From: Alexey Gladkov <gladkov.alexey@gmail.com>
To: LKML <linux-kernel@vger.kernel.org>,
Kernel Hardening <kernel-hardening@lists.openwall.com>,
Linux Containers <containers@lists.linux-foundation.org>,
linux-mm@kvack.org
Cc: Jens Axboe <axboe@kernel.dk>, Kees Cook <keescook@chromium.org>,
Jann Horn <jannh@google.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Oleg Nesterov <oleg@redhat.com>,
"Eric W . Biederman" <ebiederm@xmission.com>,
Andrew Morton <akpm@linux-foundation.org>,
Alexey Gladkov <legion@kernel.org>
Subject: [PATCH v10 1/9] Increase size of ucounts to atomic_long_t
Date: Wed, 7 Apr 2021 19:08:06 +0200 [thread overview]
Message-ID: <b39ae3fe6eca25870e88a8b0e336343e657403ee.1617814298.git.gladkov.alexey@gmail.com> (raw)
In-Reply-To: <cover.1617814298.git.gladkov.alexey@gmail.com>
RLIMIT_MSGQUEUE and RLIMIT_MEMLOCK use unsigned long to store their
counters. As a preparation for moving rlimits based on ucounts, we need
to increase the size of the variable to long.
Signed-off-by: Alexey Gladkov <gladkov.alexey@gmail.com>
---
include/linux/user_namespace.h | 4 ++--
kernel/ucount.c | 16 ++++++++--------
2 files changed, 10 insertions(+), 10 deletions(-)
diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h
index 64cf8ebdc4ec..0bb833fd41f4 100644
--- a/include/linux/user_namespace.h
+++ b/include/linux/user_namespace.h
@@ -85,7 +85,7 @@ struct user_namespace {
struct ctl_table_header *sysctls;
#endif
struct ucounts *ucounts;
- int ucount_max[UCOUNT_COUNTS];
+ long ucount_max[UCOUNT_COUNTS];
} __randomize_layout;
struct ucounts {
@@ -93,7 +93,7 @@ struct ucounts {
struct user_namespace *ns;
kuid_t uid;
int count;
- atomic_t ucount[UCOUNT_COUNTS];
+ atomic_long_t ucount[UCOUNT_COUNTS];
};
extern struct user_namespace init_user_ns;
diff --git a/kernel/ucount.c b/kernel/ucount.c
index 11b1596e2542..04c561751af1 100644
--- a/kernel/ucount.c
+++ b/kernel/ucount.c
@@ -175,14 +175,14 @@ static void put_ucounts(struct ucounts *ucounts)
kfree(ucounts);
}
-static inline bool atomic_inc_below(atomic_t *v, int u)
+static inline bool atomic_long_inc_below(atomic_long_t *v, int u)
{
- int c, old;
- c = atomic_read(v);
+ long c, old;
+ c = atomic_long_read(v);
for (;;) {
if (unlikely(c >= u))
return false;
- old = atomic_cmpxchg(v, c, c+1);
+ old = atomic_long_cmpxchg(v, c, c+1);
if (likely(old == c))
return true;
c = old;
@@ -196,17 +196,17 @@ struct ucounts *inc_ucount(struct user_namespace *ns, kuid_t uid,
struct user_namespace *tns;
ucounts = get_ucounts(ns, uid);
for (iter = ucounts; iter; iter = tns->ucounts) {
- int max;
+ long max;
tns = iter->ns;
max = READ_ONCE(tns->ucount_max[type]);
- if (!atomic_inc_below(&iter->ucount[type], max))
+ if (!atomic_long_inc_below(&iter->ucount[type], max))
goto fail;
}
return ucounts;
fail:
bad = iter;
for (iter = ucounts; iter != bad; iter = iter->ns->ucounts)
- atomic_dec(&iter->ucount[type]);
+ atomic_long_dec(&iter->ucount[type]);
put_ucounts(ucounts);
return NULL;
@@ -216,7 +216,7 @@ void dec_ucount(struct ucounts *ucounts, enum ucount_type type)
{
struct ucounts *iter;
for (iter = ucounts; iter; iter = iter->ns->ucounts) {
- int dec = atomic_dec_if_positive(&iter->ucount[type]);
+ long dec = atomic_long_dec_if_positive(&iter->ucount[type]);
WARN_ON_ONCE(dec < 0);
}
put_ucounts(ucounts);
--
2.29.3
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next prev parent reply other threads:[~2021-04-07 17:08 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-07 17:08 [PATCH v10 0/9] Count rlimits in each user namespace Alexey Gladkov
2021-04-07 17:08 ` Alexey Gladkov [this message]
2021-04-07 17:08 ` [PATCH v10 2/9] Add a reference to ucounts for each cred Alexey Gladkov
2021-04-07 17:08 ` [PATCH v10 3/9] Use atomic_t for ucounts reference counting Alexey Gladkov
2021-04-07 17:08 ` [PATCH v10 4/9] Reimplement RLIMIT_NPROC on top of ucounts Alexey Gladkov
2021-04-07 17:08 ` [PATCH v10 5/9] Reimplement RLIMIT_MSGQUEUE " Alexey Gladkov
2021-04-07 17:08 ` [PATCH v10 6/9] Reimplement RLIMIT_SIGPENDING " Alexey Gladkov
2021-04-08 8:30 ` 08ed4efad6: stress-ng.sigsegv.ops_per_sec -41.9% regression kernel test robot
2021-04-08 16:22 ` Linus Torvalds
2021-04-08 16:44 ` Alexey Gladkov
2021-04-08 18:44 ` Eric W. Biederman
2021-04-16 11:33 ` Alexey Gladkov
2021-04-23 2:47 ` Oliver Sang
2021-04-23 7:44 ` Alexey Gladkov
2021-04-28 14:36 ` Oliver Sang
2021-04-28 15:09 ` Alexey Gladkov
2021-04-07 17:08 ` [PATCH v10 7/9] Reimplement RLIMIT_MEMLOCK on top of ucounts Alexey Gladkov
2021-04-07 21:37 ` kernel test robot
2021-04-07 17:08 ` [PATCH v10 8/9] kselftests: Add test to check for rlimit changes in different user namespaces Alexey Gladkov
2021-04-07 17:08 ` [PATCH v10 9/9] ucounts: Set ucount_max to the largest positive value the type can hold Alexey Gladkov
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