Re: [PATCH 2/3] bpf: Fix access string default for CO-RE type based relocations

2024-03-20 Thread Cupertino Miranda 


David Faust writes:

> On 3/13/24 07:24, Cupertino Miranda wrote:
>> Although part of all CO-RE relocation data, type based relocations do
>> not require an access string.
>> Initial implementation defined it as an empty string.
>> On the other hand, libbpf when parsing the CO-RE relocations verifies
>> that those strings would contain "0", otherwise reports an error.
>> This patch makes GCC compliant with libbpf expectations.
>
> OK, thanks.
>
Pushed! Thanks
>>
>> gcc/Changelog:
>>  * config/bpf/btfext-out.cc (cpf_core_reloc_add): Correct for new code.
>>  Add assert to validate the string is set.
>>  * config/bpf/core-builtins.cc (cr_final): Make string struct
>>  field as const.
>>  (process_enum_value): Correct for field type change.
>>  (process_type): Set access string to "0".
>>
>> gcc/testsuite/ChangeLog:
>>  * gcc.target/bpf/core-builtin-type-based.c: Correct.
>>  * gcc.target/bpf/core-builtin-type-id.c: Correct.
>> ---
>>  gcc/config/bpf/btfext-out.cc   |  5 +++--
>>  gcc/config/bpf/core-builtins.cc| 10 ++
>>  gcc/testsuite/gcc.target/bpf/core-builtin-type-based.c |  1 +
>>  gcc/testsuite/gcc.target/bpf/core-builtin-type-id.c|  1 +
>>  4 files changed, 11 insertions(+), 6 deletions(-)
>>
>> diff --git a/gcc/config/bpf/btfext-out.cc b/gcc/config/bpf/btfext-out.cc
>> index 57c0dc323812..ff1fd0739f1e 100644
>> --- a/gcc/config/bpf/btfext-out.cc
>> +++ b/gcc/config/bpf/btfext-out.cc
>> @@ -299,8 +299,9 @@ bpf_core_reloc_add (const tree type, const char * 
>> section_name,
>>
>>/* Buffer the access string in the auxiliary strtab.  */
>>bpfcr->bpfcr_astr_off = 0;
>> -  if (accessor != NULL)
>> -bpfcr->bpfcr_astr_off = btf_ext_add_string (accessor);
>> +  gcc_assert (accessor != NULL);
>> +  bpfcr->bpfcr_astr_off = btf_ext_add_string (accessor);
>> +
>>bpfcr->bpfcr_type = get_btf_id (ctf_lookup_tree_type (ctfc, type));
>>bpfcr->bpfcr_insn_label = label;
>>bpfcr->bpfcr_kind = kind;
>> diff --git a/gcc/config/bpf/core-builtins.cc 
>> b/gcc/config/bpf/core-builtins.cc
>> index 4256fea15e49..70b14e48e6e5 100644
>> --- a/gcc/config/bpf/core-builtins.cc
>> +++ b/gcc/config/bpf/core-builtins.cc
>> @@ -205,7 +205,7 @@ struct cr_local
>>  /* Core Relocation Final data */
>>  struct cr_final
>>  {
>> -  char *str;
>> +  const char *str;
>>tree type;
>>enum btf_core_reloc_kind kind;
>>  };
>> @@ -868,8 +868,10 @@ process_enum_value (struct cr_builtins *data)
>>  {
>>if (TREE_VALUE (l) == expr)
>>  {
>> -  ret.str = (char *) ggc_alloc_atomic ((index / 10) + 1);
>> -  sprintf (ret.str, "%d", index);
>> +  char *tmp = (char *) ggc_alloc_atomic ((index / 10) + 1);
>> +  sprintf (tmp, "%d", index);
>> +  ret.str = (const char *) tmp;
>> +
>>break;
>>  }
>>index++;
>> @@ -987,7 +989,7 @@ process_type (struct cr_builtins *data)
>>|| data->kind == BPF_RELO_TYPE_MATCHES);
>>
>>struct cr_final ret;
>> -  ret.str = NULL;
>> +  ret.str = ggc_strdup ("0");
>>ret.type = data->type;
>>ret.kind = data->kind;
>>
>> diff --git a/gcc/testsuite/gcc.target/bpf/core-builtin-type-based.c 
>> b/gcc/testsuite/gcc.target/bpf/core-builtin-type-based.c
>> index 74a8d5a14d9d..9d818133c084 100644
>> --- a/gcc/testsuite/gcc.target/bpf/core-builtin-type-based.c
>> +++ b/gcc/testsuite/gcc.target/bpf/core-builtin-type-based.c
>> @@ -56,3 +56,4 @@ int foo(void *data)
>>  /* { dg-final { scan-assembler-times "0x8\[\t \]+\[^\n\]*bpfcr_kind" 13 } } 
>> BPF_TYPE_EXISTS */
>>  /* { dg-final { scan-assembler-times "0x9\[\t \]+\[^\n\]*bpfcr_kind" 11 } } 
>> BPF_TYPE_SIZE */
>>  /* { dg-final { scan-assembler-times "0xc\[\t \]+\[^\n\]*bpfcr_kind" 13 } } 
>> BPF_TYPE_MATCHES */
>> +/* { dg-final { scan-assembler-times "bpfcr_astr_off \[(\"\]+0\[(\"\]+" 37 
>> } } */
>> diff --git a/gcc/testsuite/gcc.target/bpf/core-builtin-type-id.c 
>> b/gcc/testsuite/gcc.target/bpf/core-builtin-type-id.c
>> index 4b23288eac08..9576b91bc940 100644
>> --- a/gcc/testsuite/gcc.target/bpf/core-builtin-type-id.c
>> +++ b/gcc/testsuite/gcc.target/bpf/core-builtin-type-id.c
>> @@ -38,3 +38,4 @@ int foo(void *data)
>>  /* { dg-final { scan-assembler-times "0\[\t \]+\[^\n\]*bpfcr_type" 0  { 
>> xfail *-*-* } } } */
>>  /* { dg-final { scan-assembler-times "0x6\[\t \]+\[^\n\]*bpfcr_kind" 13 } } 
>> BPF_TYPE_ID_LOCAL */
>>  /* { dg-final { scan-assembler-times "0x7\[\t \]+\[^\n\]*bpfcr_kind" 7 } } 
>> BPF_TYPE_ID_TARGET */
>> +/* { dg-final { scan-assembler-times "bpfcr_astr_off \[(\"\]+0\[(\"\]+" 20 
>> } } */

Re: [PATCH 2/3] bpf: Fix access string default for CO-RE type based relocations

2024-03-19 Thread David Faust 



On 3/13/24 07:24, Cupertino Miranda wrote:
> Although part of all CO-RE relocation data, type based relocations do
> not require an access string.
> Initial implementation defined it as an empty string.
> On the other hand, libbpf when parsing the CO-RE relocations verifies
> that those strings would contain "0", otherwise reports an error.
> This patch makes GCC compliant with libbpf expectations.

OK, thanks.

> 
> gcc/Changelog:
>   * config/bpf/btfext-out.cc (cpf_core_reloc_add): Correct for new code.
>   Add assert to validate the string is set.
>   * config/bpf/core-builtins.cc (cr_final): Make string struct
>   field as const.
>   (process_enum_value): Correct for field type change.
>   (process_type): Set access string to "0".
> 
> gcc/testsuite/ChangeLog:
>   * gcc.target/bpf/core-builtin-type-based.c: Correct.
>   * gcc.target/bpf/core-builtin-type-id.c: Correct.
> ---
>  gcc/config/bpf/btfext-out.cc   |  5 +++--
>  gcc/config/bpf/core-builtins.cc| 10 ++
>  gcc/testsuite/gcc.target/bpf/core-builtin-type-based.c |  1 +
>  gcc/testsuite/gcc.target/bpf/core-builtin-type-id.c|  1 +
>  4 files changed, 11 insertions(+), 6 deletions(-)
> 
> diff --git a/gcc/config/bpf/btfext-out.cc b/gcc/config/bpf/btfext-out.cc
> index 57c0dc323812..ff1fd0739f1e 100644
> --- a/gcc/config/bpf/btfext-out.cc
> +++ b/gcc/config/bpf/btfext-out.cc
> @@ -299,8 +299,9 @@ bpf_core_reloc_add (const tree type, const char * 
> section_name,
>  
>/* Buffer the access string in the auxiliary strtab.  */
>bpfcr->bpfcr_astr_off = 0;
> -  if (accessor != NULL)
> -bpfcr->bpfcr_astr_off = btf_ext_add_string (accessor);
> +  gcc_assert (accessor != NULL);
> +  bpfcr->bpfcr_astr_off = btf_ext_add_string (accessor);
> +
>bpfcr->bpfcr_type = get_btf_id (ctf_lookup_tree_type (ctfc, type));
>bpfcr->bpfcr_insn_label = label;
>bpfcr->bpfcr_kind = kind;
> diff --git a/gcc/config/bpf/core-builtins.cc b/gcc/config/bpf/core-builtins.cc
> index 4256fea15e49..70b14e48e6e5 100644
> --- a/gcc/config/bpf/core-builtins.cc
> +++ b/gcc/config/bpf/core-builtins.cc
> @@ -205,7 +205,7 @@ struct cr_local
>  /* Core Relocation Final data */
>  struct cr_final
>  {
> -  char *str;
> +  const char *str;
>tree type;
>enum btf_core_reloc_kind kind;
>  };
> @@ -868,8 +868,10 @@ process_enum_value (struct cr_builtins *data)
>   {
> if (TREE_VALUE (l) == expr)
>   {
> -   ret.str = (char *) ggc_alloc_atomic ((index / 10) + 1);
> -   sprintf (ret.str, "%d", index);
> +   char *tmp = (char *) ggc_alloc_atomic ((index / 10) + 1);
> +   sprintf (tmp, "%d", index);
> +   ret.str = (const char *) tmp;
> +
> break;
>   }
> index++;
> @@ -987,7 +989,7 @@ process_type (struct cr_builtins *data)
> || data->kind == BPF_RELO_TYPE_MATCHES);
>  
>struct cr_final ret;
> -  ret.str = NULL;
> +  ret.str = ggc_strdup ("0");
>ret.type = data->type;
>ret.kind = data->kind;
>  
> diff --git a/gcc/testsuite/gcc.target/bpf/core-builtin-type-based.c 
> b/gcc/testsuite/gcc.target/bpf/core-builtin-type-based.c
> index 74a8d5a14d9d..9d818133c084 100644
> --- a/gcc/testsuite/gcc.target/bpf/core-builtin-type-based.c
> +++ b/gcc/testsuite/gcc.target/bpf/core-builtin-type-based.c
> @@ -56,3 +56,4 @@ int foo(void *data)
>  /* { dg-final { scan-assembler-times "0x8\[\t \]+\[^\n\]*bpfcr_kind" 13 } } 
> BPF_TYPE_EXISTS */
>  /* { dg-final { scan-assembler-times "0x9\[\t \]+\[^\n\]*bpfcr_kind" 11 } } 
> BPF_TYPE_SIZE */
>  /* { dg-final { scan-assembler-times "0xc\[\t \]+\[^\n\]*bpfcr_kind" 13 } } 
> BPF_TYPE_MATCHES */
> +/* { dg-final { scan-assembler-times "bpfcr_astr_off \[(\"\]+0\[(\"\]+" 37 } 
> } */
> diff --git a/gcc/testsuite/gcc.target/bpf/core-builtin-type-id.c 
> b/gcc/testsuite/gcc.target/bpf/core-builtin-type-id.c
> index 4b23288eac08..9576b91bc940 100644
> --- a/gcc/testsuite/gcc.target/bpf/core-builtin-type-id.c
> +++ b/gcc/testsuite/gcc.target/bpf/core-builtin-type-id.c
> @@ -38,3 +38,4 @@ int foo(void *data)
>  /* { dg-final { scan-assembler-times "0\[\t \]+\[^\n\]*bpfcr_type" 0  { 
> xfail *-*-* } } } */
>  /* { dg-final { scan-assembler-times "0x6\[\t \]+\[^\n\]*bpfcr_kind" 13 } } 
> BPF_TYPE_ID_LOCAL */
>  /* { dg-final { scan-assembler-times "0x7\[\t \]+\[^\n\]*bpfcr_kind" 7 } } 
> BPF_TYPE_ID_TARGET */
> +/* { dg-final { scan-assembler-times "bpfcr_astr_off \[(\"\]+0\[(\"\]+" 20 } 
> } */

[PATCH 2/3] bpf: Fix access string default for CO-RE type based relocations

2024-03-13 Thread Cupertino Miranda 
Although part of all CO-RE relocation data, type based relocations do
not require an access string.
Initial implementation defined it as an empty string.
On the other hand, libbpf when parsing the CO-RE relocations verifies
that those strings would contain "0", otherwise reports an error.
This patch makes GCC compliant with libbpf expectations.

gcc/Changelog:
* config/bpf/btfext-out.cc (cpf_core_reloc_add): Correct for new code.
Add assert to validate the string is set.
* config/bpf/core-builtins.cc (cr_final): Make string struct
field as const.
(process_enum_value): Correct for field type change.
(process_type): Set access string to "0".

gcc/testsuite/ChangeLog:
* gcc.target/bpf/core-builtin-type-based.c: Correct.
* gcc.target/bpf/core-builtin-type-id.c: Correct.
---
 gcc/config/bpf/btfext-out.cc   |  5 +++--
 gcc/config/bpf/core-builtins.cc| 10 ++
 gcc/testsuite/gcc.target/bpf/core-builtin-type-based.c |  1 +
 gcc/testsuite/gcc.target/bpf/core-builtin-type-id.c|  1 +
 4 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/gcc/config/bpf/btfext-out.cc b/gcc/config/bpf/btfext-out.cc
index 57c0dc323812..ff1fd0739f1e 100644
--- a/gcc/config/bpf/btfext-out.cc
+++ b/gcc/config/bpf/btfext-out.cc
@@ -299,8 +299,9 @@ bpf_core_reloc_add (const tree type, const char * 
section_name,
 
   /* Buffer the access string in the auxiliary strtab.  */
   bpfcr->bpfcr_astr_off = 0;
-  if (accessor != NULL)
-bpfcr->bpfcr_astr_off = btf_ext_add_string (accessor);
+  gcc_assert (accessor != NULL);
+  bpfcr->bpfcr_astr_off = btf_ext_add_string (accessor);
+
   bpfcr->bpfcr_type = get_btf_id (ctf_lookup_tree_type (ctfc, type));
   bpfcr->bpfcr_insn_label = label;
   bpfcr->bpfcr_kind = kind;
diff --git a/gcc/config/bpf/core-builtins.cc b/gcc/config/bpf/core-builtins.cc
index 4256fea15e49..70b14e48e6e5 100644
--- a/gcc/config/bpf/core-builtins.cc
+++ b/gcc/config/bpf/core-builtins.cc
@@ -205,7 +205,7 @@ struct cr_local
 /* Core Relocation Final data */
 struct cr_final
 {
-  char *str;
+  const char *str;
   tree type;
   enum btf_core_reloc_kind kind;
 };
@@ -868,8 +868,10 @@ process_enum_value (struct cr_builtins *data)
{
  if (TREE_VALUE (l) == expr)
{
- ret.str = (char *) ggc_alloc_atomic ((index / 10) + 1);
- sprintf (ret.str, "%d", index);
+ char *tmp = (char *) ggc_alloc_atomic ((index / 10) + 1);
+ sprintf (tmp, "%d", index);
+ ret.str = (const char *) tmp;
+
  break;
}
  index++;
@@ -987,7 +989,7 @@ process_type (struct cr_builtins *data)
  || data->kind == BPF_RELO_TYPE_MATCHES);
 
   struct cr_final ret;
-  ret.str = NULL;
+  ret.str = ggc_strdup ("0");
   ret.type = data->type;
   ret.kind = data->kind;
 
diff --git a/gcc/testsuite/gcc.target/bpf/core-builtin-type-based.c 
b/gcc/testsuite/gcc.target/bpf/core-builtin-type-based.c
index 74a8d5a14d9d..9d818133c084 100644
--- a/gcc/testsuite/gcc.target/bpf/core-builtin-type-based.c
+++ b/gcc/testsuite/gcc.target/bpf/core-builtin-type-based.c
@@ -56,3 +56,4 @@ int foo(void *data)
 /* { dg-final { scan-assembler-times "0x8\[\t \]+\[^\n\]*bpfcr_kind" 13 } } 
BPF_TYPE_EXISTS */
 /* { dg-final { scan-assembler-times "0x9\[\t \]+\[^\n\]*bpfcr_kind" 11 } } 
BPF_TYPE_SIZE */
 /* { dg-final { scan-assembler-times "0xc\[\t \]+\[^\n\]*bpfcr_kind" 13 } } 
BPF_TYPE_MATCHES */
+/* { dg-final { scan-assembler-times "bpfcr_astr_off \[(\"\]+0\[(\"\]+" 37 } } 
*/
diff --git a/gcc/testsuite/gcc.target/bpf/core-builtin-type-id.c 
b/gcc/testsuite/gcc.target/bpf/core-builtin-type-id.c
index 4b23288eac08..9576b91bc940 100644
--- a/gcc/testsuite/gcc.target/bpf/core-builtin-type-id.c
+++ b/gcc/testsuite/gcc.target/bpf/core-builtin-type-id.c
@@ -38,3 +38,4 @@ int foo(void *data)
 /* { dg-final { scan-assembler-times "0\[\t \]+\[^\n\]*bpfcr_type" 0  { xfail 
*-*-* } } } */
 /* { dg-final { scan-assembler-times "0x6\[\t \]+\[^\n\]*bpfcr_kind" 13 } } 
BPF_TYPE_ID_LOCAL */
 /* { dg-final { scan-assembler-times "0x7\[\t \]+\[^\n\]*bpfcr_kind" 7 } } 
BPF_TYPE_ID_TARGET */
+/* { dg-final { scan-assembler-times "bpfcr_astr_off \[(\"\]+0\[(\"\]+" 20 } } 
*/
-- 
2.30.2