3 files changed, 96 insertions, 9 deletions
diff --git a/scripts/gdb/linux/cpus.py b/scripts/gdb/linux/cpus.py
index 2f11c4f9c345..f506965ea759 100644
--- a/scripts/gdb/linux/cpus.py
+++ b/scripts/gdb/linux/cpus.py
@@ -46,7 +46,7 @@ def per_cpu(var_ptr, cpu):
             # !CONFIG_SMP case
             offset = 0
     pointer = var_ptr.cast(utils.get_long_type()) + offset
-    return pointer.cast(var_ptr.type).dereference()
+    return pointer.cast(var_ptr.type)
 
 
 cpu_mask = {}
@@ -149,11 +149,29 @@ Note that VAR has to be quoted as string."""
         super(PerCpu, self).__init__("lx_per_cpu")
 
     def invoke(self, var, cpu=-1):
-        return per_cpu(var.address, cpu)
+        return per_cpu(var.address, cpu).dereference()
 
 
 PerCpu()
 
+
+class PerCpuPtr(gdb.Function):
+    """Return per-cpu pointer.
+
+$lx_per_cpu_ptr("VAR"[, CPU]): Return the per-cpu pointer called VAR for the
+given CPU number. If CPU is omitted, the CPU of the current context is used.
+Note that VAR has to be quoted as string."""
+
+    def __init__(self):
+        super(PerCpuPtr, self).__init__("lx_per_cpu_ptr")
+
+    def invoke(self, var, cpu=-1):
+        return per_cpu(var, cpu)
+
+
+PerCpuPtr()
+
+
 def get_current_task(cpu):
     task_ptr_type = task_type.get_type().pointer()
 
@@ -164,10 +182,10 @@ def get_current_task(cpu):
             var_ptr = gdb.parse_and_eval("(struct task_struct *)cpu_tasks[0].task")
             return var_ptr.dereference()
         else:
-            var_ptr = gdb.parse_and_eval("&pcpu_hot.current_task")
+            var_ptr = gdb.parse_and_eval("&current_task")
             return per_cpu(var_ptr, cpu).dereference()
     elif utils.is_target_arch("aarch64"):
-        current_task_addr = gdb.parse_and_eval("$SP_EL0")
+        current_task_addr = gdb.parse_and_eval("(unsigned long)$SP_EL0")
         if (current_task_addr >> 63) != 0:
             current_task = current_task_addr.cast(task_ptr_type)
             return current_task.dereference()
diff --git a/scripts/gdb/linux/symbols.py b/scripts/gdb/linux/symbols.py
index f6c1b063775a..b255177301e9 100644
--- a/scripts/gdb/linux/symbols.py
+++ b/scripts/gdb/linux/symbols.py
@@ -14,7 +14,9 @@
 import gdb
 import os
 import re
+import struct
 
+from itertools import count
 from linux import modules, utils, constants
 
 
@@ -53,6 +55,29 @@ if hasattr(gdb, 'Breakpoint'):
             return False
 
 
+def get_vmcore_s390():
+    with utils.qemu_phy_mem_mode():
+        vmcore_info = 0x0e0c
+        paddr_vmcoreinfo_note = gdb.parse_and_eval("*(unsigned long long *)" +
+                                                   hex(vmcore_info))
+        inferior = gdb.selected_inferior()
+        elf_note = inferior.read_memory(paddr_vmcoreinfo_note, 12)
+        n_namesz, n_descsz, n_type = struct.unpack(">III", elf_note)
+        desc_paddr = paddr_vmcoreinfo_note + len(elf_note) + n_namesz + 1
+        return gdb.parse_and_eval("(char *)" + hex(desc_paddr)).string()
+
+
+def get_kerneloffset():
+    if utils.is_target_arch('s390'):
+        try:
+            vmcore_str = get_vmcore_s390()
+        except gdb.error as e:
+            gdb.write("{}\n".format(e))
+            return None
+        return utils.parse_vmcore(vmcore_str).kerneloffset
+    return None
+
+
 class LxSymbols(gdb.Command):
     """(Re-)load symbols of Linux kernel and currently loaded modules.
 
@@ -95,10 +120,14 @@ lx-symbols command."""
         except gdb.error:
             return str(module_addr)
 
-        attrs = sect_attrs['attrs']
-        section_name_to_address = {
-            attrs[n]['battr']['attr']['name'].string(): attrs[n]['address']
-            for n in range(int(sect_attrs['nsections']))}
+        section_name_to_address = {}
+        for i in count():
+            # this is a NULL terminated array
+            if sect_attrs['grp']['bin_attrs'][i] == 0x0:
+                break
+
+            attr = sect_attrs['grp']['bin_attrs'][i].dereference()
+            section_name_to_address[attr['attr']['name'].string()] = attr['private']
 
         textaddr = section_name_to_address.get(".text", module_addr)
         args = []
@@ -155,7 +184,12 @@ lx-symbols command."""
                 obj.filename.endswith('vmlinux.debug')):
                 orig_vmlinux = obj.filename
         gdb.execute("symbol-file", to_string=True)
-        gdb.execute("symbol-file {0}".format(orig_vmlinux))
+        kerneloffset = get_kerneloffset()
+        if kerneloffset is None:
+            offset_arg = ""
+        else:
+            offset_arg = " -o " + hex(kerneloffset)
+        gdb.execute("symbol-file {0}{1}".format(orig_vmlinux, offset_arg))
 
         self.loaded_modules = []
         module_list = modules.module_list()
diff --git a/scripts/gdb/linux/utils.py b/scripts/gdb/linux/utils.py
index 245ab297ea84..03ebdccf5f69 100644
--- a/scripts/gdb/linux/utils.py
+++ b/scripts/gdb/linux/utils.py
@@ -11,6 +11,11 @@
 # This work is licensed under the terms of the GNU GPL version 2.
 #
 
+import contextlib
+import dataclasses
+import re
+import typing
+
 import gdb
 
 
@@ -216,3 +221,33 @@ def gdb_eval_or_none(expresssion):
         return gdb.parse_and_eval(expresssion)
     except gdb.error:
         return None
+
+
+@contextlib.contextmanager
+def qemu_phy_mem_mode():
+    connection = gdb.selected_inferior().connection
+    orig = connection.send_packet("qqemu.PhyMemMode")
+    if orig not in b"01":
+        raise gdb.error("Unexpected qemu.PhyMemMode")
+    orig = orig.decode()
+    if connection.send_packet("Qqemu.PhyMemMode:1") != b"OK":
+        raise gdb.error("Failed to set qemu.PhyMemMode")
+    try:
+        yield
+    finally:
+        if connection.send_packet("Qqemu.PhyMemMode:" + orig) != b"OK":
+            raise gdb.error("Failed to restore qemu.PhyMemMode")
+
+
+@dataclasses.dataclass
+class VmCore:
+    kerneloffset: typing.Optional[int]
+
+
+def parse_vmcore(s):
+    match = re.search(r"KERNELOFFSET=([0-9a-f]+)", s)
+    if match is None:
+        kerneloffset = None
+    else:
+        kerneloffset = int(match.group(1), 16)
+    return VmCore(kerneloffset=kerneloffset)