structure addresses for kernels configured with 4K pages. Without
the patch, any command that required the contents of a page structure
would fail with a readmem error.
(cldu@marvell.com, anderson@redhat.com)
"bt -l" update:
x86_64.c: In function ‘x86_64_exception_frame’:
x86_64.c:3814: warning: ‘sp’ may be used uninitialized in this function
(anderson@redhat.com)
available file and line number information for functions indicated as
the "exception RIP" in kernel exception frames. The line number
information will follow the exception frame register dump.
(anderson@redhat.com)
several command options still under development. In-kernel exception
frames are only dumped if the exception handler function is contained
within the symbol boundaries from "__exception_text_start" to
"__exception_text_end"; when ARM64 kdump is eventually implemented,
further exception-related work will be resumed.
(anderson@redhat.com)
an X86_64 kernel was loaded with a non-zero "phys_base". Without
the patch, the crash session fails with the warning message "WARNING:
cannot read linux_banner string" followed by the fatal error message
"crash: vmlinux and <dumpfile name> do not match!".
(anderson@redhat.com)
kernels that expand to a 42-bit address space when 64K pages are
configured. This is also the first crash version that has been
tested on a live ARM64 system with 4K pages, where it cleanly
make it to the "crash>" prompt. However, it should be noted that
some commands (most notably "bt") still do not work as of yet.
(anderson@redhat.com)
the crash package is built from a directory that was git-cloned
from github.com/crash-utility/crash.git, the error message has
been clarified to indicate "/usr/bin/wget is required to download
gdb-7.6.tar.gz". Without the patch, the message indicates "tar
(child): gdb-7.6.tar.gz: Cannot open: No such file or directory".
(anderson@redhat.com)
"nopl 0x0(%rax,%rax,1)" or "data32 data32 data32 xchg %ax,%ax",
which are generated when the ftrace facility is configured, the
X86_64 "dis" command will append "[FTRACE NOP]" to the line.
(anderson@redhat.com)
efficient by using the new do_list() callback function feature
as well as restricting the search to only the NUMA node that
contains the address.
(anderson@redhat.com)
is necessary to immediately perform a function for each entry in a
list while the list is being traversed. A callback function, and an
option callback data pointer, can be registered in the list_data
structure. The address of each entry in the list along with the
optional callback data pointer will be passed to the callback
function. If desired, the callback function may also dictate that
do_list() should stop the list traversal and return immediately to
its caller.
(anderson@redhat.com)
or "kmem <page-address> options. Without the patch, the first
page in a list of free page blocks is not displayed on its own
line by "kmem -F", but rather at the end of the line showing the
area number, block size, and free_area struct address that the
page is linked to. Due to this error, both "kmem <page-address>"
and "kmem -f <page-address>" would not find a page if it happened
to be the first page, or any of the contiguous pages in a multi-page
block, in the list of free pages or page blocks.
(anderson@redhat.com)
The hash queue is used for gathering and verifying lists, and the
original count of 128 may be overwhelmed if a list is extremely
large. For example, on a 256GB system with 192GB of free pages,
the "kmem -f" command takes hours to complete; with this patch,
the time is reduced to a few minutes. In addition, a new command
line option "--hash <count>" has been added to allow a user to
override the default hash queue head count of 32768.
(anderson@redhat.com)
kernel system call alias/wrapper names, for examples, "SyS_read" and
"compat_SyS_futex" instead of "sys_read" and "compat_sys_futex".
Without the patch, commands such as "dis", "sym <address>", and
"sys -c" display the alias/wrapper name instead of the real system
call name in Linux 3.10 and later kernels.
(anderson@redhat.com)
data structure and VMCOREINFO string name changes from "log" to
"printk_log" in Linux 3.11-rc4 and later kernels. Without the patch,
the command fails with the error message "crash: VMCOREINFO: no log
buffer data".
(anderson@redhat.com)
that that are configured with CONFIG_RANDOMIZE_BASE. When set to
"auto", the KASLR relocation value will be determined automatically
by comparing the "_stext" symbol value compiled into the vmlinux file
with the _stext symbol value stored in kdump vmcoreinfo data; on live
systems the comparison will be made with the "_stext" symbol value
that is found in /proc/kallsyms.
(ahonig@google.com, anderson@redhat.com)
X86_64 kernels that are configured with CONFIG_RANDOMIZE_BASE.
The offset value must be equal to the difference between the
symbol values compiled into the vmlinux file and their relocated
value.
(ahonig@google.com, anderson@redhat.com)
later kernels configured with CONFIG_SLAB, running against vmcore
files filtered with the makedumpfile(8) facility. Without the
patch, the message "crash: page excluded: kernel virtual address:
<address> type: kmem_cache buffer" is immediately followed by
the message "crash: unable to initialize kmem slab cache subsystem".
Because of a kernel data structure name change from "cache_cache" to
"kmem_cache_boot", the crash utility failed to properly downsize
the stored size of the kernel's kmem_cache data structure from the
size indicated by the vmlinux debuginfo data. This in turn could
lead to reading beyond the end of a kmem_cache data structure into
a page of memory that had been excluded from the vmcore. The fix
was also applied to kernels configured with CONFIG_SLUB.
(anderson@redhat.com)
context_switch() function so that it is not an inline function.
Without the patch, the message "crash: cannot determine thread return
address" is displayed during invocation, and backtraces of blocked
tasks may have missing or invalid frames.
(ahonig@google.com)
occurred in a KVM guest running a Linux 2.6.38 or later kernel.
Without the patch, the exception frame register dump is not displayed
above the "async_page_fault" stack frame.
(anderson@redhat.com)
generated by the invalid contents of the RIP register. Without
the patch, the exception frame register dump is not displayed
above the "page_fault" stack frame; and in a related issue, the
"bt -e" option will not find and display the exception frame.
(anderson@redhat.com)
the function frame that called into a function that was interrupted.
Without the patch, the first frame just above an IRQ exception frame
register dump may show an invalid/stale function.
(anderson@redhat.com)
indicating "WARNING: possibly bogus exception frame" generated
from a task that was in the process of being exec'd from a kernel
thread via the call_usermodehelper() facility.
(anderson@redhat.com)
a slab object, consisting of the slab cache name and the address
value, separated by a colon, and encompassed in brackets:
[slab-cache-name:address]
Enhanced the "bt -F" option such that if "-F" is entered twice,
and if the stack frame contents reference a slab cache object, both
the slab cache name and the stack contents will be displayed within
brackets.
Enhanced the "rd -S" option such that if "-S" is entered twice,
and if the memory contents reference a slab cache object, both the
slab cache name and the memory contents will be displayed within
brackets.
(anderson@redhat.com)
"-i <file>" command line option, or when accepting input from a
file as a set of commands or as a set of command arguments using the
"<" redirection character, unconditionally cease the operation if
CTRL-c is entered. Without the patch, depending upon the command
that was running when the SIGINT was received, the operation may
continue uninterruptibly until the file contents are consumed.
(anderson@redhat.com)
CONFIG_SLUB. Eash per-cpu slab object dump may show incorrect
ALLOCATED and FREE values; and as seen on Linux 3.5 and later
kernels, the TOTAL value and the number of individual objects dumped
may also be incorrect (too small).
(anderson@redhat.com)
Please enter the c mmit message for your changes. Lines starting
configured with CONFIG_SLUB. Because the the page structure's inuse
and objects fields used by SLUB were changed from discrete u16 types
to bit-fields within an unsigned int, the display of per-node partial
slab statistics are incorrect. Without the patch, the TOTAL and
ALLOCATED values are incorrectly shown as equal values, and therefore
the FREE value is always zero.
(anderson@redhat.com)
the patch, running against a Xen 4.4 hypervisor binary would fail
during session initialization with the error message "crash: invalid
structure member offset: domain_is_hvm". In addition, the PVH guest
type is being registered internally as an HVM guest type, the debug
"help -X ofs" command's display of the domain_domain_flags offset
has been fixed to show it in decimal, and the setting of the internal
dc->domain_flags has been fixed to contain all flags set, not just
the first one found.
(dslutz@verizon.com)
CONFIG_FAIR_GROUP_SCHED, but not CONFIG_CFS_BANDWIDTH. Without the
patch, the command fails with the message "runq: invalid structure
member offset: cfs_rq_throttled".
(vinayakm.list@gmail.com)
