February 2024 - Linux-stable-mirror

FAILED: patch "[PATCH] getrusage: use sig->stats_lock rather than" failed to apply to 4.19-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-4.19.y git checkout FETCH_HEAD git cherry-pick -x f7ec1cd5cc7ef3ad964b677ba82b8b77f1c93009 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024021941-showman-diaper-6105@gregkh' --subject-prefix 'PATCH 4.19.y' HEAD^.. Possible dependencies: f7ec1cd5cc7e ("getrusage: use sig->stats_lock rather than lock_task_sighand()") daa694e41375 ("getrusage: move thread_group_cputime_adjusted() outside of lock_task_sighand()") 13b7bc60b535 ("getrusage: use __for_each_thread()") c7ac8231ace9 ("getrusage: add the "signal_struct *sig" local variable") bdd565f817a7 ("y2038: rusage: use __kernel_old_timeval") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From f7ec1cd5cc7ef3ad964b677ba82b8b77f1c93009 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov <oleg(a)redhat.com> Date: Mon, 22 Jan 2024 16:50:53 +0100 Subject: [PATCH] getrusage: use sig->stats_lock rather than lock_task_sighand() lock_task_sighand() can trigger a hard lockup. If NR_CPUS threads call getrusage() at the same time and the process has NR_THREADS, spin_lock_irq will spin with irqs disabled O(NR_CPUS * NR_THREADS) time. Change getrusage() to use sig->stats_lock, it was specifically designed for this type of use. This way it runs lockless in the likely case. TODO: - Change do_task_stat() to use sig->stats_lock too, then we can remove spin_lock_irq(siglock) in wait_task_zombie(). - Turn sig->stats_lock into seqcount_rwlock_t, this way the readers in the slow mode won't exclude each other. See https://lore.kernel.org/all/20230913154907.GA26210@redhat.com/ - stats_lock has to disable irqs because ->siglock can be taken in irq context, it would be very nice to change __exit_signal() to avoid the siglock->stats_lock dependency. Link: https://lkml.kernel.org/r/20240122155053.GA26214@redhat.com Signed-off-by: Oleg Nesterov <oleg(a)redhat.com> Reported-by: Dylan Hatch <dylanbhatch(a)google.com> Tested-by: Dylan Hatch <dylanbhatch(a)google.com> Cc: Eric W. Biederman <ebiederm(a)xmission.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/kernel/sys.c b/kernel/sys.c index 70ad06ad852e..f8e543f1e38a 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1788,7 +1788,9 @@ void getrusage(struct task_struct *p, int who, struct rusage *r) unsigned long maxrss; struct mm_struct *mm; struct signal_struct *sig = p->signal; + unsigned int seq = 0; +retry: memset(r, 0, sizeof(*r)); utime = stime = 0; maxrss = 0; @@ -1800,8 +1802,7 @@ void getrusage(struct task_struct *p, int who, struct rusage *r) goto out_thread; } - if (!lock_task_sighand(p, &flags)) - return; + flags = read_seqbegin_or_lock_irqsave(&sig->stats_lock, &seq); switch (who) { case RUSAGE_BOTH: @@ -1829,14 +1830,23 @@ void getrusage(struct task_struct *p, int who, struct rusage *r) r->ru_oublock += sig->oublock; if (maxrss < sig->maxrss) maxrss = sig->maxrss; + + rcu_read_lock(); __for_each_thread(sig, t) accumulate_thread_rusage(t, r); + rcu_read_unlock(); + break; default: BUG(); } - unlock_task_sighand(p, &flags); + + if (need_seqretry(&sig->stats_lock, seq)) { + seq = 1; + goto retry; + } + done_seqretry_irqrestore(&sig->stats_lock, seq, flags); if (who == RUSAGE_CHILDREN) goto out_children;

1 year

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FAILED: patch "[PATCH] getrusage: use sig->stats_lock rather than" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x f7ec1cd5cc7ef3ad964b677ba82b8b77f1c93009 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024021940-bonfire-exert-b64f@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: f7ec1cd5cc7e ("getrusage: use sig->stats_lock rather than lock_task_sighand()") daa694e41375 ("getrusage: move thread_group_cputime_adjusted() outside of lock_task_sighand()") 13b7bc60b535 ("getrusage: use __for_each_thread()") c7ac8231ace9 ("getrusage: add the "signal_struct *sig" local variable") bdd565f817a7 ("y2038: rusage: use __kernel_old_timeval") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From f7ec1cd5cc7ef3ad964b677ba82b8b77f1c93009 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov <oleg(a)redhat.com> Date: Mon, 22 Jan 2024 16:50:53 +0100 Subject: [PATCH] getrusage: use sig->stats_lock rather than lock_task_sighand() lock_task_sighand() can trigger a hard lockup. If NR_CPUS threads call getrusage() at the same time and the process has NR_THREADS, spin_lock_irq will spin with irqs disabled O(NR_CPUS * NR_THREADS) time. Change getrusage() to use sig->stats_lock, it was specifically designed for this type of use. This way it runs lockless in the likely case. TODO: - Change do_task_stat() to use sig->stats_lock too, then we can remove spin_lock_irq(siglock) in wait_task_zombie(). - Turn sig->stats_lock into seqcount_rwlock_t, this way the readers in the slow mode won't exclude each other. See https://lore.kernel.org/all/20230913154907.GA26210@redhat.com/ - stats_lock has to disable irqs because ->siglock can be taken in irq context, it would be very nice to change __exit_signal() to avoid the siglock->stats_lock dependency. Link: https://lkml.kernel.org/r/20240122155053.GA26214@redhat.com Signed-off-by: Oleg Nesterov <oleg(a)redhat.com> Reported-by: Dylan Hatch <dylanbhatch(a)google.com> Tested-by: Dylan Hatch <dylanbhatch(a)google.com> Cc: Eric W. Biederman <ebiederm(a)xmission.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/kernel/sys.c b/kernel/sys.c index 70ad06ad852e..f8e543f1e38a 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1788,7 +1788,9 @@ void getrusage(struct task_struct *p, int who, struct rusage *r) unsigned long maxrss; struct mm_struct *mm; struct signal_struct *sig = p->signal; + unsigned int seq = 0; +retry: memset(r, 0, sizeof(*r)); utime = stime = 0; maxrss = 0; @@ -1800,8 +1802,7 @@ void getrusage(struct task_struct *p, int who, struct rusage *r) goto out_thread; } - if (!lock_task_sighand(p, &flags)) - return; + flags = read_seqbegin_or_lock_irqsave(&sig->stats_lock, &seq); switch (who) { case RUSAGE_BOTH: @@ -1829,14 +1830,23 @@ void getrusage(struct task_struct *p, int who, struct rusage *r) r->ru_oublock += sig->oublock; if (maxrss < sig->maxrss) maxrss = sig->maxrss; + + rcu_read_lock(); __for_each_thread(sig, t) accumulate_thread_rusage(t, r); + rcu_read_unlock(); + break; default: BUG(); } - unlock_task_sighand(p, &flags); + + if (need_seqretry(&sig->stats_lock, seq)) { + seq = 1; + goto retry; + } + done_seqretry_irqrestore(&sig->stats_lock, seq, flags); if (who == RUSAGE_CHILDREN) goto out_children;

1 year

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FAILED: patch "[PATCH] getrusage: use sig->stats_lock rather than" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x f7ec1cd5cc7ef3ad964b677ba82b8b77f1c93009 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024021938-kangaroo-obsessed-2a2e@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^.. Possible dependencies: f7ec1cd5cc7e ("getrusage: use sig->stats_lock rather than lock_task_sighand()") daa694e41375 ("getrusage: move thread_group_cputime_adjusted() outside of lock_task_sighand()") 13b7bc60b535 ("getrusage: use __for_each_thread()") c7ac8231ace9 ("getrusage: add the "signal_struct *sig" local variable") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From f7ec1cd5cc7ef3ad964b677ba82b8b77f1c93009 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov <oleg(a)redhat.com> Date: Mon, 22 Jan 2024 16:50:53 +0100 Subject: [PATCH] getrusage: use sig->stats_lock rather than lock_task_sighand() lock_task_sighand() can trigger a hard lockup. If NR_CPUS threads call getrusage() at the same time and the process has NR_THREADS, spin_lock_irq will spin with irqs disabled O(NR_CPUS * NR_THREADS) time. Change getrusage() to use sig->stats_lock, it was specifically designed for this type of use. This way it runs lockless in the likely case. TODO: - Change do_task_stat() to use sig->stats_lock too, then we can remove spin_lock_irq(siglock) in wait_task_zombie(). - Turn sig->stats_lock into seqcount_rwlock_t, this way the readers in the slow mode won't exclude each other. See https://lore.kernel.org/all/20230913154907.GA26210@redhat.com/ - stats_lock has to disable irqs because ->siglock can be taken in irq context, it would be very nice to change __exit_signal() to avoid the siglock->stats_lock dependency. Link: https://lkml.kernel.org/r/20240122155053.GA26214@redhat.com Signed-off-by: Oleg Nesterov <oleg(a)redhat.com> Reported-by: Dylan Hatch <dylanbhatch(a)google.com> Tested-by: Dylan Hatch <dylanbhatch(a)google.com> Cc: Eric W. Biederman <ebiederm(a)xmission.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/kernel/sys.c b/kernel/sys.c index 70ad06ad852e..f8e543f1e38a 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1788,7 +1788,9 @@ void getrusage(struct task_struct *p, int who, struct rusage *r) unsigned long maxrss; struct mm_struct *mm; struct signal_struct *sig = p->signal; + unsigned int seq = 0; +retry: memset(r, 0, sizeof(*r)); utime = stime = 0; maxrss = 0; @@ -1800,8 +1802,7 @@ void getrusage(struct task_struct *p, int who, struct rusage *r) goto out_thread; } - if (!lock_task_sighand(p, &flags)) - return; + flags = read_seqbegin_or_lock_irqsave(&sig->stats_lock, &seq); switch (who) { case RUSAGE_BOTH: @@ -1829,14 +1830,23 @@ void getrusage(struct task_struct *p, int who, struct rusage *r) r->ru_oublock += sig->oublock; if (maxrss < sig->maxrss) maxrss = sig->maxrss; + + rcu_read_lock(); __for_each_thread(sig, t) accumulate_thread_rusage(t, r); + rcu_read_unlock(); + break; default: BUG(); } - unlock_task_sighand(p, &flags); + + if (need_seqretry(&sig->stats_lock, seq)) { + seq = 1; + goto retry; + } + done_seqretry_irqrestore(&sig->stats_lock, seq, flags); if (who == RUSAGE_CHILDREN) goto out_children;

1 year

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FAILED: patch "[PATCH] getrusage: use sig->stats_lock rather than" failed to apply to 5.15-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x f7ec1cd5cc7ef3ad964b677ba82b8b77f1c93009 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024021936-joystick-decrease-def2@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: f7ec1cd5cc7e ("getrusage: use sig->stats_lock rather than lock_task_sighand()") daa694e41375 ("getrusage: move thread_group_cputime_adjusted() outside of lock_task_sighand()") 13b7bc60b535 ("getrusage: use __for_each_thread()") c7ac8231ace9 ("getrusage: add the "signal_struct *sig" local variable") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From f7ec1cd5cc7ef3ad964b677ba82b8b77f1c93009 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov <oleg(a)redhat.com> Date: Mon, 22 Jan 2024 16:50:53 +0100 Subject: [PATCH] getrusage: use sig->stats_lock rather than lock_task_sighand() lock_task_sighand() can trigger a hard lockup. If NR_CPUS threads call getrusage() at the same time and the process has NR_THREADS, spin_lock_irq will spin with irqs disabled O(NR_CPUS * NR_THREADS) time. Change getrusage() to use sig->stats_lock, it was specifically designed for this type of use. This way it runs lockless in the likely case. TODO: - Change do_task_stat() to use sig->stats_lock too, then we can remove spin_lock_irq(siglock) in wait_task_zombie(). - Turn sig->stats_lock into seqcount_rwlock_t, this way the readers in the slow mode won't exclude each other. See https://lore.kernel.org/all/20230913154907.GA26210@redhat.com/ - stats_lock has to disable irqs because ->siglock can be taken in irq context, it would be very nice to change __exit_signal() to avoid the siglock->stats_lock dependency. Link: https://lkml.kernel.org/r/20240122155053.GA26214@redhat.com Signed-off-by: Oleg Nesterov <oleg(a)redhat.com> Reported-by: Dylan Hatch <dylanbhatch(a)google.com> Tested-by: Dylan Hatch <dylanbhatch(a)google.com> Cc: Eric W. Biederman <ebiederm(a)xmission.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/kernel/sys.c b/kernel/sys.c index 70ad06ad852e..f8e543f1e38a 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1788,7 +1788,9 @@ void getrusage(struct task_struct *p, int who, struct rusage *r) unsigned long maxrss; struct mm_struct *mm; struct signal_struct *sig = p->signal; + unsigned int seq = 0; +retry: memset(r, 0, sizeof(*r)); utime = stime = 0; maxrss = 0; @@ -1800,8 +1802,7 @@ void getrusage(struct task_struct *p, int who, struct rusage *r) goto out_thread; } - if (!lock_task_sighand(p, &flags)) - return; + flags = read_seqbegin_or_lock_irqsave(&sig->stats_lock, &seq); switch (who) { case RUSAGE_BOTH: @@ -1829,14 +1830,23 @@ void getrusage(struct task_struct *p, int who, struct rusage *r) r->ru_oublock += sig->oublock; if (maxrss < sig->maxrss) maxrss = sig->maxrss; + + rcu_read_lock(); __for_each_thread(sig, t) accumulate_thread_rusage(t, r); + rcu_read_unlock(); + break; default: BUG(); } - unlock_task_sighand(p, &flags); + + if (need_seqretry(&sig->stats_lock, seq)) { + seq = 1; + goto retry; + } + done_seqretry_irqrestore(&sig->stats_lock, seq, flags); if (who == RUSAGE_CHILDREN) goto out_children;

1 year

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FAILED: patch "[PATCH] getrusage: use sig->stats_lock rather than" failed to apply to 6.1-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x f7ec1cd5cc7ef3ad964b677ba82b8b77f1c93009 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024021934-version-stamp-e8f4@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^.. Possible dependencies: f7ec1cd5cc7e ("getrusage: use sig->stats_lock rather than lock_task_sighand()") daa694e41375 ("getrusage: move thread_group_cputime_adjusted() outside of lock_task_sighand()") 13b7bc60b535 ("getrusage: use __for_each_thread()") c7ac8231ace9 ("getrusage: add the "signal_struct *sig" local variable") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From f7ec1cd5cc7ef3ad964b677ba82b8b77f1c93009 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov <oleg(a)redhat.com> Date: Mon, 22 Jan 2024 16:50:53 +0100 Subject: [PATCH] getrusage: use sig->stats_lock rather than lock_task_sighand() lock_task_sighand() can trigger a hard lockup. If NR_CPUS threads call getrusage() at the same time and the process has NR_THREADS, spin_lock_irq will spin with irqs disabled O(NR_CPUS * NR_THREADS) time. Change getrusage() to use sig->stats_lock, it was specifically designed for this type of use. This way it runs lockless in the likely case. TODO: - Change do_task_stat() to use sig->stats_lock too, then we can remove spin_lock_irq(siglock) in wait_task_zombie(). - Turn sig->stats_lock into seqcount_rwlock_t, this way the readers in the slow mode won't exclude each other. See https://lore.kernel.org/all/20230913154907.GA26210@redhat.com/ - stats_lock has to disable irqs because ->siglock can be taken in irq context, it would be very nice to change __exit_signal() to avoid the siglock->stats_lock dependency. Link: https://lkml.kernel.org/r/20240122155053.GA26214@redhat.com Signed-off-by: Oleg Nesterov <oleg(a)redhat.com> Reported-by: Dylan Hatch <dylanbhatch(a)google.com> Tested-by: Dylan Hatch <dylanbhatch(a)google.com> Cc: Eric W. Biederman <ebiederm(a)xmission.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/kernel/sys.c b/kernel/sys.c index 70ad06ad852e..f8e543f1e38a 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1788,7 +1788,9 @@ void getrusage(struct task_struct *p, int who, struct rusage *r) unsigned long maxrss; struct mm_struct *mm; struct signal_struct *sig = p->signal; + unsigned int seq = 0; +retry: memset(r, 0, sizeof(*r)); utime = stime = 0; maxrss = 0; @@ -1800,8 +1802,7 @@ void getrusage(struct task_struct *p, int who, struct rusage *r) goto out_thread; } - if (!lock_task_sighand(p, &flags)) - return; + flags = read_seqbegin_or_lock_irqsave(&sig->stats_lock, &seq); switch (who) { case RUSAGE_BOTH: @@ -1829,14 +1830,23 @@ void getrusage(struct task_struct *p, int who, struct rusage *r) r->ru_oublock += sig->oublock; if (maxrss < sig->maxrss) maxrss = sig->maxrss; + + rcu_read_lock(); __for_each_thread(sig, t) accumulate_thread_rusage(t, r); + rcu_read_unlock(); + break; default: BUG(); } - unlock_task_sighand(p, &flags); + + if (need_seqretry(&sig->stats_lock, seq)) { + seq = 1; + goto retry; + } + done_seqretry_irqrestore(&sig->stats_lock, seq, flags); if (who == RUSAGE_CHILDREN) goto out_children;

1 year

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FAILED: patch "[PATCH] getrusage: use sig->stats_lock rather than" failed to apply to 6.6-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x f7ec1cd5cc7ef3ad964b677ba82b8b77f1c93009 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024021933-passion-crucial-7362@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: f7ec1cd5cc7e ("getrusage: use sig->stats_lock rather than lock_task_sighand()") daa694e41375 ("getrusage: move thread_group_cputime_adjusted() outside of lock_task_sighand()") 13b7bc60b535 ("getrusage: use __for_each_thread()") c7ac8231ace9 ("getrusage: add the "signal_struct *sig" local variable") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From f7ec1cd5cc7ef3ad964b677ba82b8b77f1c93009 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov <oleg(a)redhat.com> Date: Mon, 22 Jan 2024 16:50:53 +0100 Subject: [PATCH] getrusage: use sig->stats_lock rather than lock_task_sighand() lock_task_sighand() can trigger a hard lockup. If NR_CPUS threads call getrusage() at the same time and the process has NR_THREADS, spin_lock_irq will spin with irqs disabled O(NR_CPUS * NR_THREADS) time. Change getrusage() to use sig->stats_lock, it was specifically designed for this type of use. This way it runs lockless in the likely case. TODO: - Change do_task_stat() to use sig->stats_lock too, then we can remove spin_lock_irq(siglock) in wait_task_zombie(). - Turn sig->stats_lock into seqcount_rwlock_t, this way the readers in the slow mode won't exclude each other. See https://lore.kernel.org/all/20230913154907.GA26210@redhat.com/ - stats_lock has to disable irqs because ->siglock can be taken in irq context, it would be very nice to change __exit_signal() to avoid the siglock->stats_lock dependency. Link: https://lkml.kernel.org/r/20240122155053.GA26214@redhat.com Signed-off-by: Oleg Nesterov <oleg(a)redhat.com> Reported-by: Dylan Hatch <dylanbhatch(a)google.com> Tested-by: Dylan Hatch <dylanbhatch(a)google.com> Cc: Eric W. Biederman <ebiederm(a)xmission.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/kernel/sys.c b/kernel/sys.c index 70ad06ad852e..f8e543f1e38a 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1788,7 +1788,9 @@ void getrusage(struct task_struct *p, int who, struct rusage *r) unsigned long maxrss; struct mm_struct *mm; struct signal_struct *sig = p->signal; + unsigned int seq = 0; +retry: memset(r, 0, sizeof(*r)); utime = stime = 0; maxrss = 0; @@ -1800,8 +1802,7 @@ void getrusage(struct task_struct *p, int who, struct rusage *r) goto out_thread; } - if (!lock_task_sighand(p, &flags)) - return; + flags = read_seqbegin_or_lock_irqsave(&sig->stats_lock, &seq); switch (who) { case RUSAGE_BOTH: @@ -1829,14 +1830,23 @@ void getrusage(struct task_struct *p, int who, struct rusage *r) r->ru_oublock += sig->oublock; if (maxrss < sig->maxrss) maxrss = sig->maxrss; + + rcu_read_lock(); __for_each_thread(sig, t) accumulate_thread_rusage(t, r); + rcu_read_unlock(); + break; default: BUG(); } - unlock_task_sighand(p, &flags); + + if (need_seqretry(&sig->stats_lock, seq)) { + seq = 1; + goto retry; + } + done_seqretry_irqrestore(&sig->stats_lock, seq, flags); if (who == RUSAGE_CHILDREN) goto out_children;

1 year

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FAILED: patch "[PATCH] getrusage: move thread_group_cputime_adjusted() outside of" failed to apply to 4.19-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-4.19.y git checkout FETCH_HEAD git cherry-pick -x daa694e4137571b4ebec330f9a9b4d54aa8b8089 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024021926-fretted-situation-ed0b@gregkh' --subject-prefix 'PATCH 4.19.y' HEAD^.. Possible dependencies: daa694e41375 ("getrusage: move thread_group_cputime_adjusted() outside of lock_task_sighand()") c7ac8231ace9 ("getrusage: add the "signal_struct *sig" local variable") bdd565f817a7 ("y2038: rusage: use __kernel_old_timeval") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From daa694e4137571b4ebec330f9a9b4d54aa8b8089 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov <oleg(a)redhat.com> Date: Mon, 22 Jan 2024 16:50:50 +0100 Subject: [PATCH] getrusage: move thread_group_cputime_adjusted() outside of lock_task_sighand() Patch series "getrusage: use sig->stats_lock", v2. This patch (of 2): thread_group_cputime() does its own locking, we can safely shift thread_group_cputime_adjusted() which does another for_each_thread loop outside of ->siglock protected section. This is also preparation for the next patch which changes getrusage() to use stats_lock instead of siglock, thread_group_cputime() takes the same lock. With the current implementation recursive read_seqbegin_or_lock() is fine, thread_group_cputime() can't enter the slow mode if the caller holds stats_lock, yet this looks more safe and better performance-wise. Link: https://lkml.kernel.org/r/20240122155023.GA26169@redhat.com Link: https://lkml.kernel.org/r/20240122155050.GA26205@redhat.com Signed-off-by: Oleg Nesterov <oleg(a)redhat.com> Reported-by: Dylan Hatch <dylanbhatch(a)google.com> Tested-by: Dylan Hatch <dylanbhatch(a)google.com> Cc: Eric W. Biederman <ebiederm(a)xmission.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/kernel/sys.c b/kernel/sys.c index e219fcfa112d..70ad06ad852e 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1785,17 +1785,19 @@ void getrusage(struct task_struct *p, int who, struct rusage *r) struct task_struct *t; unsigned long flags; u64 tgutime, tgstime, utime, stime; - unsigned long maxrss = 0; + unsigned long maxrss; + struct mm_struct *mm; struct signal_struct *sig = p->signal; - memset((char *)r, 0, sizeof (*r)); + memset(r, 0, sizeof(*r)); utime = stime = 0; + maxrss = 0; if (who == RUSAGE_THREAD) { task_cputime_adjusted(current, &utime, &stime); accumulate_thread_rusage(p, r); maxrss = sig->maxrss; - goto out; + goto out_thread; } if (!lock_task_sighand(p, &flags)) @@ -1819,9 +1821,6 @@ void getrusage(struct task_struct *p, int who, struct rusage *r) fallthrough; case RUSAGE_SELF: - thread_group_cputime_adjusted(p, &tgutime, &tgstime); - utime += tgutime; - stime += tgstime; r->ru_nvcsw += sig->nvcsw; r->ru_nivcsw += sig->nivcsw; r->ru_minflt += sig->min_flt; @@ -1839,19 +1838,24 @@ void getrusage(struct task_struct *p, int who, struct rusage *r) } unlock_task_sighand(p, &flags); -out: + if (who == RUSAGE_CHILDREN) + goto out_children; + + thread_group_cputime_adjusted(p, &tgutime, &tgstime); + utime += tgutime; + stime += tgstime; + +out_thread: + mm = get_task_mm(p); + if (mm) { + setmax_mm_hiwater_rss(&maxrss, mm); + mmput(mm); + } + +out_children: + r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */ r->ru_utime = ns_to_kernel_old_timeval(utime); r->ru_stime = ns_to_kernel_old_timeval(stime); - - if (who != RUSAGE_CHILDREN) { - struct mm_struct *mm = get_task_mm(p); - - if (mm) { - setmax_mm_hiwater_rss(&maxrss, mm); - mmput(mm); - } - } - r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */ } SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru)

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FAILED: patch "[PATCH] getrusage: move thread_group_cputime_adjusted() outside of" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x daa694e4137571b4ebec330f9a9b4d54aa8b8089 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024021925-cornstalk-army-948b@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: daa694e41375 ("getrusage: move thread_group_cputime_adjusted() outside of lock_task_sighand()") c7ac8231ace9 ("getrusage: add the "signal_struct *sig" local variable") bdd565f817a7 ("y2038: rusage: use __kernel_old_timeval") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From daa694e4137571b4ebec330f9a9b4d54aa8b8089 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov <oleg(a)redhat.com> Date: Mon, 22 Jan 2024 16:50:50 +0100 Subject: [PATCH] getrusage: move thread_group_cputime_adjusted() outside of lock_task_sighand() Patch series "getrusage: use sig->stats_lock", v2. This patch (of 2): thread_group_cputime() does its own locking, we can safely shift thread_group_cputime_adjusted() which does another for_each_thread loop outside of ->siglock protected section. This is also preparation for the next patch which changes getrusage() to use stats_lock instead of siglock, thread_group_cputime() takes the same lock. With the current implementation recursive read_seqbegin_or_lock() is fine, thread_group_cputime() can't enter the slow mode if the caller holds stats_lock, yet this looks more safe and better performance-wise. Link: https://lkml.kernel.org/r/20240122155023.GA26169@redhat.com Link: https://lkml.kernel.org/r/20240122155050.GA26205@redhat.com Signed-off-by: Oleg Nesterov <oleg(a)redhat.com> Reported-by: Dylan Hatch <dylanbhatch(a)google.com> Tested-by: Dylan Hatch <dylanbhatch(a)google.com> Cc: Eric W. Biederman <ebiederm(a)xmission.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/kernel/sys.c b/kernel/sys.c index e219fcfa112d..70ad06ad852e 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1785,17 +1785,19 @@ void getrusage(struct task_struct *p, int who, struct rusage *r) struct task_struct *t; unsigned long flags; u64 tgutime, tgstime, utime, stime; - unsigned long maxrss = 0; + unsigned long maxrss; + struct mm_struct *mm; struct signal_struct *sig = p->signal; - memset((char *)r, 0, sizeof (*r)); + memset(r, 0, sizeof(*r)); utime = stime = 0; + maxrss = 0; if (who == RUSAGE_THREAD) { task_cputime_adjusted(current, &utime, &stime); accumulate_thread_rusage(p, r); maxrss = sig->maxrss; - goto out; + goto out_thread; } if (!lock_task_sighand(p, &flags)) @@ -1819,9 +1821,6 @@ void getrusage(struct task_struct *p, int who, struct rusage *r) fallthrough; case RUSAGE_SELF: - thread_group_cputime_adjusted(p, &tgutime, &tgstime); - utime += tgutime; - stime += tgstime; r->ru_nvcsw += sig->nvcsw; r->ru_nivcsw += sig->nivcsw; r->ru_minflt += sig->min_flt; @@ -1839,19 +1838,24 @@ void getrusage(struct task_struct *p, int who, struct rusage *r) } unlock_task_sighand(p, &flags); -out: + if (who == RUSAGE_CHILDREN) + goto out_children; + + thread_group_cputime_adjusted(p, &tgutime, &tgstime); + utime += tgutime; + stime += tgstime; + +out_thread: + mm = get_task_mm(p); + if (mm) { + setmax_mm_hiwater_rss(&maxrss, mm); + mmput(mm); + } + +out_children: + r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */ r->ru_utime = ns_to_kernel_old_timeval(utime); r->ru_stime = ns_to_kernel_old_timeval(stime); - - if (who != RUSAGE_CHILDREN) { - struct mm_struct *mm = get_task_mm(p); - - if (mm) { - setmax_mm_hiwater_rss(&maxrss, mm); - mmput(mm); - } - } - r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */ } SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru)

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FAILED: patch "[PATCH] getrusage: move thread_group_cputime_adjusted() outside of" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x daa694e4137571b4ebec330f9a9b4d54aa8b8089 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024021924-steersman-sixtieth-0e6e@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^.. Possible dependencies: daa694e41375 ("getrusage: move thread_group_cputime_adjusted() outside of lock_task_sighand()") c7ac8231ace9 ("getrusage: add the "signal_struct *sig" local variable") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From daa694e4137571b4ebec330f9a9b4d54aa8b8089 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov <oleg(a)redhat.com> Date: Mon, 22 Jan 2024 16:50:50 +0100 Subject: [PATCH] getrusage: move thread_group_cputime_adjusted() outside of lock_task_sighand() Patch series "getrusage: use sig->stats_lock", v2. This patch (of 2): thread_group_cputime() does its own locking, we can safely shift thread_group_cputime_adjusted() which does another for_each_thread loop outside of ->siglock protected section. This is also preparation for the next patch which changes getrusage() to use stats_lock instead of siglock, thread_group_cputime() takes the same lock. With the current implementation recursive read_seqbegin_or_lock() is fine, thread_group_cputime() can't enter the slow mode if the caller holds stats_lock, yet this looks more safe and better performance-wise. Link: https://lkml.kernel.org/r/20240122155023.GA26169@redhat.com Link: https://lkml.kernel.org/r/20240122155050.GA26205@redhat.com Signed-off-by: Oleg Nesterov <oleg(a)redhat.com> Reported-by: Dylan Hatch <dylanbhatch(a)google.com> Tested-by: Dylan Hatch <dylanbhatch(a)google.com> Cc: Eric W. Biederman <ebiederm(a)xmission.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/kernel/sys.c b/kernel/sys.c index e219fcfa112d..70ad06ad852e 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1785,17 +1785,19 @@ void getrusage(struct task_struct *p, int who, struct rusage *r) struct task_struct *t; unsigned long flags; u64 tgutime, tgstime, utime, stime; - unsigned long maxrss = 0; + unsigned long maxrss; + struct mm_struct *mm; struct signal_struct *sig = p->signal; - memset((char *)r, 0, sizeof (*r)); + memset(r, 0, sizeof(*r)); utime = stime = 0; + maxrss = 0; if (who == RUSAGE_THREAD) { task_cputime_adjusted(current, &utime, &stime); accumulate_thread_rusage(p, r); maxrss = sig->maxrss; - goto out; + goto out_thread; } if (!lock_task_sighand(p, &flags)) @@ -1819,9 +1821,6 @@ void getrusage(struct task_struct *p, int who, struct rusage *r) fallthrough; case RUSAGE_SELF: - thread_group_cputime_adjusted(p, &tgutime, &tgstime); - utime += tgutime; - stime += tgstime; r->ru_nvcsw += sig->nvcsw; r->ru_nivcsw += sig->nivcsw; r->ru_minflt += sig->min_flt; @@ -1839,19 +1838,24 @@ void getrusage(struct task_struct *p, int who, struct rusage *r) } unlock_task_sighand(p, &flags); -out: + if (who == RUSAGE_CHILDREN) + goto out_children; + + thread_group_cputime_adjusted(p, &tgutime, &tgstime); + utime += tgutime; + stime += tgstime; + +out_thread: + mm = get_task_mm(p); + if (mm) { + setmax_mm_hiwater_rss(&maxrss, mm); + mmput(mm); + } + +out_children: + r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */ r->ru_utime = ns_to_kernel_old_timeval(utime); r->ru_stime = ns_to_kernel_old_timeval(stime); - - if (who != RUSAGE_CHILDREN) { - struct mm_struct *mm = get_task_mm(p); - - if (mm) { - setmax_mm_hiwater_rss(&maxrss, mm); - mmput(mm); - } - } - r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */ } SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru)

1 year

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FAILED: patch "[PATCH] getrusage: move thread_group_cputime_adjusted() outside of" failed to apply to 5.15-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x daa694e4137571b4ebec330f9a9b4d54aa8b8089 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024021923-promptly-dedicate-e327@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: daa694e41375 ("getrusage: move thread_group_cputime_adjusted() outside of lock_task_sighand()") c7ac8231ace9 ("getrusage: add the "signal_struct *sig" local variable") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From daa694e4137571b4ebec330f9a9b4d54aa8b8089 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov <oleg(a)redhat.com> Date: Mon, 22 Jan 2024 16:50:50 +0100 Subject: [PATCH] getrusage: move thread_group_cputime_adjusted() outside of lock_task_sighand() Patch series "getrusage: use sig->stats_lock", v2. This patch (of 2): thread_group_cputime() does its own locking, we can safely shift thread_group_cputime_adjusted() which does another for_each_thread loop outside of ->siglock protected section. This is also preparation for the next patch which changes getrusage() to use stats_lock instead of siglock, thread_group_cputime() takes the same lock. With the current implementation recursive read_seqbegin_or_lock() is fine, thread_group_cputime() can't enter the slow mode if the caller holds stats_lock, yet this looks more safe and better performance-wise. Link: https://lkml.kernel.org/r/20240122155023.GA26169@redhat.com Link: https://lkml.kernel.org/r/20240122155050.GA26205@redhat.com Signed-off-by: Oleg Nesterov <oleg(a)redhat.com> Reported-by: Dylan Hatch <dylanbhatch(a)google.com> Tested-by: Dylan Hatch <dylanbhatch(a)google.com> Cc: Eric W. Biederman <ebiederm(a)xmission.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/kernel/sys.c b/kernel/sys.c index e219fcfa112d..70ad06ad852e 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1785,17 +1785,19 @@ void getrusage(struct task_struct *p, int who, struct rusage *r) struct task_struct *t; unsigned long flags; u64 tgutime, tgstime, utime, stime; - unsigned long maxrss = 0; + unsigned long maxrss; + struct mm_struct *mm; struct signal_struct *sig = p->signal; - memset((char *)r, 0, sizeof (*r)); + memset(r, 0, sizeof(*r)); utime = stime = 0; + maxrss = 0; if (who == RUSAGE_THREAD) { task_cputime_adjusted(current, &utime, &stime); accumulate_thread_rusage(p, r); maxrss = sig->maxrss; - goto out; + goto out_thread; } if (!lock_task_sighand(p, &flags)) @@ -1819,9 +1821,6 @@ void getrusage(struct task_struct *p, int who, struct rusage *r) fallthrough; case RUSAGE_SELF: - thread_group_cputime_adjusted(p, &tgutime, &tgstime); - utime += tgutime; - stime += tgstime; r->ru_nvcsw += sig->nvcsw; r->ru_nivcsw += sig->nivcsw; r->ru_minflt += sig->min_flt; @@ -1839,19 +1838,24 @@ void getrusage(struct task_struct *p, int who, struct rusage *r) } unlock_task_sighand(p, &flags); -out: + if (who == RUSAGE_CHILDREN) + goto out_children; + + thread_group_cputime_adjusted(p, &tgutime, &tgstime); + utime += tgutime; + stime += tgstime; + +out_thread: + mm = get_task_mm(p); + if (mm) { + setmax_mm_hiwater_rss(&maxrss, mm); + mmput(mm); + } + +out_children: + r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */ r->ru_utime = ns_to_kernel_old_timeval(utime); r->ru_stime = ns_to_kernel_old_timeval(stime); - - if (who != RUSAGE_CHILDREN) { - struct mm_struct *mm = get_task_mm(p); - - if (mm) { - setmax_mm_hiwater_rss(&maxrss, mm); - mmput(mm); - } - } - r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */ } SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru)

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