Re: [RFC PATCH 4/4] objtool/powerpc: Add --mcount specific implementation
Christophe Leroy wrote:
Le 16/06/2022 à 15:57, Peter Zijlstra a écrit :
On Thu, Jun 16, 2022 at 01:40:34PM +, Christophe Leroy wrote:
sizeof(u64) is always 8 by definition.
So if size is 8 we are working on a binary file for a 64 bits target, if
not it means we are working for a 32 bits target.
Cross-builds invalidate this I think. Best to look at something like:
elf->ehdr.e_ident[EI_CLASS] == ELFCLASS32
Yes that's what it does indirectly:
int size = elf_class_size(elf);
With
static inline int elf_class_size(struct elf *elf)
{
if (elf->ehdr.e_ident[EI_CLASS] == ELFCLASS32)
return sizeof(u32);
else
return sizeof(u64);
}
Ok, those come from the below patch:
https://lore.kernel.org/all/c4b06b5b314183d85615765a5ce421a057674bd8.1653398233.git.christophe.le...@csgroup.eu/T/#u
I guess it would have been clearer if 'size' was named differently:
'addr_size' perhaps?
- Naveen
Re: [RFC PATCH 4/4] objtool/powerpc: Add --mcount specific implementation
Le 16/06/2022 à 15:57, Peter Zijlstra a écrit :
> On Thu, Jun 16, 2022 at 01:40:34PM +, Christophe Leroy wrote:
>> sizeof(u64) is always 8 by definition.
>>
>> So if size is 8 we are working on a binary file for a 64 bits target, if
>> not it means we are working for a 32 bits target.
>
> Cross-builds invalidate this I think. Best to look at something like:
>
>elf->ehdr.e_ident[EI_CLASS] == ELFCLASS32
>
>
Yes that's what it does indirectly:
int size = elf_class_size(elf);
With
static inline int elf_class_size(struct elf *elf)
{
if (elf->ehdr.e_ident[EI_CLASS] == ELFCLASS32)
return sizeof(u32);
else
return sizeof(u64);
}
Re: [RFC PATCH 4/4] objtool/powerpc: Add --mcount specific implementation
On Thu, Jun 16, 2022 at 01:40:34PM +, Christophe Leroy wrote: > sizeof(u64) is always 8 by definition. > > So if size is 8 we are working on a binary file for a 64 bits target, if > not it means we are working for a 32 bits target. Cross-builds invalidate this I think. Best to look at something like: elf->ehdr.e_ident[EI_CLASS] == ELFCLASS32
Re: [RFC PATCH 4/4] objtool/powerpc: Add --mcount specific implementation
Le 16/06/2022 à 15:34, Naveen N. Rao a écrit :
> Christophe Leroy wrote:
>>
>>
>> Le 25/05/2022 à 19:27, Christophe Leroy a écrit :
>>>
>>>
>>> Le 24/05/2022 à 15:33, Christophe Leroy a écrit :
Le 24/05/2022 à 13:00, Sathvika Vasireddy a écrit :
>>
>>> +{
>>> + switch (elf->ehdr.e_machine) {
>>> + case EM_X86_64:
>>> + return R_X86_64_64;
>>> + case EM_PPC64:
>>> + return R_PPC64_ADDR64;
>>> + default:
>>> + WARN("unknown machine...");
>>> + exit(-1);
>>> + }
>>> +}
>> Wouldn't it be better to make that function arch specific ?
>
> This is so that we can support cross architecture builds.
>
I'm not sure I follow you here.
This is only based on the target, it doesn't depend on the build
host so
I can't the link with cross arch builds.
The same as you have arch_decode_instruction(), you could have
arch_elf_reloc_type_long()
It would make sense indeed, because there is no point in supporting X86
relocation when you don't support X86 instruction decoding.
>>>
>>> Could simply be some macro defined in
>>> tools/objtool/arch/powerpc/include/arch/elf.h and
>>> tools/objtool/arch/x86/include/arch/elf.h
>>>
>>> The x86 version would be:
>>>
>>> #define R_ADDR(elf) R_X86_64_64
>>>
>>> And the powerpc version would be:
>>>
>>> #define R_ADDR(elf) (elf->ehdr.e_machine == EM_PPC64 ? R_PPC64_ADDR64
>>> : R_PPC_ADDR32)
>>>
>>
>> Well, looking once more, and taking into account the patch from Chen
>> https://lore.kernel.org/lkml/20220531020744.236970-4-chenzhong...@huawei.com/
>>
>>
>>
>> It would be easier to just define two macros:
>>
>> #define R_ABS64 R_PPC64_ADDR64
>> #define R_ABS32 R_PPC_ADDR32
>>
>> And then in the caller, as we know the size, do something like
>>
>> size == sizeof(u64) ? R_ABS64 : R_ABS32;
>
> How does 'sizeof(u64)' work here?
>
sizeof(u64) is always 8 by definition.
So if size is 8 we are working on a binary file for a 64 bits target, if
not it means we are working for a 32 bits target.
Christophe
Re: [RFC PATCH 4/4] objtool/powerpc: Add --mcount specific implementation
Christophe Leroy wrote:
Le 25/05/2022 à 19:27, Christophe Leroy a écrit :
Le 24/05/2022 à 15:33, Christophe Leroy a écrit :
Le 24/05/2022 à 13:00, Sathvika Vasireddy a écrit :
+{
+ switch (elf->ehdr.e_machine) {
+ case EM_X86_64:
+ return R_X86_64_64;
+ case EM_PPC64:
+ return R_PPC64_ADDR64;
+ default:
+ WARN("unknown machine...");
+ exit(-1);
+ }
+}
Wouldn't it be better to make that function arch specific ?
This is so that we can support cross architecture builds.
I'm not sure I follow you here.
This is only based on the target, it doesn't depend on the build host so
I can't the link with cross arch builds.
The same as you have arch_decode_instruction(), you could have
arch_elf_reloc_type_long()
It would make sense indeed, because there is no point in supporting X86
relocation when you don't support X86 instruction decoding.
Could simply be some macro defined in
tools/objtool/arch/powerpc/include/arch/elf.h and
tools/objtool/arch/x86/include/arch/elf.h
The x86 version would be:
#define R_ADDR(elf) R_X86_64_64
And the powerpc version would be:
#define R_ADDR(elf) (elf->ehdr.e_machine == EM_PPC64 ? R_PPC64_ADDR64 :
R_PPC_ADDR32)
Well, looking once more, and taking into account the patch from Chen
https://lore.kernel.org/lkml/20220531020744.236970-4-chenzhong...@huawei.com/
It would be easier to just define two macros:
#define R_ABS64 R_PPC64_ADDR64
#define R_ABS32 R_PPC_ADDR32
And then in the caller, as we know the size, do something like
size == sizeof(u64) ? R_ABS64 : R_ABS32;
How does 'sizeof(u64)' work here?
- Naveen
Re: [RFC PATCH 4/4] objtool/powerpc: Add --mcount specific implementation
Le 25/05/2022 à 19:27, Christophe Leroy a écrit :
Le 24/05/2022 à 15:33, Christophe Leroy a écrit :
Le 24/05/2022 à 13:00, Sathvika Vasireddy a écrit :
+{
+ switch (elf->ehdr.e_machine) {
+ case EM_X86_64:
+ return R_X86_64_64;
+ case EM_PPC64:
+ return R_PPC64_ADDR64;
+ default:
+ WARN("unknown machine...");
+ exit(-1);
+ }
+}
Wouldn't it be better to make that function arch specific ?
This is so that we can support cross architecture builds.
I'm not sure I follow you here.
This is only based on the target, it doesn't depend on the build host so
I can't the link with cross arch builds.
The same as you have arch_decode_instruction(), you could have
arch_elf_reloc_type_long()
It would make sense indeed, because there is no point in supporting X86
relocation when you don't support X86 instruction decoding.
Could simply be some macro defined in
tools/objtool/arch/powerpc/include/arch/elf.h and
tools/objtool/arch/x86/include/arch/elf.h
The x86 version would be:
#define R_ADDR(elf) R_X86_64_64
And the powerpc version would be:
#define R_ADDR(elf) (elf->ehdr.e_machine == EM_PPC64 ? R_PPC64_ADDR64 :
R_PPC_ADDR32)
Well, looking once more, and taking into account the patch from Chen
https://lore.kernel.org/lkml/20220531020744.236970-4-chenzhong...@huawei.com/
It would be easier to just define two macros:
#define R_ABS64 R_PPC64_ADDR64
#define R_ABS32 R_PPC_ADDR32
And then in the caller, as we know the size, do something like
size == sizeof(u64) ? R_ABS64 : R_ABS32;
Christophe
Re: [RFC PATCH 4/4] objtool/powerpc: Add --mcount specific implementation
Le 24/05/2022 à 15:33, Christophe Leroy a écrit :
Le 24/05/2022 à 13:00, Sathvika Vasireddy a écrit :
+{
+ switch (elf->ehdr.e_machine) {
+ case EM_X86_64:
+ return R_X86_64_64;
+ case EM_PPC64:
+ return R_PPC64_ADDR64;
+ default:
+ WARN("unknown machine...");
+ exit(-1);
+ }
+}
Wouldn't it be better to make that function arch specific ?
This is so that we can support cross architecture builds.
I'm not sure I follow you here.
This is only based on the target, it doesn't depend on the build host so
I can't the link with cross arch builds.
The same as you have arch_decode_instruction(), you could have
arch_elf_reloc_type_long()
It would make sense indeed, because there is no point in supporting X86
relocation when you don't support X86 instruction decoding.
Could simply be some macro defined in
tools/objtool/arch/powerpc/include/arch/elf.h and
tools/objtool/arch/x86/include/arch/elf.h
The x86 version would be:
#define R_ADDR(elf) R_X86_64_64
And the powerpc version would be:
#define R_ADDR(elf) (elf->ehdr.e_machine == EM_PPC64 ? R_PPC64_ADDR64 :
R_PPC_ADDR32)
Christophe
Re: [RFC PATCH 4/4] objtool/powerpc: Add --mcount specific implementation
Le 24/05/2022 à 13:00, Sathvika Vasireddy a écrit :
> [Vous ne recevez pas souvent de courriers de la part de
> s...@linux.vnet.ibm.com. Découvrez pourquoi cela peut être important à
> l’adresse https://aka.ms/LearnAboutSenderIdentification.]
>
> On 24/05/22 15:05, Christophe Leroy wrote:
>>
>> Le 23/05/2022 à 19:55, Sathvika Vasireddy a écrit :
>>> This patch enables objtool --mcount on powerpc, and
>>> adds implementation specific to powerpc.
>>>
>>> Signed-off-by: Sathvika Vasireddy
>>> ---
>>> arch/powerpc/Kconfig | 1 +
>>> tools/objtool/arch/powerpc/decode.c | 14 ++
>>> tools/objtool/check.c | 12 +++-
>>> tools/objtool/elf.c | 13 +
>>> tools/objtool/include/objtool/elf.h | 1 +
>>> 5 files changed, 36 insertions(+), 5 deletions(-)
>>>
>>> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
>>> index 732a3f91ee5e..3373d44a1298 100644
>>> --- a/arch/powerpc/Kconfig
>>> +++ b/arch/powerpc/Kconfig
>>> @@ -233,6 +233,7 @@ config PPC
>>> select HAVE_NMI if PERF_EVENTS || (PPC64
>>> && PPC_BOOK3S)
>>> select HAVE_OPTPROBES
>>> select HAVE_OBJTOOL if PPC64
>>> + select HAVE_OBJTOOL_MCOUNT if HAVE_OBJTOOL
>>> select HAVE_PERF_EVENTS
>>> select HAVE_PERF_EVENTS_NMI if PPC64
>>> select HAVE_PERF_REGS
>>> diff --git a/tools/objtool/arch/powerpc/decode.c
>>> b/tools/objtool/arch/powerpc/decode.c
>>> index e3b77a6ce357..ad3d79fffac2 100644
>>> --- a/tools/objtool/arch/powerpc/decode.c
>>> +++ b/tools/objtool/arch/powerpc/decode.c
>>> @@ -40,12 +40,26 @@ int arch_decode_instruction(struct objtool_file
>>> *file, const struct section *sec
>>> struct list_head *ops_list)
>>> {
>>> u32 insn;
>>> + unsigned int opcode;
>>>
>>> *immediate = 0;
>>> memcpy(&insn, sec->data->d_buf+offset, 4);
>>> *len = 4;
>>> *type = INSN_OTHER;
>>>
>>> + opcode = (insn >> 26);
>> You dont need the brackets here.
>>
>>> +
>>> + switch (opcode) {
>>> + case 18: /* bl */
>>> + if ((insn & 3) == 1) {
>>> + *type = INSN_CALL;
>>> + *immediate = insn & 0x3fc;
>>> + if (*immediate & 0x200)
>>> + *immediate -= 0x400;
>>> + }
>>> + break;
>>> + }
>>> +
>>> return 0;
>>> }
>>>
>>> diff --git a/tools/objtool/check.c b/tools/objtool/check.c
>>> index 056302d58e23..fd8bad092f89 100644
>>> --- a/tools/objtool/check.c
>>> +++ b/tools/objtool/check.c
>>> @@ -832,7 +832,7 @@ static int create_mcount_loc_sections(struct
>>> objtool_file *file)
>>>
>>> if (elf_add_reloc_to_insn(file->elf, sec,
>>> idx * sizeof(unsigned long),
>>> - R_X86_64_64,
>>> + elf_reloc_type_long(file->elf),
>>> insn->sec, insn->offset))
>>> return -1;
>>>
>>> @@ -2183,7 +2183,7 @@ static int classify_symbols(struct objtool_file
>>> *file)
>>> if (arch_is_retpoline(func))
>>> func->retpoline_thunk = true;
>>>
>>> - if (!strcmp(func->name, "__fentry__"))
>>> + if ((!strcmp(func->name, "__fentry__")) ||
>>> (!strcmp(func->name, "_mcount")))
>>> func->fentry = true;
>>>
>>> if (is_profiling_func(func->name))
>>> @@ -2259,9 +2259,11 @@ static int decode_sections(struct objtool_file
>>> *file)
>>> * Must be before add_jump_destinations(), which depends on 'func'
>>> * being set for alternatives, to enable proper sibling call
>>> detection.
>>> */
>>> - ret = add_special_section_alts(file);
>>> - if (ret)
>>> - return ret;
>>> + if (opts.stackval || opts.orc || opts.uaccess || opts.noinstr) {
>>> + ret = add_special_section_alts(file);
>>> + if (ret)
>>> + return ret;
>>> + }
>> I think this change should be a patch by itself, it's not related to
>> powerpc.
> Makes sense. I'll make this a separate patch in the next revision.
Great. Can you base your next revision on the one I just sent out ?
I will now start looking at inline static calls for PPC32.
>>
>>>
>>> ret = add_jump_destinations(file);
>>> if (ret)
>>> diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
>>> index c25e957c1e52..95763060d551 100644
>>> --- a/tools/objtool/elf.c
>>> +++ b/tools/objtool/elf.c
>>> @@ -793,6 +793,19 @@ elf_create_section_symbol(struct elf *elf,
>>> struct section *sec)
>>> return sym;
>>> }
>>>
>>> +int elf_reloc_type_long(struct elf *elf)
>> Not sure it's a good name, because for 32 bits we have to use 'int'.
> Sure, I'll rename it to elf_reloc_type() or some such.
Re: [RFC PATCH 4/4] objtool/powerpc: Add --mcount specific implementation
On 24/05/22 15:05, Christophe Leroy wrote:
Le 23/05/2022 à 19:55, Sathvika Vasireddy a écrit :
This patch enables objtool --mcount on powerpc, and
adds implementation specific to powerpc.
Signed-off-by: Sathvika Vasireddy
---
arch/powerpc/Kconfig| 1 +
tools/objtool/arch/powerpc/decode.c | 14 ++
tools/objtool/check.c | 12 +++-
tools/objtool/elf.c | 13 +
tools/objtool/include/objtool/elf.h | 1 +
5 files changed, 36 insertions(+), 5 deletions(-)
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 732a3f91ee5e..3373d44a1298 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -233,6 +233,7 @@ config PPC
select HAVE_NMI if PERF_EVENTS || (PPC64 &&
PPC_BOOK3S)
select HAVE_OPTPROBES
select HAVE_OBJTOOL if PPC64
+ select HAVE_OBJTOOL_MCOUNT if HAVE_OBJTOOL
select HAVE_PERF_EVENTS
select HAVE_PERF_EVENTS_NMI if PPC64
select HAVE_PERF_REGS
diff --git a/tools/objtool/arch/powerpc/decode.c
b/tools/objtool/arch/powerpc/decode.c
index e3b77a6ce357..ad3d79fffac2 100644
--- a/tools/objtool/arch/powerpc/decode.c
+++ b/tools/objtool/arch/powerpc/decode.c
@@ -40,12 +40,26 @@ int arch_decode_instruction(struct objtool_file *file,
const struct section *sec
struct list_head *ops_list)
{
u32 insn;
+ unsigned int opcode;
*immediate = 0;
memcpy(&insn, sec->data->d_buf+offset, 4);
*len = 4;
*type = INSN_OTHER;
+ opcode = (insn >> 26);
You dont need the brackets here.
+
+ switch (opcode) {
+ case 18: /* bl */
+ if ((insn & 3) == 1) {
+ *type = INSN_CALL;
+ *immediate = insn & 0x3fc;
+ if (*immediate & 0x200)
+ *immediate -= 0x400;
+ }
+ break;
+ }
+
return 0;
}
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 056302d58e23..fd8bad092f89 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -832,7 +832,7 @@ static int create_mcount_loc_sections(struct objtool_file
*file)
if (elf_add_reloc_to_insn(file->elf, sec,
idx * sizeof(unsigned long),
- R_X86_64_64,
+ elf_reloc_type_long(file->elf),
insn->sec, insn->offset))
return -1;
@@ -2183,7 +2183,7 @@ static int classify_symbols(struct objtool_file *file)
if (arch_is_retpoline(func))
func->retpoline_thunk = true;
- if (!strcmp(func->name, "__fentry__"))
+ if ((!strcmp(func->name, "__fentry__")) || (!strcmp(func->name,
"_mcount")))
func->fentry = true;
if (is_profiling_func(func->name))
@@ -2259,9 +2259,11 @@ static int decode_sections(struct objtool_file *file)
* Must be before add_jump_destinations(), which depends on 'func'
* being set for alternatives, to enable proper sibling call detection.
*/
- ret = add_special_section_alts(file);
- if (ret)
- return ret;
+ if (opts.stackval || opts.orc || opts.uaccess || opts.noinstr) {
+ ret = add_special_section_alts(file);
+ if (ret)
+ return ret;
+ }
I think this change should be a patch by itself, it's not related to
powerpc.
Makes sense. I'll make this a separate patch in the next revision.
ret = add_jump_destinations(file);
if (ret)
diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index c25e957c1e52..95763060d551 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -793,6 +793,19 @@ elf_create_section_symbol(struct elf *elf, struct section
*sec)
return sym;
}
+int elf_reloc_type_long(struct elf *elf)
Not sure it's a good name, because for 32 bits we have to use 'int'.
Sure, I'll rename it to elf_reloc_type() or some such.
+{
+ switch (elf->ehdr.e_machine) {
+ case EM_X86_64:
+ return R_X86_64_64;
+ case EM_PPC64:
+ return R_PPC64_ADDR64;
+ default:
+ WARN("unknown machine...");
+ exit(-1);
+ }
+}
Wouldn't it be better to make that function arch specific ?
This is so that we can support cross architecture builds.
Thanks for reviewing!
- Sathvika
Re: [RFC PATCH 4/4] objtool/powerpc: Add --mcount specific implementation
Le 23/05/2022 à 19:55, Sathvika Vasireddy a écrit :
> This patch enables objtool --mcount on powerpc, and
> adds implementation specific to powerpc.
>
> Signed-off-by: Sathvika Vasireddy
> ---
> arch/powerpc/Kconfig| 1 +
> tools/objtool/arch/powerpc/decode.c | 14 ++
> tools/objtool/check.c | 12 +++-
> tools/objtool/elf.c | 13 +
> tools/objtool/include/objtool/elf.h | 1 +
> 5 files changed, 36 insertions(+), 5 deletions(-)
>
> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
> index 732a3f91ee5e..3373d44a1298 100644
> --- a/arch/powerpc/Kconfig
> +++ b/arch/powerpc/Kconfig
> @@ -233,6 +233,7 @@ config PPC
> select HAVE_NMI if PERF_EVENTS || (PPC64 &&
> PPC_BOOK3S)
> select HAVE_OPTPROBES
> select HAVE_OBJTOOL if PPC64
> + select HAVE_OBJTOOL_MCOUNT if HAVE_OBJTOOL
> select HAVE_PERF_EVENTS
> select HAVE_PERF_EVENTS_NMI if PPC64
> select HAVE_PERF_REGS
> diff --git a/tools/objtool/arch/powerpc/decode.c
> b/tools/objtool/arch/powerpc/decode.c
> index e3b77a6ce357..ad3d79fffac2 100644
> --- a/tools/objtool/arch/powerpc/decode.c
> +++ b/tools/objtool/arch/powerpc/decode.c
> @@ -40,12 +40,26 @@ int arch_decode_instruction(struct objtool_file *file,
> const struct section *sec
> struct list_head *ops_list)
> {
> u32 insn;
> + unsigned int opcode;
>
> *immediate = 0;
> memcpy(&insn, sec->data->d_buf+offset, 4);
> *len = 4;
> *type = INSN_OTHER;
>
> + opcode = (insn >> 26);
You dont need the brackets here.
> +
> + switch (opcode) {
> + case 18: /* bl */
> + if ((insn & 3) == 1) {
> + *type = INSN_CALL;
> + *immediate = insn & 0x3fc;
> + if (*immediate & 0x200)
> + *immediate -= 0x400;
> + }
> + break;
> + }
> +
> return 0;
> }
>
> diff --git a/tools/objtool/check.c b/tools/objtool/check.c
> index 056302d58e23..fd8bad092f89 100644
> --- a/tools/objtool/check.c
> +++ b/tools/objtool/check.c
> @@ -832,7 +832,7 @@ static int create_mcount_loc_sections(struct objtool_file
> *file)
>
> if (elf_add_reloc_to_insn(file->elf, sec,
> idx * sizeof(unsigned long),
> - R_X86_64_64,
> + elf_reloc_type_long(file->elf),
> insn->sec, insn->offset))
> return -1;
>
> @@ -2183,7 +2183,7 @@ static int classify_symbols(struct objtool_file *file)
> if (arch_is_retpoline(func))
> func->retpoline_thunk = true;
>
> - if (!strcmp(func->name, "__fentry__"))
> + if ((!strcmp(func->name, "__fentry__")) ||
> (!strcmp(func->name, "_mcount")))
> func->fentry = true;
>
> if (is_profiling_func(func->name))
> @@ -2259,9 +2259,11 @@ static int decode_sections(struct objtool_file *file)
>* Must be before add_jump_destinations(), which depends on 'func'
>* being set for alternatives, to enable proper sibling call detection.
>*/
> - ret = add_special_section_alts(file);
> - if (ret)
> - return ret;
> + if (opts.stackval || opts.orc || opts.uaccess || opts.noinstr) {
> + ret = add_special_section_alts(file);
> + if (ret)
> + return ret;
> + }
I think this change should be a patch by itself, it's not related to
powerpc.
>
> ret = add_jump_destinations(file);
> if (ret)
> diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
> index c25e957c1e52..95763060d551 100644
> --- a/tools/objtool/elf.c
> +++ b/tools/objtool/elf.c
> @@ -793,6 +793,19 @@ elf_create_section_symbol(struct elf *elf, struct
> section *sec)
> return sym;
> }
>
> +int elf_reloc_type_long(struct elf *elf)
Not sure it's a good name, because for 32 bits we have to use 'int'.
> +{
> + switch (elf->ehdr.e_machine) {
> + case EM_X86_64:
> + return R_X86_64_64;
> + case EM_PPC64:
> + return R_PPC64_ADDR64;
> + default:
> + WARN("unknown machine...");
> + exit(-1);
> + }
> +}
Wouldn't it be better to make that function arch specific ?
> +
> int elf_add_reloc_to_insn(struct elf *elf, struct section *sec,
> unsigned long offset, unsigned int type,
> struct section *insn_sec, unsigned long insn_off)
> diff --git a/tools/objtool/include/objtool/elf.h
> b/tools/objtool/include/objtool/elf.h
> index adebfbc2b518..c43e23c0b3c8 100644
> --- a/tools/objtool/include/objtool/elf.h
[RFC PATCH 4/4] objtool/powerpc: Add --mcount specific implementation
This patch enables objtool --mcount on powerpc, and
adds implementation specific to powerpc.
Signed-off-by: Sathvika Vasireddy
---
arch/powerpc/Kconfig| 1 +
tools/objtool/arch/powerpc/decode.c | 14 ++
tools/objtool/check.c | 12 +++-
tools/objtool/elf.c | 13 +
tools/objtool/include/objtool/elf.h | 1 +
5 files changed, 36 insertions(+), 5 deletions(-)
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 732a3f91ee5e..3373d44a1298 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -233,6 +233,7 @@ config PPC
select HAVE_NMI if PERF_EVENTS || (PPC64 &&
PPC_BOOK3S)
select HAVE_OPTPROBES
select HAVE_OBJTOOL if PPC64
+ select HAVE_OBJTOOL_MCOUNT if HAVE_OBJTOOL
select HAVE_PERF_EVENTS
select HAVE_PERF_EVENTS_NMI if PPC64
select HAVE_PERF_REGS
diff --git a/tools/objtool/arch/powerpc/decode.c
b/tools/objtool/arch/powerpc/decode.c
index e3b77a6ce357..ad3d79fffac2 100644
--- a/tools/objtool/arch/powerpc/decode.c
+++ b/tools/objtool/arch/powerpc/decode.c
@@ -40,12 +40,26 @@ int arch_decode_instruction(struct objtool_file *file,
const struct section *sec
struct list_head *ops_list)
{
u32 insn;
+ unsigned int opcode;
*immediate = 0;
memcpy(&insn, sec->data->d_buf+offset, 4);
*len = 4;
*type = INSN_OTHER;
+ opcode = (insn >> 26);
+
+ switch (opcode) {
+ case 18: /* bl */
+ if ((insn & 3) == 1) {
+ *type = INSN_CALL;
+ *immediate = insn & 0x3fc;
+ if (*immediate & 0x200)
+ *immediate -= 0x400;
+ }
+ break;
+ }
+
return 0;
}
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 056302d58e23..fd8bad092f89 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -832,7 +832,7 @@ static int create_mcount_loc_sections(struct objtool_file
*file)
if (elf_add_reloc_to_insn(file->elf, sec,
idx * sizeof(unsigned long),
- R_X86_64_64,
+ elf_reloc_type_long(file->elf),
insn->sec, insn->offset))
return -1;
@@ -2183,7 +2183,7 @@ static int classify_symbols(struct objtool_file *file)
if (arch_is_retpoline(func))
func->retpoline_thunk = true;
- if (!strcmp(func->name, "__fentry__"))
+ if ((!strcmp(func->name, "__fentry__")) ||
(!strcmp(func->name, "_mcount")))
func->fentry = true;
if (is_profiling_func(func->name))
@@ -2259,9 +2259,11 @@ static int decode_sections(struct objtool_file *file)
* Must be before add_jump_destinations(), which depends on 'func'
* being set for alternatives, to enable proper sibling call detection.
*/
- ret = add_special_section_alts(file);
- if (ret)
- return ret;
+ if (opts.stackval || opts.orc || opts.uaccess || opts.noinstr) {
+ ret = add_special_section_alts(file);
+ if (ret)
+ return ret;
+ }
ret = add_jump_destinations(file);
if (ret)
diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index c25e957c1e52..95763060d551 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -793,6 +793,19 @@ elf_create_section_symbol(struct elf *elf, struct section
*sec)
return sym;
}
+int elf_reloc_type_long(struct elf *elf)
+{
+ switch (elf->ehdr.e_machine) {
+ case EM_X86_64:
+ return R_X86_64_64;
+ case EM_PPC64:
+ return R_PPC64_ADDR64;
+ default:
+ WARN("unknown machine...");
+ exit(-1);
+ }
+}
+
int elf_add_reloc_to_insn(struct elf *elf, struct section *sec,
unsigned long offset, unsigned int type,
struct section *insn_sec, unsigned long insn_off)
diff --git a/tools/objtool/include/objtool/elf.h
b/tools/objtool/include/objtool/elf.h
index adebfbc2b518..c43e23c0b3c8 100644
--- a/tools/objtool/include/objtool/elf.h
+++ b/tools/objtool/include/objtool/elf.h
@@ -144,6 +144,7 @@ static inline bool has_multiple_files(struct elf *elf)
struct elf *elf_open_read(const char *name, int flags);
struct section *elf_create_section(struct elf *elf, const char *name, unsigned
int sh_flags, size_t entsize, int nr);
+int elf_reloc_type_long(struct elf *elf);
int elf_add_reloc(struct elf *elf, struct section *sec, unsigned long offset,
unsigned in
