October 2022 - Linux-stable-mirror

FAILED: patch "[PATCH] ring-buffer: Add ring_buffer_wake_waiters()" 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>. Possible dependencies: 7e9fbbb1b776 ("ring-buffer: Add ring_buffer_wake_waiters()") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 7e9fbbb1b776d8d7969551565bc246f74ec53b27 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Google)" <rostedt(a)goodmis.org> Date: Wed, 28 Sep 2022 13:39:38 -0400 Subject: [PATCH] ring-buffer: Add ring_buffer_wake_waiters() On closing of a file that represents a ring buffer or flushing the file, there may be waiters on the ring buffer that needs to be woken up and exit the ring_buffer_wait() function. Add ring_buffer_wake_waiters() to wake up the waiters on the ring buffer and allow them to exit the wait loop. Link: https://lkml.kernel.org/r/20220928133938.28dc2c27@gandalf.local.home Cc: stable(a)vger.kernel.org Cc: Ingo Molnar <mingo(a)kernel.org> Cc: Andrew Morton <akpm(a)linux-foundation.org> Fixes: 15693458c4bc0 ("tracing/ring-buffer: Move poll wake ups into ring buffer code") Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h index dac53fd3afea..2504df9a0453 100644 --- a/include/linux/ring_buffer.h +++ b/include/linux/ring_buffer.h @@ -101,7 +101,7 @@ __ring_buffer_alloc(unsigned long size, unsigned flags, struct lock_class_key *k int ring_buffer_wait(struct trace_buffer *buffer, int cpu, int full); __poll_t ring_buffer_poll_wait(struct trace_buffer *buffer, int cpu, struct file *filp, poll_table *poll_table); - +void ring_buffer_wake_waiters(struct trace_buffer *buffer, int cpu); #define RING_BUFFER_ALL_CPUS -1 diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 5a7d818ca3ea..3046deacf7b3 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -413,6 +413,7 @@ struct rb_irq_work { struct irq_work work; wait_queue_head_t waiters; wait_queue_head_t full_waiters; + long wait_index; bool waiters_pending; bool full_waiters_pending; bool wakeup_full; @@ -924,6 +925,37 @@ static void rb_wake_up_waiters(struct irq_work *work) } } +/** + * ring_buffer_wake_waiters - wake up any waiters on this ring buffer + * @buffer: The ring buffer to wake waiters on + * + * In the case of a file that represents a ring buffer is closing, + * it is prudent to wake up any waiters that are on this. + */ +void ring_buffer_wake_waiters(struct trace_buffer *buffer, int cpu) +{ + struct ring_buffer_per_cpu *cpu_buffer; + struct rb_irq_work *rbwork; + + if (cpu == RING_BUFFER_ALL_CPUS) { + + /* Wake up individual ones too. One level recursion */ + for_each_buffer_cpu(buffer, cpu) + ring_buffer_wake_waiters(buffer, cpu); + + rbwork = &buffer->irq_work; + } else { + cpu_buffer = buffer->buffers[cpu]; + rbwork = &cpu_buffer->irq_work; + } + + rbwork->wait_index++; + /* make sure the waiters see the new index */ + smp_wmb(); + + rb_wake_up_waiters(&rbwork->work); +} + /** * ring_buffer_wait - wait for input to the ring buffer * @buffer: buffer to wait on @@ -939,6 +971,7 @@ int ring_buffer_wait(struct trace_buffer *buffer, int cpu, int full) struct ring_buffer_per_cpu *cpu_buffer; DEFINE_WAIT(wait); struct rb_irq_work *work; + long wait_index; int ret = 0; /* @@ -957,6 +990,7 @@ int ring_buffer_wait(struct trace_buffer *buffer, int cpu, int full) work = &cpu_buffer->irq_work; } + wait_index = READ_ONCE(work->wait_index); while (true) { if (full) @@ -1021,6 +1055,11 @@ int ring_buffer_wait(struct trace_buffer *buffer, int cpu, int full) } schedule(); + + /* Make sure to see the new wait index */ + smp_rmb(); + if (wait_index != work->wait_index) + break; } if (full)

2 years, 2 months

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FAILED: patch "[PATCH] tracing: Fix reading strings from synthetic events" 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>. Possible dependencies: 0934ae9977c2 ("tracing: Fix reading strings from synthetic events") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 0934ae9977c27133449b6dd8c6213970e7eece38 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Google)" <rostedt(a)goodmis.org> Date: Wed, 12 Oct 2022 06:40:58 -0400 Subject: [PATCH] tracing: Fix reading strings from synthetic events The follow commands caused a crash: # cd /sys/kernel/tracing # echo 's:open char file[]' > dynamic_events # echo 'hist:keys=common_pid:file=filename:onchange($file).trace(open,$file)' > events/syscalls/sys_enter_openat/trigger' # echo 1 > events/synthetic/open/enable BOOM! The problem is that the synthetic event field "char file[]" will read the value given to it as a string without any memory checks to make sure the address is valid. The above example will pass in the user space address and the sythetic event code will happily call strlen() on it and then strscpy() where either one will cause an oops when accessing user space addresses. Use the helper functions from trace_kprobe and trace_eprobe that can read strings safely (and actually succeed when the address is from user space and the memory is mapped in). Now the above can show: packagekitd-1721 [000] ...2. 104.597170: open: file=/usr/lib/rpm/fileattrs/cmake.attr in:imjournal-978 [006] ...2. 104.599642: open: file=/var/lib/rsyslog/imjournal.state.tmp packagekitd-1721 [000] ...2. 104.626308: open: file=/usr/lib/rpm/fileattrs/debuginfo.attr Link: https://lkml.kernel.org/r/20221012104534.826549315@goodmis.org Cc: stable(a)vger.kernel.org Cc: Andrew Morton <akpm(a)linux-foundation.org> Cc: Tom Zanussi <zanussi(a)kernel.org> Acked-by: Masami Hiramatsu (Google) <mhiramat(a)kernel.org> Reviewed-by: Tom Zanussi <zanussi(a)kernel.org> Fixes: bd82631d7ccdc ("tracing: Add support for dynamic strings to synthetic events") Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c index 5e8c07aef071..e310052dc83c 100644 --- a/kernel/trace/trace_events_synth.c +++ b/kernel/trace/trace_events_synth.c @@ -17,6 +17,8 @@ /* for gfp flag names */ #include <linux/trace_events.h> #include <trace/events/mmflags.h> +#include "trace_probe.h" +#include "trace_probe_kernel.h" #include "trace_synth.h" @@ -409,6 +411,7 @@ static unsigned int trace_string(struct synth_trace_event *entry, { unsigned int len = 0; char *str_field; + int ret; if (is_dynamic) { u32 data_offset; @@ -417,19 +420,27 @@ static unsigned int trace_string(struct synth_trace_event *entry, data_offset += event->n_u64 * sizeof(u64); data_offset += data_size; - str_field = (char *)entry + data_offset; - - len = strlen(str_val) + 1; - strscpy(str_field, str_val, len); + len = kern_fetch_store_strlen((unsigned long)str_val); data_offset |= len << 16; *(u32 *)&entry->fields[*n_u64] = data_offset; + ret = kern_fetch_store_string((unsigned long)str_val, &entry->fields[*n_u64], entry); + (*n_u64)++; } else { str_field = (char *)&entry->fields[*n_u64]; - strscpy(str_field, str_val, STR_VAR_LEN_MAX); +#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE + if ((unsigned long)str_val < TASK_SIZE) + ret = strncpy_from_user_nofault(str_field, str_val, STR_VAR_LEN_MAX); + else +#endif + ret = strncpy_from_kernel_nofault(str_field, str_val, STR_VAR_LEN_MAX); + + if (ret < 0) + strcpy(str_field, FAULT_STRING); + (*n_u64) += STR_VAR_LEN_MAX / sizeof(u64); } @@ -462,7 +473,7 @@ static notrace void trace_event_raw_event_synth(void *__data, val_idx = var_ref_idx[field_pos]; str_val = (char *)(long)var_ref_vals[val_idx]; - len = strlen(str_val) + 1; + len = kern_fetch_store_strlen((unsigned long)str_val); fields_size += len; }

2 years, 2 months

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FAILED: patch "[PATCH] tracing: Add ioctl() to force ring buffer waiters to wake up" 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>. Possible dependencies: 01b2a5217173 ("tracing: Add ioctl() to force ring buffer waiters to wake up") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 01b2a52171735c6eea80ee2f355f32bea6c41418 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Google)" <rostedt(a)goodmis.org> Date: Thu, 29 Sep 2022 09:50:29 -0400 Subject: [PATCH] tracing: Add ioctl() to force ring buffer waiters to wake up If a process is waiting on the ring buffer for data, there currently isn't a clean way to force it to wake up. Add an ioctl call that will force any tasks that are waiting on the trace_pipe_raw file to wake up. Link: https://lkml.kernel.org/r/20220929095029.117f913f@gandalf.local.home Cc: stable(a)vger.kernel.org Cc: Ingo Molnar <mingo(a)kernel.org> Cc: Andrew Morton <akpm(a)linux-foundation.org> Fixes: e30f53aad2202 ("tracing: Do not busy wait in buffer splice") Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index e101b0764b39..58afc83afc9d 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -8349,12 +8349,34 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos, return ret; } +/* An ioctl call with cmd 0 to the ring buffer file will wake up all waiters */ +static long tracing_buffers_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + struct ftrace_buffer_info *info = file->private_data; + struct trace_iterator *iter = &info->iter; + + if (cmd) + return -ENOIOCTLCMD; + + mutex_lock(&trace_types_lock); + + iter->wait_index++; + /* Make sure the waiters see the new wait_index */ + smp_wmb(); + + ring_buffer_wake_waiters(iter->array_buffer->buffer, iter->cpu_file); + + mutex_unlock(&trace_types_lock); + return 0; +} + static const struct file_operations tracing_buffers_fops = { .open = tracing_buffers_open, .read = tracing_buffers_read, .poll = tracing_buffers_poll, .release = tracing_buffers_release, .splice_read = tracing_buffers_splice_read, + .unlocked_ioctl = tracing_buffers_ioctl, .llseek = no_llseek, };

2 years, 2 months

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FAILED: patch "[PATCH] tracing: Add ioctl() to force ring buffer waiters to wake up" 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>. Possible dependencies: 01b2a5217173 ("tracing: Add ioctl() to force ring buffer waiters to wake up") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 01b2a52171735c6eea80ee2f355f32bea6c41418 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Google)" <rostedt(a)goodmis.org> Date: Thu, 29 Sep 2022 09:50:29 -0400 Subject: [PATCH] tracing: Add ioctl() to force ring buffer waiters to wake up If a process is waiting on the ring buffer for data, there currently isn't a clean way to force it to wake up. Add an ioctl call that will force any tasks that are waiting on the trace_pipe_raw file to wake up. Link: https://lkml.kernel.org/r/20220929095029.117f913f@gandalf.local.home Cc: stable(a)vger.kernel.org Cc: Ingo Molnar <mingo(a)kernel.org> Cc: Andrew Morton <akpm(a)linux-foundation.org> Fixes: e30f53aad2202 ("tracing: Do not busy wait in buffer splice") Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index e101b0764b39..58afc83afc9d 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -8349,12 +8349,34 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos, return ret; } +/* An ioctl call with cmd 0 to the ring buffer file will wake up all waiters */ +static long tracing_buffers_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + struct ftrace_buffer_info *info = file->private_data; + struct trace_iterator *iter = &info->iter; + + if (cmd) + return -ENOIOCTLCMD; + + mutex_lock(&trace_types_lock); + + iter->wait_index++; + /* Make sure the waiters see the new wait_index */ + smp_wmb(); + + ring_buffer_wake_waiters(iter->array_buffer->buffer, iter->cpu_file); + + mutex_unlock(&trace_types_lock); + return 0; +} + static const struct file_operations tracing_buffers_fops = { .open = tracing_buffers_open, .read = tracing_buffers_read, .poll = tracing_buffers_poll, .release = tracing_buffers_release, .splice_read = tracing_buffers_splice_read, + .unlocked_ioctl = tracing_buffers_ioctl, .llseek = no_llseek, };

2 years, 2 months

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FAILED: patch "[PATCH] ring-buffer: Add ring_buffer_wake_waiters()" 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>. Possible dependencies: 7e9fbbb1b776 ("ring-buffer: Add ring_buffer_wake_waiters()") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 7e9fbbb1b776d8d7969551565bc246f74ec53b27 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Google)" <rostedt(a)goodmis.org> Date: Wed, 28 Sep 2022 13:39:38 -0400 Subject: [PATCH] ring-buffer: Add ring_buffer_wake_waiters() On closing of a file that represents a ring buffer or flushing the file, there may be waiters on the ring buffer that needs to be woken up and exit the ring_buffer_wait() function. Add ring_buffer_wake_waiters() to wake up the waiters on the ring buffer and allow them to exit the wait loop. Link: https://lkml.kernel.org/r/20220928133938.28dc2c27@gandalf.local.home Cc: stable(a)vger.kernel.org Cc: Ingo Molnar <mingo(a)kernel.org> Cc: Andrew Morton <akpm(a)linux-foundation.org> Fixes: 15693458c4bc0 ("tracing/ring-buffer: Move poll wake ups into ring buffer code") Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h index dac53fd3afea..2504df9a0453 100644 --- a/include/linux/ring_buffer.h +++ b/include/linux/ring_buffer.h @@ -101,7 +101,7 @@ __ring_buffer_alloc(unsigned long size, unsigned flags, struct lock_class_key *k int ring_buffer_wait(struct trace_buffer *buffer, int cpu, int full); __poll_t ring_buffer_poll_wait(struct trace_buffer *buffer, int cpu, struct file *filp, poll_table *poll_table); - +void ring_buffer_wake_waiters(struct trace_buffer *buffer, int cpu); #define RING_BUFFER_ALL_CPUS -1 diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 5a7d818ca3ea..3046deacf7b3 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -413,6 +413,7 @@ struct rb_irq_work { struct irq_work work; wait_queue_head_t waiters; wait_queue_head_t full_waiters; + long wait_index; bool waiters_pending; bool full_waiters_pending; bool wakeup_full; @@ -924,6 +925,37 @@ static void rb_wake_up_waiters(struct irq_work *work) } } +/** + * ring_buffer_wake_waiters - wake up any waiters on this ring buffer + * @buffer: The ring buffer to wake waiters on + * + * In the case of a file that represents a ring buffer is closing, + * it is prudent to wake up any waiters that are on this. + */ +void ring_buffer_wake_waiters(struct trace_buffer *buffer, int cpu) +{ + struct ring_buffer_per_cpu *cpu_buffer; + struct rb_irq_work *rbwork; + + if (cpu == RING_BUFFER_ALL_CPUS) { + + /* Wake up individual ones too. One level recursion */ + for_each_buffer_cpu(buffer, cpu) + ring_buffer_wake_waiters(buffer, cpu); + + rbwork = &buffer->irq_work; + } else { + cpu_buffer = buffer->buffers[cpu]; + rbwork = &cpu_buffer->irq_work; + } + + rbwork->wait_index++; + /* make sure the waiters see the new index */ + smp_wmb(); + + rb_wake_up_waiters(&rbwork->work); +} + /** * ring_buffer_wait - wait for input to the ring buffer * @buffer: buffer to wait on @@ -939,6 +971,7 @@ int ring_buffer_wait(struct trace_buffer *buffer, int cpu, int full) struct ring_buffer_per_cpu *cpu_buffer; DEFINE_WAIT(wait); struct rb_irq_work *work; + long wait_index; int ret = 0; /* @@ -957,6 +990,7 @@ int ring_buffer_wait(struct trace_buffer *buffer, int cpu, int full) work = &cpu_buffer->irq_work; } + wait_index = READ_ONCE(work->wait_index); while (true) { if (full) @@ -1021,6 +1055,11 @@ int ring_buffer_wait(struct trace_buffer *buffer, int cpu, int full) } schedule(); + + /* Make sure to see the new wait index */ + smp_rmb(); + if (wait_index != work->wait_index) + break; } if (full)

2 years, 2 months

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FAILED: patch "[PATCH] tracing: Add ioctl() to force ring buffer waiters to wake up" failed to apply to 4.14-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.14-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>. Possible dependencies: 01b2a5217173 ("tracing: Add ioctl() to force ring buffer waiters to wake up") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 01b2a52171735c6eea80ee2f355f32bea6c41418 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Google)" <rostedt(a)goodmis.org> Date: Thu, 29 Sep 2022 09:50:29 -0400 Subject: [PATCH] tracing: Add ioctl() to force ring buffer waiters to wake up If a process is waiting on the ring buffer for data, there currently isn't a clean way to force it to wake up. Add an ioctl call that will force any tasks that are waiting on the trace_pipe_raw file to wake up. Link: https://lkml.kernel.org/r/20220929095029.117f913f@gandalf.local.home Cc: stable(a)vger.kernel.org Cc: Ingo Molnar <mingo(a)kernel.org> Cc: Andrew Morton <akpm(a)linux-foundation.org> Fixes: e30f53aad2202 ("tracing: Do not busy wait in buffer splice") Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index e101b0764b39..58afc83afc9d 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -8349,12 +8349,34 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos, return ret; } +/* An ioctl call with cmd 0 to the ring buffer file will wake up all waiters */ +static long tracing_buffers_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + struct ftrace_buffer_info *info = file->private_data; + struct trace_iterator *iter = &info->iter; + + if (cmd) + return -ENOIOCTLCMD; + + mutex_lock(&trace_types_lock); + + iter->wait_index++; + /* Make sure the waiters see the new wait_index */ + smp_wmb(); + + ring_buffer_wake_waiters(iter->array_buffer->buffer, iter->cpu_file); + + mutex_unlock(&trace_types_lock); + return 0; +} + static const struct file_operations tracing_buffers_fops = { .open = tracing_buffers_open, .read = tracing_buffers_read, .poll = tracing_buffers_poll, .release = tracing_buffers_release, .splice_read = tracing_buffers_splice_read, + .unlocked_ioctl = tracing_buffers_ioctl, .llseek = no_llseek, };

2 years, 2 months

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FAILED: patch "[PATCH] ring-buffer: Add ring_buffer_wake_waiters()" failed to apply to 4.14-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.14-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>. Possible dependencies: 7e9fbbb1b776 ("ring-buffer: Add ring_buffer_wake_waiters()") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 7e9fbbb1b776d8d7969551565bc246f74ec53b27 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Google)" <rostedt(a)goodmis.org> Date: Wed, 28 Sep 2022 13:39:38 -0400 Subject: [PATCH] ring-buffer: Add ring_buffer_wake_waiters() On closing of a file that represents a ring buffer or flushing the file, there may be waiters on the ring buffer that needs to be woken up and exit the ring_buffer_wait() function. Add ring_buffer_wake_waiters() to wake up the waiters on the ring buffer and allow them to exit the wait loop. Link: https://lkml.kernel.org/r/20220928133938.28dc2c27@gandalf.local.home Cc: stable(a)vger.kernel.org Cc: Ingo Molnar <mingo(a)kernel.org> Cc: Andrew Morton <akpm(a)linux-foundation.org> Fixes: 15693458c4bc0 ("tracing/ring-buffer: Move poll wake ups into ring buffer code") Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h index dac53fd3afea..2504df9a0453 100644 --- a/include/linux/ring_buffer.h +++ b/include/linux/ring_buffer.h @@ -101,7 +101,7 @@ __ring_buffer_alloc(unsigned long size, unsigned flags, struct lock_class_key *k int ring_buffer_wait(struct trace_buffer *buffer, int cpu, int full); __poll_t ring_buffer_poll_wait(struct trace_buffer *buffer, int cpu, struct file *filp, poll_table *poll_table); - +void ring_buffer_wake_waiters(struct trace_buffer *buffer, int cpu); #define RING_BUFFER_ALL_CPUS -1 diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 5a7d818ca3ea..3046deacf7b3 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -413,6 +413,7 @@ struct rb_irq_work { struct irq_work work; wait_queue_head_t waiters; wait_queue_head_t full_waiters; + long wait_index; bool waiters_pending; bool full_waiters_pending; bool wakeup_full; @@ -924,6 +925,37 @@ static void rb_wake_up_waiters(struct irq_work *work) } } +/** + * ring_buffer_wake_waiters - wake up any waiters on this ring buffer + * @buffer: The ring buffer to wake waiters on + * + * In the case of a file that represents a ring buffer is closing, + * it is prudent to wake up any waiters that are on this. + */ +void ring_buffer_wake_waiters(struct trace_buffer *buffer, int cpu) +{ + struct ring_buffer_per_cpu *cpu_buffer; + struct rb_irq_work *rbwork; + + if (cpu == RING_BUFFER_ALL_CPUS) { + + /* Wake up individual ones too. One level recursion */ + for_each_buffer_cpu(buffer, cpu) + ring_buffer_wake_waiters(buffer, cpu); + + rbwork = &buffer->irq_work; + } else { + cpu_buffer = buffer->buffers[cpu]; + rbwork = &cpu_buffer->irq_work; + } + + rbwork->wait_index++; + /* make sure the waiters see the new index */ + smp_wmb(); + + rb_wake_up_waiters(&rbwork->work); +} + /** * ring_buffer_wait - wait for input to the ring buffer * @buffer: buffer to wait on @@ -939,6 +971,7 @@ int ring_buffer_wait(struct trace_buffer *buffer, int cpu, int full) struct ring_buffer_per_cpu *cpu_buffer; DEFINE_WAIT(wait); struct rb_irq_work *work; + long wait_index; int ret = 0; /* @@ -957,6 +990,7 @@ int ring_buffer_wait(struct trace_buffer *buffer, int cpu, int full) work = &cpu_buffer->irq_work; } + wait_index = READ_ONCE(work->wait_index); while (true) { if (full) @@ -1021,6 +1055,11 @@ int ring_buffer_wait(struct trace_buffer *buffer, int cpu, int full) } schedule(); + + /* Make sure to see the new wait index */ + smp_rmb(); + if (wait_index != work->wait_index) + break; } if (full)

2 years, 2 months

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FAILED: patch "[PATCH] tracing: Add ioctl() to force ring buffer waiters to wake up" failed to apply to 4.9-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.9-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>. Possible dependencies: 01b2a5217173 ("tracing: Add ioctl() to force ring buffer waiters to wake up") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 01b2a52171735c6eea80ee2f355f32bea6c41418 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Google)" <rostedt(a)goodmis.org> Date: Thu, 29 Sep 2022 09:50:29 -0400 Subject: [PATCH] tracing: Add ioctl() to force ring buffer waiters to wake up If a process is waiting on the ring buffer for data, there currently isn't a clean way to force it to wake up. Add an ioctl call that will force any tasks that are waiting on the trace_pipe_raw file to wake up. Link: https://lkml.kernel.org/r/20220929095029.117f913f@gandalf.local.home Cc: stable(a)vger.kernel.org Cc: Ingo Molnar <mingo(a)kernel.org> Cc: Andrew Morton <akpm(a)linux-foundation.org> Fixes: e30f53aad2202 ("tracing: Do not busy wait in buffer splice") Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index e101b0764b39..58afc83afc9d 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -8349,12 +8349,34 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos, return ret; } +/* An ioctl call with cmd 0 to the ring buffer file will wake up all waiters */ +static long tracing_buffers_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + struct ftrace_buffer_info *info = file->private_data; + struct trace_iterator *iter = &info->iter; + + if (cmd) + return -ENOIOCTLCMD; + + mutex_lock(&trace_types_lock); + + iter->wait_index++; + /* Make sure the waiters see the new wait_index */ + smp_wmb(); + + ring_buffer_wake_waiters(iter->array_buffer->buffer, iter->cpu_file); + + mutex_unlock(&trace_types_lock); + return 0; +} + static const struct file_operations tracing_buffers_fops = { .open = tracing_buffers_open, .read = tracing_buffers_read, .poll = tracing_buffers_poll, .release = tracing_buffers_release, .splice_read = tracing_buffers_splice_read, + .unlocked_ioctl = tracing_buffers_ioctl, .llseek = no_llseek, };

2 years, 2 months

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FAILED: patch "[PATCH] ring-buffer: Add ring_buffer_wake_waiters()" failed to apply to 4.9-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.9-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>. Possible dependencies: 7e9fbbb1b776 ("ring-buffer: Add ring_buffer_wake_waiters()") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 7e9fbbb1b776d8d7969551565bc246f74ec53b27 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Google)" <rostedt(a)goodmis.org> Date: Wed, 28 Sep 2022 13:39:38 -0400 Subject: [PATCH] ring-buffer: Add ring_buffer_wake_waiters() On closing of a file that represents a ring buffer or flushing the file, there may be waiters on the ring buffer that needs to be woken up and exit the ring_buffer_wait() function. Add ring_buffer_wake_waiters() to wake up the waiters on the ring buffer and allow them to exit the wait loop. Link: https://lkml.kernel.org/r/20220928133938.28dc2c27@gandalf.local.home Cc: stable(a)vger.kernel.org Cc: Ingo Molnar <mingo(a)kernel.org> Cc: Andrew Morton <akpm(a)linux-foundation.org> Fixes: 15693458c4bc0 ("tracing/ring-buffer: Move poll wake ups into ring buffer code") Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h index dac53fd3afea..2504df9a0453 100644 --- a/include/linux/ring_buffer.h +++ b/include/linux/ring_buffer.h @@ -101,7 +101,7 @@ __ring_buffer_alloc(unsigned long size, unsigned flags, struct lock_class_key *k int ring_buffer_wait(struct trace_buffer *buffer, int cpu, int full); __poll_t ring_buffer_poll_wait(struct trace_buffer *buffer, int cpu, struct file *filp, poll_table *poll_table); - +void ring_buffer_wake_waiters(struct trace_buffer *buffer, int cpu); #define RING_BUFFER_ALL_CPUS -1 diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 5a7d818ca3ea..3046deacf7b3 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -413,6 +413,7 @@ struct rb_irq_work { struct irq_work work; wait_queue_head_t waiters; wait_queue_head_t full_waiters; + long wait_index; bool waiters_pending; bool full_waiters_pending; bool wakeup_full; @@ -924,6 +925,37 @@ static void rb_wake_up_waiters(struct irq_work *work) } } +/** + * ring_buffer_wake_waiters - wake up any waiters on this ring buffer + * @buffer: The ring buffer to wake waiters on + * + * In the case of a file that represents a ring buffer is closing, + * it is prudent to wake up any waiters that are on this. + */ +void ring_buffer_wake_waiters(struct trace_buffer *buffer, int cpu) +{ + struct ring_buffer_per_cpu *cpu_buffer; + struct rb_irq_work *rbwork; + + if (cpu == RING_BUFFER_ALL_CPUS) { + + /* Wake up individual ones too. One level recursion */ + for_each_buffer_cpu(buffer, cpu) + ring_buffer_wake_waiters(buffer, cpu); + + rbwork = &buffer->irq_work; + } else { + cpu_buffer = buffer->buffers[cpu]; + rbwork = &cpu_buffer->irq_work; + } + + rbwork->wait_index++; + /* make sure the waiters see the new index */ + smp_wmb(); + + rb_wake_up_waiters(&rbwork->work); +} + /** * ring_buffer_wait - wait for input to the ring buffer * @buffer: buffer to wait on @@ -939,6 +971,7 @@ int ring_buffer_wait(struct trace_buffer *buffer, int cpu, int full) struct ring_buffer_per_cpu *cpu_buffer; DEFINE_WAIT(wait); struct rb_irq_work *work; + long wait_index; int ret = 0; /* @@ -957,6 +990,7 @@ int ring_buffer_wait(struct trace_buffer *buffer, int cpu, int full) work = &cpu_buffer->irq_work; } + wait_index = READ_ONCE(work->wait_index); while (true) { if (full) @@ -1021,6 +1055,11 @@ int ring_buffer_wait(struct trace_buffer *buffer, int cpu, int full) } schedule(); + + /* Make sure to see the new wait index */ + smp_rmb(); + if (wait_index != work->wait_index) + break; } if (full)

2 years, 2 months

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FAILED: patch "[PATCH] tracing: Add "(fault)" name injection to kernel probes" 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>. Possible dependencies: 2e9906f84fc7 ("tracing: Add "(fault)" name injection to kernel probes") f1d3cbfaafc1 ("tracing: Move duplicate code of trace_kprobe/eprobe.c into header") 7491e2c44278 ("tracing: Add a probe that attaches to trace events") 007517a01995 ("tracing/probe: Change traceprobe_set_print_fmt() to take a type") bc87cf0a08d4 ("trace: Add a generic function to read/write u64 values from tracefs") d262271d0483 ("tracing/dynevent: Delegate parsing to create function") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 2e9906f84fc7c99388bb7123ade167250d50f1c0 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Google)" <rostedt(a)goodmis.org> Date: Wed, 12 Oct 2022 06:40:57 -0400 Subject: [PATCH] tracing: Add "(fault)" name injection to kernel probes Have the specific functions for kernel probes that read strings to inject the "(fault)" name directly. trace_probes.c does this too (for uprobes) but as the code to read strings are going to be used by synthetic events (and perhaps other utilities), it simplifies the code by making sure those other uses do not need to implement the "(fault)" name injection as well. Link: https://lkml.kernel.org/r/20221012104534.644803645@goodmis.org Cc: stable(a)vger.kernel.org Cc: Andrew Morton <akpm(a)linux-foundation.org> Cc: Tom Zanussi <zanussi(a)kernel.org> Acked-by: Masami Hiramatsu (Google) <mhiramat(a)kernel.org> Reviewed-by: Tom Zanussi <zanussi(a)kernel.org> Fixes: bd82631d7ccdc ("tracing: Add support for dynamic strings to synthetic events") Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> diff --git a/kernel/trace/trace_probe_kernel.h b/kernel/trace/trace_probe_kernel.h index 1d43df29a1f8..77dbd9ff9782 100644 --- a/kernel/trace/trace_probe_kernel.h +++ b/kernel/trace/trace_probe_kernel.h @@ -2,6 +2,8 @@ #ifndef __TRACE_PROBE_KERNEL_H_ #define __TRACE_PROBE_KERNEL_H_ +#define FAULT_STRING "(fault)" + /* * This depends on trace_probe.h, but can not include it due to * the way trace_probe_tmpl.h is used by trace_kprobe.c and trace_eprobe.c. @@ -13,8 +15,16 @@ static nokprobe_inline int kern_fetch_store_strlen_user(unsigned long addr) { const void __user *uaddr = (__force const void __user *)addr; + int ret; - return strnlen_user_nofault(uaddr, MAX_STRING_SIZE); + ret = strnlen_user_nofault(uaddr, MAX_STRING_SIZE); + /* + * strnlen_user_nofault returns zero on fault, insert the + * FAULT_STRING when that occurs. + */ + if (ret <= 0) + return strlen(FAULT_STRING) + 1; + return ret; } /* Return the length of string -- including null terminal byte */ @@ -34,7 +44,18 @@ kern_fetch_store_strlen(unsigned long addr) len++; } while (c && ret == 0 && len < MAX_STRING_SIZE); - return (ret < 0) ? ret : len; + /* For faults, return enough to hold the FAULT_STRING */ + return (ret < 0) ? strlen(FAULT_STRING) + 1 : len; +} + +static nokprobe_inline void set_data_loc(int ret, void *dest, void *__dest, void *base, int len) +{ + if (ret >= 0) { + *(u32 *)dest = make_data_loc(ret, __dest - base); + } else { + strscpy(__dest, FAULT_STRING, len); + ret = strlen(__dest) + 1; + } } /* @@ -55,8 +76,7 @@ kern_fetch_store_string_user(unsigned long addr, void *dest, void *base) __dest = get_loc_data(dest, base); ret = strncpy_from_user_nofault(__dest, uaddr, maxlen); - if (ret >= 0) - *(u32 *)dest = make_data_loc(ret, __dest - base); + set_data_loc(ret, dest, __dest, base, maxlen); return ret; } @@ -87,8 +107,7 @@ kern_fetch_store_string(unsigned long addr, void *dest, void *base) * probing. */ ret = strncpy_from_kernel_nofault(__dest, (void *)addr, maxlen); - if (ret >= 0) - *(u32 *)dest = make_data_loc(ret, __dest - base); + set_data_loc(ret, dest, __dest, base, maxlen); return ret; }

2 years, 2 months

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