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[PATCH OLK-6.6] tools/interference: add ifstool utility for kernel interference statistics
by Tengda Wu 09 Mar '26

09 Mar '26

hulk inclusion category: feature bugzilla: https://atomgit.com/openeuler/kernel/issues/7429 -------------------------------- As real-time and high-performance workloads become more sensitive to execution jitter, observability into kernel-induced "noise" is critical. The CONFIG_IFS infrastructure provides this telemetry, but raw data from cgroups is difficult to parse and visualize manually. Introduce ifstool, a userspace utility to monitor and analyze the interference.stat interface. Signed-off-by: Tengda Wu <wutengda2(a)huawei.com> --- tools/Makefile | 11 +- tools/kspect/Makefile | 28 +++ tools/kspect/README | 64 ++++++ tools/kspect/ifstool | 396 ++++++++++++++++++++++++++++++++++ tools/kspect/ifstool.1 | 81 +++++++ tools/kspect/requirements.txt | 2 + 6 files changed, 578 insertions(+), 4 deletions(-) create mode 100644 tools/kspect/Makefile create mode 100644 tools/kspect/README create mode 100644 tools/kspect/ifstool create mode 100644 tools/kspect/ifstool.1 create mode 100644 tools/kspect/requirements.txt diff --git a/tools/Makefile b/tools/Makefile index 37e9f6804832..153817f0cc17 100644 --- a/tools/Makefile +++ b/tools/Makefile @@ -22,6 +22,7 @@ help: @echo ' hv - tools used when in Hyper-V clients' @echo ' iio - IIO tools' @echo ' intel-speed-select - Intel Speed Select tool' + @echo ' kspect - KSPECT tools' @echo ' kvm_stat - top-like utility for displaying kvm statistics' @echo ' leds - LEDs tools' @echo ' nolibc - nolibc headers testing and installation' @@ -69,7 +70,7 @@ acpi: FORCE cpupower: FORCE $(call descend,power/$@) -cgroup counter firewire hv guest bootconfig spi usb virtio mm bpf iio gpio objtool leds wmi pci firmware debugging tracing: FORCE +cgroup counter firewire hv guest bootconfig spi usb virtio mm bpf iio gpio objtool leds wmi pci firmware debugging tracing kspect: FORCE $(call descend,$@) bpf/%: FORCE @@ -120,7 +121,8 @@ all: acpi cgroup counter cpupower gpio hv firewire \ perf selftests bootconfig spi turbostat usb \ virtio mm bpf x86_energy_perf_policy \ tmon freefall iio objtool kvm_stat wmi \ - pci debugging tracing thermal thermometer thermal-engine + pci debugging tracing thermal thermometer thermal-engine \ + kspect acpi_install: $(call descend,power/$(@:_install=),install) @@ -128,7 +130,7 @@ acpi_install: cpupower_install: $(call descend,power/$(@:_install=),install) -cgroup_install counter_install firewire_install gpio_install hv_install iio_install perf_install bootconfig_install spi_install usb_install virtio_install mm_install bpf_install objtool_install wmi_install pci_install debugging_install tracing_install: +cgroup_install counter_install firewire_install gpio_install hv_install iio_install perf_install bootconfig_install spi_install usb_install virtio_install mm_install bpf_install objtool_install wmi_install pci_install debugging_install tracing_install kspect_install: $(call descend,$(@:_install=),install) selftests_install: @@ -161,7 +163,8 @@ install: acpi_install cgroup_install counter_install cpupower_install gpio_insta virtio_install mm_install bpf_install x86_energy_perf_policy_install \ tmon_install freefall_install objtool_install kvm_stat_install \ wmi_install pci_install debugging_install intel-speed-select_install \ - tracing_install thermometer_install thermal-engine_install + tracing_install thermometer_install thermal-engine_install \ + kspect_install acpi_clean: $(call descend,power/acpi,clean) diff --git a/tools/kspect/Makefile b/tools/kspect/Makefile new file mode 100644 index 000000000000..ffb380ddc885 --- /dev/null +++ b/tools/kspect/Makefile @@ -0,0 +1,28 @@ +# SPDX-License-Identifier: GPL-2.0 + +PREFIX ?= /usr/local +BINDIR = $(PREFIX)/bin +MANDIR = $(PREFIX)/share/man/man1 + +MAN1 = ifstool.1 +TARGET = ifstool + +all: man + +man: $(MAN1) + +install-man: + install -d $(MANDIR) + install -m 0644 $(MAN1) $(MANDIR) + +install-tools: + install -d $(BINDIR) + install -m 0755 $(TARGET) $(BINDIR) + +install: install-tools install-man + +uninstall: + rm -f $(BINDIR)/$(TARGET) + rm -f $(MANDIR)/$(MAN1) + +.PHONY: all install-tools install-man install diff --git a/tools/kspect/README b/tools/kspect/README new file mode 100644 index 000000000000..afb92a7f98d0 --- /dev/null +++ b/tools/kspect/README @@ -0,0 +1,64 @@ +IFSTOOL - Interference Statistics Analytical Utility + +Overview +======== +IFSTOOL is a specialized userspace utility designed to facilitate the +monitoring and analysis of Interference Statistics (CONFIG_IFS). + +The IFS infrastructure is a kernel-level framework that provides critical +observability into execution jitter (noise) that disrupts task determinism. +It monitors and quantifies the CPU time stolen by kernel-level activities, +such as: interrupt handling, softirqs, and lock contention. The framework +exposes this telemetry via the interference.stat control file within the +cgroup hierarchy. + +IFSTOOL interfaces with the interference.stat file to export raw metrics +into structured CSV data and interactive HTML-based distribution reports. + +Setup +===== +The host environment must meet the following criteria: + +* Kernel: Compiled with `CONFIG_IFS=y`. +* Boot Parameters: `cgroup_ifs=1` added to the kernel command line. +* Python Runtime: Python 3.x with `pandas` and `plotly` libraries. +* Cgroup Hierarchy: Either v2 unified or v1 with the cpu subsystem mounted. + +Build +===== +IFSTOOL provides a Makefile to streamline the installation of the +executable and its documentation. + + $ make install + +Run +=== +IFSTOOL operates via two primary functional modes: monitor and report. + +1. **Monitor:** Capture raw interference data from a target cgroup. + + $ ifstool monitor --cgroup docker/<cid> --interval 1 --output capture.csv + +2. **Report:** Transform captured CSV data into an interactive HTML dashboard. + + - Provide only --base for a single-session deep dive: + + $ ifstool report --base capture.csv + + - Provide both --base and --curr to render a differential report, + ideal for validating optimizations: + + $ ifstool report --base baseline.csv --curr current.csv + +HTML Description +================ +The generated HTML report provides a multi-dimensional view of kernel noise: + +- Total Time Delta Trend: A time-series line chart illustrating the incremental + nanoseconds of interference per category (e.g., irq, spinlock). +- Latency Heatmaps: A frequency-domain visualization of the kernel's internal + histogram. + - X-axis: Wall-clock time of the trace. + - Y-axis: Latency magnitude (logarithmic buckets from ns to s). + - Color Intensity: Represents the density (event count) of interference + within that specific latency window. diff --git a/tools/kspect/ifstool b/tools/kspect/ifstool new file mode 100644 index 000000000000..dcaa8a84272d --- /dev/null +++ b/tools/kspect/ifstool @@ -0,0 +1,396 @@ +#!/usr/bin/env python3 +# SPDX-License-Identifier: GPL-2.0-only +# +# ifstool: A tool to monitor and report interference statistics (CONFIG_IFS). +# +# Copyright(c) 2026. Huawei Technologies Co., Ltd +# +# Authors: +# Tengda Wu <wutengda2(a)huawei.com> + +import os +import time +import re +import csv +import argparse +import pandas as pd +import plotly.graph_objects as go +from plotly.subplots import make_subplots + + +class InterferenceTool: + """ + A utility class to monitor Linux cgroup interference statistics (CONFIG_IFS) + and generate visual comparison reports between baseline and current data. + """ + + def __init__(self): + # Default path for cgroup v2 interference stats + self.base_path = "/sys/fs/cgroup" + + def parse_stat(self, content): + """ + Parses the raw content of the interference.stat file. + + Args: + content (str): Raw string content from the stat file. + Returns: + tuple: (total_times dict, distributions dict) + """ + + total_times, distributions = {}, {} + + # Split content into sections: Top-level totals and various distributions + # Uses positive lookahead to split before a word followed by ' distribution' + sections = re.split(r"\n(?=[a-z]+ distribution)", content) + + # Parse global total times (first section) + for line in sections[0].strip().split("\n"): + match = re.match(r"^([a-z]+)\s+(\d+)$", line.strip()) + if match: + total_times[match.group(1)] = int(match.group(2)) + + # Parse histogram distributions (subsequent sections) + for section in sections[1:]: + lines = section.strip().split("\n") + # Extract header name (e.g., 'spinlock distribution') + header = lines[0].replace(" distribution", "").strip() + # Parse bucket key-value pairs (e.g., '[64 ns, 128 ns) : 143791') + dist_data = { + l.split(":")[0].strip(): int(l.split(":")[1].strip()) + for l in lines[1:] + if ":" in l + } + distributions[header] = dist_data + + return total_times, distributions + + def monitor(self, cgroup_id, interval, duration, output_csv): + """ + Periodically samples interference stats and saves results to a CSV file. + + Args: + cgroup_id (str): The specific cgroup folder name. + interval (float): Seconds between samples. + duration (int): Total monitoring time in seconds. + output_csv (str): Filename to save sampled data. + """ + + candidates = [ + os.path.join(self.base_path, cgroup_id), + os.path.join(self.base_path, "cpu", cgroup_id), # cgroup v1 + ] + path = next((p for p in candidates if os.path.exists(p)), None) + + if not path: + print( + f"\n[!] No access to cgroup: {os.path.join(self.base_path, cgroup_id)}" + ) + print(" Hint: You can find the correct cid by executing:") + print(" cat /proc/<PID>/cgroup") + return + + path = os.path.join(path, "interference.stat") + if not os.path.exists(path): + print(f"\n[!] Interface file '{path}' not found.") + print(" This usually happens due to one of the following:") + print(" 1. Kernel is not compiled with CONFIG_IFS=y") + print(" 2. Kernel boot parameter 'cgroup_ifs=1' is missing") + print(" 3. The current cgroup is not managed by the IFS controller") + return + + print( + f"[*] Starting monitor: {cgroup_id}, interval: {interval}s, duration: {duration}s" + ) + + data_list = [] + start_time = time.time() + + try: + while (time.time() - start_time) < duration: + ts = time.strftime("%H:%M:%S") + # Using fractional seconds in timestamp for sub-second intervals + if interval < 1.0: + ts = time.strftime("%H:%M:%S") + f".{int((time.time()%1)*100):02d}" + + with open(path, "r") as f: + total_times, dists = self.parse_stat(f.read()) + + # Append total time metrics + for cat, val in total_times.items(): + data_list.append([ts, cgroup_id, cat, "total_time_ns", val]) + + # Append bucket distribution metrics + for cat, dist in dists.items(): + for b, c in dist.items(): + data_list.append([ts, cgroup_id, cat, f"bucket_{b}", c]) + + time.sleep(interval) + except KeyboardInterrupt: + print("\n[!] Monitoring interrupted by user.") + + # Write buffered data to CSV + with open(output_csv, "w", newline="") as f: + writer = csv.writer(f) + writer.writerow( + ["timestamp", "cgroup_id", "category", "metric_type", "value"] + ) + writer.writerows(data_list) + print(f"[+] Data exported successfully: {output_csv}") + + def bucket_key(self, bucket_str): + """ + Parsing logic for histogram bucket labels to enable correct numerical sorting. + Example input: "bucket_[67.10 ms, 134.21 ms)" + + Returns: + float: The value converted to nanoseconds (ns). + """ + try: + # Regex to capture the first number and its unit (ns|us|ms|s) + match = re.search(r"(\d+\.?\d*)\s*(ns|us|ms|s)", bucket_str) + if not match: + return 0 + + value = float(match.group(1)) + unit = match.group(2).lower() + + # Conversion factors to nanoseconds + factors = {"ns": 1, "us": 1000, "ms": 1000000, "s": 1000000000} + + return value * factors.get(unit, 1) + except Exception: + return 0 + + def report(self, base_csv, curr_csv, output_html): + """ + Loads two CSV files and generates an interactive HTML dashboard. + + Args: + base_csv (str): Path to baseline data. + curr_csv (str): Path to current data. + output_html (str): Path to generate the HTML report. + """ + + df_b = pd.read_csv(base_csv) + single_mode = curr_csv is None or base_csv == curr_csv + df_c = None if single_mode else pd.read_csv(curr_csv) + + # Get unique union of categories present in both datasets + all_dfs = [df_b] if single_mode else [df_b, df_c] + categories = sorted( + list(set().union(*(df.category.unique() for df in all_dfs))) + ) + + # Color mapping to ensure consistent colors for categories across plots + color_sequence = [ + "#636EFA", + "#EF553B", + "#00CC96", + "#AB63FA", + "#FFA15A", + "#19D3F3", + "#FF6692", + "#B6E880", + "#FF97FF", + "#FECB52", + ] + color_map = { + cat: color_sequence[i % len(color_sequence)] + for i, cat in enumerate(categories) + } + + # Build HTML content with CSS for layout + html_parts = ["<html><head><title>IFS Analysis Dashboard</title>"] + col_width = "100%" if single_mode else "49.5%" + html_parts.append( + f"""<style> + body{{font-family:'Segoe UI',sans-serif; background:#f0f2f5; padding:20px; color:#333;}} + .card{{background:white; padding:15px; margin-bottom:20px; border-radius:10px; box-shadow:0 2px 5px rgba(0,0,0,0.05);}} + .row-container{{display:flex; gap:15px; justify-content:space-between;}} + .col-item{{width:{col_width}; min-width:0;}} + .stat-box{{display:flex; gap:10px; margin:5px 0; font-size:0.85em; color:#555;}} + .stat-item{{background:#f1f3f5; padding:4px 8px; border-radius:4px; border-left:3px solid #007bff;}} + .section-header{{margin:30px 0 15px 0; padding-bottom:10px; border-bottom:2px solid #ddd;}} + </style></head><body>""" + ) + + title = "Performance Analysis" if single_mode else "Performance Comparison" + html_parts.append(f"<h2>{title} (CONFIG_IFS)</h2>") + info = ( + f"File: {base_csv}" + if single_mode + else f"Baseline: {base_csv} | Current: {curr_csv}" + ) + html_parts.append(f"<p style='color:#666;'>{info}</p>") + + # --- Part 1: Total Time Trends (Line Charts) --- + html_parts.append("<div class='card'>") + html_parts.append("<h3 style='margin-top:0;'>Total Time Delta (ns) Trend</h3>") + + # Subplots ensure Y-axis can be matched for direct visual comparison + fig_line = make_subplots( + rows=1, + cols=1 if single_mode else 2, + horizontal_spacing=0.05, + subplot_titles=("Latency",) if single_mode else ("Baseline", "Current"), + ) + + plot_configs = ( + [("Data", df_b)] if single_mode else [("Baseline", df_b), ("Current", df_c)] + ) + for i, (name, df) in enumerate(plot_configs, 1): + for cat in categories: + sub = df[ + (df["category"] == cat) & (df["metric_type"] == "total_time_ns") + ].sort_values("timestamp") + if not sub.empty: + y_val = sub["value"].diff().fillna(0) + fig_line.add_trace( + go.Scatter( + x=sub["timestamp"], + y=y_val, + name=f"{cat} ({name})", + legendgroup=cat, + mode="lines+markers", + line=dict(color=color_map[cat], width=2), + marker=dict(color=color_map[cat], size=6), + ), + row=1, + col=i, + ) + + # Sync Y-axes scale for baseline and current plots + if not single_mode: + fig_line.update_yaxes(matches="y", row=1, col=2) + fig_line.update_layout( + height=500, template="plotly_white", margin=dict(t=50, b=20) + ) + html_parts.append(fig_line.to_html(full_html=False, include_plotlyjs="cdn")) + html_parts.append("</div>") + + html_parts.append( + "<h3 class='section-header'>Detailed Latency Distribution</h3>" + ) + + # --- Part 2: Distribution Heatmaps --- + for cat in categories: + + def get_m_and_stats(df): + """Processes raw metrics into a delta-count matrix for heatmap visualization.""" + sub = df[ + (df["category"] == cat) + & (df["metric_type"].str.startswith("bucket_")) + ] + if sub.empty: + return pd.DataFrame(), {} + + # Transform to matrix (Buckets vs Time) + p = sub.pivot( + index="metric_type", columns="timestamp", values="value" + ).sort_index(axis=1) + # Sort Y-axis buckets based on numerical time value + p = p.reindex(sorted(p.index, key=self.bucket_key)) + # Calculate incremental change (delta) + delta = p.diff(axis=1).fillna(0) + return delta, { + "Total": int(delta.values.sum()), + "Peak": int(delta.values.max()), + } + + m_b, stats_b = get_m_and_stats(df_b) + m_c, stats_c = (None, None) if single_mode else get_m_and_stats(df_c) + + # Determine global max for heatmap color scaling consistency + z_vals = [m_b.values.max() if not m_b.empty else 0] + if not single_mode: + z_vals.append(m_c.values.max() if not m_c.empty else 0) + global_max_z = max(z_vals + [1]) + + html_parts.append(f"<div class='card'><h4>Category: {cat.upper()}</h4>") + html_parts.append("<div class='row-container'>") + + configs = ( + [("Data", m_b, stats_b)] + if single_mode + else [("Baseline", m_b, stats_b), ("Current", m_c, stats_c)] + ) + for name, m, stats in configs: + html_parts.append("<div class='col-item'>") + if not m.empty: + # Display summary statistics + html_parts.append("<div class='stat-box'>") + for k, v in stats.items(): + html_parts.append( + f"<div class='stat-item'><b>{k}:</b> {v}</div>" + ) + html_parts.append("</div>") + + # Generate Heatmap + fig = go.Figure( + data=go.Heatmap( + z=m.values, + x=m.columns, + y=m.index, + colorscale="Viridis", + zmin=0, + zmax=global_max_z, + colorbar=dict(title="Count", thickness=10, len=0.7), + ) + ) + fig.update_layout( + height=400, + margin=dict(l=120, r=0, t=10, b=30), + template="plotly_white", + ) + html_parts.append( + fig.to_html(full_html=False, include_plotlyjs="cdn") + ) + else: + html_parts.append( + "<div style='height:100px; display:flex; align-items:center; justify-content:center; background:#fafafa; color:#ccc;'>No Data</div>" + ) + html_parts.append("</div>") + + html_parts.append("</div></div>") # end row-container & card + + # Save the final HTML report + with open(output_html, "w") as f: + f.writelines(html_parts + ["</body></html>"]) + print(f"[+] Comparison report generated: {output_html}") + + +if __name__ == "__main__": + parser = argparse.ArgumentParser() + sub = parser.add_subparsers(dest="mode") + + # Monitor Mode Arguments + p_mon = sub.add_parser("monitor") + p_mon.add_argument( + "-G", "--cgroup", required=True, help="Cgroup name (e.g. 'docker/cid'" + ) + p_mon.add_argument( + "-i", "--interval", type=float, default=1.0, help="Sampling interval (sec)" + ) + p_mon.add_argument( + "-d", "--duration", type=int, default=30, help="Sampling duration (sec)" + ) + p_mon.add_argument("-o", "--output", default="capture.csv") + + # Report Mode Arguments + p_comp = sub.add_parser("report") + p_comp.add_argument("-b", "--base", required=True, help="Baseline CSV file") + p_comp.add_argument( + "-c", "--curr", default=None, help="Current CSV file (optional, for comparison)" + ) + p_comp.add_argument("-o", "--output", default="report.html") + + args = parser.parse_args() + tool = InterferenceTool() + + if args.mode == "monitor": + tool.monitor(args.cgroup, args.interval, args.duration, args.output) + elif args.mode == "report": + tool.report(args.base, args.curr, args.output) + else: + parser.print_help() diff --git a/tools/kspect/ifstool.1 b/tools/kspect/ifstool.1 new file mode 100644 index 000000000000..347d54f36bec --- /dev/null +++ b/tools/kspect/ifstool.1 @@ -0,0 +1,81 @@ +.TH IFSTOOL 1 "March 2026" "Linux" "User Commands" +.SH NAME +ifstool \- Analyze kernel interference statistics (CONFIG_IFS) +.SH SYNOPSIS +.B ifstool monitor +[\fB\-G\fR|\fB\-\-cgroup\fR \fICGROUP_ID\fR] [\fB\-d\fR|\fB\-\-duration\fR \fISEC\fR] [\fB\-i\fR|\fB\-\-interval\fR \fISEC\fR] [\fB\-o\fR|\fB\-\-output\fR \fICSV\fR] +.br +.B ifstool report +[\fB\-b\fR|\fB\-\-base\fR \fICSV\fR] [\fB\-c\fR|\fB\-\-curr\fR \fICSV\fR] [\fB\-o\fR|\fB\-\-output\fR \fIHTML\fR] + +.SH DESCRIPTION +.B IFSTOOL +is a specialized userspace utility designed to facilitate the monitoring and analysis of Interference Statistics (\fBCONFIG_IFS\fR). + +The \fBIFS infrastructure\fR is a kernel-level framework providing critical observability into execution jitter (noise) that disrupts task determinism. It quantifies CPU time stolen by kernel activities such as interrupt handling, softirqs, and lock contention. This telemetry is exposed via the \fBinterference.stat\fR control file within the cgroup hierarchy. + +\fBIFSTOOL\fR interfaces with this file to export raw metrics into structured CSV data and interactive HTML-based distribution reports. + +.SH SETUP +The host environment must meet the following criteria: +.IP \[bu] 2 +\fBKernel:\fR Compiled with \fBCONFIG_IFS=y\fR. +.IP \[bu] 2 +\fBBoot Parameters:\fR \fBcgroup_ifs=1\fR must be added to the kernel command line. +.IP \[bu] 2 +\fBPython Runtime:\fR Python 3.x with \fBpandas\fR and \fBplotly\fR libraries. +.IP \[bu] 2 +\fBCgroup Hierarchy:\fR Either v2 unified or v1 (with the \fBcpu\fR subsystem mounted). + +.SH COMMANDS +.SS monitor +Capture raw interference data from a target cgroup. +.TP +\fB\-G, \-\-cgroup\fR \fICGROUP_ID\fR +Specify the cgroup identifier (e.g., \fIdocker/<cid>\fR or \fIsystem.slice\fR). +.TP +\fB\-d, \-\-duration\fR \fISEC\fR +Total collection time in seconds (default: 30). +.TP +\fB\-i, \-\-interval\fR \fISEC\fR +Sampling interval in seconds; supports floating point (default: 1.0). + +.SS report +Transform captured CSV data into an interactive HTML dashboard. +.TP +\fB\-b, \-\-base\fR \fICSV\fR +Primary capture file for analysis. +.TP +\fB\-c, \-\-curr\fR \fICSV\fR +Optional secondary file for differential (comparison) analysis. + +.SH HTML REPORT STRUCTURE +The generated HTML report provides a multi-dimensional view of kernel noise: +.IP "Total Time Delta Trend" 4 +A time-series line chart illustrating the incremental nanoseconds of interference per category (e.g., irq, spinlock). +.IP "Latency Heatmaps" 4 +A frequency-domain visualization of the kernel's internal histogram: +.RS 8 +.IP "X-axis:" 8 +Wall-clock time of the trace. +.IP "Y-axis:" 8 +Latency magnitude (logarithmic buckets from ns to s). +.IP "Color Intensity:" 8 +Represents the event count (density) of interference within that specific latency window. +.RE + +.SH EXAMPLES +Monitor a Docker container for 10 seconds: +.IP +.B $ ifstool monitor \-\-cgroup docker/<cid> \-\-duration 10 \-\-interval 1 +.PP +Generate a single-session deep dive: +.IP +.B $ ifstool report \-\-base capture.csv +.PP +Generate a differential report between two traces: +.IP +.B $ ifstool report \-\-base baseline.csv \-\-curr current.csv + +.SH AUTHOR +Tengda Wu <wutengda2(a)huawei.com> \ No newline at end of file diff --git a/tools/kspect/requirements.txt b/tools/kspect/requirements.txt new file mode 100644 index 000000000000..8e5e376a0e9a --- /dev/null +++ b/tools/kspect/requirements.txt @@ -0,0 +1,2 @@ +pandas==3.* +plotly==6.* -- 2.34.1

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[PATCH openEuler-1.0-LTS] [Huawei] PCI: Fix AB-BA deadlock between aer_isr() and device_shutdown()
by Hongtao Zhang 09 Mar '26

09 Mar '26

From: Ziming Du <duziming2(a)huawei.com> Offering: HULK hulk inclusion category: bugfix bugzilla: 190803 -------------------------------- During system shutdown, a deadlock may occur between AER recovery process and device shutdown as follows: The device_shutdown path holds the device_lock throughout the entire process and waits for the irq handlers to complete when release nodes: device_shutdown device_lock # A hold device_lock pci_device_shutdown pcie_port_device_remove remove_iter device_unregister device_del bus_remove_device device_release_driver devres_release_all release_nodes # B wait for irq handlers The aer_isr path will acquire device_lock in pci_bus_reset(): aer_isr # B execute irq process aer_isr_one_error aer_process_err_devices handle_error_source pcie_do_recovery aer_root_reset pci_bus_error_reset pci_bus_reset # A acquire device_lock The circular dependency causes system hang. Fix it by using pci_bus_trylock() instead of pci_bus_lock() in pci_bus_reset(). When the lock is unavailable, return -EAGAIN, as in similar cases. Fixes: c4eed62a2143 ("PCI/ERR: Use slot reset if available") Signed-off-by: Ziming Du <duziming2(a)huawei.com> Signed-off-by: Zhang Hongtao <zhanghongtao35(a)huawei.com> --- drivers/pci/pci.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index b93605616d4e4..d1a8531df0271 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -5309,15 +5309,21 @@ static int pci_bus_reset(struct pci_bus *bus, int probe) if (probe) return 0; - pci_bus_lock(bus); + /* + * Replace blocking lock with trylock to prevent deadlock during bus reset. + * Same as above except return -EAGAIN if the bus cannot be locked. + */ + if (pci_bus_trylock(bus)) { + might_sleep(); - might_sleep(); + ret = pci_bridge_secondary_bus_reset(bus->self); - ret = pci_bridge_secondary_bus_reset(bus->self); + pci_bus_unlock(bus); - pci_bus_unlock(bus); + return ret; + } - return ret; + return -EAGAIN; } /** -- 2.43.0

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[PATCH OLK-6.6 0/4] fixup CVE-2025-39981
by Jiacheng Yu 09 Mar '26

09 Mar '26

CVE-2025-39981 Jianpeng Chang (1): Bluetooth: MGMT: Fix memory leak in set_ssp_complete Luiz Augusto von Dentz (1): Bluetooth: MGMT: Fix possible UAFs Pauli Virtanen (1): Bluetooth: MGMT: fix crash in set_mesh_sync and set_mesh_complete Roman Smirnov (1): Bluetooth: mgmt: remove NULL check in mgmt_set_connectable_complete() include/net/bluetooth/mgmt.h | 2 +- net/bluetooth/mgmt.c | 263 +++++++++++++++++++++++++---------- net/bluetooth/mgmt_util.c | 46 ++++++ net/bluetooth/mgmt_util.h | 3 + 4 files changed, 237 insertions(+), 77 deletions(-) -- 2.43.0

2 5

[PATCH OLK-6.6] net: yt6801: add link info for yt6801
by Frank_Sae 09 Mar '26

09 Mar '26

yt6801 inclusion category: bugfix bugzilla: https://https://atomgit.com/openeuler/kernel/issues/7229 -------------------------------------------------------------------- add link info for yt6801 to fix that the link info is not update on os installation. Signed-off-by: Frank_Sae <Frank.Sae(a)motor-comm.com> --- .../ethernet/motorcomm/yt6801/yt6801_main.c | 90 +++++++++++++++++++ 1 file changed, 90 insertions(+) diff --git a/drivers/net/ethernet/motorcomm/yt6801/yt6801_main.c b/drivers/net/ethernet/motorcomm/yt6801/yt6801_main.c index 01eed3ace..cb54329ef 100644 --- a/drivers/net/ethernet/motorcomm/yt6801/yt6801_main.c +++ b/drivers/net/ethernet/motorcomm/yt6801/yt6801_main.c @@ -27,6 +27,95 @@ const struct net_device_ops *fxgmac_get_netdev_ops(void); static void fxgmac_napi_enable(struct fxgmac_pdata *priv); +const struct ethtool_ops *fxgmac_get_ethtool_ops(void); + +#define MII_SPEC_STATUS 0x11 /* PHY specific status */ +#define FXGMAC_EPHY_LINK_STATUS BIT(10) +#define PHY_MII_SPEC_DUPLEX BIT(13) + +static int fxgmac_get_link_ksettings(struct net_device *netdev, + struct ethtool_link_ksettings *cmd) +{ + struct fxgmac_pdata *pdata = netdev_priv(netdev); + struct phy_device *phydev = netdev->phydev; + u32 duplex, regval, link_status; + u32 adv = 0xFFFFFFFF; + + ethtool_link_ksettings_zero_link_mode(cmd, supported); + ethtool_link_ksettings_zero_link_mode(cmd, advertising); + + /* set the supported link speeds */ + ethtool_link_ksettings_add_link_mode(cmd, supported, 1000baseT_Full); + ethtool_link_ksettings_add_link_mode(cmd, supported, 100baseT_Full); + ethtool_link_ksettings_add_link_mode(cmd, supported, 100baseT_Half); + ethtool_link_ksettings_add_link_mode(cmd, supported, 10baseT_Full); + ethtool_link_ksettings_add_link_mode(cmd, supported, 10baseT_Half); + + /* Indicate pause support */ + ethtool_link_ksettings_add_link_mode(cmd, supported, Pause); + ethtool_link_ksettings_add_link_mode(cmd, supported, Asym_Pause); + + regval = phy_read(phydev, MII_ADVERTISE); + + if (field_get(ADVERTISE_PAUSE_CAP, regval)) + ethtool_link_ksettings_add_link_mode(cmd, advertising, Pause); + + if (field_get(ADVERTISE_PAUSE_ASYM, regval)) + ethtool_link_ksettings_add_link_mode(cmd, advertising, Asym_Pause); + + ethtool_link_ksettings_add_link_mode(cmd, supported, MII); + cmd->base.port = PORT_MII; + + ethtool_link_ksettings_add_link_mode(cmd, supported, Autoneg); + regval = phy_read(phydev, MII_BMCR); + + regval = field_get(BMCR_ANENABLE, regval); + if (regval) { + ethtool_link_ksettings_add_link_mode(cmd, advertising, Autoneg); + + regval = phy_read(phydev, MII_ADVERTISE); + + if (adv & ADVERTISE_10HALF) + ethtool_link_ksettings_add_link_mode(cmd, advertising, 10baseT_Half); + if (adv & ADVERTISE_10FULL) + ethtool_link_ksettings_add_link_mode(cmd, advertising, 10baseT_Full); + if (adv & ADVERTISE_100HALF) + ethtool_link_ksettings_add_link_mode(cmd, advertising, 100baseT_Half); + if (adv & ADVERTISE_100FULL) + ethtool_link_ksettings_add_link_mode(cmd, advertising, 100baseT_Full); + + adv = phy_read(phydev, MII_CTRL1000); + + if (adv & ADVERTISE_1000FULL) + ethtool_link_ksettings_add_link_mode(cmd, advertising, 1000baseT_Full); + } + + cmd->base.autoneg = 1; + + regval = phy_read(phydev, MII_SPEC_STATUS); + + link_status = field_get(FXGMAC_EPHY_LINK_STATUS, regval); + if (link_status) { + duplex = field_get(PHY_MII_SPEC_DUPLEX, regval); + cmd->base.duplex = duplex; + cmd->base.speed = pdata->mac_speed; + } else { + cmd->base.duplex = DUPLEX_UNKNOWN; + cmd->base.speed = SPEED_UNKNOWN; + } + + return 0; +} + +static const struct ethtool_ops fxgmac_ethtool_ops = { + .get_link = ethtool_op_get_link, + .get_link_ksettings = fxgmac_get_link_ksettings, +}; + +const struct ethtool_ops *fxgmac_get_ethtool_ops(void) +{ + return &fxgmac_ethtool_ops; +} #define PHY_WR_CONFIG(reg_offset) (0x8000205 + ((reg_offset) * 0x10000)) static int fxgmac_phy_write_reg(struct fxgmac_pdata *priv, u32 reg_id, u32 data) @@ -1899,6 +1988,7 @@ static int fxgmac_init(struct fxgmac_pdata *priv, bool save_private_reg) FXGMAC_JUMBO_PACKET_MTU + (ETH_HLEN + VLAN_HLEN + ETH_FCS_LEN); ndev->netdev_ops = fxgmac_get_netdev_ops();/* Set device operations */ + ndev->ethtool_ops = fxgmac_get_ethtool_ops();/* Set device operations */ /* Set device features */ if (priv->hw_feat.tso) { -- 2.34.1

2 1

[PATCH OLK-5.10] ksmbd: fix use-after-free in kerberos authentication
by Yongjian Sun 09 Mar '26

09 Mar '26

From: Sean Heelan <seanheelan(a)gmail.com> mainline inclusion from mainline-v6.15-rc5 commit e86e9134e1d1c90a960dd57f59ce574d27b9a124 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/10609 CVE: CVE-2025-37778 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?… -------------------------------- Setting sess->user = NULL was introduced to fix the dangling pointer created by ksmbd_free_user. However, it is possible another thread could be operating on the session and make use of sess->user after it has been passed to ksmbd_free_user but before sess->user is set to NULL. Cc: stable(a)vger.kernel.org Signed-off-by: Sean Heelan <seanheelan(a)gmail.com> Acked-by: Namjae Jeon <linkinjeon(a)kernel.org> Signed-off-by: Steve French <stfrench(a)microsoft.com> Conflicts: fs/smb/server/smb2pdu.c fs/ksmbd/smb2pdu.c fs/smb/server/auth.c fs/ksmbd/auth.c [mainline commit 38c8a9a52082 changed the file name] [mainline commit 1e440d5b25b7 still has issues] Signed-off-by: Yongjian Sun <sunyongjian1(a)huawei.com> --- fs/ksmbd/auth.c | 14 +++++++++++++- fs/ksmbd/smb2pdu.c | 3 --- 2 files changed, 13 insertions(+), 4 deletions(-) diff --git a/fs/ksmbd/auth.c b/fs/ksmbd/auth.c index d8dabd19823f..c5916064b85e 100644 --- a/fs/ksmbd/auth.c +++ b/fs/ksmbd/auth.c @@ -514,7 +514,19 @@ int ksmbd_krb5_authenticate(struct ksmbd_session *sess, char *in_blob, retval = -ENOMEM; goto out; } - sess->user = user; + + if (!sess->user) { + /* First successful authentication */ + sess->user = user; + } else { + if (!ksmbd_compare_user(sess->user, user)) { + ksmbd_debug(AUTH, "different user tried to reuse session\n"); + retval = -EPERM; + ksmbd_free_user(user); + goto out; + } + ksmbd_free_user(user); + } memcpy(sess->sess_key, resp->payload, resp->session_key_len); memcpy(out_blob, resp->payload + resp->session_key_len, diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c index 13f2a81d3621..1588867b4e71 100644 --- a/fs/ksmbd/smb2pdu.c +++ b/fs/ksmbd/smb2pdu.c @@ -1612,9 +1612,6 @@ static int krb5_authenticate(struct ksmbd_work *work, if (prev_sess_id && prev_sess_id != sess->id) destroy_previous_session(conn, sess->user, prev_sess_id); - if (sess->state == SMB2_SESSION_VALID) - ksmbd_free_user(sess->user); - retval = ksmbd_krb5_authenticate(sess, in_blob, in_len, out_blob, &out_len); if (retval) { -- 2.39.2

2 1

[PATCH openEuler-1.0-LTS] PCI: Fix pci_slot_trylock() error handling
by Ziming Du 09 Mar '26

09 Mar '26

From: Jinhui Guo <guojinhui.liam(a)bytedance.com> mainline inclusion from mainline-v7.0-rc1 commit 9368d1ee62829b08aa31836b3ca003803caf0b72 category: bugfix bugzilla: https://atomgit.com/openeuler/kernel/issues/8599 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?… -------------------------------- Commit a4e772898f8b ("PCI: Add missing bridge lock to pci_bus_lock()") delegates the bridge device's pci_dev_trylock() to pci_bus_trylock() in pci_slot_trylock(), but it forgets to remove the corresponding pci_dev_unlock() when pci_bus_trylock() fails. Before a4e772898f8b, the code did: if (!pci_dev_trylock(dev)) /* <- lock bridge device */ goto unlock; if (dev->subordinate) { if (!pci_bus_trylock(dev->subordinate)) { pci_dev_unlock(dev); /* <- unlock bridge device */ goto unlock; } } After a4e772898f8b the bridge-device lock is no longer taken, but the pci_dev_unlock(dev) on the failure path was left in place, leading to the bug. This yields one of two errors: 1. A warning that the lock is being unlocked when no one holds it. 2. An incorrect unlock of a lock that belongs to another thread. Fix it by removing the now-redundant pci_dev_unlock(dev) on the failure path. [Same patch later posted by Keith at https://patch.msgid.link/20260116184150.3013258-1-kbusch@meta.com] Fixes: a4e772898f8b ("PCI: Add missing bridge lock to pci_bus_lock()") Signed-off-by: Jinhui Guo <guojinhui.liam(a)bytedance.com> Signed-off-by: Bjorn Helgaas <bhelgaas(a)google.com> Reviewed-by: Dan Williams <dan.j.williams(a)intel.com> Cc: stable(a)vger.kernel.org Link: https://patch.msgid.link/20251212145528.2555-1-guojinhui.liam@bytedance.com Signed-off-by: Ziming Du <duziming2(a)huawei.com> --- drivers/pci/pci.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index b93605616d4e4..fbef3c37f37fa 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -5144,10 +5144,8 @@ static int pci_slot_trylock(struct pci_slot *slot) if (!dev->slot || dev->slot != slot) continue; if (dev->subordinate) { - if (!pci_bus_trylock(dev->subordinate)) { - pci_dev_unlock(dev); + if (!pci_bus_trylock(dev->subordinate)) goto unlock; - } } else if (!pci_dev_trylock(dev)) goto unlock; } -- 2.43.0

2 1

[PATCH OLK-5.10] [Backport] sched/rt: Skip currently executing CPU in rto_next_cpu()
by Chen Jinghuang 09 Mar '26

09 Mar '26

mainline inclusion from mainline-v7.0-rc1 commit 94894c9c477e53bcea052e075c53f89df3d2a33e category: bugfix bugzilla: https://atomgit.com/openeuler/kernel/issues/8689 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?… -------------------------------- CPU0 becomes overloaded when hosting a CPU-bound RT task, a non-CPU-bound RT task, and a CFS task stuck in kernel space. When other CPUs switch from RT to non-RT tasks, RT load balancing (LB) is triggered; with HAVE_RT_PUSH_IPI enabled, they send IPIs to CPU0 to drive the execution of rto_push_irq_work_func. During push_rt_task on CPU0, if next_task->prio < rq->donor->prio, resched_curr() sets NEED_RESCHED and after the push operation completes, CPU0 calls rto_next_cpu(). Since only CPU0 is overloaded in this scenario, rto_next_cpu() should ideally return -1 (no further IPI needed). However, multiple CPUs invoking tell_cpu_to_push() during LB increments rd->rto_loop_next. Even when rd->rto_cpu is set to -1, the mismatch between rd->rto_loop and rd->rto_loop_next forces rto_next_cpu() to restart its search from -1. With CPU0 remaining overloaded (satisfying rt_nr_migratory && rt_nr_total > 1), it gets reselected, causing CPU0 to queue irq_work to itself and send self-IPIs repeatedly. As long as CPU0 stays overloaded and other CPUs run pull_rt_tasks(), it falls into an infinite self-IPI loop, which triggers a CPU hardlockup due to continuous self-interrupts. The trigging scenario is as follows: cpu0 cpu1 cpu2 pull_rt_task tell_cpu_to_push <------------irq_work_queue_on rto_push_irq_work_func push_rt_task resched_curr(rq) pull_rt_task rto_next_cpu tell_cpu_to_push <-------------------------- atomic_inc(rto_loop_next) rd->rto_loop != next rto_next_cpu irq_work_queue_on rto_push_irq_work_func Fix redundant self-IPI by filtering the initiating CPU in rto_next_cpu(). This solution has been verified to effectively eliminate spurious self-IPIs and prevent CPU hardlockup scenarios. Fixes: 4bdced5c9a29 ("sched/rt: Simplify the IPI based RT balancing logic") Suggested-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> Suggested-by: K Prateek Nayak <kprateek.nayak(a)amd.com> Signed-off-by: Chen Jinghuang <chenjinghuang2(a)huawei.com> Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org> Reviewed-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> Reviewed-by: Valentin Schneider <vschneid(a)redhat.com> Link: https://patch.msgid.link/20260122012533.673768-1-chenjinghuang2@huawei.com Signed-off-by: Chen Jinghuang <chenjinghuang2(a)huawei.com> --- kernel/sched/rt.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index ddbc857a28b8..dbc3a40a68fa 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -2013,6 +2013,7 @@ static void push_rt_tasks(struct rq *rq) */ static int rto_next_cpu(struct root_domain *rd) { + int this_cpu = smp_processor_id(); int next; int cpu; @@ -2036,6 +2037,10 @@ static int rto_next_cpu(struct root_domain *rd) rd->rto_cpu = cpu; + /* Do not send IPI to self */ + if (cpu == this_cpu) + continue; + if (cpu < nr_cpu_ids) return cpu; -- 2.34.1

2 1

[PATCH OLK-6.6] arm64/mpam: Fix warning of schedule state in resctrl_arch_mon_ctx_alloc()
by Zeng Heng 09 Mar '26

09 Mar '26

hulk inclusion category: bugfix bugzilla: https://atomgit.com/openeuler/kernel/issues/8686 ------------------ resctrl_arch_mon_ctx_alloc() triggers a scheduling state warning when calling kmalloc() while the task is in a non-running state: do not call blocking ops when !TASK_RUNNING; state=1 set at prepare_to_wait WARNING: CPU: 78 PID: 12592 at kernel/sched/core.c:10584 _might_sleep Call trace: _might_sleep+0x1cc/0xf8 _kmalloc_cache_alloc_node+0x3a0/0x4e0 kmalloc_trace+0x44/0x120 resctrl_arch_mon_ctx_alloc+0xf0/0x178 mon_event_read+0xa0/0x308 mkdir_mondata_subdir+0x24c/0x330 mkdir_mondata_all+0x17c/0x248 rdt_get_tree+0x2e8/0x680 vfs_get_tree+0x5c/0x190 do_new_mount+0x27c/0x408 path_mount+0x2ac/0x448 arm64_sys_mount+0x1d4/0x228 Refactor the call sequence in resctrl_arch_mon_ctx_alloc() and ensure the allocation is performed in TASK_RUNNING state to avoid schedule state corrupted. Fixes: 9119da143939 ("arm_mpam: resctrl: Allow resctrl to allocate monitors") Signed-off-by: Zeng Heng <zengheng4(a)huawei.com> --- drivers/platform/mpam/mpam_resctrl.c | 24 +++++++++++------------- 1 file changed, 11 insertions(+), 13 deletions(-) diff --git a/drivers/platform/mpam/mpam_resctrl.c b/drivers/platform/mpam/mpam_resctrl.c index 9950cc4eebf4..a33957651732 100644 --- a/drivers/platform/mpam/mpam_resctrl.c +++ b/drivers/platform/mpam/mpam_resctrl.c @@ -388,32 +388,30 @@ struct rdt_resource *resctrl_arch_get_resource(enum resctrl_res_level l) return &mpam_resctrl_exports[l].resctrl_res; } -static void *resctrl_arch_mon_ctx_alloc_no_wait(struct rdt_resource *r, - int evtid) +static u32 resctrl_arch_mon_ctx_alloc_no_wait(struct rdt_resource *r, + int evtid) { - u32 *ret = kmalloc(sizeof(*ret), GFP_KERNEL); - - if (!ret) - return ERR_PTR(-ENOMEM); - - *ret = __mon_is_rmid_idx; - return ret; + return __mon_is_rmid_idx; } void *resctrl_arch_mon_ctx_alloc(struct rdt_resource *r, int evtid) { DEFINE_WAIT(wait); - void *ret; + u32 *ret; + + ret = kmalloc(sizeof(*ret), GFP_KERNEL); + if (!ret) + return ERR_PTR(-ENOMEM); might_sleep(); do { prepare_to_wait(&resctrl_mon_ctx_waiters, &wait, TASK_INTERRUPTIBLE); - ret = resctrl_arch_mon_ctx_alloc_no_wait(r, evtid); - if (PTR_ERR(ret) == -ENOSPC) + *ret = resctrl_arch_mon_ctx_alloc_no_wait(r, evtid); + if (*ret == -ENOSPC) schedule(); - } while (PTR_ERR(ret) == -ENOSPC && !signal_pending(current)); + } while (*ret == -ENOSPC && !signal_pending(current)); finish_wait(&resctrl_mon_ctx_waiters, &wait); return ret; -- 2.25.1

2 1

[PATCH OLK-6.6 0/2] Fix TLBI broadcast optimization loss and incorrect dvmbm handling
by Tian Zheng 09 Mar '26

09 Mar '26

Fix 1 In the TLBI broadcast-optimization feature, the SYS_LSUDVM_CTRL_EL2 register controls whether the feature is enabled. When LPI low-power mode is enabled, this register is cleared as the pCPU powers down into LPI mode, causing the TLBI broadcast optimization to stop working. The fix saves and restores this control register in the callbacks for entering and exiting LPI mode. Fix 2 The current TLBI broadcast-optimization logic only supports normal VMs. If the feature is enabled globally, VMs that are not yet adapted for it, such as CCA will use an incorrect TLBI broadcast bitmap, which can cause a panic in CCA VMs. The fix moves the actual enable/disable of the dvmbm functionality into the vcpu load and vcpu put functions. Tian Zheng (2): KVM: arm64: Fix TLBI optimization broken in LPI mode KVM: arm64: Fix CCA guest panic when dvmbm is enabled arch/arm64/kvm/arm.c | 6 ++++++ arch/arm64/kvm/hisilicon/hisi_virt.c | 8 +++----- arch/arm64/kvm/hisilicon/hisi_virt.h | 19 +++++++++++++++++++ 3 files changed, 28 insertions(+), 5 deletions(-) -- 2.33.0

1 2

[PATCH OLK-5.10] SUNRPC: Ensure the transport backchannel association
by Dong Chenchen 09 Mar '26

09 Mar '26

From: Benjamin Coddington <bcodding(a)redhat.com> mainline inclusion from mainline-v5.12-rc6 commit 98b5cee37389b899de044bc4aac56e6ff33dbd4d category: bugfix bugzilla: https://atomgit.com/openeuler/kernel/issues/8655 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?… -------------------------------- If the server sends CB_ calls on a connection that is not associated with the backchannel, refuse to process the call and shut down the connection. This avoids a NULL dereference crash in xprt_complete_bc_request(). There's not much more we can do in this situation unless we want to look into allowing all connections to be associated with the fore and back channel. Signed-off-by: Benjamin Coddington <bcodding(a)redhat.com> Signed-off-by: Trond Myklebust <trond.myklebust(a)hammerspace.com> Signed-off-by: Dong Chenchen <dongchenchen2(a)huawei.com> --- net/sunrpc/xprtsock.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c index 1ef469ddea89..a6580946ab69 100644 --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -558,6 +558,10 @@ xs_read_stream_call(struct sock_xprt *transport, struct msghdr *msg, int flags) struct rpc_rqst *req; ssize_t ret; + /* Is this transport associated with the backchannel? */ + if (!xprt->bc_serv) + return -ESHUTDOWN; + /* Look up and lock the request corresponding to the given XID */ req = xprt_lookup_bc_request(xprt, transport->recv.xid); if (!req) { -- 2.25.1

2 1