Message ID | 20200723034643.33537-2-changhuaixin@linux.alibaba.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | Build ORC fast lookup table in scripts/sorttable tool | expand |
* Huaixin Chang <changhuaixin@linux.alibaba.com> wrote: > In order to edit orc_lookup table via sorttable, type of section > orc_lookup needs to be SHT_PROGBITS instead of SHT_NOBITS. > > Linker script doesn't seem to allow manual specification of the section > type, so just write a byte into the section instead. > > Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> > Signed-off-by: Huaixin Chang <changhuaixin@linux.alibaba.com> > Signed-off-by: Shile Zhang <shile.zhang@linux.alibaba.com> > --- > include/asm-generic/vmlinux.lds.h | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h > index db600ef218d7..49f4f5bc6165 100644 > --- a/include/asm-generic/vmlinux.lds.h > +++ b/include/asm-generic/vmlinux.lds.h > @@ -826,6 +826,8 @@ > . += (((SIZEOF(.text) + LOOKUP_BLOCK_SIZE - 1) / \ > LOOKUP_BLOCK_SIZE) + 1) * 4; \ > orc_lookup_end = .; \ > + /* HACK: force SHT_PROGBITS so sorttable can edit: */ \ > + BYTE(1); \ Cc:-ing Masahiro Yamada, maybe there's a cleaner solution to this? Thanks, Ingo
Hi, Ingo Another way to write SHT_PROGBITS is using elf_create_section to write orc_lookup table headers, when orc_unwind_ip table and orc_unwind table are written. Is this a better solution? diff --git a/tools/objtool/orc_gen.c b/tools/objtool/orc_gen.c index 3f98dcfbc177..860d4dcec8e6 100644 --- a/tools/objtool/orc_gen.c +++ b/tools/objtool/orc_gen.c @@ -183,6 +183,10 @@ int create_orc_sections(struct objtool_file *file) u_sec = elf_create_section(file->elf, ".orc_unwind", sizeof(struct orc_entry), idx); + /* make flags of section orc_lookup right */ + if (!elf_create_section(file->elf, ".orc_lookup", sizeof(int), 0)) + return -1; + /* populate sections */ idx = 0; for_each_sec(file, sec) { Thanks, Huaixin > On Jul 23, 2020, at 11:46 AM, Huaixin Chang <changhuaixin@linux.alibaba.com> wrote: > > In order to edit orc_lookup table via sorttable, type of section > orc_lookup needs to be SHT_PROGBITS instead of SHT_NOBITS. > > Linker script doesn't seem to allow manual specification of the section > type, so just write a byte into the section instead. > > Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> > Signed-off-by: Huaixin Chang <changhuaixin@linux.alibaba.com> > Signed-off-by: Shile Zhang <shile.zhang@linux.alibaba.com> > --- > include/asm-generic/vmlinux.lds.h | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h > index db600ef218d7..49f4f5bc6165 100644 > --- a/include/asm-generic/vmlinux.lds.h > +++ b/include/asm-generic/vmlinux.lds.h > @@ -826,6 +826,8 @@ > . += (((SIZEOF(.text) + LOOKUP_BLOCK_SIZE - 1) / \ > LOOKUP_BLOCK_SIZE) + 1) * 4; \ > orc_lookup_end = .; \ > + /* HACK: force SHT_PROGBITS so sorttable can edit: */ \ > + BYTE(1); \ > } > #else > #define ORC_UNWIND_TABLE > -- > 2.14.4.44.g2045bb6
* changhuaixin <changhuaixin@linux.alibaba.com> wrote: > Hi, Ingo > > Another way to write SHT_PROGBITS is using elf_create_section to write orc_lookup table headers, when orc_unwind_ip table and orc_unwind table are written. Is this a better solution? > > diff --git a/tools/objtool/orc_gen.c b/tools/objtool/orc_gen.c > index 3f98dcfbc177..860d4dcec8e6 100644 > --- a/tools/objtool/orc_gen.c > +++ b/tools/objtool/orc_gen.c > @@ -183,6 +183,10 @@ int create_orc_sections(struct objtool_file *file) > u_sec = elf_create_section(file->elf, ".orc_unwind", > sizeof(struct orc_entry), idx); > > + /* make flags of section orc_lookup right */ > + if (!elf_create_section(file->elf, ".orc_lookup", sizeof(int), 0)) > + return -1; > + > /* populate sections */ > idx = 0; > for_each_sec(file, sec) { Looks much nicer IMO. Mind turning this into a proper patch that does it plus reverts the hack? Thanks, Ingo
> On Aug 6, 2020, at 11:08 PM, Ingo Molnar <mingo@kernel.org> wrote: > > > * changhuaixin <changhuaixin@linux.alibaba.com> wrote: > >> Hi, Ingo >> >> Another way to write SHT_PROGBITS is using elf_create_section to write orc_lookup table headers, when orc_unwind_ip table and orc_unwind table are written. Is this a better solution? >> >> diff --git a/tools/objtool/orc_gen.c b/tools/objtool/orc_gen.c >> index 3f98dcfbc177..860d4dcec8e6 100644 >> --- a/tools/objtool/orc_gen.c >> +++ b/tools/objtool/orc_gen.c >> @@ -183,6 +183,10 @@ int create_orc_sections(struct objtool_file *file) >> u_sec = elf_create_section(file->elf, ".orc_unwind", >> sizeof(struct orc_entry), idx); >> >> + /* make flags of section orc_lookup right */ >> + if (!elf_create_section(file->elf, ".orc_lookup", sizeof(int), 0)) >> + return -1; >> + >> /* populate sections */ >> idx = 0; >> for_each_sec(file, sec) { > > Looks much nicer IMO. > > Mind turning this into a proper patch that does it plus reverts the > hack? > A new patchset is sent. Thanks, huaixin > Thanks, > > Ingo
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index db600ef218d7..49f4f5bc6165 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -826,6 +826,8 @@ . += (((SIZEOF(.text) + LOOKUP_BLOCK_SIZE - 1) / \ LOOKUP_BLOCK_SIZE) + 1) * 4; \ orc_lookup_end = .; \ + /* HACK: force SHT_PROGBITS so sorttable can edit: */ \ + BYTE(1); \ } #else #define ORC_UNWIND_TABLE