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authorLinus Torvalds <torvalds@linux-foundation.org>2023-02-24 02:55:40 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2023-02-24 02:55:40 +0100
commitd2980d8d826554fa6981d621e569a453787472f8 (patch)
treed75ddea276ae8bf42ecf528f9862714a8bccf8f4 /scripts/gdb
parentMerge tag 'mm-stable-2023-02-20-13-37' of git://git.kernel.org/pub/scm/linux/... (diff)
parentUpdate CREDITS file entry for Jesper Juhl (diff)
downloadlinux-d2980d8d826554fa6981d621e569a453787472f8.tar.xz
linux-d2980d8d826554fa6981d621e569a453787472f8.zip
Merge tag 'mm-nonmm-stable-2023-02-20-15-29' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull non-MM updates from Andrew Morton: "There is no particular theme here - mainly quick hits all over the tree. Most notable is a set of zlib changes from Mikhail Zaslonko which enhances and fixes zlib's use of S390 hardware support: 'lib/zlib: Set of s390 DFLTCC related patches for kernel zlib'" * tag 'mm-nonmm-stable-2023-02-20-15-29' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (55 commits) Update CREDITS file entry for Jesper Juhl sparc: allow PM configs for sparc32 COMPILE_TEST hung_task: print message when hung_task_warnings gets down to zero. arch/Kconfig: fix indentation scripts/tags.sh: fix the Kconfig tags generation when using latest ctags nilfs2: prevent WARNING in nilfs_dat_commit_end() lib/zlib: remove redundation assignement of avail_in dfltcc_gdht() lib/Kconfig.debug: do not enable DEBUG_PREEMPT by default lib/zlib: DFLTCC always switch to software inflate for Z_PACKET_FLUSH option lib/zlib: DFLTCC support inflate with small window lib/zlib: Split deflate and inflate states for DFLTCC lib/zlib: DFLTCC not writing header bits when avail_out == 0 lib/zlib: fix DFLTCC ignoring flush modes when avail_in == 0 lib/zlib: fix DFLTCC not flushing EOBS when creating raw streams lib/zlib: implement switching between DFLTCC and software lib/zlib: adjust offset calculation for dfltcc_state nilfs2: replace WARN_ONs for invalid DAT metadata block requests scripts/spelling.txt: add "exsits" pattern and fix typo instances fs: gracefully handle ->get_block not mapping bh in __mpage_writepage cramfs: Kconfig: fix spelling & punctuation ...
Diffstat (limited to 'scripts/gdb')
-rw-r--r--scripts/gdb/linux/mm.py222
-rw-r--r--scripts/gdb/vmlinux-gdb.py1
2 files changed, 223 insertions, 0 deletions
diff --git a/scripts/gdb/linux/mm.py b/scripts/gdb/linux/mm.py
new file mode 100644
index 000000000000..30d837f3dfae
--- /dev/null
+++ b/scripts/gdb/linux/mm.py
@@ -0,0 +1,222 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# gdb helper commands and functions for Linux kernel debugging
+#
+# routines to introspect page table
+#
+# Authors:
+# Dmitrii Bundin <dmitrii.bundin.a@gmail.com>
+#
+
+import gdb
+
+from linux import utils
+
+PHYSICAL_ADDRESS_MASK = gdb.parse_and_eval('0xfffffffffffff')
+
+
+def page_mask(level=1):
+ # 4KB
+ if level == 1:
+ return gdb.parse_and_eval('(u64) ~0xfff')
+ # 2MB
+ elif level == 2:
+ return gdb.parse_and_eval('(u64) ~0x1fffff')
+ # 1GB
+ elif level == 3:
+ return gdb.parse_and_eval('(u64) ~0x3fffffff')
+ else:
+ raise Exception(f'Unknown page level: {level}')
+
+
+#page_offset_base in case CONFIG_DYNAMIC_MEMORY_LAYOUT is disabled
+POB_NO_DYNAMIC_MEM_LAYOUT = '0xffff888000000000'
+def _page_offset_base():
+ pob_symbol = gdb.lookup_global_symbol('page_offset_base')
+ pob = pob_symbol.name if pob_symbol else POB_NO_DYNAMIC_MEM_LAYOUT
+ return gdb.parse_and_eval(pob)
+
+
+def is_bit_defined_tupled(data, offset):
+ return offset, bool(data >> offset & 1)
+
+def content_tupled(data, bit_start, bit_end):
+ return (bit_start, bit_end), data >> bit_start & ((1 << (1 + bit_end - bit_start)) - 1)
+
+def entry_va(level, phys_addr, translating_va):
+ def start_bit(level):
+ if level == 5:
+ return 48
+ elif level == 4:
+ return 39
+ elif level == 3:
+ return 30
+ elif level == 2:
+ return 21
+ elif level == 1:
+ return 12
+ else:
+ raise Exception(f'Unknown level {level}')
+
+ entry_offset = ((translating_va >> start_bit(level)) & 511) * 8
+ entry_va = _page_offset_base() + phys_addr + entry_offset
+ return entry_va
+
+class Cr3():
+ def __init__(self, cr3, page_levels):
+ self.cr3 = cr3
+ self.page_levels = page_levels
+ self.page_level_write_through = is_bit_defined_tupled(cr3, 3)
+ self.page_level_cache_disabled = is_bit_defined_tupled(cr3, 4)
+ self.next_entry_physical_address = cr3 & PHYSICAL_ADDRESS_MASK & page_mask()
+
+ def next_entry(self, va):
+ next_level = self.page_levels
+ return PageHierarchyEntry(entry_va(next_level, self.next_entry_physical_address, va), next_level)
+
+ def mk_string(self):
+ return f"""\
+cr3:
+ {'cr3 binary data': <30} {hex(self.cr3)}
+ {'next entry physical address': <30} {hex(self.next_entry_physical_address)}
+ ---
+ {'bit' : <4} {self.page_level_write_through[0]: <10} {'page level write through': <30} {self.page_level_write_through[1]}
+ {'bit' : <4} {self.page_level_cache_disabled[0]: <10} {'page level cache disabled': <30} {self.page_level_cache_disabled[1]}
+"""
+
+
+class PageHierarchyEntry():
+ def __init__(self, address, level):
+ data = int.from_bytes(
+ memoryview(gdb.selected_inferior().read_memory(address, 8)),
+ "little"
+ )
+ if level == 1:
+ self.is_page = True
+ self.entry_present = is_bit_defined_tupled(data, 0)
+ self.read_write = is_bit_defined_tupled(data, 1)
+ self.user_access_allowed = is_bit_defined_tupled(data, 2)
+ self.page_level_write_through = is_bit_defined_tupled(data, 3)
+ self.page_level_cache_disabled = is_bit_defined_tupled(data, 4)
+ self.entry_was_accessed = is_bit_defined_tupled(data, 5)
+ self.dirty = is_bit_defined_tupled(data, 6)
+ self.pat = is_bit_defined_tupled(data, 7)
+ self.global_translation = is_bit_defined_tupled(data, 8)
+ self.page_physical_address = data & PHYSICAL_ADDRESS_MASK & page_mask(level)
+ self.next_entry_physical_address = None
+ self.hlat_restart_with_ordinary = is_bit_defined_tupled(data, 11)
+ self.protection_key = content_tupled(data, 59, 62)
+ self.executed_disable = is_bit_defined_tupled(data, 63)
+ else:
+ page_size = is_bit_defined_tupled(data, 7)
+ page_size_bit = page_size[1]
+ self.is_page = page_size_bit
+ self.entry_present = is_bit_defined_tupled(data, 0)
+ self.read_write = is_bit_defined_tupled(data, 1)
+ self.user_access_allowed = is_bit_defined_tupled(data, 2)
+ self.page_level_write_through = is_bit_defined_tupled(data, 3)
+ self.page_level_cache_disabled = is_bit_defined_tupled(data, 4)
+ self.entry_was_accessed = is_bit_defined_tupled(data, 5)
+ self.page_size = page_size
+ self.dirty = is_bit_defined_tupled(
+ data, 6) if page_size_bit else None
+ self.global_translation = is_bit_defined_tupled(
+ data, 8) if page_size_bit else None
+ self.pat = is_bit_defined_tupled(
+ data, 12) if page_size_bit else None
+ self.page_physical_address = data & PHYSICAL_ADDRESS_MASK & page_mask(level) if page_size_bit else None
+ self.next_entry_physical_address = None if page_size_bit else data & PHYSICAL_ADDRESS_MASK & page_mask()
+ self.hlat_restart_with_ordinary = is_bit_defined_tupled(data, 11)
+ self.protection_key = content_tupled(data, 59, 62) if page_size_bit else None
+ self.executed_disable = is_bit_defined_tupled(data, 63)
+ self.address = address
+ self.page_entry_binary_data = data
+ self.page_hierarchy_level = level
+
+ def next_entry(self, va):
+ if self.is_page or not self.entry_present[1]:
+ return None
+
+ next_level = self.page_hierarchy_level - 1
+ return PageHierarchyEntry(entry_va(next_level, self.next_entry_physical_address, va), next_level)
+
+
+ def mk_string(self):
+ if not self.entry_present[1]:
+ return f"""\
+level {self.page_hierarchy_level}:
+ {'entry address': <30} {hex(self.address)}
+ {'page entry binary data': <30} {hex(self.page_entry_binary_data)}
+ ---
+ PAGE ENTRY IS NOT PRESENT!
+"""
+ elif self.is_page:
+ def page_size_line(ps_bit, ps, level):
+ return "" if level == 1 else f"{'bit': <3} {ps_bit: <5} {'page size': <30} {ps}"
+
+ return f"""\
+level {self.page_hierarchy_level}:
+ {'entry address': <30} {hex(self.address)}
+ {'page entry binary data': <30} {hex(self.page_entry_binary_data)}
+ {'page size': <30} {'1GB' if self.page_hierarchy_level == 3 else '2MB' if self.page_hierarchy_level == 2 else '4KB' if self.page_hierarchy_level == 1 else 'Unknown page size for level:' + self.page_hierarchy_level}
+ {'page physical address': <30} {hex(self.page_physical_address)}
+ ---
+ {'bit': <4} {self.entry_present[0]: <10} {'entry present': <30} {self.entry_present[1]}
+ {'bit': <4} {self.read_write[0]: <10} {'read/write access allowed': <30} {self.read_write[1]}
+ {'bit': <4} {self.user_access_allowed[0]: <10} {'user access allowed': <30} {self.user_access_allowed[1]}
+ {'bit': <4} {self.page_level_write_through[0]: <10} {'page level write through': <30} {self.page_level_write_through[1]}
+ {'bit': <4} {self.page_level_cache_disabled[0]: <10} {'page level cache disabled': <30} {self.page_level_cache_disabled[1]}
+ {'bit': <4} {self.entry_was_accessed[0]: <10} {'entry has been accessed': <30} {self.entry_was_accessed[1]}
+ {"" if self.page_hierarchy_level == 1 else f"{'bit': <4} {self.page_size[0]: <10} {'page size': <30} {self.page_size[1]}"}
+ {'bit': <4} {self.dirty[0]: <10} {'page dirty': <30} {self.dirty[1]}
+ {'bit': <4} {self.global_translation[0]: <10} {'global translation': <30} {self.global_translation[1]}
+ {'bit': <4} {self.hlat_restart_with_ordinary[0]: <10} {'restart to ordinary': <30} {self.hlat_restart_with_ordinary[1]}
+ {'bit': <4} {self.pat[0]: <10} {'pat': <30} {self.pat[1]}
+ {'bits': <4} {str(self.protection_key[0]): <10} {'protection key': <30} {self.protection_key[1]}
+ {'bit': <4} {self.executed_disable[0]: <10} {'execute disable': <30} {self.executed_disable[1]}
+"""
+ else:
+ return f"""\
+level {self.page_hierarchy_level}:
+ {'entry address': <30} {hex(self.address)}
+ {'page entry binary data': <30} {hex(self.page_entry_binary_data)}
+ {'next entry physical address': <30} {hex(self.next_entry_physical_address)}
+ ---
+ {'bit': <4} {self.entry_present[0]: <10} {'entry present': <30} {self.entry_present[1]}
+ {'bit': <4} {self.read_write[0]: <10} {'read/write access allowed': <30} {self.read_write[1]}
+ {'bit': <4} {self.user_access_allowed[0]: <10} {'user access allowed': <30} {self.user_access_allowed[1]}
+ {'bit': <4} {self.page_level_write_through[0]: <10} {'page level write through': <30} {self.page_level_write_through[1]}
+ {'bit': <4} {self.page_level_cache_disabled[0]: <10} {'page level cache disabled': <30} {self.page_level_cache_disabled[1]}
+ {'bit': <4} {self.entry_was_accessed[0]: <10} {'entry has been accessed': <30} {self.entry_was_accessed[1]}
+ {'bit': <4} {self.page_size[0]: <10} {'page size': <30} {self.page_size[1]}
+ {'bit': <4} {self.hlat_restart_with_ordinary[0]: <10} {'restart to ordinary': <30} {self.hlat_restart_with_ordinary[1]}
+ {'bit': <4} {self.executed_disable[0]: <10} {'execute disable': <30} {self.executed_disable[1]}
+"""
+
+
+class TranslateVM(gdb.Command):
+ """Prints the entire paging structure used to translate a given virtual address.
+
+Having an address space of the currently executed process translates the virtual address
+and prints detailed information of all paging structure levels used for the transaltion.
+Currently supported arch: x86"""
+
+ def __init__(self):
+ super(TranslateVM, self).__init__('translate-vm', gdb.COMMAND_USER)
+
+ def invoke(self, arg, from_tty):
+ if utils.is_target_arch("x86"):
+ vm_address = gdb.parse_and_eval(f'{arg}')
+ cr3_data = gdb.parse_and_eval('$cr3')
+ cr4 = gdb.parse_and_eval('$cr4')
+ page_levels = 5 if cr4 & (1 << 12) else 4
+ page_entry = Cr3(cr3_data, page_levels)
+ while page_entry:
+ gdb.write(page_entry.mk_string())
+ page_entry = page_entry.next_entry(vm_address)
+ else:
+ gdb.GdbError("Virtual address translation is not"
+ "supported for this arch")
+
+
+TranslateVM()
diff --git a/scripts/gdb/vmlinux-gdb.py b/scripts/gdb/vmlinux-gdb.py
index 3e8d3669f0ce..3a5b44cd6bfe 100644
--- a/scripts/gdb/vmlinux-gdb.py
+++ b/scripts/gdb/vmlinux-gdb.py
@@ -37,3 +37,4 @@ else:
import linux.clk
import linux.genpd
import linux.device
+ import linux.mm