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" <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Thadeu Lima de Souza Cascardo <[email protected]>
Cc: Josh Poimboeuf <[email protected]>
Cc: Peter Zijlstra (Intel) <[email protected]>
Cc: linuxppc-dev <[email protected]>
Cc: LKML <[email protected]>
Signed-off-by: Srikar Dronamraju <[email protected]>
---
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
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" <[email protected]>
> Cc: Jiri Olsa <[email protected]>
> Cc: Thadeu Lima de Souza Cascardo <[email protected]>
Reviewed-by: Thadeu Lima de Souza Cascardo <[email protected]>
The other instances of readelf --wide on faddr2line use --section-headers and
should not required the same mangling.
Cascardo.
> Cc: Josh Poimboeuf <[email protected]>
> Cc: Peter Zijlstra (Intel) <[email protected]>
> Cc: linuxppc-dev <[email protected]>
> Cc: LKML <[email protected]>
> Signed-off-by: Srikar Dronamraju <[email protected]>
> ---
> 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
>
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" <[email protected]>
>> Cc: Jiri Olsa <[email protected]>
>> Cc: Thadeu Lima de Souza Cascardo <[email protected]>
>
> Reviewed-by: Thadeu Lima de Souza Cascardo <[email protected]>
>
> 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 <[email protected]>
- Naveen
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" <[email protected]>
>>> Cc: Jiri Olsa <[email protected]>
>>> Cc: Thadeu Lima de Souza Cascardo <[email protected]>
>>
>> Reviewed-by: Thadeu Lima de Souza Cascardo <[email protected]>
>>
>> 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 <[email protected]>
>
>
> - Naveen
>
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
The following commit has been merged into the objtool/urgent branch of tip:
Commit-ID: 2d77de1581bb5b470486edaf17a7d70151131afd
Gitweb: https://git.kernel.org/tip/2d77de1581bb5b470486edaf17a7d70151131afd
Author: Srikar Dronamraju <[email protected]>
AuthorDate: Tue, 27 Sep 2022 13:22:11 +05:30
Committer: Peter Zijlstra <[email protected]>
CommitterDate: Wed, 16 Nov 2022 10:42:10 +01:00
scripts/faddr2line: Fix regression in name resolution on ppc64le
Commit 1d1a0e7c5100 ("scripts/faddr2line: Fix overlapping text section
failures") can cause faddr2line to fail on ppc64le on some
distributions, while it works fine on other distributions. The failure
can be attributed to differences in the readelf output.
$ ./scripts/faddr2line vmlinux find_busiest_group+0x00
no match for find_busiest_group+0x00
On ppc64le, readelf adds the localentry tag before the symbol name on
some distributions, and adds the localentry tag after the symbol name on
other distributions. This problem has been discussed previously:
https://lore.kernel.org/bpf/20191211160133.GB4580@calabresa/
This problem can be overcome by filtering out the localentry tags in the
readelf output. Similar fixes are already present in the kernel by way
of the following commits:
1fd6cee127e2 ("libbpf: Fix VERSIONED_SYM_COUNT number parsing")
aa915931ac3e ("libbpf: Fix readelf output parsing for Fedora")
[jpoimboe: rework commit log]
Fixes: 1d1a0e7c5100 ("scripts/faddr2line: Fix overlapping text section failures")
Signed-off-by: Srikar Dronamraju <[email protected]>
Acked-by: Naveen N. Rao <[email protected]>
Reviewed-by: Thadeu Lima de Souza Cascardo <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Josh Poimboeuf <[email protected]>
Signed-off-by: Peter Zijlstra <[email protected]>
---
scripts/faddr2line | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/scripts/faddr2line b/scripts/faddr2line
index 5514c23..0e73aca 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