diff mbox series

[3/3] bpf: Corrected index computation when present with unnamed struct fields

Message ID 20240313142441.180242-3-cupertino.miranda@oracle.com
State New
Headers show
Series [1/3] bpf: Fix CO-RE field expression builtins | expand

Commit Message

Cupertino Miranda March 13, 2024, 2:24 p.m. UTC 
Any unnamed structure field if not a member of the BTF_KIND_STRUCT.
For that reason, CO-RE access strings indexes should take that in
consideration. This patch adds a condition to the incrementer that
computes the index for the field access.

gcc/ChangeLog:
	* config/bpf/core-builtins.cc (bpf_core_get_index): Check if
	field contains a DECL_NAME.

gcc/testsuite/ChangeLog:
	* gcc.target/bpf/core-builtin-fieldinfo-offset-1.c: Add
	testcase for unnamed fields.
---
 gcc/config/bpf/core-builtins.cc                        |  6 +++++-
 .../gcc.target/bpf/core-builtin-fieldinfo-offset-1.c   | 10 ++++++++--
 2 files changed, 13 insertions(+), 3 deletions(-)

Comments

David Faust March 19, 2024, 5:07 p.m. UTC | #1 
On 3/13/24 07:24, Cupertino Miranda wrote:
> Any unnamed structure field if not a member of the BTF_KIND_STRUCT.
typo: if -> is

I'd suggest to clarify that "any unnamed structure field" is really
any unnamed non-struct-or-union field, since anonymous inner structs
and unions certainly are present in BTF (and you handle them here).

> For that reason, CO-RE access strings indexes should take that in
> consideration. This patch adds a condition to the incrementer that
> computes the index for the field access.

Otherwise, OK.
Thanks.

> 
> gcc/ChangeLog:
> 	* config/bpf/core-builtins.cc (bpf_core_get_index): Check if
> 	field contains a DECL_NAME.
> 
> gcc/testsuite/ChangeLog:
> 	* gcc.target/bpf/core-builtin-fieldinfo-offset-1.c: Add
> 	testcase for unnamed fields.
> ---
>  gcc/config/bpf/core-builtins.cc                        |  6 +++++-
>  .../gcc.target/bpf/core-builtin-fieldinfo-offset-1.c   | 10 ++++++++--
>  2 files changed, 13 insertions(+), 3 deletions(-)
> 
> diff --git a/gcc/config/bpf/core-builtins.cc b/gcc/config/bpf/core-builtins.cc
> index 70b14e48e6e5..8333ad81d0e0 100644
> --- a/gcc/config/bpf/core-builtins.cc
> +++ b/gcc/config/bpf/core-builtins.cc
> @@ -553,7 +553,11 @@ bpf_core_get_index (const tree node, bool *valid)
>  	{
>  	  if (l == node)
>  	    return i;
> -	  i++;
> +	  /* Skip unnamed padding, not represented by BTF.  */
> +	  if (DECL_NAME(l) != NULL_TREE
> +	      || TREE_CODE (TREE_TYPE (l)) == UNION_TYPE
> +	      || TREE_CODE (TREE_TYPE (l)) == RECORD_TYPE)
> +	    i++;
>  	}
>      }
>    else if (code == ARRAY_REF || code == ARRAY_RANGE_REF || code == MEM_REF)
> diff --git a/gcc/testsuite/gcc.target/bpf/core-builtin-fieldinfo-offset-1.c b/gcc/testsuite/gcc.target/bpf/core-builtin-fieldinfo-offset-1.c
> index 27654205287d..8b1d8b012a2a 100644
> --- a/gcc/testsuite/gcc.target/bpf/core-builtin-fieldinfo-offset-1.c
> +++ b/gcc/testsuite/gcc.target/bpf/core-builtin-fieldinfo-offset-1.c
> @@ -14,6 +14,9 @@ struct T {
>    struct S s[2];
>    char c;
>    char d;
> +  int a: 1;
> +  int:31;
> +  int f;
>  };
>  
>  enum {
> @@ -38,7 +41,9 @@ unsigned int foo (struct T *t)
>    unsigned e1 = __builtin_preserve_field_info (bar()->d, FIELD_BYTE_OFFSET);
>    unsigned e2 = __builtin_preserve_field_info (bar()->s[1].a4, FIELD_BYTE_OFFSET);
>  
> -  return s0a1 + s0a4 + s0x + s1a1 + s1a4 + s1x + c + d + e1 + e2;
> +  unsigned f1 = __builtin_preserve_field_info (t->f, FIELD_BYTE_OFFSET);
> +
> +  return s0a1 + s0a4 + s0x + s1a1 + s1a4 + s1x + c + d + e1 + e2 + f1;
>  }
>  
>  /* { dg-final { scan-assembler-times "\[\t \]mov\[\t \]%r\[0-9\],4" 2 } } */
> @@ -65,5 +70,6 @@ unsigned int foo (struct T *t)
>  /* { dg-final { scan-assembler-times "bpfcr_astr_off \\(\"0:1:1:4\"\\)" 1 } } */
>  /* { dg-final { scan-assembler-times "bpfcr_astr_off \\(\"0:2\"\\)" 1 } } */
>  /* { dg-final { scan-assembler-times "bpfcr_astr_off \\(\"0:3\"\\)" 2 } } */
> +/* { dg-final { scan-assembler-times "bpfcr_astr_off \\(\"0:5\"\\)" 1 } } */
>  
> -/* { dg-final { scan-assembler-times "0\[\t \]+\[^\n\]*bpfcr_kind" 10 } } */
> +/* { dg-final { scan-assembler-times "0\[\t \]+\[^\n\]*bpfcr_kind" 11 } } */
Cupertino Miranda March 20, 2024, 8:32 p.m. UTC | #2 
David Faust writes:

> On 3/13/24 07:24, Cupertino Miranda wrote:
>> Any unnamed structure field if not a member of the BTF_KIND_STRUCT.
> typo: if -> is
>
> I'd suggest to clarify that "any unnamed structure field" is really
> any unnamed non-struct-or-union field, since anonymous inner structs
> and unions certainly are present in BTF (and you handle them here).
>
>> For that reason, CO-RE access strings indexes should take that in
>> consideration. This patch adds a condition to the incrementer that
>> computes the index for the field access.
>
> Otherwise, OK.
> Thanks.

Corrected and Pushed. Thanks
>
>>
>> gcc/ChangeLog:
>> 	* config/bpf/core-builtins.cc (bpf_core_get_index): Check if
>> 	field contains a DECL_NAME.
>>
>> gcc/testsuite/ChangeLog:
>> 	* gcc.target/bpf/core-builtin-fieldinfo-offset-1.c: Add
>> 	testcase for unnamed fields.
>> ---
>>  gcc/config/bpf/core-builtins.cc                        |  6 +++++-
>>  .../gcc.target/bpf/core-builtin-fieldinfo-offset-1.c   | 10 ++++++++--
>>  2 files changed, 13 insertions(+), 3 deletions(-)
>>
>> diff --git a/gcc/config/bpf/core-builtins.cc b/gcc/config/bpf/core-builtins.cc
>> index 70b14e48e6e5..8333ad81d0e0 100644
>> --- a/gcc/config/bpf/core-builtins.cc
>> +++ b/gcc/config/bpf/core-builtins.cc
>> @@ -553,7 +553,11 @@ bpf_core_get_index (const tree node, bool *valid)
>>  	{
>>  	  if (l == node)
>>  	    return i;
>> -	  i++;
>> +	  /* Skip unnamed padding, not represented by BTF.  */
>> +	  if (DECL_NAME(l) != NULL_TREE
>> +	      || TREE_CODE (TREE_TYPE (l)) == UNION_TYPE
>> +	      || TREE_CODE (TREE_TYPE (l)) == RECORD_TYPE)
>> +	    i++;
>>  	}
>>      }
>>    else if (code == ARRAY_REF || code == ARRAY_RANGE_REF || code == MEM_REF)
>> diff --git a/gcc/testsuite/gcc.target/bpf/core-builtin-fieldinfo-offset-1.c b/gcc/testsuite/gcc.target/bpf/core-builtin-fieldinfo-offset-1.c
>> index 27654205287d..8b1d8b012a2a 100644
>> --- a/gcc/testsuite/gcc.target/bpf/core-builtin-fieldinfo-offset-1.c
>> +++ b/gcc/testsuite/gcc.target/bpf/core-builtin-fieldinfo-offset-1.c
>> @@ -14,6 +14,9 @@ struct T {
>>    struct S s[2];
>>    char c;
>>    char d;
>> +  int a: 1;
>> +  int:31;
>> +  int f;
>>  };
>>
>>  enum {
>> @@ -38,7 +41,9 @@ unsigned int foo (struct T *t)
>>    unsigned e1 = __builtin_preserve_field_info (bar()->d, FIELD_BYTE_OFFSET);
>>    unsigned e2 = __builtin_preserve_field_info (bar()->s[1].a4, FIELD_BYTE_OFFSET);
>>
>> -  return s0a1 + s0a4 + s0x + s1a1 + s1a4 + s1x + c + d + e1 + e2;
>> +  unsigned f1 = __builtin_preserve_field_info (t->f, FIELD_BYTE_OFFSET);
>> +
>> +  return s0a1 + s0a4 + s0x + s1a1 + s1a4 + s1x + c + d + e1 + e2 + f1;
>>  }
>>
>>  /* { dg-final { scan-assembler-times "\[\t \]mov\[\t \]%r\[0-9\],4" 2 } } */
>> @@ -65,5 +70,6 @@ unsigned int foo (struct T *t)
>>  /* { dg-final { scan-assembler-times "bpfcr_astr_off \\(\"0:1:1:4\"\\)" 1 } } */
>>  /* { dg-final { scan-assembler-times "bpfcr_astr_off \\(\"0:2\"\\)" 1 } } */
>>  /* { dg-final { scan-assembler-times "bpfcr_astr_off \\(\"0:3\"\\)" 2 } } */
>> +/* { dg-final { scan-assembler-times "bpfcr_astr_off \\(\"0:5\"\\)" 1 } } */
>>
>> -/* { dg-final { scan-assembler-times "0\[\t \]+\[^\n\]*bpfcr_kind" 10 } } */
>> +/* { dg-final { scan-assembler-times "0\[\t \]+\[^\n\]*bpfcr_kind" 11 } } */
diff mbox series

Patch

diff --git a/gcc/config/bpf/core-builtins.cc b/gcc/config/bpf/core-builtins.cc
index 70b14e48e6e5..8333ad81d0e0 100644
--- a/gcc/config/bpf/core-builtins.cc
+++ b/gcc/config/bpf/core-builtins.cc
@@ -553,7 +553,11 @@  bpf_core_get_index (const tree node, bool *valid)
 	{
 	  if (l == node)
 	    return i;
-	  i++;
+	  /* Skip unnamed padding, not represented by BTF.  */
+	  if (DECL_NAME(l) != NULL_TREE
+	      || TREE_CODE (TREE_TYPE (l)) == UNION_TYPE
+	      || TREE_CODE (TREE_TYPE (l)) == RECORD_TYPE)
+	    i++;
 	}
     }
   else if (code == ARRAY_REF || code == ARRAY_RANGE_REF || code == MEM_REF)
diff --git a/gcc/testsuite/gcc.target/bpf/core-builtin-fieldinfo-offset-1.c b/gcc/testsuite/gcc.target/bpf/core-builtin-fieldinfo-offset-1.c
index 27654205287d..8b1d8b012a2a 100644
--- a/gcc/testsuite/gcc.target/bpf/core-builtin-fieldinfo-offset-1.c
+++ b/gcc/testsuite/gcc.target/bpf/core-builtin-fieldinfo-offset-1.c
@@ -14,6 +14,9 @@  struct T {
   struct S s[2];
   char c;
   char d;
+  int a: 1;
+  int:31;
+  int f;
 };
 
 enum {
@@ -38,7 +41,9 @@  unsigned int foo (struct T *t)
   unsigned e1 = __builtin_preserve_field_info (bar()->d, FIELD_BYTE_OFFSET);
   unsigned e2 = __builtin_preserve_field_info (bar()->s[1].a4, FIELD_BYTE_OFFSET);
 
-  return s0a1 + s0a4 + s0x + s1a1 + s1a4 + s1x + c + d + e1 + e2;
+  unsigned f1 = __builtin_preserve_field_info (t->f, FIELD_BYTE_OFFSET);
+
+  return s0a1 + s0a4 + s0x + s1a1 + s1a4 + s1x + c + d + e1 + e2 + f1;
 }
 
 /* { dg-final { scan-assembler-times "\[\t \]mov\[\t \]%r\[0-9\],4" 2 } } */
@@ -65,5 +70,6 @@  unsigned int foo (struct T *t)
 /* { dg-final { scan-assembler-times "bpfcr_astr_off \\(\"0:1:1:4\"\\)" 1 } } */
 /* { dg-final { scan-assembler-times "bpfcr_astr_off \\(\"0:2\"\\)" 1 } } */
 /* { dg-final { scan-assembler-times "bpfcr_astr_off \\(\"0:3\"\\)" 2 } } */
+/* { dg-final { scan-assembler-times "bpfcr_astr_off \\(\"0:5\"\\)" 1 } } */
 
-/* { dg-final { scan-assembler-times "0\[\t \]+\[^\n\]*bpfcr_kind" 10 } } */
+/* { dg-final { scan-assembler-times "0\[\t \]+\[^\n\]*bpfcr_kind" 11 } } */