Go to file
Athira Rajeev e59fea47f8 perf symbols: Fix DSO kernel load and symbol process to correctly map DSO to its long_name, type and adjust_symbols
Test "object code reading" fails sometimes for kernel address as below:

    Reading object code for memory address: 0xc000000000004c3c
    File is: [kernel.kallsyms]
    On file address is: 0x14c3c
    dso__data_read_offset failed
    test child finished with -1
    ---- end ----
    Object code reading: FAILED!

Here dso__data_read_offset() fails for symbol address
0xc000000000004c3c. This is because the DSO long_name here is
"[kernel.kallsyms]" and hence open_dso() fails to open this file. There
is an incorrect DSO to map handling here. The key points here are:

- The DSO long_name is set to "[kernel.kallsyms]". This file is
  not present and hence returns error
- The DSO binary type is set to DSO_BINARY_TYPE__NOT_FOUND
- The DSO adjust_symbols member is set to zero

In the end dso__data_read_offset() returns -1 and the address 0x14c3c
can not be resolved. Hence the test fails. But the address actually maps
to the kernel DSO

    # objdump -z -d --start-address=0xc000000000004c3c --stop-address=0xc000000000004cbc /home/athira/linux/vmlinux

    /home/athira/linux/vmlinux:     file format elf64-powerpcle

    Disassembly of section .head.text:

    c000000000004c3c <exc_virt_0x4c00_system_call+0x3c>:
    c000000000004c3c:	a6 02 9b 7d 	mfsrr1  r12
    c000000000004c40:	78 13 42 7c 	mr      r2,r2
    c000000000004c44:	18 00 4d e9 	ld      r10,24(r13)
    c000000000004c48:	60 c6 4a 61 	ori     r10,r10,50784
    c000000000004c4c:	a6 03 49 7d 	mtctr   r10

Fix dso__process_kernel_symbol() to set the binary_type and
adjust_symbols members. dso->adjust_symbols is used by
map__rip_2objdump() which converts the symbol start address to the
objdump address. Also set dso->long_name in dso__load_vmlinux().

Suggested-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Disha Goel <disgoel@linux.vnet.ibm.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linuxppc-dev@lists.ozlabs.org
Link: https://lore.kernel.org/r/20230811051546.70039-1-atrajeev@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2023-08-11 11:27:50 -03:00
arch x86/CPU/AMD: Do not leak quotient data after a division by 0 2023-08-09 07:55:00 -07:00
block block-6.5-2023-07-21 2023-07-22 11:05:15 -07:00
certs KEYS: Add missing function documentation 2023-04-24 16:15:52 +03:00
crypto crypto: algif_hash - Fix race between MORE and non-MORE sends 2023-07-08 22:48:42 +10:00
Documentation Merge remote-tracking branch 'torvalds/master' into perf-tools-next 2023-08-10 10:36:00 -03:00
drivers tpm: Add a helper for checking hwrng enabled 2023-08-09 10:05:15 -07:00
fs two ksmbd server fixes 2023-08-09 21:12:56 -07:00
include Add a mitigation for the speculative RAS (Return Address Stack) overflow 2023-08-07 16:35:44 -07:00
init Kbuild updates for v6.5 2023-07-01 09:24:31 -07:00
io_uring io_uring-6.5-2023-07-28 2023-07-28 10:19:44 -07:00
ipc Merge branch 'work.namespace' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2023-02-24 19:20:07 -08:00
kernel workqueue: Fixes for v6.5-rc5 2023-08-07 13:07:12 -07:00
lib workqueue: Fixes for v6.5-rc5 2023-08-07 13:07:12 -07:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm mm: Fix access_remote_vm() regression on tagged addresses 2023-08-09 08:05:23 -07:00
net Two patches to improve RBD exclusive lock interaction with 2023-08-04 11:29:38 -07:00
rust rust: fix bindgen build error with UBSAN_BOUNDS_STRICT 2023-08-04 17:10:50 +02:00
samples arm64: ftrace: Add direct call trampoline samples support 2023-07-10 17:51:54 -04:00
scripts x86: 2023-07-30 11:19:08 -07:00
security sysctl: set variable key_sysctls storage-class-specifier to static 2023-08-07 17:55:54 +00:00
sound ASoC: Fixes for v6.5 2023-07-27 14:54:23 +02:00
tools perf symbols: Fix DSO kernel load and symbol process to correctly map DSO to its long_name, type and adjust_symbols 2023-08-11 11:27:50 -03:00
usr initramfs: Encode dependency on KBUILD_BUILD_TIMESTAMP 2023-06-06 17:54:49 +09:00
virt KVM: Grab a reference to KVM for VM and vCPU stats file descriptors 2023-07-29 11:05:28 -04:00
.clang-format iommu: Add for_each_group_device() 2023-05-23 08:15:51 +02:00
.cocciconfig
.get_maintainer.ignore
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore Revert ".gitignore: ignore *.cover and *.mbx" 2023-07-04 15:05:12 -07:00
.mailmap mailmap: update remaining active codeaurora.org email addresses 2023-07-27 13:07:05 -07:00
.rustfmt.toml
COPYING
CREDITS - Address -Wmissing-prototype warnings 2023-06-26 16:43:54 -07:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig
MAINTAINERS Merge remote-tracking branch 'torvalds/master' into perf-tools-next 2023-08-10 10:36:00 -03:00
Makefile Linux 6.5-rc5 2023-08-06 15:07:51 -07:00
README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.