const char *prefix,
> if (get_oid_mb(opts->from_treeish, &rev))
> die(_("could not resolve %s"), opts->from_treeish);
>
> - setup_new_branch_info_and_source_tree(&new_branch_info,
> + setup_new_branch_info_and_source_tree(new_branch_info,
> opts, &rev,
> opts->from_treeish);
>
> @@ -1717,7 +1737,7 @@ static int checkout_main(int argc, const char **argv, const char *prefix,
> * Try to give more helpful suggestion.
> * new_branch && argc > 1 will be caught later.
> */
> - if (opts->new_branch && argc == 1 && !new_branch_info.commit)
> + if (opts->new_branch && argc == 1 && !new_branch_info->commit)
> die(_("'%s' is not a commit and a branch '%s' cannot be created from it"),
> argv[0], opts->new_branch);
>
> @@ -1766,11 +1786,10 @@ static int checkout_main(int argc, const char **argv, const char *prefix,
> strbuf_release(&buf);
> }
>
> - UNLEAK(opts);
> if (opts->patch_mode || opts->pathspec.nr)
> - return checkout_paths(opts, &new_branch_info);
> + return checkout_paths(opts, new_branch_info);
> else
> - return checkout_branch(opts, &new_branch_info);
> + return checkout_branch(opts, new_branch_info);
> }
>
> int cmd_checkout(int argc, const char **argv, const char *prefix)
> @@ -1789,6 +1808,7 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
> OPT_END()
> };
> int ret;
> + struct branch_info new_branch_info = { 0 };
>
> memset(&opts, 0, sizeof(opts));
> opts.dwim_new_local_branch = 1;
> @@ -1819,7 +1839,9 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
> options = add_checkout_path_options(&opts, options);
>
> ret = checkout_main(argc, argv, prefix, &opts,
> - options, checkout_usage);
> + options, checkout_usage, &new_branch_info);
> + branch_info_release(&new_branch_info);
> + clear_pathspec(&opts.pathspec);
> FREE_AND_NULL(options);
> return ret;
> }
> @@ -1840,6 +1862,7 @@ int cmd_switch(int argc, const char **argv, const char *prefix)
> OPT_END()
> };
> int ret;
> + struct branch_info new_branch_info = { 0 };
>
> memset(&opts, 0, sizeof(opts));
> opts.dwim_new_local_branch = 1;
> @@ -1859,7 +1882,8 @@ int cmd_switch(int argc, const char **argv, const char *prefix)
> cb_option = 'c';
>
> ret = checkout_main(argc, argv, prefix, &opts,
> - options, switch_branch_usage);
> + options, switch_branch_usage, &new_branch_info);
> + branch_info_release(&new_branch_info);
> FREE_AND_NULL(options);
> return ret;
> }
> @@ -1881,6 +1905,7 @@ int cmd_restore(int argc, const char **argv, const char *prefix)
> OPT_END()
> };
> int ret;
> + struct branch_info new_branch_info = { 0 };
>
> memset(&opts, 0, sizeof(opts));
> opts.accept_ref = 0;
> @@ -1896,7 +1921,8 @@ int cmd_restore(int argc, const char **argv, const char *prefix)
> options = add_checkout_path_options(&opts, options);
>
> ret = checkout_main(argc, argv, prefix, &opts,
> - options, restore_usage);
> + options, restore_usage, &new_branch_info);
> + branch_info_release(&new_branch_info);
> FREE_AND_NULL(options);
> return ret;
> }
> diff --git a/t/t1005-read-tree-reset.sh b/t/t1005-read-tree-reset.sh
> index 83b09e13106..12e30d77d09 100755
> --- a/t/t1005-read-tree-reset.sh
> +++ b/t/t1005-read-tree-reset.sh
> @@ -2,6 +2,7 @@
>
> test_description='read-tree -u --reset'
>
> +TEST_PASSES_SANITIZE_LEAK=true
> . ./test-lib.sh
> . "$TEST_DIRECTORY"/lib-read-tree.sh
>
> diff --git a/t/t1406-submodule-ref-store.sh b/t/t1406-submodule-ref-store.sh
> index 0a87058971e..3c19edcf30b 100755
> --- a/t/t1406-submodule-ref-store.sh
> +++ b/t/t1406-submodule-ref-store.sh
> @@ -5,6 +5,7 @@ test_description='test submodule ref store api'
> GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
> export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
>
> +TEST_PASSES_SANITIZE_LEAK=true
> . ./test-lib.sh
>
> RUN="test-tool ref-store submodule:sub"
> diff --git a/t/t2008-checkout-subdir.sh b/t/t2008-checkout-subdir.sh
> index eadb9434ae7..8a518a44ea2 100755
> --- a/t/t2008-checkout-subdir.sh
> +++ b/t/t2008-checkout-subdir.sh
> @@ -4,6 +4,7 @@
>
> test_description='git checkout from subdirectories'
>
> +TEST_PASSES_SANITIZE_LEAK=true
> . ./test-lib.sh
>
> test_expect_success setup '
> diff --git a/t/t2014-checkout-switch.sh b/t/t2014-checkout-switch.sh
> index ccfb1471135..c138bdde4fe 100755
> --- a/t/t2014-checkout-switch.sh
> +++ b/t/t2014-checkout-switch.sh
> @@ -1,6 +1,8 @@
> #!/bin/sh
>
> test_description='Peter MacMillan'
> +
> +TEST_PASSES_SANITIZE_LEAK=true
> . ./test-lib.sh
>
> test_expect_success setup '
> diff --git a/t/t2026-checkout-pathspec-file.sh b/t/t2026-checkout-pathspec-file.sh
> index 43d31d79485..9db11f86dd6 100755
> --- a/t/t2026-checkout-pathspec-file.sh
> +++ b/t/t2026-checkout-pathspec-file.sh
> @@ -2,6 +2,7 @@
>
> test_description='checkout --pathspec-from-file'
>
> +TEST_PASSES_SANITIZE_LEAK=true
> . ./test-lib.sh
>
> test_tick
> diff --git a/t/t9102-git-svn-deep-rmdir.sh b/t/t9102-git-svn-deep-rmdir.sh
> index 66cd51102c8..7b2049caa0c 100755
> --- a/t/t9102-git-svn-deep-rmdir.sh
> +++ b/t/t9102-git-svn-deep-rmdir.sh
> @@ -1,5 +1,7 @@
> #!/bin/sh
> test_description='git svn rmdir'
> +
> +TEST_PASSES_SANITIZE_LEAK=true
> . ./lib-git-svn.sh
>
> test_expect_success 'initialize repo' '
>
next prev parent reply other threads:[~2021-10-24 18:30 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-14 0:10 [PATCH] checkout: fix "branch info" memory leaks Ævar Arnfjörð Bjarmason
2021-10-14 9:36 ` Phillip Wood
2021-10-14 19:54 ` To "const char *" and cast on free(), or "char *" and no cast Ævar Arnfjörð Bjarmason
2021-10-14 20:22 ` Junio C Hamano
2021-10-15 10:03 ` Phillip Wood
2021-10-15 16:00 ` Junio C Hamano
2021-10-14 23:36 ` Eric Wong
2021-10-15 9:50 ` Phillip Wood
2021-10-21 20:16 ` [PATCH v2] checkout: fix "branch info" memory leaks Ævar Arnfjörð Bjarmason
2021-10-24 18:30 ` Phillip Wood [this message]
2021-11-03 11:36 ` [PATCH v3] " Ævar Arnfjörð Bjarmason
2021-11-16 18:27 ` [PATCH v4] " Ævar Arnfjörð Bjarmason
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
List information: http://vger.kernel.org/majordomo-info.html
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=5ea4bf80-6dfb-5124-3082-c54844e11832@gmail.com \
--to=phillip.wood123@gmail.com \
--cc=avarab@gmail.com \
--cc=e@80x24.org \
--cc=git@vger.kernel.org \
--cc=gitster@pobox.com \
--cc=newren@gmail.com \
--cc=pclouds@gmail.com \
--cc=peff@peff.net \
--cc=phillip.wood@dunelm.org.uk \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
Code repositories for project(s) associated with this public inbox
https://80x24.org/mirrors/git.git
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).