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Message-Id: <18b439960a2de06e9352c36b8d04fb149a024a86.1615372955.git.gladkov.alexey@gmail.com> Date: Wed, 10 Mar 2021 13:01:26 +0100 From: Alexey Gladkov <gladkov.alexey@...il.com> To: LKML <linux-kernel@...r.kernel.org>, io-uring@...r.kernel.org, Kernel Hardening <kernel-hardening@...ts.openwall.com>, Linux Containers <containers@...ts.linux-foundation.org>, linux-mm@...ck.org Cc: Alexey Gladkov <legion@...nel.org>, Andrew Morton <akpm@...ux-foundation.org>, Christian Brauner <christian.brauner@...ntu.com>, "Eric W . Biederman" <ebiederm@...ssion.com>, Jann Horn <jannh@...gle.com>, Jens Axboe <axboe@...nel.dk>, Kees Cook <keescook@...omium.org>, Linus Torvalds <torvalds@...ux-foundation.org>, Oleg Nesterov <oleg@...hat.com> Subject: [PATCH v8 1/8] Increase size of ucounts to atomic_long_t 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@...il.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); -- 2.29.2
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