linux-toradex.git/scripts/faddr2line, branch v6.11-rc5 Linux kernel for Apalis and Colibri modules scripts/faddr2line: Check only two symbols when calculating symbol size 2024-07-03T06:38:37+00:00 Brian Johannesmeyer bjohannesmeyer@gmail.com 2024-04-15T14:55:38+00:00 c02904f05ff805d6c0631634d5751ebd338f75ec Rather than looping through each symbol in a particular section to calculate a symbol's size, grep for the symbol and its immediate successor, and only use those two symbols. Signed-off-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com> Link: https://lore.kernel.org/r/20240415145538.1938745-8-bjohannesmeyer@gmail.com Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> 
Rather than looping through each symbol in a particular section to
calculate a symbol's size, grep for the symbol and its immediate
successor, and only use those two symbols.

Signed-off-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com>
Link: https://lore.kernel.org/r/20240415145538.1938745-8-bjohannesmeyer@gmail.com
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
scripts/faddr2line: Remove call to addr2line from find_dir_prefix() 2024-07-03T06:38:37+00:00 Brian Johannesmeyer bjohannesmeyer@gmail.com 2024-04-15T14:55:37+00:00 406b5c12aad8110e1b1f9355f176cac43cd1fecb Use the single long-running faddr2line process from find_dir_prefix(). Signed-off-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com> Link: https://lore.kernel.org/r/20240415145538.1938745-7-bjohannesmeyer@gmail.com Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> 
Use the single long-running faddr2line process from find_dir_prefix().

Signed-off-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com>
Link: https://lore.kernel.org/r/20240415145538.1938745-7-bjohannesmeyer@gmail.com
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
scripts/faddr2line: Invoke addr2line as a single long-running process 2024-07-03T06:38:36+00:00 Brian Johannesmeyer bjohannesmeyer@gmail.com 2024-04-15T14:55:36+00:00 e36b69e918112430ee53e24238bb87f5146f9acf Rather than invoking a separate addr2line process for each address, invoke a single addr2line coprocess, and pass each address to its stdin. Previous work [0] applied a similar change to perf, leading to a ~60x speed-up [1]. If using an object file that is _not_ vmlinux, faddr2line passes a section name argument to addr2line. Because we do not know until runtime which section names will be passed to addr2line, we cannot apply this change to non-vmlinux object files. Hence, it only applies to vmlinux. [0] commit be8ecc57f180 ("perf srcline: Use long-running addr2line per DSO") [1] Link: https://eighty-twenty.org/2021/09/09/perf-addr2line-speed-improvement Signed-off-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com> Link: https://lore.kernel.org/r/20240415145538.1938745-6-bjohannesmeyer@gmail.com Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> 
Rather than invoking a separate addr2line process for each address, invoke
a single addr2line coprocess, and pass each address to its stdin. Previous
work [0] applied a similar change to perf, leading to a ~60x speed-up [1].

If using an object file that is _not_ vmlinux, faddr2line passes a section
name argument to addr2line. Because we do not know until runtime which
section names will be passed to addr2line, we cannot apply this change to
non-vmlinux object files. Hence, it only applies to vmlinux.

[0] commit be8ecc57f180 ("perf srcline: Use long-running addr2line per
DSO")
[1] Link:
https://eighty-twenty.org/2021/09/09/perf-addr2line-speed-improvement

Signed-off-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com>
Link: https://lore.kernel.org/r/20240415145538.1938745-6-bjohannesmeyer@gmail.com
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
scripts/faddr2line: Pass --addresses argument to addr2line 2024-07-03T06:38:36+00:00 Brian Johannesmeyer bjohannesmeyer@gmail.com 2024-04-15T14:55:35+00:00 5b280de46d2bcea9def0dd84b1e86f8b42ca70b9 In preparation for identifying an addr2line sentinel. See previous work [0], which applies a similar change to perf. [0] commit 8dc26b6f718a ("perf srcline: Make sentinel reading for binutils addr2line more robust") Signed-off-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com> Link: https://lore.kernel.org/r/20240415145538.1938745-5-bjohannesmeyer@gmail.com Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> 
In preparation for identifying an addr2line sentinel. See previous work
[0], which applies a similar change to perf.

[0] commit 8dc26b6f718a ("perf srcline: Make sentinel reading for binutils
addr2line more robust")

Signed-off-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com>
Link: https://lore.kernel.org/r/20240415145538.1938745-5-bjohannesmeyer@gmail.com
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
scripts/faddr2line: Check vmlinux only once 2024-07-03T06:38:36+00:00 Brian Johannesmeyer bjohannesmeyer@gmail.com 2024-04-15T14:55:34+00:00 2c809186ccf0e3a4cb952da181f9c28436133081 Rather than checking whether the object file is vmlinux for each invocation of __faddr2line, check it only once beforehand. Signed-off-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com> Link: https://lore.kernel.org/r/20240415145538.1938745-4-bjohannesmeyer@gmail.com Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> 
Rather than checking whether the object file is vmlinux for each invocation
of __faddr2line, check it only once beforehand.

Signed-off-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com>
Link: https://lore.kernel.org/r/20240415145538.1938745-4-bjohannesmeyer@gmail.com
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
scripts/faddr2line: Combine three readelf calls into one 2024-07-03T06:38:36+00:00 Brian Johannesmeyer bjohannesmeyer@gmail.com 2024-04-15T14:55:33+00:00 b8d9d9496c1e78a8fd89f4fe9923d12b3c9ad8a3 Rather than calling readelf three separate times to collect three different types of info, call it only once, and parse out the different types of info from its output. Signed-off-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com> Link: https://lore.kernel.org/r/20240415145538.1938745-3-bjohannesmeyer@gmail.com Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> 
Rather than calling readelf three separate times to collect three different
types of info, call it only once, and parse out the different types of info
from its output.

Signed-off-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com>
Link: https://lore.kernel.org/r/20240415145538.1938745-3-bjohannesmeyer@gmail.com
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
scripts/faddr2line: Reduce number of readelf calls to three 2024-07-03T06:38:36+00:00 Brian Johannesmeyer bjohannesmeyer@gmail.com 2024-04-15T14:55:32+00:00 39cf650d68289d41d484f4c29fea0124df2e09aa Rather than calling readelf several times for each invocation of __faddr2line, call readelf only three times at the beginning, and save its result for future use. Signed-off-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com> Link: https://lore.kernel.org/r/20240415145538.1938745-2-bjohannesmeyer@gmail.com Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> 
Rather than calling readelf several times for each invocation of
__faddr2line, call readelf only three times at the beginning, and save its
result for future use.

Signed-off-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com>
Link: https://lore.kernel.org/r/20240415145538.1938745-2-bjohannesmeyer@gmail.com
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
scripts/faddr2line: Skip over mapping symbols in output from readelf 2023-10-23T15:36:46+00:00 Will Deacon will@kernel.org 2023-10-02T16:57:49+00:00 60fd39af33d3f63c4c94bd06784ebdf0d883f5c9 Mapping symbols emitted in the readelf output can confuse the 'faddr2line' symbol size calculation, resulting in the erroneous rejection of valid offsets. This is especially prevalent when building an arm64 kernel with CONFIG_CFI_CLANG=y, where most functions are prefixed with a 32-bit data value in a '$d.n' section. For example: 447538: ffff800080014b80 548 FUNC GLOBAL DEFAULT 2 do_one_initcall 104: ffff800080014c74 0 NOTYPE LOCAL DEFAULT 2 $x.73 106: ffff800080014d30 0 NOTYPE LOCAL DEFAULT 2 $x.75 111: ffff800080014da4 0 NOTYPE LOCAL DEFAULT 2 $d.78 112: ffff800080014da8 0 NOTYPE LOCAL DEFAULT 2 $x.79 36: ffff800080014de0 200 FUNC LOCAL DEFAULT 2 run_init_process Adding a warning to do_one_initcall() results in: | WARNING: CPU: 0 PID: 1 at init/main.c:1236 do_one_initcall+0xf4/0x260 Which 'faddr2line' refuses to accept: $ ./scripts/faddr2line vmlinux do_one_initcall+0xf4/0x260 skipping do_one_initcall address at 0xffff800080014c74 due to size mismatch (0x260 != 0x224) no match for do_one_initcall+0xf4/0x260 Filter out these entries from readelf using a shell reimplementation of is_mapping_symbol(), so that the size of a symbol is calculated as a delta to the next symbol present in ksymtab. Suggested-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Will Deacon <will@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Link: https://lore.kernel.org/r/20231002165750.1661-4-will@kernel.org Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> 
Mapping symbols emitted in the readelf output can confuse the
'faddr2line' symbol size calculation, resulting in the erroneous
rejection of valid offsets. This is especially prevalent when building
an arm64 kernel with CONFIG_CFI_CLANG=y, where most functions are
prefixed with a 32-bit data value in a '$d.n' section. For example:

447538: ffff800080014b80   548 FUNC    GLOBAL DEFAULT    2 do_one_initcall
   104: ffff800080014c74     0 NOTYPE  LOCAL  DEFAULT    2 $x.73
   106: ffff800080014d30     0 NOTYPE  LOCAL  DEFAULT    2 $x.75
   111: ffff800080014da4     0 NOTYPE  LOCAL  DEFAULT    2 $d.78
   112: ffff800080014da8     0 NOTYPE  LOCAL  DEFAULT    2 $x.79
    36: ffff800080014de0   200 FUNC    LOCAL  DEFAULT    2 run_init_process

Adding a warning to do_one_initcall() results in:

  | WARNING: CPU: 0 PID: 1 at init/main.c:1236 do_one_initcall+0xf4/0x260

Which 'faddr2line' refuses to accept:

$ ./scripts/faddr2line vmlinux do_one_initcall+0xf4/0x260
skipping do_one_initcall address at 0xffff800080014c74 due to size mismatch (0x260 != 0x224)
no match for do_one_initcall+0xf4/0x260

Filter out these entries from readelf using a shell reimplementation of
is_mapping_symbol(), so that the size of a symbol is calculated as a
delta to the next symbol present in ksymtab.

Suggested-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20231002165750.1661-4-will@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
scripts/faddr2line: Use LLVM addr2line and readelf if LLVM=1 2023-10-23T15:36:33+00:00 Will Deacon will@kernel.org 2023-10-02T16:57:48+00:00 86bf86e19d308a1dba41e5f1f7e8cc105a5efa49 GNU utilities cannot necessarily parse objects built by LLVM, which can result in confusing errors when using 'faddr2line': $ CROSS_COMPILE=aarch64-linux-gnu- ./scripts/faddr2line vmlinux do_one_initcall+0xf4/0x260 aarch64-linux-gnu-addr2line: vmlinux: unknown type [0x13] section `.relr.dyn' aarch64-linux-gnu-addr2line: DWARF error: invalid or unhandled FORM value: 0x25 do_one_initcall+0xf4/0x260: aarch64-linux-gnu-addr2line: vmlinux: unknown type [0x13] section `.relr.dyn' aarch64-linux-gnu-addr2line: DWARF error: invalid or unhandled FORM value: 0x25 $x.73 at main.c:? Although this can be worked around by setting CROSS_COMPILE to "llvm=-", it's cleaner to follow the same syntax as the top-level Makefile and accept LLVM= as an indication to use the llvm- tools, optionally specifying their location or specific version number. Suggested-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Will Deacon <will@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Link: https://lore.kernel.org/r/20231002165750.1661-3-will@kernel.org Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> 
GNU utilities cannot necessarily parse objects built by LLVM, which can
result in confusing errors when using 'faddr2line':

$ CROSS_COMPILE=aarch64-linux-gnu- ./scripts/faddr2line vmlinux do_one_initcall+0xf4/0x260
aarch64-linux-gnu-addr2line: vmlinux: unknown type [0x13] section `.relr.dyn'
aarch64-linux-gnu-addr2line: DWARF error: invalid or unhandled FORM value: 0x25
do_one_initcall+0xf4/0x260:
aarch64-linux-gnu-addr2line: vmlinux: unknown type [0x13] section `.relr.dyn'
aarch64-linux-gnu-addr2line: DWARF error: invalid or unhandled FORM value: 0x25
$x.73 at main.c:?

Although this can be worked around by setting CROSS_COMPILE to "llvm=-",
it's cleaner to follow the same syntax as the top-level Makefile and
accept LLVM= as an indication to use the llvm- tools, optionally
specifying their location or specific version number.

Suggested-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20231002165750.1661-3-will@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
scripts/faddr2line: Don't filter out non-function symbols from readelf 2023-10-23T15:35:01+00:00 Will Deacon will@kernel.org 2023-10-02T16:57:47+00:00 180af1a5bdaf8d4964837a46a9fce8c3a7fd2d97 As Josh points out in 20230724234734.zy67gm674vl3p3wv@treble: > Problem is, I think the kernel's symbol printing code prints the > nearest kallsyms symbol, and there are some valid non-FUNC code > symbols. For example, syscall_return_via_sysret. so we shouldn't be considering only 'FUNC'-type symbols in the output from readelf. Drop the function symbol type filtering from the faddr2line outer loop. Suggested-by: Josh Poimboeuf <jpoimboe@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Link: https://lore.kernel.org/r/20230724234734.zy67gm674vl3p3wv@treble Signed-off-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20231002165750.1661-2-will@kernel.org Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> 
As Josh points out in 20230724234734.zy67gm674vl3p3wv@treble:

> Problem is, I think the kernel's symbol printing code prints the
> nearest kallsyms symbol, and there are some valid non-FUNC code
> symbols.  For example, syscall_return_via_sysret.

so we shouldn't be considering only 'FUNC'-type symbols in the output
from readelf.

Drop the function symbol type filtering from the faddr2line outer loop.

Suggested-by: Josh Poimboeuf <jpoimboe@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20230724234734.zy67gm674vl3p3wv@treble
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20231002165750.1661-2-will@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>