Merge tag 'mm-nonmm-stable-2025-12-06-11-14' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-MM updates from Andrew Morton:

 - "panic: sys_info: Refactor and fix a potential issue" (Andy Shevchenko)
   fixes a build issue and does some cleanup in ib/sys_info.c

 - "Implement mul_u64_u64_div_u64_roundup()" (David Laight)
   enhances the 64-bit math code on behalf of a PWM driver and beefs up
   the test module for these library functions

 - "scripts/gdb/symbols: make BPF debug info available to GDB" (Ilya Leoshkevich)
   makes BPF symbol names, sizes, and line numbers available to the GDB
   debugger

 - "Enable hung_task and lockup cases to dump system info on demand" (Feng Tang)
   adds a sysctl which can be used to cause additional info dumping when
   the hung-task and lockup detectors fire

 - "lib/base64: add generic encoder/decoder, migrate users" (Kuan-Wei Chiu)
   adds a general base64 encoder/decoder to lib/ and migrates several
   users away from their private implementations

 - "rbree: inline rb_first() and rb_last()" (Eric Dumazet)
   makes TCP a little faster

 - "liveupdate: Rework KHO for in-kernel users" (Pasha Tatashin)
   reworks the KEXEC Handover interfaces in preparation for Live Update
   Orchestrator (LUO), and possibly for other future clients

 - "kho: simplify state machine and enable dynamic updates" (Pasha Tatashin)
   increases the flexibility of KEXEC Handover. Also preparation for LUO

 - "Live Update Orchestrator" (Pasha Tatashin)
   is a major new feature targeted at cloud environments. Quoting the
   cover letter:

      This series introduces the Live Update Orchestrator, a kernel
      subsystem designed to facilitate live kernel updates using a
      kexec-based reboot. This capability is critical for cloud
      environments, allowing hypervisors to be updated with minimal
      downtime for running virtual machines. LUO achieves this by
      preserving the state of selected resources, such as memory,
      devices and their dependencies, across the kernel transition.

      As a key feature, this series includes support for preserving
      memfd file descriptors, which allows critical in-memory data, such
      as guest RAM or any other large memory region, to be maintained in
      RAM across the kexec reboot.

   Mike Rappaport merits a mention here, for his extensive review and
   testing work.

 - "kexec: reorganize kexec and kdump sysfs" (Sourabh Jain)
   moves the kexec and kdump sysfs entries from /sys/kernel/ to
   /sys/kernel/kexec/ and adds back-compatibility symlinks which can
   hopefully be removed one day

 - "kho: fixes for vmalloc restoration" (Mike Rapoport)
   fixes a BUG which was being hit during KHO restoration of vmalloc()
   regions

* tag 'mm-nonmm-stable-2025-12-06-11-14' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (139 commits)
  calibrate: update header inclusion
  Reinstate "resource: avoid unnecessary lookups in find_next_iomem_res()"
  vmcoreinfo: track and log recoverable hardware errors
  kho: fix restoring of contiguous ranges of order-0 pages
  kho: kho_restore_vmalloc: fix initialization of pages array
  MAINTAINERS: TPM DEVICE DRIVER: update the W-tag
  init: replace simple_strtoul with kstrtoul to improve lpj_setup
  KHO: fix boot failure due to kmemleak access to non-PRESENT pages
  Documentation/ABI: new kexec and kdump sysfs interface
  Documentation/ABI: mark old kexec sysfs deprecated
  kexec: move sysfs entries to /sys/kernel/kexec
  test_kho: always print restore status
  kho: free chunks using free_page() instead of kfree()
  selftests/liveupdate: add kexec test for multiple and empty sessions
  selftests/liveupdate: add simple kexec-based selftest for LUO
  selftests/liveupdate: add userspace API selftests
  docs: add documentation for memfd preservation via LUO
  mm: memfd_luo: allow preserving memfd
  liveupdate: luo_file: add private argument to store runtime state
  mm: shmem: export some functions to internal.h
  ...

1 files changed, 93 insertions, 12 deletions

diff --git a/scripts/gdb/linux/symbols.py b/scripts/gdb/linux/symbols.py
index 6edb99221675..d4308b726183 100644
--- a/scripts/gdb/linux/symbols.py
+++ b/scripts/gdb/linux/symbols.py
@@ -11,13 +11,14 @@
 # This work is licensed under the terms of the GNU GPL version 2.
 #
 
+import atexit
 import gdb
 import os
 import re
 import struct
 
 from itertools import count
-from linux import modules, utils, constants
+from linux import bpf, constants, modules, utils
 
 
 if hasattr(gdb, 'Breakpoint'):
@@ -114,17 +115,27 @@ class LxSymbols(gdb.Command):
 The kernel (vmlinux) is taken from the current working directly. Modules (.ko)
 are scanned recursively, starting in the same directory. Optionally, the module
 search path can be extended by a space separated list of paths passed to the
-lx-symbols command."""
+lx-symbols command.
+
+When the -bpf flag is specified, symbols from the currently loaded BPF programs
+are loaded as well."""
 
     module_paths = []
     module_files = []
     module_files_updated = False
     loaded_modules = []
     breakpoint = None
+    bpf_prog_monitor = None
+    bpf_ksym_monitor = None
+    bpf_progs = {}
+    # The remove-symbol-file command, even when invoked with -a, requires the
+    # respective object file to exist, so keep them around.
+    bpf_debug_objs = {}
 
     def __init__(self):
         super(LxSymbols, self).__init__("lx-symbols", gdb.COMMAND_FILES,
                                         gdb.COMPLETE_FILENAME)
+        atexit.register(self.cleanup_bpf)
 
     def _update_module_files(self):
         self.module_files = []
@@ -197,6 +208,51 @@ lx-symbols command."""
         else:
             gdb.write("no module object found for '{0}'\n".format(module_name))
 
+    def add_bpf_prog(self, prog):
+        if prog["jited"]:
+            self.bpf_progs[int(prog["bpf_func"])] = prog
+
+    def remove_bpf_prog(self, prog):
+        self.bpf_progs.pop(int(prog["bpf_func"]), None)
+
+    def add_bpf_ksym(self, ksym):
+        addr = int(ksym["start"])
+        name = bpf.get_ksym_name(ksym)
+        with utils.pagination_off():
+            gdb.write("loading @{addr}: {name}\n".format(
+                addr=hex(addr), name=name))
+            debug_obj = bpf.generate_debug_obj(ksym, self.bpf_progs.get(addr))
+            if debug_obj is None:
+                return
+            try:
+                cmdline = "add-symbol-file {obj} {addr}".format(
+                    obj=debug_obj.name, addr=hex(addr))
+                gdb.execute(cmdline, to_string=True)
+            except:
+                debug_obj.close()
+                raise
+            self.bpf_debug_objs[addr] = debug_obj
+
+    def remove_bpf_ksym(self, ksym):
+        addr = int(ksym["start"])
+        debug_obj = self.bpf_debug_objs.pop(addr, None)
+        if debug_obj is None:
+            return
+        try:
+            name = bpf.get_ksym_name(ksym)
+            gdb.write("unloading @{addr}: {name}\n".format(
+                addr=hex(addr), name=name))
+            cmdline = "remove-symbol-file {path}".format(path=debug_obj.name)
+            gdb.execute(cmdline, to_string=True)
+        finally:
+            debug_obj.close()
+
+    def cleanup_bpf(self):
+        self.bpf_progs = {}
+        while len(self.bpf_debug_objs) > 0:
+            self.bpf_debug_objs.popitem()[1].close()
+
+
     def load_all_symbols(self):
         gdb.write("loading vmlinux\n")
 
@@ -224,34 +280,59 @@ lx-symbols command."""
         else:
             [self.load_module_symbols(module) for module in module_list]
 
+        self.cleanup_bpf()
+        if self.bpf_prog_monitor is not None:
+            self.bpf_prog_monitor.notify_initial()
+        if self.bpf_ksym_monitor is not None:
+            self.bpf_ksym_monitor.notify_initial()
+
         for saved_state in saved_states:
             saved_state['breakpoint'].enabled = saved_state['enabled']
 
     def invoke(self, arg, from_tty):
         skip_decompressor()
 
-        self.module_paths = [os.path.abspath(os.path.expanduser(p))
-                             for p in arg.split()]
+        monitor_bpf = False
+        self.module_paths = []
+        for p in arg.split():
+            if p == "-bpf":
+                monitor_bpf = True
+            else:
+                p.append(os.path.abspath(os.path.expanduser(p)))
         self.module_paths.append(os.getcwd())
 
+        if self.breakpoint is not None:
+            self.breakpoint.delete()
+            self.breakpoint = None
+        if self.bpf_prog_monitor is not None:
+            self.bpf_prog_monitor.delete()
+            self.bpf_prog_monitor = None
+        if self.bpf_ksym_monitor is not None:
+            self.bpf_ksym_monitor.delete()
+            self.bpf_ksym_monitor = None
+
         # enforce update
         self.module_files = []
         self.module_files_updated = False
 
         self.load_all_symbols()
 
-        if not modules.has_modules():
+        if not hasattr(gdb, 'Breakpoint'):
+            gdb.write("Note: symbol update on module and BPF loading not "
+                      "supported with this gdb version\n")
             return
 
-        if hasattr(gdb, 'Breakpoint'):
-            if self.breakpoint is not None:
-                self.breakpoint.delete()
-                self.breakpoint = None
+        if modules.has_modules():
             self.breakpoint = LoadModuleBreakpoint(
                 "kernel/module/main.c:do_init_module", self)
-        else:
-            gdb.write("Note: symbol update on module loading not supported "
-                      "with this gdb version\n")
+
+        if monitor_bpf:
+            if constants.LX_CONFIG_BPF_SYSCALL:
+                self.bpf_prog_monitor = bpf.ProgMonitor(self.add_bpf_prog,
+                                                        self.remove_bpf_prog)
+            if constants.LX_CONFIG_BPF and constants.LX_CONFIG_BPF_JIT:
+                self.bpf_ksym_monitor = bpf.KsymMonitor(self.add_bpf_ksym,
+                                                        self.remove_bpf_ksym)
 
 
 LxSymbols()