* [PATCH] scripts/faddr2line: Fix regression in name resolution on ppc64le
@ 2022-09-27 7:52 Srikar Dronamraju
2022-09-27 11:19 ` Thadeu Lima de Souza Cascardo
0 siblings, 1 reply; 5+ messages in thread
From: Srikar Dronamraju @ 2022-09-27 7:52 UTC (permalink / raw)
To: LKML
Cc: Thadeu Lima de Souza Cascardo, Srikar Dronamraju, Peter Zijlstra,
Jiri Olsa, Josh Poimboeuf, Naveen N. Rao, linuxppc-dev
Commit 1d1a0e7c5100 ("scripts/faddr2line: Fix overlapping text section failures")
can cause scripts/faddr2line to fail on ppc64le machines on few
distributions, while working on other distributions. The failure can be
attributed to difference in readelf output on various distributions.
$ ./scripts/faddr2line vmlinux find_busiest_group+0x00
no match for find_busiest_group+0x00
Expected output was:
$ ./scripts/faddr2line vmlinux find_busiest_group+0x00
find_busiest_group+0x00/0x3d0:
find_busiest_group at kernel/sched/fair.c:9595
On ppc64le, readelf adds localentry tag before the symbol name on few
distributions and adds the localentry tag after the symbol name on few
other distributions. This problem has been discussed in the reference
URL given below. This problem can be overcome by filtering out
localentry tags in readelf output. Similar fixes are already present in
kernel by way of commits:
1fd6cee127e2 ("libbpf: Fix VERSIONED_SYM_COUNT number parsing")
aa915931ac3e ("libbpf: Fix readelf output parsing for Fedora")
Fixes: 1d1a0e7c5100 ("scripts/faddr2line: Fix overlapping text section failures")
Reference: https://lore.kernel.org/bpf/20191211160133.GB4580@calabresa/
Cc: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: linuxppc-dev <linuxppc-dev@lists.ozlabs.org>
Cc: LKML <linux-kernel@vger.kernel.org>
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
---
scripts/faddr2line | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/scripts/faddr2line b/scripts/faddr2line
index 5514c23f45c2..0e73aca4f908 100755
--- a/scripts/faddr2line
+++ b/scripts/faddr2line
@@ -74,7 +74,8 @@ command -v ${ADDR2LINE} >/dev/null 2>&1 || die "${ADDR2LINE} isn't installed"
find_dir_prefix() {
local objfile=$1
- local start_kernel_addr=$(${READELF} --symbols --wide $objfile | ${AWK} '$8 == "start_kernel" {printf "0x%s", $2}')
+ local start_kernel_addr=$(${READELF} --symbols --wide $objfile | sed 's/\[.*\]//' |
+ ${AWK} '$8 == "start_kernel" {printf "0x%s", $2}')
[[ -z $start_kernel_addr ]] && return
local file_line=$(${ADDR2LINE} -e $objfile $start_kernel_addr)
@@ -178,7 +179,7 @@ __faddr2line() {
found=2
break
fi
- done < <(${READELF} --symbols --wide $objfile | ${AWK} -v sec=$sym_sec '$7 == sec' | sort --key=2)
+ done < <(${READELF} --symbols --wide $objfile | sed 's/\[.*\]//' | ${AWK} -v sec=$sym_sec '$7 == sec' | sort --key=2)
if [[ $found = 0 ]]; then
warn "can't find symbol: sym_name: $sym_name sym_sec: $sym_sec sym_addr: $sym_addr sym_elf_size: $sym_elf_size"
@@ -259,7 +260,7 @@ __faddr2line() {
DONE=1
- done < <(${READELF} --symbols --wide $objfile | ${AWK} -v fn=$sym_name '$4 == "FUNC" && $8 == fn')
+ done < <(${READELF} --symbols --wide $objfile | sed 's/\[.*\]//' | ${AWK} -v fn=$sym_name '$4 == "FUNC" && $8 == fn')
}
[[ $# -lt 2 ]] && usage
base-commit: bf682942cd26ce9cd5e87f73ae099b383041e782
--
2.31.1
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH] scripts/faddr2line: Fix regression in name resolution on ppc64le
2022-09-27 7:52 [PATCH] scripts/faddr2line: Fix regression in name resolution on ppc64le Srikar Dronamraju
@ 2022-09-27 11:19 ` Thadeu Lima de Souza Cascardo
2022-09-30 10:09 ` Naveen N. Rao
0 siblings, 1 reply; 5+ messages in thread
From: Thadeu Lima de Souza Cascardo @ 2022-09-27 11:19 UTC (permalink / raw)
To: Srikar Dronamraju
Cc: Peter Zijlstra, LKML, Jiri Olsa, Josh Poimboeuf, Naveen N. Rao,
linuxppc-dev
On Tue, Sep 27, 2022 at 01:22:11PM +0530, Srikar Dronamraju wrote:
> Commit 1d1a0e7c5100 ("scripts/faddr2line: Fix overlapping text section failures")
> can cause scripts/faddr2line to fail on ppc64le machines on few
> distributions, while working on other distributions. The failure can be
> attributed to difference in readelf output on various distributions.
>
> $ ./scripts/faddr2line vmlinux find_busiest_group+0x00
> no match for find_busiest_group+0x00
>
> Expected output was:
> $ ./scripts/faddr2line vmlinux find_busiest_group+0x00
> find_busiest_group+0x00/0x3d0:
> find_busiest_group at kernel/sched/fair.c:9595
>
> On ppc64le, readelf adds localentry tag before the symbol name on few
> distributions and adds the localentry tag after the symbol name on few
> other distributions. This problem has been discussed in the reference
> URL given below. This problem can be overcome by filtering out
> localentry tags in readelf output. Similar fixes are already present in
> kernel by way of commits:
>
> 1fd6cee127e2 ("libbpf: Fix VERSIONED_SYM_COUNT number parsing")
> aa915931ac3e ("libbpf: Fix readelf output parsing for Fedora")
>
> Fixes: 1d1a0e7c5100 ("scripts/faddr2line: Fix overlapping text section failures")
> Reference: https://lore.kernel.org/bpf/20191211160133.GB4580@calabresa/
> Cc: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
> Cc: Jiri Olsa <jolsa@kernel.org>
> Cc: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Reviewed-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
The other instances of readelf --wide on faddr2line use --section-headers and
should not required the same mangling.
Cascardo.
> Cc: Josh Poimboeuf <jpoimboe@redhat.com>
> Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
> Cc: linuxppc-dev <linuxppc-dev@lists.ozlabs.org>
> Cc: LKML <linux-kernel@vger.kernel.org>
> Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
> ---
> scripts/faddr2line | 7 ++++---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/scripts/faddr2line b/scripts/faddr2line
> index 5514c23f45c2..0e73aca4f908 100755
> --- a/scripts/faddr2line
> +++ b/scripts/faddr2line
> @@ -74,7 +74,8 @@ command -v ${ADDR2LINE} >/dev/null 2>&1 || die "${ADDR2LINE} isn't installed"
> find_dir_prefix() {
> local objfile=$1
>
> - local start_kernel_addr=$(${READELF} --symbols --wide $objfile | ${AWK} '$8 == "start_kernel" {printf "0x%s", $2}')
> + local start_kernel_addr=$(${READELF} --symbols --wide $objfile | sed 's/\[.*\]//' |
> + ${AWK} '$8 == "start_kernel" {printf "0x%s", $2}')
> [[ -z $start_kernel_addr ]] && return
>
> local file_line=$(${ADDR2LINE} -e $objfile $start_kernel_addr)
> @@ -178,7 +179,7 @@ __faddr2line() {
> found=2
> break
> fi
> - done < <(${READELF} --symbols --wide $objfile | ${AWK} -v sec=$sym_sec '$7 == sec' | sort --key=2)
> + done < <(${READELF} --symbols --wide $objfile | sed 's/\[.*\]//' | ${AWK} -v sec=$sym_sec '$7 == sec' | sort --key=2)
>
> if [[ $found = 0 ]]; then
> warn "can't find symbol: sym_name: $sym_name sym_sec: $sym_sec sym_addr: $sym_addr sym_elf_size: $sym_elf_size"
> @@ -259,7 +260,7 @@ __faddr2line() {
>
> DONE=1
>
> - done < <(${READELF} --symbols --wide $objfile | ${AWK} -v fn=$sym_name '$4 == "FUNC" && $8 == fn')
> + done < <(${READELF} --symbols --wide $objfile | sed 's/\[.*\]//' | ${AWK} -v fn=$sym_name '$4 == "FUNC" && $8 == fn')
> }
>
> [[ $# -lt 2 ]] && usage
>
> base-commit: bf682942cd26ce9cd5e87f73ae099b383041e782
> --
> 2.31.1
>
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH] scripts/faddr2line: Fix regression in name resolution on ppc64le
2022-09-27 11:19 ` Thadeu Lima de Souza Cascardo
@ 2022-09-30 10:09 ` Naveen N. Rao
2022-11-14 12:21 ` Christophe Leroy
0 siblings, 1 reply; 5+ messages in thread
From: Naveen N. Rao @ 2022-09-30 10:09 UTC (permalink / raw)
To: Thadeu Lima de Souza Cascardo, Srikar Dronamraju
Cc: Peter Zijlstra, linuxppc-dev, LKML, Jiri Olsa, Josh Poimboeuf
Thadeu Lima de Souza Cascardo wrote:
> On Tue, Sep 27, 2022 at 01:22:11PM +0530, Srikar Dronamraju wrote:
>> Commit 1d1a0e7c5100 ("scripts/faddr2line: Fix overlapping text section failures")
>> can cause scripts/faddr2line to fail on ppc64le machines on few
>> distributions, while working on other distributions. The failure can be
>> attributed to difference in readelf output on various distributions.
>>
>> $ ./scripts/faddr2line vmlinux find_busiest_group+0x00
>> no match for find_busiest_group+0x00
>>
>> Expected output was:
>> $ ./scripts/faddr2line vmlinux find_busiest_group+0x00
>> find_busiest_group+0x00/0x3d0:
>> find_busiest_group at kernel/sched/fair.c:9595
>>
>> On ppc64le, readelf adds localentry tag before the symbol name on few
>> distributions and adds the localentry tag after the symbol name on few
>> other distributions. This problem has been discussed in the reference
>> URL given below. This problem can be overcome by filtering out
>> localentry tags in readelf output. Similar fixes are already present in
>> kernel by way of commits:
>>
>> 1fd6cee127e2 ("libbpf: Fix VERSIONED_SYM_COUNT number parsing")
>> aa915931ac3e ("libbpf: Fix readelf output parsing for Fedora")
>>
>> Fixes: 1d1a0e7c5100 ("scripts/faddr2line: Fix overlapping text section failures")
>> Reference: https://lore.kernel.org/bpf/20191211160133.GB4580@calabresa/
>> Cc: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
>> Cc: Jiri Olsa <jolsa@kernel.org>
>> Cc: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
>
> Reviewed-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
>
> The other instances of readelf --wide on faddr2line use --section-headers and
> should not required the same mangling.
There's one usage of readelf with --file-header in faddr2line which also
doesn't need this. The extra information being printed is from st_other
and is very specific to the symbol table.
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
- Naveen
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH] scripts/faddr2line: Fix regression in name resolution on ppc64le
2022-09-30 10:09 ` Naveen N. Rao
@ 2022-11-14 12:21 ` Christophe Leroy
2022-11-14 19:30 ` Josh Poimboeuf
0 siblings, 1 reply; 5+ messages in thread
From: Christophe Leroy @ 2022-11-14 12:21 UTC (permalink / raw)
To: Josh Poimboeuf, Ingo Molnar
Cc: Thadeu Lima de Souza Cascardo, Srikar Dronamraju, Peter Zijlstra,
LKML, Jiri Olsa, Josh Poimboeuf, Naveen N. Rao, linuxppc-dev
Gentle ping ... Can this fix be merged ?
Thanks
Le 30/09/2022 à 12:09, Naveen N. Rao a écrit :
> Thadeu Lima de Souza Cascardo wrote:
>> On Tue, Sep 27, 2022 at 01:22:11PM +0530, Srikar Dronamraju wrote:
>>> Commit 1d1a0e7c5100 ("scripts/faddr2line: Fix overlapping text
>>> section failures")
>>> can cause scripts/faddr2line to fail on ppc64le machines on few
>>> distributions, while working on other distributions. The failure can be
>>> attributed to difference in readelf output on various distributions.
>>>
>>> $ ./scripts/faddr2line vmlinux find_busiest_group+0x00
>>> no match for find_busiest_group+0x00
>>>
>>> Expected output was:
>>> $ ./scripts/faddr2line vmlinux find_busiest_group+0x00
>>> find_busiest_group+0x00/0x3d0:
>>> find_busiest_group at kernel/sched/fair.c:9595
>>>
>>> On ppc64le, readelf adds localentry tag before the symbol name on few
>>> distributions and adds the localentry tag after the symbol name on few
>>> other distributions. This problem has been discussed in the reference
>>> URL given below. This problem can be overcome by filtering out
>>> localentry tags in readelf output. Similar fixes are already present in
>>> kernel by way of commits:
>>>
>>> 1fd6cee127e2 ("libbpf: Fix VERSIONED_SYM_COUNT number parsing")
>>> aa915931ac3e ("libbpf: Fix readelf output parsing for Fedora")
>>>
>>> Fixes: 1d1a0e7c5100 ("scripts/faddr2line: Fix overlapping text
>>> section failures")
>>> Reference: https://lore.kernel.org/bpf/20191211160133.GB4580@calabresa/
>>> Cc: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
>>> Cc: Jiri Olsa <jolsa@kernel.org>
>>> Cc: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
>>
>> Reviewed-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
>>
>> The other instances of readelf --wide on faddr2line use
>> --section-headers and
>> should not required the same mangling.
>
> There's one usage of readelf with --file-header in faddr2line which also
> doesn't need this. The extra information being printed is from st_other
> and is very specific to the symbol table.
>
> Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
>
>
> - Naveen
>
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH] scripts/faddr2line: Fix regression in name resolution on ppc64le
2022-11-14 12:21 ` Christophe Leroy
@ 2022-11-14 19:30 ` Josh Poimboeuf
0 siblings, 0 replies; 5+ messages in thread
From: Josh Poimboeuf @ 2022-11-14 19:30 UTC (permalink / raw)
To: Christophe Leroy
Cc: Thadeu Lima de Souza Cascardo, Srikar Dronamraju, Peter Zijlstra,
LKML, Ingo Molnar, Jiri Olsa, Josh Poimboeuf, Naveen N. Rao,
linuxppc-dev
On Mon, Nov 14, 2022 at 12:21:33PM +0000, Christophe Leroy wrote:
> Gentle ping ... Can this fix be merged ?
Thanks for the reminder. Looks good, I'll go ahead and take it.
--
Josh
^ permalink raw reply [flat|nested] 5+ messages in thread
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2022-09-27 7:52 [PATCH] scripts/faddr2line: Fix regression in name resolution on ppc64le Srikar Dronamraju
2022-09-27 11:19 ` Thadeu Lima de Souza Cascardo
2022-09-30 10:09 ` Naveen N. Rao
2022-11-14 12:21 ` Christophe Leroy
2022-11-14 19:30 ` Josh Poimboeuf
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