2022-10-02 11:09:19

by Sathvika Vasireddy

[permalink] [raw]
Subject: [PATCH v4 11/16] objtool: Add --mnop as an option to --mcount

Some architectures (powerpc) may not support ftrace locations being nop'ed
out at build time. Introduce CONFIG_HAVE_OBJTOOL_NOP_MCOUNT for objtool, as
a means for architectures to enable nop'ing of ftrace locations. Add --mnop
as an option to objtool --mcount, to indicate support for the same.

Also, make sure that --mnop can be passed as an option to objtool only when
--mcount is passed.

Signed-off-by: Sathvika Vasireddy <[email protected]>
---
Makefile | 4 +++-
arch/x86/Kconfig | 1 +
kernel/trace/Kconfig | 7 +++++++
scripts/Makefile.lib | 1 +
tools/objtool/builtin-check.c | 14 ++++++++++++++
tools/objtool/check.c | 19 ++++++++++---------
tools/objtool/include/objtool/builtin.h | 1 +
7 files changed, 37 insertions(+), 10 deletions(-)

diff --git a/Makefile b/Makefile
index a5e9d9388649..b2230ad14748 100644
--- a/Makefile
+++ b/Makefile
@@ -857,7 +857,9 @@ ifdef CONFIG_FTRACE_MCOUNT_USE_CC
endif
endif
ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
- CC_FLAGS_USING += -DCC_USING_NOP_MCOUNT
+ ifdef CONFIG_HAVE_OBJTOOL_NOP_MCOUNT
+ CC_FLAGS_USING += -DCC_USING_NOP_MCOUNT
+ endif
endif
ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
ifdef CONFIG_HAVE_C_RECORDMCOUNT
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index f9920f1341c8..2a79a05c4402 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -189,6 +189,7 @@ config X86
select HAVE_CONTEXT_TRACKING_USER_OFFSTACK if HAVE_CONTEXT_TRACKING_USER
select HAVE_C_RECORDMCOUNT
select HAVE_OBJTOOL_MCOUNT if HAVE_OBJTOOL
+ select HAVE_OBJTOOL_NOP_MCOUNT if HAVE_OBJTOOL_MCOUNT
select HAVE_BUILDTIME_MCOUNT_SORT
select HAVE_DEBUG_KMEMLEAK
select HAVE_DMA_CONTIGUOUS
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 1052126bdca2..9c696cb24756 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -76,6 +76,13 @@ config HAVE_OBJTOOL_MCOUNT
help
Arch supports objtool --mcount

+config HAVE_OBJTOOL_NOP_MCOUNT
+ bool
+ help
+ Arch supports the objtool options --mcount with --mnop.
+ An architecture can select this if it wants to enable nop'ing
+ of ftrace locations.
+
config HAVE_C_RECORDMCOUNT
bool
help
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 3fb6a99e78c4..ce14e3b8577f 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -234,6 +234,7 @@ objtool_args = \
$(if $(CONFIG_HAVE_NOINSTR_HACK), --hacks=noinstr) \
$(if $(CONFIG_X86_KERNEL_IBT), --ibt) \
$(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount) \
+ $(if $(CONFIG_HAVE_OBJTOOL_NOP_MCOUNT), --mnop) \
$(if $(CONFIG_UNWINDER_ORC), --orc) \
$(if $(CONFIG_RETPOLINE), --retpoline) \
$(if $(CONFIG_RETHUNK), --rethunk) \
diff --git a/tools/objtool/builtin-check.c b/tools/objtool/builtin-check.c
index 24fbe803a0d3..9bd347d3c244 100644
--- a/tools/objtool/builtin-check.c
+++ b/tools/objtool/builtin-check.c
@@ -82,6 +82,7 @@ const struct option check_options[] = {
OPT_BOOLEAN(0, "dry-run", &opts.dryrun, "don't write modifications"),
OPT_BOOLEAN(0, "link", &opts.link, "object is a linked object"),
OPT_BOOLEAN(0, "module", &opts.module, "object is part of a kernel module"),
+ OPT_BOOLEAN(0, "mnop", &opts.mnop, "nop out mcount call sites"),
OPT_BOOLEAN(0, "no-unreachable", &opts.no_unreachable, "skip 'unreachable instruction' warnings"),
OPT_BOOLEAN(0, "sec-address", &opts.sec_address, "print section addresses in warnings"),
OPT_BOOLEAN(0, "stats", &opts.stats, "print statistics"),
@@ -150,6 +151,16 @@ static bool opts_valid(void)
return false;
}

+static bool mnop_opts_valid(void)
+{
+ if (opts.mnop && !opts.mcount) {
+ ERROR("--mnop requires --mcount");
+ return false;
+ }
+
+ return true;
+}
+
static bool link_opts_valid(struct objtool_file *file)
{
if (opts.link)
@@ -198,6 +209,9 @@ int objtool_run(int argc, const char **argv)
if (!file)
return 1;

+ if (!mnop_opts_valid())
+ return 1;
+
if (!link_opts_valid(file))
return 1;

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 738de23cb9e8..35827e6c6df9 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -1233,17 +1233,18 @@ static void annotate_call_site(struct objtool_file *file,
if (opts.mcount && sym->fentry) {
if (sibling)
WARN_FUNC("Tail call to __fentry__ !?!?", insn->sec, insn->offset);
+ if (opts.mnop) {
+ if (reloc) {
+ reloc->type = R_NONE;
+ elf_write_reloc(file->elf, reloc);
+ }

- if (reloc) {
- reloc->type = R_NONE;
- elf_write_reloc(file->elf, reloc);
- }
-
- elf_write_insn(file->elf, insn->sec,
- insn->offset, insn->len,
- arch_nop_insn(insn->len));
+ elf_write_insn(file->elf, insn->sec,
+ insn->offset, insn->len,
+ arch_nop_insn(insn->len));

- insn->type = INSN_NOP;
+ insn->type = INSN_NOP;
+ }

list_add_tail(&insn->call_node, &file->mcount_loc_list);
return;
diff --git a/tools/objtool/include/objtool/builtin.h b/tools/objtool/include/objtool/builtin.h
index 42a52f1a0add..0785707c5a92 100644
--- a/tools/objtool/include/objtool/builtin.h
+++ b/tools/objtool/include/objtool/builtin.h
@@ -31,6 +31,7 @@ struct opts {
bool backup;
bool dryrun;
bool link;
+ bool mnop;
bool module;
bool no_unreachable;
bool sec_address;
--
2.31.1


2022-10-02 17:48:34

by Christophe Leroy

[permalink] [raw]
Subject: Re: [PATCH v4 11/16] objtool: Add --mnop as an option to --mcount



Le 02/10/2022 à 12:42, Sathvika Vasireddy a écrit :
> Some architectures (powerpc) may not support ftrace locations being nop'ed
> out at build time. Introduce CONFIG_HAVE_OBJTOOL_NOP_MCOUNT for objtool, as
> a means for architectures to enable nop'ing of ftrace locations. Add --mnop
> as an option to objtool --mcount, to indicate support for the same.
>
> Also, make sure that --mnop can be passed as an option to objtool only when
> --mcount is passed.
>
> Signed-off-by: Sathvika Vasireddy <[email protected]>

Reviewed-by: Christophe Leroy <[email protected]>

> ---
> Makefile | 4 +++-
> arch/x86/Kconfig | 1 +
> kernel/trace/Kconfig | 7 +++++++
> scripts/Makefile.lib | 1 +
> tools/objtool/builtin-check.c | 14 ++++++++++++++
> tools/objtool/check.c | 19 ++++++++++---------
> tools/objtool/include/objtool/builtin.h | 1 +
> 7 files changed, 37 insertions(+), 10 deletions(-)
>
> diff --git a/Makefile b/Makefile
> index a5e9d9388649..b2230ad14748 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -857,7 +857,9 @@ ifdef CONFIG_FTRACE_MCOUNT_USE_CC
> endif
> endif
> ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
> - CC_FLAGS_USING += -DCC_USING_NOP_MCOUNT
> + ifdef CONFIG_HAVE_OBJTOOL_NOP_MCOUNT
> + CC_FLAGS_USING += -DCC_USING_NOP_MCOUNT
> + endif
> endif
> ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
> ifdef CONFIG_HAVE_C_RECORDMCOUNT
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index f9920f1341c8..2a79a05c4402 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -189,6 +189,7 @@ config X86
> select HAVE_CONTEXT_TRACKING_USER_OFFSTACK if HAVE_CONTEXT_TRACKING_USER
> select HAVE_C_RECORDMCOUNT
> select HAVE_OBJTOOL_MCOUNT if HAVE_OBJTOOL
> + select HAVE_OBJTOOL_NOP_MCOUNT if HAVE_OBJTOOL_MCOUNT
> select HAVE_BUILDTIME_MCOUNT_SORT
> select HAVE_DEBUG_KMEMLEAK
> select HAVE_DMA_CONTIGUOUS
> diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
> index 1052126bdca2..9c696cb24756 100644
> --- a/kernel/trace/Kconfig
> +++ b/kernel/trace/Kconfig
> @@ -76,6 +76,13 @@ config HAVE_OBJTOOL_MCOUNT
> help
> Arch supports objtool --mcount
>
> +config HAVE_OBJTOOL_NOP_MCOUNT
> + bool
> + help
> + Arch supports the objtool options --mcount with --mnop.
> + An architecture can select this if it wants to enable nop'ing
> + of ftrace locations.
> +
> config HAVE_C_RECORDMCOUNT
> bool
> help
> diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
> index 3fb6a99e78c4..ce14e3b8577f 100644
> --- a/scripts/Makefile.lib
> +++ b/scripts/Makefile.lib
> @@ -234,6 +234,7 @@ objtool_args = \
> $(if $(CONFIG_HAVE_NOINSTR_HACK), --hacks=noinstr) \
> $(if $(CONFIG_X86_KERNEL_IBT), --ibt) \
> $(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount) \
> + $(if $(CONFIG_HAVE_OBJTOOL_NOP_MCOUNT), --mnop) \
> $(if $(CONFIG_UNWINDER_ORC), --orc) \
> $(if $(CONFIG_RETPOLINE), --retpoline) \
> $(if $(CONFIG_RETHUNK), --rethunk) \
> diff --git a/tools/objtool/builtin-check.c b/tools/objtool/builtin-check.c
> index 24fbe803a0d3..9bd347d3c244 100644
> --- a/tools/objtool/builtin-check.c
> +++ b/tools/objtool/builtin-check.c
> @@ -82,6 +82,7 @@ const struct option check_options[] = {
> OPT_BOOLEAN(0, "dry-run", &opts.dryrun, "don't write modifications"),
> OPT_BOOLEAN(0, "link", &opts.link, "object is a linked object"),
> OPT_BOOLEAN(0, "module", &opts.module, "object is part of a kernel module"),
> + OPT_BOOLEAN(0, "mnop", &opts.mnop, "nop out mcount call sites"),
> OPT_BOOLEAN(0, "no-unreachable", &opts.no_unreachable, "skip 'unreachable instruction' warnings"),
> OPT_BOOLEAN(0, "sec-address", &opts.sec_address, "print section addresses in warnings"),
> OPT_BOOLEAN(0, "stats", &opts.stats, "print statistics"),
> @@ -150,6 +151,16 @@ static bool opts_valid(void)
> return false;
> }
>
> +static bool mnop_opts_valid(void)
> +{
> + if (opts.mnop && !opts.mcount) {
> + ERROR("--mnop requires --mcount");
> + return false;
> + }
> +
> + return true;
> +}
> +
> static bool link_opts_valid(struct objtool_file *file)
> {
> if (opts.link)
> @@ -198,6 +209,9 @@ int objtool_run(int argc, const char **argv)
> if (!file)
> return 1;
>
> + if (!mnop_opts_valid())
> + return 1;
> +
> if (!link_opts_valid(file))
> return 1;
>
> diff --git a/tools/objtool/check.c b/tools/objtool/check.c
> index 738de23cb9e8..35827e6c6df9 100644
> --- a/tools/objtool/check.c
> +++ b/tools/objtool/check.c
> @@ -1233,17 +1233,18 @@ static void annotate_call_site(struct objtool_file *file,
> if (opts.mcount && sym->fentry) {
> if (sibling)
> WARN_FUNC("Tail call to __fentry__ !?!?", insn->sec, insn->offset);
> + if (opts.mnop) {
> + if (reloc) {
> + reloc->type = R_NONE;
> + elf_write_reloc(file->elf, reloc);
> + }
>
> - if (reloc) {
> - reloc->type = R_NONE;
> - elf_write_reloc(file->elf, reloc);
> - }
> -
> - elf_write_insn(file->elf, insn->sec,
> - insn->offset, insn->len,
> - arch_nop_insn(insn->len));
> + elf_write_insn(file->elf, insn->sec,
> + insn->offset, insn->len,
> + arch_nop_insn(insn->len));
>
> - insn->type = INSN_NOP;
> + insn->type = INSN_NOP;
> + }
>
> list_add_tail(&insn->call_node, &file->mcount_loc_list);
> return;
> diff --git a/tools/objtool/include/objtool/builtin.h b/tools/objtool/include/objtool/builtin.h
> index 42a52f1a0add..0785707c5a92 100644
> --- a/tools/objtool/include/objtool/builtin.h
> +++ b/tools/objtool/include/objtool/builtin.h
> @@ -31,6 +31,7 @@ struct opts {
> bool backup;
> bool dryrun;
> bool link;
> + bool mnop;
> bool module;
> bool no_unreachable;
> bool sec_address;

2022-10-10 12:19:43

by Naveen N. Rao

[permalink] [raw]
Subject: Re: [PATCH v4 11/16] objtool: Add --mnop as an option to --mcount

Sathvika Vasireddy wrote:
> Some architectures (powerpc) may not support ftrace locations being nop'ed
> out at build time. Introduce CONFIG_HAVE_OBJTOOL_NOP_MCOUNT for objtool, as
> a means for architectures to enable nop'ing of ftrace locations. Add --mnop
> as an option to objtool --mcount, to indicate support for the same.
>
> Also, make sure that --mnop can be passed as an option to objtool only when
> --mcount is passed.
>
> Signed-off-by: Sathvika Vasireddy <[email protected]>
> ---
> Makefile | 4 +++-
> arch/x86/Kconfig | 1 +
> kernel/trace/Kconfig | 7 +++++++
> scripts/Makefile.lib | 1 +
> tools/objtool/builtin-check.c | 14 ++++++++++++++
> tools/objtool/check.c | 19 ++++++++++---------
> tools/objtool/include/objtool/builtin.h | 1 +
> 7 files changed, 37 insertions(+), 10 deletions(-)
>
> diff --git a/Makefile b/Makefile
> index a5e9d9388649..b2230ad14748 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -857,7 +857,9 @@ ifdef CONFIG_FTRACE_MCOUNT_USE_CC
> endif
> endif
> ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
> - CC_FLAGS_USING += -DCC_USING_NOP_MCOUNT
> + ifdef CONFIG_HAVE_OBJTOOL_NOP_MCOUNT
> + CC_FLAGS_USING += -DCC_USING_NOP_MCOUNT
> + endif
> endif
> ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
> ifdef CONFIG_HAVE_C_RECORDMCOUNT
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index f9920f1341c8..2a79a05c4402 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -189,6 +189,7 @@ config X86
> select HAVE_CONTEXT_TRACKING_USER_OFFSTACK if HAVE_CONTEXT_TRACKING_USER
> select HAVE_C_RECORDMCOUNT
> select HAVE_OBJTOOL_MCOUNT if HAVE_OBJTOOL
> + select HAVE_OBJTOOL_NOP_MCOUNT if HAVE_OBJTOOL_MCOUNT
> select HAVE_BUILDTIME_MCOUNT_SORT
> select HAVE_DEBUG_KMEMLEAK
> select HAVE_DMA_CONTIGUOUS
> diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
> index 1052126bdca2..9c696cb24756 100644
> --- a/kernel/trace/Kconfig
> +++ b/kernel/trace/Kconfig
> @@ -76,6 +76,13 @@ config HAVE_OBJTOOL_MCOUNT
> help
> Arch supports objtool --mcount
>
> +config HAVE_OBJTOOL_NOP_MCOUNT
> + bool
> + help
> + Arch supports the objtool options --mcount with --mnop.
> + An architecture can select this if it wants to enable nop'ing
> + of ftrace locations.
> +
> config HAVE_C_RECORDMCOUNT
> bool
> help
> diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
> index 3fb6a99e78c4..ce14e3b8577f 100644
> --- a/scripts/Makefile.lib
> +++ b/scripts/Makefile.lib
> @@ -234,6 +234,7 @@ objtool_args = \
> $(if $(CONFIG_HAVE_NOINSTR_HACK), --hacks=noinstr) \
> $(if $(CONFIG_X86_KERNEL_IBT), --ibt) \
> $(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount) \
> + $(if $(CONFIG_HAVE_OBJTOOL_NOP_MCOUNT), --mnop) \

This still won't help: for instance, if CONFIG_FTRACE itself is
disabled. I think we should make this depend on
CONFIG_FTRACE_MCOUNT_USE_OBJTOOL. The below change works for me:

diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 54d2d6451bdacc..fd3f55a1fdb7bb 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -245,8 +245,8 @@ objtool_args = \
$(if $(CONFIG_HAVE_JUMP_LABEL_HACK), --hacks=jump_label) \
$(if $(CONFIG_HAVE_NOINSTR_HACK), --hacks=noinstr) \
$(if $(CONFIG_X86_KERNEL_IBT), --ibt) \
- $(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount) \
- $(if $(CONFIG_HAVE_OBJTOOL_NOP_MCOUNT), --mnop) \
+ $(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), \
+ $(if $(CONFIG_HAVE_OBJTOOL_NOP_MCOUNT), --mcount --mnop, --mcount)) \
$(if $(CONFIG_UNWINDER_ORC), --orc) \
$(if $(CONFIG_RETPOLINE), --retpoline) \
$(if $(CONFIG_RETHUNK), --rethunk) \


- Naveen

2022-10-11 20:51:32

by Josh Poimboeuf

[permalink] [raw]
Subject: Re: [PATCH v4 11/16] objtool: Add --mnop as an option to --mcount

On Mon, Oct 10, 2022 at 05:07:46PM +0530, Naveen N. Rao wrote:
> > +++ b/scripts/Makefile.lib
> > @@ -234,6 +234,7 @@ objtool_args = \
> > $(if $(CONFIG_HAVE_NOINSTR_HACK), --hacks=noinstr) \
> > $(if $(CONFIG_X86_KERNEL_IBT), --ibt) \
> > $(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount) \
> > + $(if $(CONFIG_HAVE_OBJTOOL_NOP_MCOUNT), --mnop) \
>
> This still won't help: for instance, if CONFIG_FTRACE itself is disabled. I
> think we should make this depend on CONFIG_FTRACE_MCOUNT_USE_OBJTOOL. The
> below change works for me:
>
> diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
> index 54d2d6451bdacc..fd3f55a1fdb7bb 100644
> --- a/scripts/Makefile.lib
> +++ b/scripts/Makefile.lib
> @@ -245,8 +245,8 @@ objtool_args = \
> $(if $(CONFIG_HAVE_JUMP_LABEL_HACK), --hacks=jump_label) \
> $(if $(CONFIG_HAVE_NOINSTR_HACK), --hacks=noinstr) \
> $(if $(CONFIG_X86_KERNEL_IBT), --ibt) \
> - $(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount) \
> - $(if $(CONFIG_HAVE_OBJTOOL_NOP_MCOUNT), --mnop) \
> + $(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), \
> + $(if $(CONFIG_HAVE_OBJTOOL_NOP_MCOUNT), --mcount --mnop, --mcount)) \
> $(if $(CONFIG_UNWINDER_ORC), --orc) \
> $(if $(CONFIG_RETPOLINE), --retpoline) \
> $(if $(CONFIG_RETHUNK), --rethunk) \

This has a new conflict, may need something like:

--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -256,6 +256,9 @@ objtool-args-$(CONFIG_HAVE_JUMP_LABEL_HACK) += --hacks=jump_label
objtool-args-$(CONFIG_HAVE_NOINSTR_HACK) += --hacks=noinstr
objtool-args-$(CONFIG_X86_KERNEL_IBT) += --ibt
objtool-args-$(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL) += --mcount
+ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
+objtool-args-$(CONFIG_HAVE_OBJTOOL_NOP_MCOUNT) += --mnop
+endif
objtool-args-$(CONFIG_UNWINDER_ORC) += --orc
objtool-args-$(CONFIG_RETPOLINE) += --retpoline
objtool-args-$(CONFIG_RETHUNK) += --rethunk

2022-10-12 14:03:44

by Naveen N. Rao

[permalink] [raw]
Subject: Re: [PATCH v4 11/16] objtool: Add --mnop as an option to --mcount

Josh Poimboeuf wrote:
> On Mon, Oct 10, 2022 at 05:07:46PM +0530, Naveen N. Rao wrote:
>> > +++ b/scripts/Makefile.lib
>> > @@ -234,6 +234,7 @@ objtool_args = \
>> > $(if $(CONFIG_HAVE_NOINSTR_HACK), --hacks=noinstr) \
>> > $(if $(CONFIG_X86_KERNEL_IBT), --ibt) \
>> > $(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount) \
>> > + $(if $(CONFIG_HAVE_OBJTOOL_NOP_MCOUNT), --mnop) \
>>
>> This still won't help: for instance, if CONFIG_FTRACE itself is disabled. I
>> think we should make this depend on CONFIG_FTRACE_MCOUNT_USE_OBJTOOL. The
>> below change works for me:
>>
>> diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
>> index 54d2d6451bdacc..fd3f55a1fdb7bb 100644
>> --- a/scripts/Makefile.lib
>> +++ b/scripts/Makefile.lib
>> @@ -245,8 +245,8 @@ objtool_args = \
>> $(if $(CONFIG_HAVE_JUMP_LABEL_HACK), --hacks=jump_label) \
>> $(if $(CONFIG_HAVE_NOINSTR_HACK), --hacks=noinstr) \
>> $(if $(CONFIG_X86_KERNEL_IBT), --ibt) \
>> - $(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount) \
>> - $(if $(CONFIG_HAVE_OBJTOOL_NOP_MCOUNT), --mnop) \
>> + $(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), \
>> + $(if $(CONFIG_HAVE_OBJTOOL_NOP_MCOUNT), --mcount --mnop, --mcount)) \
>> $(if $(CONFIG_UNWINDER_ORC), --orc) \
>> $(if $(CONFIG_RETPOLINE), --retpoline) \
>> $(if $(CONFIG_RETHUNK), --rethunk) \
>
> This has a new conflict, may need something like:
>
> --- a/scripts/Makefile.lib
> +++ b/scripts/Makefile.lib
> @@ -256,6 +256,9 @@ objtool-args-$(CONFIG_HAVE_JUMP_LABEL_HACK) += --hacks=jump_label
> objtool-args-$(CONFIG_HAVE_NOINSTR_HACK) += --hacks=noinstr
> objtool-args-$(CONFIG_X86_KERNEL_IBT) += --ibt
> objtool-args-$(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL) += --mcount
> +ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
> +objtool-args-$(CONFIG_HAVE_OBJTOOL_NOP_MCOUNT) += --mnop
> +endif
> objtool-args-$(CONFIG_UNWINDER_ORC) += --orc
> objtool-args-$(CONFIG_RETPOLINE) += --retpoline
> objtool-args-$(CONFIG_RETHUNK) += --rethunk

Thanks. That's definitely simpler.

I haven't checked if there are any other conflicts with
tip/objtool/core though. Not sure how to proceed here.


- Naveen