From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Thomas Gleixner <tglx@linutronix.de>,
"Peter Zijlstra (Intel)" <peterz@infradead.org>,
Lee Jones <lee.jones@linaro.org>
Subject: [PATCH 4.4 10/38] futex: Simplify fixup_pi_state_owner()
Date: Mon, 8 Feb 2021 16:00:32 +0100 [thread overview]
Message-ID: <20210208145805.692256519@linuxfoundation.org> (raw)
In-Reply-To: <20210208145805.279815326@linuxfoundation.org>
From: Lee Jones <lee.jones@linaro.org>
From: Thomas Gleixner <tglx@linutronix.de>
[ Upstream commit f2dac39d93987f7de1e20b3988c8685523247ae2 ]
Too many gotos already and an upcoming fix would make it even more
unreadable.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
kernel/futex.c | 41 +++++++++++++++++++++++++++--------------
1 file changed, 27 insertions(+), 14 deletions(-)
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -2237,18 +2237,16 @@ static void unqueue_me_pi(struct futex_q
spin_unlock(q->lock_ptr);
}
-static int fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q,
- struct task_struct *argowner)
+static int __fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q,
+ struct task_struct *argowner)
{
struct futex_pi_state *pi_state = q->pi_state;
- u32 uval, uninitialized_var(curval), newval;
struct task_struct *oldowner, *newowner;
- u32 newtid;
- int ret;
-
- lockdep_assert_held(q->lock_ptr);
+ u32 uval, curval, newval, newtid;
+ int err = 0;
oldowner = pi_state->owner;
+
/* Owner died? */
if (!pi_state->owner)
newtid |= FUTEX_OWNER_DIED;
@@ -2289,7 +2287,7 @@ retry:
if (__rt_mutex_futex_trylock(&pi_state->pi_mutex)) {
/* We got the lock after all, nothing to fix. */
- return 0;
+ return 1;
}
/*
@@ -2304,7 +2302,7 @@ retry:
* We raced against a concurrent self; things are
* already fixed up. Nothing to do.
*/
- return 0;
+ return 1;
}
newowner = argowner;
}
@@ -2345,7 +2343,7 @@ retry:
handle_fault:
spin_unlock(q->lock_ptr);
- ret = fault_in_user_writeable(uaddr);
+ err = fault_in_user_writeable(uaddr);
spin_lock(q->lock_ptr);
@@ -2353,12 +2351,27 @@ handle_fault:
* Check if someone else fixed it for us:
*/
if (pi_state->owner != oldowner)
- return 0;
+ return argowner == current;
+
+ /* Retry if err was -EAGAIN or the fault in succeeded */
+ if (!err)
+ goto retry;
- if (ret)
- return ret;
+ return err;
+}
+
+static int fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q,
+ struct task_struct *argowner)
+{
+ struct futex_pi_state *pi_state = q->pi_state;
+ int ret;
+
+ lockdep_assert_held(q->lock_ptr);
- goto retry;
+ raw_spin_lock_irq(&pi_state->pi_mutex.wait_lock);
+ ret = __fixup_pi_state_owner(uaddr, q, argowner);
+ raw_spin_unlock_irq(&pi_state->pi_mutex.wait_lock);
+ return ret;
}
static long futex_wait_restart(struct restart_block *restart);
next prev parent reply other threads:[~2021-02-08 15:03 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-08 15:00 [PATCH 4.4 00/38] 4.4.257-rc1 review Greg Kroah-Hartman
2021-02-08 15:00 ` [PATCH 4.4 01/38] net_sched: reject silly cell_log in qdisc_get_rtab() Greg Kroah-Hartman
2021-02-08 15:00 ` [PATCH 4.4 02/38] futex,rt_mutex: Provide futex specific rt_mutex API Greg Kroah-Hartman
2021-02-08 15:00 ` [PATCH 4.4 03/38] futex: Remove rt_mutex_deadlock_account_*() Greg Kroah-Hartman
2021-02-08 15:00 ` [PATCH 4.4 04/38] futex: Rework inconsistent rt_mutex/futex_q state Greg Kroah-Hartman
2021-02-08 15:00 ` [PATCH 4.4 05/38] futex: Avoid violating the 10th rule of futex Greg Kroah-Hartman
2021-02-08 15:00 ` [PATCH 4.4 06/38] futex: Replace pointless printk in fixup_owner() Greg Kroah-Hartman
2021-02-08 15:00 ` [PATCH 4.4 07/38] futex: Provide and use pi_state_update_owner() Greg Kroah-Hartman
2021-02-08 15:00 ` [PATCH 4.4 08/38] rtmutex: Remove unused argument from rt_mutex_proxy_unlock() Greg Kroah-Hartman
2021-02-08 15:00 ` [PATCH 4.4 09/38] futex: Use pi_state_update_owner() in put_pi_state() Greg Kroah-Hartman
2021-02-08 15:00 ` Greg Kroah-Hartman [this message]
2021-02-08 15:00 ` [PATCH 4.4 11/38] futex: Handle faults correctly for PI futexes Greg Kroah-Hartman
2021-02-08 15:00 ` [PATCH 4.4 12/38] usb: udc: core: Use lock when write to soft_connect Greg Kroah-Hartman
2021-02-08 15:00 ` [PATCH 4.4 13/38] scsi: libfc: Avoid invoking response handler twice if ep is already completed Greg Kroah-Hartman
2021-02-08 15:00 ` [PATCH 4.4 14/38] scsi: ibmvfc: Set default timeout to avoid crash during migration Greg Kroah-Hartman
2021-02-08 15:00 ` [PATCH 4.4 15/38] stable: clamp SUBLEVEL in 4.4 and 4.9 Greg Kroah-Hartman
2021-02-08 15:00 ` [PATCH 4.4 16/38] USB: serial: cp210x: add pid/vid for WSDA-200-USB Greg Kroah-Hartman
2021-02-08 15:00 ` [PATCH 4.4 17/38] USB: serial: cp210x: add new VID/PID for supporting Teraoka AD2000 Greg Kroah-Hartman
2021-02-08 15:00 ` [PATCH 4.4 18/38] USB: serial: option: Adding support for Cinterion MV31 Greg Kroah-Hartman
2021-02-08 15:00 ` [PATCH 4.4 19/38] Input: i8042 - unbreak Pegatron C15B Greg Kroah-Hartman
2021-02-08 15:00 ` [PATCH 4.4 20/38] net: lapb: Copy the skb before sending a packet Greg Kroah-Hartman
2021-02-08 15:00 ` [PATCH 4.4 21/38] ELF/MIPS build fix Greg Kroah-Hartman
2021-02-08 15:00 ` [PATCH 4.4 22/38] elfcore: fix building with clang Greg Kroah-Hartman
2021-02-09 12:52 ` Pavel Machek
2021-02-09 13:01 ` Greg Kroah-Hartman
2021-02-09 19:10 ` Greg Kroah-Hartman
2021-02-08 15:00 ` [PATCH 4.4 23/38] USB: gadget: legacy: fix an error code in eth_bind() Greg Kroah-Hartman
2021-02-08 15:00 ` [PATCH 4.4 24/38] USB: usblp: dont call usb_set_interface if theres a single alt Greg Kroah-Hartman
2021-02-08 15:00 ` [PATCH 4.4 25/38] usb: dwc2: Fix endpoint direction check in ep_from_windex Greg Kroah-Hartman
2021-02-08 15:00 ` [PATCH 4.4 26/38] mac80211: fix station rate table updates on assoc Greg Kroah-Hartman
2021-02-08 15:00 ` [PATCH 4.4 27/38] kretprobe: Avoid re-registration of the same kretprobe earlier Greg Kroah-Hartman
2021-02-08 15:00 ` [PATCH 4.4 28/38] cifs: report error instead of invalid when revalidating a dentry fails Greg Kroah-Hartman
2021-02-08 15:00 ` [PATCH 4.4 29/38] mmc: core: Limit retries when analyse of SDIO tuples fails Greg Kroah-Hartman
2021-02-08 15:00 ` [PATCH 4.4 30/38] ARM: footbridge: fix dc21285 PCI configuration accessors Greg Kroah-Hartman
2021-02-08 15:00 ` [PATCH 4.4 31/38] mm: hugetlbfs: fix cannot migrate the fallocated HugeTLB page Greg Kroah-Hartman
2021-02-08 15:00 ` [PATCH 4.4 32/38] mm: hugetlb: fix a race between isolating and freeing page Greg Kroah-Hartman
2021-02-08 15:00 ` [PATCH 4.4 33/38] mm: hugetlb: remove VM_BUG_ON_PAGE from page_huge_active Greg Kroah-Hartman
2021-02-08 15:00 ` [PATCH 4.4 34/38] x86/build: Disable CET instrumentation in the kernel Greg Kroah-Hartman
2021-02-08 15:00 ` [PATCH 4.4 35/38] x86/apic: Add extra serialization for non-serializing MSRs Greg Kroah-Hartman
2021-02-08 15:00 ` [PATCH 4.4 36/38] Input: xpad - sync supported devices with fork on GitHub Greg Kroah-Hartman
2021-02-08 15:00 ` [PATCH 4.4 37/38] ACPI: thermal: Do not call acpi_thermal_check() directly Greg Kroah-Hartman
2021-02-08 15:01 ` [PATCH 4.4 38/38] ALSA: hda/realtek - Fix typo of pincfg for Dell quirk Greg Kroah-Hartman
2021-02-08 18:36 ` [PATCH 4.4 00/38] 4.4.257-rc1 review Pavel Machek
2021-02-08 20:43 ` Shuah Khan
2021-02-09 18:09 ` Guenter Roeck
2021-02-10 5:04 ` Naresh Kamboju
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