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* [PATCH] tools/perf: Fix dso kernel load and symbol process to correctly map dso to its long_name, type and adjust_symbols
@ 2023-08-11  5:15 Athira Rajeev
  2023-08-11  9:49 ` Adrian Hunter
  0 siblings, 1 reply; 3+ messages in thread
From: Athira Rajeev @ 2023-08-11  5:15 UTC (permalink / raw)
  To: acme, jolsa, irogers, namhyung
  Cc: linux-perf-users, linuxppc-dev, maddy, atrajeev, kjain, disgoel,
	Adrian Hunter

Test "object cocde 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 the 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 is:
- dso long_name is set to [kernel.kallsyms]. This file is
  not present and hence returns error
- DSO binary type is set to DSO_BINARY_TYPE__NOT_FOUND
- dso adjust_symbols 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 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 the dso__process_kernel_symbol function to set the
binary_type and adjust_symbols. adjust_symbols is used by
function "map__rip_2objdump" which converts symbol start
address to objdump address. Also set the dso long_name during
dso__load_vmlinux function.

Suggested-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
---
Note: Found similar discussion here in thread:
      https://www.spinics.net/lists/linux-perf-users/msg06337.html
      where Adrian proposed the fix, but looks like this was
      not added to the perf. Hence addeed Suggested-by from Adrian.

      Additional to the fix proposed by Adrian, the patch also
      adds setting of adjust_symbols which is needed for
      map__rip_2objdump to convert symbol start to objdump address.

 tools/perf/util/symbol-elf.c |  2 ++
 tools/perf/util/symbol.c     | 15 ++++++++++-----
 2 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index 252d26a59e64..9e7eeaf616b8 100644
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -1440,6 +1440,8 @@ static int dso__process_kernel_symbol(struct dso *dso, struct map *map,
 		curr_dso->kernel = dso->kernel;
 		curr_dso->long_name = dso->long_name;
 		curr_dso->long_name_len = dso->long_name_len;
+		curr_dso->binary_type = dso->binary_type;
+		curr_dso->adjust_symbols = dso->adjust_symbols;
 		curr_map = map__new2(start, curr_dso);
 		dso__put(curr_dso);
 		if (curr_map == NULL)
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index f849f9ef68e6..3f36675b7c8f 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -2204,15 +2204,20 @@ int dso__load_vmlinux(struct dso *dso, struct map *map,
 	if (symsrc__init(&ss, dso, symfs_vmlinux, symtab_type))
 		return -1;
 
+	/*
+	 * dso__load_sym() may copy 'dso' which will result in the copies having
+	 * an incorrect long name unless we set it here first.
+	 */
+	dso__set_long_name(dso, vmlinux, vmlinux_allocated);
+	if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
+		dso->binary_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
+	else
+		dso->binary_type = DSO_BINARY_TYPE__VMLINUX;
+
 	err = dso__load_sym(dso, map, &ss, &ss, 0);
 	symsrc__destroy(&ss);
 
 	if (err > 0) {
-		if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
-			dso->binary_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
-		else
-			dso->binary_type = DSO_BINARY_TYPE__VMLINUX;
-		dso__set_long_name(dso, vmlinux, vmlinux_allocated);
 		dso__set_loaded(dso);
 		pr_debug("Using %s for symbols\n", symfs_vmlinux);
 	}
-- 
2.31.1


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH] tools/perf: Fix dso kernel load and symbol process to correctly map dso to its long_name, type and adjust_symbols
  2023-08-11  5:15 [PATCH] tools/perf: Fix dso kernel load and symbol process to correctly map dso to its long_name, type and adjust_symbols Athira Rajeev
@ 2023-08-11  9:49 ` Adrian Hunter
  2023-08-11 13:46   ` Arnaldo Carvalho de Melo
  0 siblings, 1 reply; 3+ messages in thread
From: Adrian Hunter @ 2023-08-11  9:49 UTC (permalink / raw)
  To: Athira Rajeev, acme, jolsa, irogers, namhyung
  Cc: linux-perf-users, linuxppc-dev, maddy, kjain, disgoel

On 11/08/23 08:15, Athira Rajeev wrote:
> Test "object cocde 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 the 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 is:
> - dso long_name is set to [kernel.kallsyms]. This file is
>   not present and hence returns error
> - DSO binary type is set to DSO_BINARY_TYPE__NOT_FOUND
> - dso adjust_symbols 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 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 the dso__process_kernel_symbol function to set the
> binary_type and adjust_symbols. adjust_symbols is used by
> function "map__rip_2objdump" which converts symbol start
> address to objdump address. Also set the dso long_name during
> dso__load_vmlinux function.
> 
> 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>

> ---
> Note: Found similar discussion here in thread:
>       https://www.spinics.net/lists/linux-perf-users/msg06337.html
>       where Adrian proposed the fix, but looks like this was
>       not added to the perf. Hence addeed Suggested-by from Adrian.
> 
>       Additional to the fix proposed by Adrian, the patch also
>       adds setting of adjust_symbols which is needed for
>       map__rip_2objdump to convert symbol start to objdump address.
> 
>  tools/perf/util/symbol-elf.c |  2 ++
>  tools/perf/util/symbol.c     | 15 ++++++++++-----
>  2 files changed, 12 insertions(+), 5 deletions(-)
> 
> diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
> index 252d26a59e64..9e7eeaf616b8 100644
> --- a/tools/perf/util/symbol-elf.c
> +++ b/tools/perf/util/symbol-elf.c
> @@ -1440,6 +1440,8 @@ static int dso__process_kernel_symbol(struct dso *dso, struct map *map,
>  		curr_dso->kernel = dso->kernel;
>  		curr_dso->long_name = dso->long_name;
>  		curr_dso->long_name_len = dso->long_name_len;
> +		curr_dso->binary_type = dso->binary_type;
> +		curr_dso->adjust_symbols = dso->adjust_symbols;
>  		curr_map = map__new2(start, curr_dso);
>  		dso__put(curr_dso);
>  		if (curr_map == NULL)
> diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
> index f849f9ef68e6..3f36675b7c8f 100644
> --- a/tools/perf/util/symbol.c
> +++ b/tools/perf/util/symbol.c
> @@ -2204,15 +2204,20 @@ int dso__load_vmlinux(struct dso *dso, struct map *map,
>  	if (symsrc__init(&ss, dso, symfs_vmlinux, symtab_type))
>  		return -1;
>  
> +	/*
> +	 * dso__load_sym() may copy 'dso' which will result in the copies having
> +	 * an incorrect long name unless we set it here first.
> +	 */
> +	dso__set_long_name(dso, vmlinux, vmlinux_allocated);
> +	if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
> +		dso->binary_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
> +	else
> +		dso->binary_type = DSO_BINARY_TYPE__VMLINUX;
> +
>  	err = dso__load_sym(dso, map, &ss, &ss, 0);
>  	symsrc__destroy(&ss);
>  
>  	if (err > 0) {
> -		if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
> -			dso->binary_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
> -		else
> -			dso->binary_type = DSO_BINARY_TYPE__VMLINUX;
> -		dso__set_long_name(dso, vmlinux, vmlinux_allocated);
>  		dso__set_loaded(dso);
>  		pr_debug("Using %s for symbols\n", symfs_vmlinux);
>  	}


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] tools/perf: Fix dso kernel load and symbol process to correctly map dso to its long_name, type and adjust_symbols
  2023-08-11  9:49 ` Adrian Hunter
@ 2023-08-11 13:46   ` Arnaldo Carvalho de Melo
  0 siblings, 0 replies; 3+ messages in thread
From: Arnaldo Carvalho de Melo @ 2023-08-11 13:46 UTC (permalink / raw)
  To: Adrian Hunter
  Cc: Athira Rajeev, jolsa, irogers, namhyung, linux-perf-users,
	linuxppc-dev, maddy, kjain, disgoel

Em Fri, Aug 11, 2023 at 12:49:35PM +0300, Adrian Hunter escreveu:
> On 11/08/23 08:15, Athira Rajeev wrote:
> > Test "object cocde 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 the 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 is:
> > - dso long_name is set to [kernel.kallsyms]. This file is
> >   not present and hence returns error
> > - DSO binary type is set to DSO_BINARY_TYPE__NOT_FOUND
> > - dso adjust_symbols 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 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 the dso__process_kernel_symbol function to set the
> > binary_type and adjust_symbols. adjust_symbols is used by
> > function "map__rip_2objdump" which converts symbol start
> > address to objdump address. Also set the dso long_name during
> > dso__load_vmlinux function.
> > 
> > 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>

Thanks, applied.

- Arnaldo

 
> > ---
> > Note: Found similar discussion here in thread:
> >       https://www.spinics.net/lists/linux-perf-users/msg06337.html
> >       where Adrian proposed the fix, but looks like this was
> >       not added to the perf. Hence addeed Suggested-by from Adrian.
> > 
> >       Additional to the fix proposed by Adrian, the patch also
> >       adds setting of adjust_symbols which is needed for
> >       map__rip_2objdump to convert symbol start to objdump address.
> > 
> >  tools/perf/util/symbol-elf.c |  2 ++
> >  tools/perf/util/symbol.c     | 15 ++++++++++-----
> >  2 files changed, 12 insertions(+), 5 deletions(-)
> > 
> > diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
> > index 252d26a59e64..9e7eeaf616b8 100644
> > --- a/tools/perf/util/symbol-elf.c
> > +++ b/tools/perf/util/symbol-elf.c
> > @@ -1440,6 +1440,8 @@ static int dso__process_kernel_symbol(struct dso *dso, struct map *map,
> >  		curr_dso->kernel = dso->kernel;
> >  		curr_dso->long_name = dso->long_name;
> >  		curr_dso->long_name_len = dso->long_name_len;
> > +		curr_dso->binary_type = dso->binary_type;
> > +		curr_dso->adjust_symbols = dso->adjust_symbols;
> >  		curr_map = map__new2(start, curr_dso);
> >  		dso__put(curr_dso);
> >  		if (curr_map == NULL)
> > diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
> > index f849f9ef68e6..3f36675b7c8f 100644
> > --- a/tools/perf/util/symbol.c
> > +++ b/tools/perf/util/symbol.c
> > @@ -2204,15 +2204,20 @@ int dso__load_vmlinux(struct dso *dso, struct map *map,
> >  	if (symsrc__init(&ss, dso, symfs_vmlinux, symtab_type))
> >  		return -1;
> >  
> > +	/*
> > +	 * dso__load_sym() may copy 'dso' which will result in the copies having
> > +	 * an incorrect long name unless we set it here first.
> > +	 */
> > +	dso__set_long_name(dso, vmlinux, vmlinux_allocated);
> > +	if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
> > +		dso->binary_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
> > +	else
> > +		dso->binary_type = DSO_BINARY_TYPE__VMLINUX;
> > +
> >  	err = dso__load_sym(dso, map, &ss, &ss, 0);
> >  	symsrc__destroy(&ss);
> >  
> >  	if (err > 0) {
> > -		if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
> > -			dso->binary_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
> > -		else
> > -			dso->binary_type = DSO_BINARY_TYPE__VMLINUX;
> > -		dso__set_long_name(dso, vmlinux, vmlinux_allocated);
> >  		dso__set_loaded(dso);
> >  		pr_debug("Using %s for symbols\n", symfs_vmlinux);
> >  	}
> 

-- 

- Arnaldo

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2023-08-11 13:47 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2023-08-11  5:15 [PATCH] tools/perf: Fix dso kernel load and symbol process to correctly map dso to its long_name, type and adjust_symbols Athira Rajeev
2023-08-11  9:49 ` Adrian Hunter
2023-08-11 13:46   ` Arnaldo Carvalho de Melo

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