* [PATCH 1/3] perf genelf: Set ELF program header addresses properly
2023-12-12 7:05 [PATCH 0/3] perf tools: Random fixes for DWARF unwind Namhyung Kim
@ 2023-12-12 7:05 ` Namhyung Kim
2023-12-12 18:07 ` Ian Rogers
2023-12-12 7:05 ` [PATCH 2/3] perf unwind-libdw: Handle JIT-generated DSOs properly Namhyung Kim
` (3 subsequent siblings)
4 siblings, 1 reply; 12+ messages in thread
From: Namhyung Kim @ 2023-12-12 7:05 UTC (permalink / raw)
To: Arnaldo Carvalho de Melo, Jiri Olsa
Cc: Ian Rogers, Adrian Hunter, Peter Zijlstra, Ingo Molnar, LKML,
linux-perf-users, Milian Wolff, Pablo Galindo, Fangrui Song
The text section starts after the ELF headers so PHDR.p_vaddr and
others should have the correct addresses.
Fixes: babd04386b1d ("perf jit: Include program header in ELF files")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
tools/perf/util/genelf.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/tools/perf/util/genelf.c b/tools/perf/util/genelf.c
index fefc72066c4e..ac17a3cb59dc 100644
--- a/tools/perf/util/genelf.c
+++ b/tools/perf/util/genelf.c
@@ -293,9 +293,9 @@ jit_write_elf(int fd, uint64_t load_addr, const char *sym,
*/
phdr = elf_newphdr(e, 1);
phdr[0].p_type = PT_LOAD;
- phdr[0].p_offset = 0;
- phdr[0].p_vaddr = 0;
- phdr[0].p_paddr = 0;
+ phdr[0].p_offset = GEN_ELF_TEXT_OFFSET;
+ phdr[0].p_vaddr = GEN_ELF_TEXT_OFFSET;
+ phdr[0].p_paddr = GEN_ELF_TEXT_OFFSET;
phdr[0].p_filesz = csize;
phdr[0].p_memsz = csize;
phdr[0].p_flags = PF_X | PF_R;
--
2.43.0.472.g3155946c3a-goog
^ permalink raw reply related [flat|nested] 12+ messages in thread* Re: [PATCH 1/3] perf genelf: Set ELF program header addresses properly
2023-12-12 7:05 ` [PATCH 1/3] perf genelf: Set ELF program header addresses properly Namhyung Kim
@ 2023-12-12 18:07 ` Ian Rogers
0 siblings, 0 replies; 12+ messages in thread
From: Ian Rogers @ 2023-12-12 18:07 UTC (permalink / raw)
To: Namhyung Kim
Cc: Arnaldo Carvalho de Melo, Jiri Olsa, Adrian Hunter,
Peter Zijlstra, Ingo Molnar, LKML, linux-perf-users, Milian Wolff,
Pablo Galindo, Fangrui Song
On Mon, Dec 11, 2023 at 11:05 PM Namhyung Kim <namhyung@kernel.org> wrote:
>
> The text section starts after the ELF headers so PHDR.p_vaddr and
> others should have the correct addresses.
>
> Fixes: babd04386b1d ("perf jit: Include program header in ELF files")
> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Reviewed-by: Ian Rogers <irogers@google.com>
Thanks,
Ian
> ---
> tools/perf/util/genelf.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/tools/perf/util/genelf.c b/tools/perf/util/genelf.c
> index fefc72066c4e..ac17a3cb59dc 100644
> --- a/tools/perf/util/genelf.c
> +++ b/tools/perf/util/genelf.c
> @@ -293,9 +293,9 @@ jit_write_elf(int fd, uint64_t load_addr, const char *sym,
> */
> phdr = elf_newphdr(e, 1);
> phdr[0].p_type = PT_LOAD;
> - phdr[0].p_offset = 0;
> - phdr[0].p_vaddr = 0;
> - phdr[0].p_paddr = 0;
> + phdr[0].p_offset = GEN_ELF_TEXT_OFFSET;
> + phdr[0].p_vaddr = GEN_ELF_TEXT_OFFSET;
> + phdr[0].p_paddr = GEN_ELF_TEXT_OFFSET;
> phdr[0].p_filesz = csize;
> phdr[0].p_memsz = csize;
> phdr[0].p_flags = PF_X | PF_R;
> --
> 2.43.0.472.g3155946c3a-goog
>
^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH 2/3] perf unwind-libdw: Handle JIT-generated DSOs properly
2023-12-12 7:05 [PATCH 0/3] perf tools: Random fixes for DWARF unwind Namhyung Kim
2023-12-12 7:05 ` [PATCH 1/3] perf genelf: Set ELF program header addresses properly Namhyung Kim
@ 2023-12-12 7:05 ` Namhyung Kim
2023-12-12 18:07 ` Ian Rogers
2023-12-12 7:05 ` [PATCH 3/3] perf unwind-libunwind: Fix base address for .eh_frame Namhyung Kim
` (2 subsequent siblings)
4 siblings, 1 reply; 12+ messages in thread
From: Namhyung Kim @ 2023-12-12 7:05 UTC (permalink / raw)
To: Arnaldo Carvalho de Melo, Jiri Olsa
Cc: Ian Rogers, Adrian Hunter, Peter Zijlstra, Ingo Molnar, LKML,
linux-perf-users, Milian Wolff, Pablo Galindo, Fangrui Song
Usually DSOs are mapped from the beginning of the file, so the base
address of the DSO can be calculated by map->start - map->pgoff.
However, JIT DSOs which are generated by `perf inject -j`, are mapped
only the code segment. This makes unwind-libdw code confusing and
rejects processing unwinds in the JIT DSOs. It should use the map
start address as base for them to fix the confusion.
Fixes: 1fe627da3033 ("perf unwind: Take pgoff into account when reporting elf to libdwfl")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
tools/perf/util/unwind-libdw.c | 21 +++++++++++++++++----
1 file changed, 17 insertions(+), 4 deletions(-)
diff --git a/tools/perf/util/unwind-libdw.c b/tools/perf/util/unwind-libdw.c
index 8554db3fc0d7..6013335a8dae 100644
--- a/tools/perf/util/unwind-libdw.c
+++ b/tools/perf/util/unwind-libdw.c
@@ -46,6 +46,7 @@ static int __report_module(struct addr_location *al, u64 ip,
{
Dwfl_Module *mod;
struct dso *dso = NULL;
+ Dwarf_Addr base;
/*
* Some callers will use al->sym, so we can't just use the
* cheaper thread__find_map() here.
@@ -58,13 +59,25 @@ static int __report_module(struct addr_location *al, u64 ip,
if (!dso)
return 0;
+ /*
+ * The generated JIT DSO files only map the code segment without
+ * ELF headers. Since JIT codes used to be packed in a memory
+ * segment, calculating the base address using pgoff falls into
+ * a different code in another DSO. So just use the map->start
+ * directly to pick the correct one.
+ */
+ if (!strncmp(dso->long_name, "/tmp/jitted-", 12))
+ base = map__start(al->map);
+ else
+ base = map__start(al->map) - map__pgoff(al->map);
+
mod = dwfl_addrmodule(ui->dwfl, ip);
if (mod) {
Dwarf_Addr s;
dwfl_module_info(mod, NULL, &s, NULL, NULL, NULL, NULL, NULL);
- if (s != map__start(al->map) - map__pgoff(al->map))
- mod = 0;
+ if (s != base)
+ mod = NULL;
}
if (!mod) {
@@ -72,14 +85,14 @@ static int __report_module(struct addr_location *al, u64 ip,
__symbol__join_symfs(filename, sizeof(filename), dso->long_name);
mod = dwfl_report_elf(ui->dwfl, dso->short_name, filename, -1,
- map__start(al->map) - map__pgoff(al->map), false);
+ base, false);
}
if (!mod) {
char filename[PATH_MAX];
if (dso__build_id_filename(dso, filename, sizeof(filename), false))
mod = dwfl_report_elf(ui->dwfl, dso->short_name, filename, -1,
- map__start(al->map) - map__pgoff(al->map), false);
+ base, false);
}
if (mod) {
--
2.43.0.472.g3155946c3a-goog
^ permalink raw reply related [flat|nested] 12+ messages in thread* Re: [PATCH 2/3] perf unwind-libdw: Handle JIT-generated DSOs properly
2023-12-12 7:05 ` [PATCH 2/3] perf unwind-libdw: Handle JIT-generated DSOs properly Namhyung Kim
@ 2023-12-12 18:07 ` Ian Rogers
2023-12-13 22:13 ` Namhyung Kim
0 siblings, 1 reply; 12+ messages in thread
From: Ian Rogers @ 2023-12-12 18:07 UTC (permalink / raw)
To: Namhyung Kim
Cc: Arnaldo Carvalho de Melo, Jiri Olsa, Adrian Hunter,
Peter Zijlstra, Ingo Molnar, LKML, linux-perf-users, Milian Wolff,
Pablo Galindo, Fangrui Song
On Mon, Dec 11, 2023 at 11:05 PM Namhyung Kim <namhyung@kernel.org> wrote:
>
> Usually DSOs are mapped from the beginning of the file, so the base
> address of the DSO can be calculated by map->start - map->pgoff.
>
> However, JIT DSOs which are generated by `perf inject -j`, are mapped
> only the code segment. This makes unwind-libdw code confusing and
> rejects processing unwinds in the JIT DSOs. It should use the map
> start address as base for them to fix the confusion.
>
> Fixes: 1fe627da3033 ("perf unwind: Take pgoff into account when reporting elf to libdwfl")
> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> ---
> tools/perf/util/unwind-libdw.c | 21 +++++++++++++++++----
> 1 file changed, 17 insertions(+), 4 deletions(-)
>
> diff --git a/tools/perf/util/unwind-libdw.c b/tools/perf/util/unwind-libdw.c
> index 8554db3fc0d7..6013335a8dae 100644
> --- a/tools/perf/util/unwind-libdw.c
> +++ b/tools/perf/util/unwind-libdw.c
> @@ -46,6 +46,7 @@ static int __report_module(struct addr_location *al, u64 ip,
> {
> Dwfl_Module *mod;
> struct dso *dso = NULL;
> + Dwarf_Addr base;
> /*
> * Some callers will use al->sym, so we can't just use the
> * cheaper thread__find_map() here.
> @@ -58,13 +59,25 @@ static int __report_module(struct addr_location *al, u64 ip,
> if (!dso)
> return 0;
>
> + /*
> + * The generated JIT DSO files only map the code segment without
> + * ELF headers. Since JIT codes used to be packed in a memory
> + * segment, calculating the base address using pgoff falls into
> + * a different code in another DSO. So just use the map->start
> + * directly to pick the correct one.
> + */
> + if (!strncmp(dso->long_name, "/tmp/jitted-", 12))
Perhaps it would be better to test:
dso->symtab_type == DSO_BINARY_TYPE__JAVA_JIT
Thanks,
Ian
> + base = map__start(al->map);
> + else
> + base = map__start(al->map) - map__pgoff(al->map);
> +
> mod = dwfl_addrmodule(ui->dwfl, ip);
> if (mod) {
> Dwarf_Addr s;
>
> dwfl_module_info(mod, NULL, &s, NULL, NULL, NULL, NULL, NULL);
> - if (s != map__start(al->map) - map__pgoff(al->map))
> - mod = 0;
> + if (s != base)
> + mod = NULL;
> }
>
> if (!mod) {
> @@ -72,14 +85,14 @@ static int __report_module(struct addr_location *al, u64 ip,
>
> __symbol__join_symfs(filename, sizeof(filename), dso->long_name);
> mod = dwfl_report_elf(ui->dwfl, dso->short_name, filename, -1,
> - map__start(al->map) - map__pgoff(al->map), false);
> + base, false);
> }
> if (!mod) {
> char filename[PATH_MAX];
>
> if (dso__build_id_filename(dso, filename, sizeof(filename), false))
> mod = dwfl_report_elf(ui->dwfl, dso->short_name, filename, -1,
> - map__start(al->map) - map__pgoff(al->map), false);
> + base, false);
> }
>
> if (mod) {
> --
> 2.43.0.472.g3155946c3a-goog
>
^ permalink raw reply [flat|nested] 12+ messages in thread* Re: [PATCH 2/3] perf unwind-libdw: Handle JIT-generated DSOs properly
2023-12-12 18:07 ` Ian Rogers
@ 2023-12-13 22:13 ` Namhyung Kim
0 siblings, 0 replies; 12+ messages in thread
From: Namhyung Kim @ 2023-12-13 22:13 UTC (permalink / raw)
To: Ian Rogers
Cc: Arnaldo Carvalho de Melo, Jiri Olsa, Adrian Hunter,
Peter Zijlstra, Ingo Molnar, LKML, linux-perf-users, Milian Wolff,
Pablo Galindo, Fangrui Song
On Tue, Dec 12, 2023 at 10:07 AM Ian Rogers <irogers@google.com> wrote:
>
> On Mon, Dec 11, 2023 at 11:05 PM Namhyung Kim <namhyung@kernel.org> wrote:
> >
> > Usually DSOs are mapped from the beginning of the file, so the base
> > address of the DSO can be calculated by map->start - map->pgoff.
> >
> > However, JIT DSOs which are generated by `perf inject -j`, are mapped
> > only the code segment. This makes unwind-libdw code confusing and
> > rejects processing unwinds in the JIT DSOs. It should use the map
> > start address as base for them to fix the confusion.
> >
> > Fixes: 1fe627da3033 ("perf unwind: Take pgoff into account when reporting elf to libdwfl")
> > Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> > ---
> > tools/perf/util/unwind-libdw.c | 21 +++++++++++++++++----
> > 1 file changed, 17 insertions(+), 4 deletions(-)
> >
> > diff --git a/tools/perf/util/unwind-libdw.c b/tools/perf/util/unwind-libdw.c
> > index 8554db3fc0d7..6013335a8dae 100644
> > --- a/tools/perf/util/unwind-libdw.c
> > +++ b/tools/perf/util/unwind-libdw.c
> > @@ -46,6 +46,7 @@ static int __report_module(struct addr_location *al, u64 ip,
> > {
> > Dwfl_Module *mod;
> > struct dso *dso = NULL;
> > + Dwarf_Addr base;
> > /*
> > * Some callers will use al->sym, so we can't just use the
> > * cheaper thread__find_map() here.
> > @@ -58,13 +59,25 @@ static int __report_module(struct addr_location *al, u64 ip,
> > if (!dso)
> > return 0;
> >
> > + /*
> > + * The generated JIT DSO files only map the code segment without
> > + * ELF headers. Since JIT codes used to be packed in a memory
> > + * segment, calculating the base address using pgoff falls into
> > + * a different code in another DSO. So just use the map->start
> > + * directly to pick the correct one.
> > + */
> > + if (!strncmp(dso->long_name, "/tmp/jitted-", 12))
>
> Perhaps it would be better to test:
> dso->symtab_type == DSO_BINARY_TYPE__JAVA_JIT
Well.. it's a little different. The JAVA_JIT type files have
"/tmp/perf-" prefix and it's a plain text file (for symbols).
While this is an ELF file generated by `perf inject -j`.
Thanks,
Namhyung
^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH 3/3] perf unwind-libunwind: Fix base address for .eh_frame
2023-12-12 7:05 [PATCH 0/3] perf tools: Random fixes for DWARF unwind Namhyung Kim
2023-12-12 7:05 ` [PATCH 1/3] perf genelf: Set ELF program header addresses properly Namhyung Kim
2023-12-12 7:05 ` [PATCH 2/3] perf unwind-libdw: Handle JIT-generated DSOs properly Namhyung Kim
@ 2023-12-12 7:05 ` Namhyung Kim
2023-12-12 18:08 ` Ian Rogers
2023-12-12 18:10 ` [PATCH 0/3] perf tools: Random fixes for DWARF unwind Ian Rogers
2023-12-14 22:07 ` Arnaldo Carvalho de Melo
4 siblings, 1 reply; 12+ messages in thread
From: Namhyung Kim @ 2023-12-12 7:05 UTC (permalink / raw)
To: Arnaldo Carvalho de Melo, Jiri Olsa
Cc: Ian Rogers, Adrian Hunter, Peter Zijlstra, Ingo Molnar, LKML,
linux-perf-users, Milian Wolff, Pablo Galindo, Fangrui Song
The base address of a DSO mapping should start at the start of the file.
Usually DSOs are mapped from the pgoff 0 so it doesn't matter when it
uses the start of the map address. But generated DSOs for JIT codes
doesn't start from the 0 so it should subtract the offset to calculate
the .eh_frame table offsets correctly.
Fixes: dc2cf4ca866f ("perf unwind: Fix segbase for ld.lld linked objects")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
tools/perf/util/unwind-libunwind-local.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/perf/util/unwind-libunwind-local.c b/tools/perf/util/unwind-libunwind-local.c
index c0641882fd2f..5e5c3395a499 100644
--- a/tools/perf/util/unwind-libunwind-local.c
+++ b/tools/perf/util/unwind-libunwind-local.c
@@ -327,7 +327,7 @@ static int read_unwind_spec_eh_frame(struct dso *dso, struct unwind_info *ui,
maps__for_each_entry(thread__maps(ui->thread), map_node) {
struct map *map = map_node->map;
- u64 start = map__start(map);
+ u64 start = map__start(map) - map__pgoff(map);
if (map__dso(map) == dso && start < base_addr)
base_addr = start;
--
2.43.0.472.g3155946c3a-goog
^ permalink raw reply related [flat|nested] 12+ messages in thread* Re: [PATCH 3/3] perf unwind-libunwind: Fix base address for .eh_frame
2023-12-12 7:05 ` [PATCH 3/3] perf unwind-libunwind: Fix base address for .eh_frame Namhyung Kim
@ 2023-12-12 18:08 ` Ian Rogers
0 siblings, 0 replies; 12+ messages in thread
From: Ian Rogers @ 2023-12-12 18:08 UTC (permalink / raw)
To: Namhyung Kim
Cc: Arnaldo Carvalho de Melo, Jiri Olsa, Adrian Hunter,
Peter Zijlstra, Ingo Molnar, LKML, linux-perf-users, Milian Wolff,
Pablo Galindo, Fangrui Song
On Mon, Dec 11, 2023 at 11:05 PM Namhyung Kim <namhyung@kernel.org> wrote:
>
> The base address of a DSO mapping should start at the start of the file.
> Usually DSOs are mapped from the pgoff 0 so it doesn't matter when it
> uses the start of the map address. But generated DSOs for JIT codes
> doesn't start from the 0 so it should subtract the offset to calculate
> the .eh_frame table offsets correctly.
>
> Fixes: dc2cf4ca866f ("perf unwind: Fix segbase for ld.lld linked objects")
> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Reviewed-by: Ian Rogers <irogers@google.com>
Thanks,
Ian
> ---
> tools/perf/util/unwind-libunwind-local.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/tools/perf/util/unwind-libunwind-local.c b/tools/perf/util/unwind-libunwind-local.c
> index c0641882fd2f..5e5c3395a499 100644
> --- a/tools/perf/util/unwind-libunwind-local.c
> +++ b/tools/perf/util/unwind-libunwind-local.c
> @@ -327,7 +327,7 @@ static int read_unwind_spec_eh_frame(struct dso *dso, struct unwind_info *ui,
>
> maps__for_each_entry(thread__maps(ui->thread), map_node) {
> struct map *map = map_node->map;
> - u64 start = map__start(map);
> + u64 start = map__start(map) - map__pgoff(map);
>
> if (map__dso(map) == dso && start < base_addr)
> base_addr = start;
> --
> 2.43.0.472.g3155946c3a-goog
>
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH 0/3] perf tools: Random fixes for DWARF unwind
2023-12-12 7:05 [PATCH 0/3] perf tools: Random fixes for DWARF unwind Namhyung Kim
` (2 preceding siblings ...)
2023-12-12 7:05 ` [PATCH 3/3] perf unwind-libunwind: Fix base address for .eh_frame Namhyung Kim
@ 2023-12-12 18:10 ` Ian Rogers
2023-12-13 0:54 ` Pablo Galindo Salgado
2023-12-14 22:07 ` Arnaldo Carvalho de Melo
4 siblings, 1 reply; 12+ messages in thread
From: Ian Rogers @ 2023-12-12 18:10 UTC (permalink / raw)
To: Namhyung Kim
Cc: Arnaldo Carvalho de Melo, Jiri Olsa, Adrian Hunter,
Peter Zijlstra, Ingo Molnar, LKML, linux-perf-users, Milian Wolff,
Pablo Galindo, Fangrui Song
On Mon, Dec 11, 2023 at 11:05 PM Namhyung Kim <namhyung@kernel.org> wrote:
>
> Hello,
>
> I've found a couple of issues on the unwind code while I'm playing with
> the JIT-dump code for the CPython. The code assumes normal DSOs mapped
> from the beginning of the file and aligned to the page size. But it's
> not true for the JIT-dumped DSOs which are generated for each function.
We have a JIT test in:
https://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools-next.git/tree/tools/perf/tests/shell/test_java_symbol.sh?h=perf-tools-next
It'd be great if we could do similar for CPython.
Thanks,
Ian
> Depending on the JIT implementation, the code address and accompanied
> ELF info (like ELF file headers and unwind info) can be overlapped to
> adjacent (JIT-dumped) DSOs. So it should take more care when it
> calculates the mapping address for the DSO.
>
> It seems these changes need to go to the stable trees but they are
> changed a lot since then so I'm not sure.
>
> Thanks,
> Namhyung
>
>
> Namhyung Kim (3):
> perf genelf: Set ELF program header addresses properly
> perf unwind-libdw: Handle JIT-generated DSOs properly
> perf unwind-libunwind: Fix base address for .eh_frame
>
> tools/perf/util/genelf.c | 6 +++---
> tools/perf/util/unwind-libdw.c | 21 +++++++++++++++++----
> tools/perf/util/unwind-libunwind-local.c | 2 +-
> 3 files changed, 21 insertions(+), 8 deletions(-)
>
> --
> 2.43.0.472.g3155946c3a-goog
>
^ permalink raw reply [flat|nested] 12+ messages in thread* Re: [PATCH 0/3] perf tools: Random fixes for DWARF unwind
2023-12-12 18:10 ` [PATCH 0/3] perf tools: Random fixes for DWARF unwind Ian Rogers
@ 2023-12-13 0:54 ` Pablo Galindo Salgado
2023-12-13 22:07 ` Namhyung Kim
0 siblings, 1 reply; 12+ messages in thread
From: Pablo Galindo Salgado @ 2023-12-13 0:54 UTC (permalink / raw)
To: Ian Rogers
Cc: Namhyung Kim, Arnaldo Carvalho de Melo, Jiri Olsa, Adrian Hunter,
Peter Zijlstra, Ingo Molnar, LKML, linux-perf-users, Milian Wolff,
Fangrui Song
> It'd be great if we could do similar for CPython.
We (the CPython team) plan to release the perf jitdump support for
Python 3.13 (around next October) so you will need to build from
source or wait until is officially released for that test.
Pablo
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH 0/3] perf tools: Random fixes for DWARF unwind
2023-12-13 0:54 ` Pablo Galindo Salgado
@ 2023-12-13 22:07 ` Namhyung Kim
0 siblings, 0 replies; 12+ messages in thread
From: Namhyung Kim @ 2023-12-13 22:07 UTC (permalink / raw)
To: Pablo Galindo Salgado
Cc: Ian Rogers, Arnaldo Carvalho de Melo, Jiri Olsa, Adrian Hunter,
Peter Zijlstra, Ingo Molnar, LKML, linux-perf-users, Milian Wolff,
Fangrui Song
On Tue, Dec 12, 2023 at 4:54 PM Pablo Galindo Salgado
<pablogsal@gmail.com> wrote:
>
> > It'd be great if we could do similar for CPython.
>
> We (the CPython team) plan to release the perf jitdump support for
> Python 3.13 (around next October) so you will need to build from
> source or wait until is officially released for that test.
Okay, I hope we can have all the fixes asap and most distros ship
the latest version by then.
Thanks,
Namhyung
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH 0/3] perf tools: Random fixes for DWARF unwind
2023-12-12 7:05 [PATCH 0/3] perf tools: Random fixes for DWARF unwind Namhyung Kim
` (3 preceding siblings ...)
2023-12-12 18:10 ` [PATCH 0/3] perf tools: Random fixes for DWARF unwind Ian Rogers
@ 2023-12-14 22:07 ` Arnaldo Carvalho de Melo
4 siblings, 0 replies; 12+ messages in thread
From: Arnaldo Carvalho de Melo @ 2023-12-14 22:07 UTC (permalink / raw)
To: Namhyung Kim
Cc: Jiri Olsa, Ian Rogers, Adrian Hunter, Peter Zijlstra, Ingo Molnar,
LKML, linux-perf-users, Milian Wolff, Pablo Galindo, Fangrui Song
Em Mon, Dec 11, 2023 at 11:05:43PM -0800, Namhyung Kim escreveu:
> Hello,
>
> I've found a couple of issues on the unwind code while I'm playing with
> the JIT-dump code for the CPython. The code assumes normal DSOs mapped
> from the beginning of the file and aligned to the page size. But it's
> not true for the JIT-dumped DSOs which are generated for each function.
>
> Depending on the JIT implementation, the code address and accompanied
> ELF info (like ELF file headers and unwind info) can be overlapped to
> adjacent (JIT-dumped) DSOs. So it should take more care when it
> calculates the mapping address for the DSO.
>
> It seems these changes need to go to the stable trees but they are
> changed a lot since then so I'm not sure.
>
Thanks, applied to perf-tools-next.
- Arnaldo
>
> Namhyung Kim (3):
> perf genelf: Set ELF program header addresses properly
> perf unwind-libdw: Handle JIT-generated DSOs properly
> perf unwind-libunwind: Fix base address for .eh_frame
>
> tools/perf/util/genelf.c | 6 +++---
> tools/perf/util/unwind-libdw.c | 21 +++++++++++++++++----
> tools/perf/util/unwind-libunwind-local.c | 2 +-
> 3 files changed, 21 insertions(+), 8 deletions(-)
>
> --
> 2.43.0.472.g3155946c3a-goog
>
--
- Arnaldo
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