diff mbox series

[4/5] bpf: implementation of func_info in .BTF.ext.

Message ID 20240220102427.1512739-5-cupertino.miranda@oracle.com
State New
Headers
Series [1/5] btf: fixed type id in BTF_KIND_FUNC struct data. |

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Commit Message

Cupertino Miranda Feb. 20, 2024, 10:24 a.m. UTC 
  Kernel verifier complains in some particular cases for missing func_info
implementation in .BTF.ext. This patch implements it.

Strings are cached locally in coreout.cc to avoid adding duplicated
strings in the string list. This string deduplication should eventually
be moved to the CTFC functions such that this happens widely.

With this implementation, the CO-RE relocations information was also
simplified and integrated with the FuncInfo structures.

gcc/Changelog:
	PR target/113453
	* config/bpf/bpf.cc (bpf_function_prologue): Defined target
	hook.
	* config/bpf/coreout.cc (brf_ext_info_section)
	(btf_ext_info): Moved from coreout.h
	(btf_ext_funcinfo, btf_ext_lineinfo): Added struct.
	(bpf_core_reloc): Renamed to btf_ext_core_reloc.
	(btf_ext): Added static variable.
	(btfext_info_sec_find_or_add, SEARCH_NODE_AND_RETURN)
	(bpf_create_or_find_funcinfo, bpt_create_core_reloc)
	(btf_ext_add_string, btf_funcinfo_type_callback)
	(btf_add_func_info_for, btf_validate_funcinfo)
	(btf_ext_info_len, output_btfext_func_info): Added function.
	(output_btfext_header, bpf_core_reloc_add)
	(output_btfext_core_relocs, btf_ext_init, btf_ext_output):
	Changed to support new structs.
	* config/bpf/coreout.h (btf_ext_funcinfo, btf_ext_lineinfo):
	Moved and changed in coreout.cc.
	(btf_add_func_info_for, btf_ext_add_string): Added prototypes.

gcc/testsuite/ChangeLog:
	PR target/113453
	* gcc.target/bpf/btfext-funcinfo-nocore.c: Added.
	* gcc.target/bpf/btfext-funcinfo.c: Added.
	* gcc.target/bpf/core-attr-5.c: Fixed regexp.
	* gcc.target/bpf/core-attr-6.c: Fixed regexp.
	* gcc.target/bpf/core-builtin-fieldinfo-offset-1.c: Fixed regexp.
	* gcc.target/bpf/core-section-1.c: Fixed regexp
---
 gcc/config/bpf/bpf.cc                         |  12 +
 gcc/config/bpf/coreout.cc                     | 518 +++++++++++++-----
 gcc/config/bpf/coreout.h                      |  20 +-
 .../gcc.target/bpf/btfext-funcinfo-nocore.c   |  42 ++
 .../gcc.target/bpf/btfext-funcinfo.c          |  46 ++
 gcc/testsuite/gcc.target/bpf/core-attr-5.c    |   9 +-
 gcc/testsuite/gcc.target/bpf/core-attr-6.c    |   6 +-
 .../bpf/core-builtin-fieldinfo-offset-1.c     |  13 +-
 gcc/testsuite/gcc.target/bpf/core-section-1.c |   2 +-
 9 files changed, 506 insertions(+), 162 deletions(-)
 create mode 100644 gcc/testsuite/gcc.target/bpf/btfext-funcinfo-nocore.c
 create mode 100644 gcc/testsuite/gcc.target/bpf/btfext-funcinfo.c
diff mbox series

Patch

diff --git a/gcc/config/bpf/bpf.cc b/gcc/config/bpf/bpf.cc
index 4318b26b9cda..ea47e3a8dbfb 100644
--- a/gcc/config/bpf/bpf.cc
+++ b/gcc/config/bpf/bpf.cc
@@ -385,6 +385,18 @@  bpf_compute_frame_layout (void)
 #undef TARGET_COMPUTE_FRAME_LAYOUT
 #define TARGET_COMPUTE_FRAME_LAYOUT bpf_compute_frame_layout
 
+/* Defined to initialize data for func_info region in .BTF.ext section.  */
+
+static void
+bpf_function_prologue (FILE *f ATTRIBUTE_UNUSED)
+{
+  if (btf_debuginfo_p ())
+    btf_add_func_info_for (cfun->decl, current_function_func_begin_label);
+}
+
+#undef TARGET_ASM_FUNCTION_PROLOGUE
+#define TARGET_ASM_FUNCTION_PROLOGUE bpf_function_prologue
+
 /* Expand to the instructions in a function prologue.  This function
    is called when expanding the 'prologue' pattern in bpf.md.  */
 
diff --git a/gcc/config/bpf/coreout.cc b/gcc/config/bpf/coreout.cc
index 2f06ec2a0f29..31b2abc3151b 100644
--- a/gcc/config/bpf/coreout.cc
+++ b/gcc/config/bpf/coreout.cc
@@ -31,6 +31,7 @@ 
 #include "btf.h"
 #include "rtl.h"
 #include "tree-pretty-print.h"
+#include "cgraph.h"
 
 #include "coreout.h"
 
@@ -95,64 +96,193 @@ 
    result, a single .BTF.ext section can contain CO-RE relocations for multiple
    programs in distinct sections.  */
 
-/* Internal representation of a BPF CO-RE relocation record.  */
+/* BTF.ext debug info section.  */
+static GTY (()) section * btf_ext_info_section;
+
+#ifndef BTF_EXT_INFO_SECTION_NAME
+#define BTF_EXT_INFO_SECTION_NAME ".BTF.ext"
+#endif
+#define BTF_EXT_INFO_SECTION_FLAGS (SECTION_DEBUG)
+
+#ifndef BTF_EXT_INFO_SECTION_LABEL
+#define BTF_EXT_INFO_SECTION_LABEL "Lbtfext"
+#endif
+
+#define MAX_BTF_EXT_LABEL_BYTES 40
+static char btf_ext_info_section_label[MAX_BTF_EXT_LABEL_BYTES];
+
+/* A funcinfo record, in the .BTF.ext funcinfo section.  */
+struct GTY ((chain_next ("%h.next"))) btf_ext_funcinfo
+{
+  uint32_t type;     /* Type ID of a BTF_KIND_FUNC type.  */
+  const char *fnname;
+  const char *label;
+
+  struct btf_ext_funcinfo *next; /* Linked list to collect func_info elems.  */
+};
+
+/* A lineinfo record, in the .BTF.ext lineinfo section.  */
+struct GTY ((chain_next ("%h.next"))) btf_ext_lineinfo
+{
+  uint32_t insn_off;      /* Offset of the instruction.  */
+  uint32_t file_name_off; /* Offset of file name in BTF string table.  */
+  uint32_t line_off;      /* Offset of source line in BTF string table.  */
+  uint32_t line_col;      /* Line number (bits 31-11) and column (11-0).  */
 
-typedef struct GTY (()) bpf_core_reloc {
+  struct btf_ext_lineinfo *next; /* Linked list to collect line_info elems.  */
+};
+
+/* Internal representation of a BPF CO-RE relocation record.  */
+struct GTY ((chain_next ("%h.next"))) btf_ext_core_reloc {
   unsigned int bpfcr_type;		/* BTF type ID of container.  */
   unsigned int  bpfcr_astr_off;		/* Offset of access string in .BTF
 					   string table.  */
   rtx_code_label * bpfcr_insn_label;	/* RTX label attached to instruction
 					   to patch.  */
   enum btf_core_reloc_kind bpfcr_kind;	/* Kind of relocation to perform.  */
-} bpf_core_reloc_t;
 
-typedef bpf_core_reloc_t * bpf_core_reloc_ref;
+  struct {
+    const char *accessor_str;
+    tree type;
+  } info;
 
-/* Internal representation of a CO-RE relocation (sub)section of the
-   .BTF.ext information. One such section is generated for each ELF section
-   in the output object having relocations that a BPF loader must resolve.  */
+  struct btf_ext_core_reloc *next;
+};
 
-typedef struct GTY (()) bpf_core_section {
-  /* Name of ELF section to which these CO-RE relocations apply.  */
-  const char * name;
+/* Main data structure to keep .BTF.ext section data.  */
+struct GTY ((chain_next ("%h.next"))) btf_ext_info_sec {
+  const char *sec_name;
+  uint32_t   sec_name_off; /* offset to section name.  */
+
+  struct {
+    uint32_t num_info;
+    struct btf_ext_funcinfo *head;
+  } func_info;
+  struct {
+    uint32_t num_info;
+    struct btf_ext_lineinfo *head;
+  } line_info;
+  struct {
+    uint32_t num_info;
+    struct btf_ext_core_reloc *head;
+  } core_info;
+
+  struct btf_ext_info_sec *next;
+};
 
-  /* Offset of section name in .BTF string table.  */
-  uint32_t name_offset;
+static GTY (()) struct btf_ext_info_sec *btf_ext = NULL;
 
-  /* Relocations in the section.  */
-  vec <bpf_core_reloc_ref, va_gc> * GTY (()) relocs;
-} bpf_core_section_t;
+/* Helper function to add a section structure to the linked list with entry
+   point in info static variable.  */
 
-typedef bpf_core_section_t * bpf_core_section_ref;
+static struct btf_ext_info_sec *
+btfext_info_sec_find_or_add (const char *sec_name, bool add)
+{
+  struct btf_ext_info_sec **tmp = &btf_ext;
 
-/* BTF.ext debug info section.  */
+  while (*tmp != NULL)
+    {
+      if (strcmp ((*tmp)->sec_name, sec_name) == 0)
+	return *tmp;
+      tmp = &((*tmp)->next);
+    }
 
-static GTY (()) section * btf_ext_info_section;
+  if (add == false)
+    return NULL;
 
-static int btf_ext_label_num;
+  struct btf_ext_info_sec *ret = ggc_cleared_alloc<struct btf_ext_info_sec> ();
+  *tmp = ret;
 
-#ifndef BTF_EXT_INFO_SECTION_NAME
-#define BTF_EXT_INFO_SECTION_NAME ".BTF.ext"
-#endif
+  /* Set data for section info.  */
+  ret->sec_name = sec_name;
+  ret->sec_name_off = btf_ext_add_string (sec_name);
 
-#define BTF_EXT_INFO_SECTION_FLAGS (SECTION_DEBUG)
+  return ret;
+}
 
-#define MAX_BTF_EXT_LABEL_BYTES 40
+#define SEARCH_NODE_AND_RETURN(TYPE, FIELD, CONDITION) ({ \
+  TYPE **head = &(FIELD); \
+  while (*head != NULL) \
+    { \
+      if (CONDITION) \
+	return (*head); \
+      head = &((*head)->next); \
+    } \
+  head; \
+})
+
+/* Function to create or find a funcinfo node in info.  */
+
+static struct btf_ext_funcinfo *
+bpf_create_or_find_funcinfo (const char *fnname, const char *sec_name,
+			     btf_ext_info_sec **in_sec = NULL)
+{
+  struct btf_ext_info_sec *sec_elem =
+    btfext_info_sec_find_or_add (sec_name, true);
 
-static char btf_ext_info_section_label[MAX_BTF_EXT_LABEL_BYTES];
+  if (in_sec != NULL)
+    *in_sec = sec_elem;
 
-#ifndef BTF_EXT_INFO_SECTION_LABEL
-#define BTF_EXT_INFO_SECTION_LABEL "Lbtfext"
-#endif
+  struct btf_ext_funcinfo **head =
+    SEARCH_NODE_AND_RETURN(struct btf_ext_funcinfo,
+			   sec_elem->func_info.head,
+			   strcmp ((*head)->fnname, fnname) == 0);
 
-static GTY (()) vec<bpf_core_section_ref, va_gc> *bpf_core_sections;
+  *head = ggc_cleared_alloc<struct btf_ext_funcinfo> ();
+  (*head)->fnname = fnname;
+  (*head)->label = NULL;
 
-struct GTY(()) bpf_core_extra {
-  const char *accessor_str;
-  tree type;
+  return *head;
+}
+
+/* Function to create a core_reloc node in info.  */
+
+static struct btf_ext_core_reloc *
+bpf_create_core_reloc (const char *sec_name,
+		       struct btf_ext_info_sec **in_sec = NULL)
+{
+  struct btf_ext_info_sec *sec_elem =
+    btfext_info_sec_find_or_add (sec_name, true);
+
+  if (in_sec != NULL)
+    *in_sec = sec_elem;
+
+  struct btf_ext_core_reloc **head =
+    SEARCH_NODE_AND_RETURN(struct btf_ext_core_reloc,
+			   sec_elem->core_info.head,
+			   false);
+
+  *head = ggc_cleared_alloc<struct btf_ext_core_reloc> ();
+
+  return *head;
+}
+
+/* String caching to avoid repeated strings added to BTF string table.  */
+struct GTY((chain_next ("%h.next"))) string_cache {
+  const char *str;
+  unsigned int offset;
+  struct string_cache *next;
 };
-typedef struct bpf_core_extra *bpf_core_extra_ref;
-static GTY(()) hash_map<bpf_core_reloc_ref, bpf_core_extra_ref> *bpf_comment_info;
+static GTY(()) struct string_cache *btf_ext_strings = NULL;
+
+unsigned int
+btf_ext_add_string (const char *str)
+{
+  ctf_container_ref ctfc = ctf_get_tu_ctfc ();
+  struct string_cache **tmp = &btf_ext_strings;
+  while (*tmp != NULL)
+    {
+      if (strcmp ((*tmp)->str, str) == 0)
+	return (*tmp)->offset;
+      tmp = &((*tmp)->next);
+    }
+
+  *tmp = ggc_cleared_alloc<struct string_cache> ();
+  (*tmp)->str = ggc_strdup (str);
+  ctf_add_string (ctfc, (*tmp)->str, &((*tmp)->offset), CTF_AUX_STRTAB);
+
+  return (*tmp)->offset;
+}
 
 /* Create a new BPF CO-RE relocation record, and add it to the appropriate
    CO-RE section.  */
@@ -162,42 +292,23 @@  bpf_core_reloc_add (const tree type, const char * section_name,
 		    rtx_code_label *label,
 		    enum btf_core_reloc_kind kind)
 {
-  bpf_core_reloc_ref bpfcr = ggc_cleared_alloc<bpf_core_reloc_t> ();
-  bpf_core_extra_ref info = ggc_cleared_alloc<struct bpf_core_extra> ();
+  struct btf_ext_info_sec *sec = NULL;
+  struct btf_ext_core_reloc *bpfcr = bpf_create_core_reloc (section_name, &sec);
+
   ctf_container_ref ctfc = ctf_get_tu_ctfc ();
 
   /* Buffer the access string in the auxiliary strtab.  */
-  ctf_add_string (ctfc, accessor, &(bpfcr->bpfcr_astr_off), CTF_AUX_STRTAB);
+  bpfcr->bpfcr_astr_off = 0;
+  if (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;
 
-  info->accessor_str = accessor;
-  info->type = type;
-  bpf_comment_info->put (bpfcr, info);
-
-  /* Add the CO-RE reloc to the appropriate section.  */
-  bpf_core_section_ref sec;
-  int i;
-  FOR_EACH_VEC_ELT (*bpf_core_sections, i, sec)
-    if (strcmp (sec->name, section_name) == 0)
-      {
-	vec_safe_push (sec->relocs, bpfcr);
-	return;
-      }
+  bpfcr->info.accessor_str = accessor;
+  bpfcr->info.type = type;
 
-  /* If the CO-RE section does not yet exist, create it.  */
-  sec = ggc_cleared_alloc<bpf_core_section_t> ();
-
-  ctf_add_string (ctfc, section_name, &sec->name_offset, CTF_AUX_STRTAB);
-  if (strcmp (section_name, ""))
-    ctfc->ctfc_aux_strlen += strlen (section_name) + 1;
-
-  sec->name = section_name;
-  vec_alloc (sec->relocs, 1);
-  vec_safe_push (sec->relocs, bpfcr);
-
-  vec_safe_push (bpf_core_sections, sec);
+  sec->core_info.num_info += 1;
 }
 
 /* Return the 0-based index of the field NODE in its containing struct or union
@@ -243,6 +354,113 @@  bpf_core_get_sou_member_index (ctf_container_ref ctfc, const tree node)
   return -1;
 }
 
+/* Helper function to check if a particular named function exists as a
+   BTF_KIND_FUNC type record.  */
+
+static bool
+btf_funcinfo_type_callback (ctf_dtdef_ref func, void *data)
+{
+  struct btf_ext_funcinfo *info = (struct btf_ext_funcinfo *) data;
+  if (strcmp (func->dtd_name, info->fnname) == 0)
+    {
+      uint32_t type = func->dtd_type;
+      info->type = type;
+      return true;
+    }
+  return false;
+}
+
+/* Entry point function to add a func_info  in local data structures
+   represented by info static variable.
+   This function is used in bpf.cc.  */
+
+struct btf_ext_funcinfo *
+btf_add_func_info_for (tree decl, const char *label)
+{
+  const char *fnname = IDENTIFIER_POINTER (DECL_NAME (decl));
+  const char *sec_name = decl_section_name (decl);
+
+  /* Finding suffixed function names, due to the function cloning base on
+     optimizations.
+     This is required to recover the original function name that is the one
+     used in BTF_KIND_FUNC type records.  */
+  const char *cp_ptr = strstr (fnname, ".");
+  if (cp_ptr != NULL)
+    {
+      char new_name[100];
+      strcpy (new_name, fnname);
+      int pos = cp_ptr - fnname;
+      new_name[pos] = 0;
+      fnname = ggc_strdup (new_name);
+    }
+
+  if (sec_name == NULL)
+    sec_name = ".text";
+
+  struct btf_ext_info_sec *sec = NULL;
+  struct btf_ext_funcinfo *info =
+    bpf_create_or_find_funcinfo (fnname, sec_name, &sec);
+
+  info->label = label;
+  return info;
+}
+
+/* This function traverses all func_info entries and verified they do have a
+   BTF_KIND_FUNC type record associated.  If they do not it is marked as
+   invalided by clearing the associated label.  */
+
+static void
+btf_validate_funcinfo (btf_ext_info_sec *sec)
+{
+  while (sec != NULL)
+    {
+      struct btf_ext_funcinfo *funcinfo = sec->func_info.head;
+      while (funcinfo != NULL)
+	{
+	  bool found = traverse_btf_func_types (btf_funcinfo_type_callback,
+						funcinfo);
+	  if (found == true)
+	    sec->func_info.num_info += 1;
+	  else
+	    funcinfo->label = NULL;
+
+	  funcinfo = funcinfo->next;
+	}
+      sec = sec->next;
+    }
+}
+
+/* Compute the section size in section for func_info, line_info and core_info
+   regions of .BTF.ext.  */
+
+static void
+btf_ext_info_len (uint32_t *fi_len, uint32_t *li_len, uint32_t *cr_len)
+{
+  *fi_len = *li_len = *cr_len = 0;
+  struct btf_ext_info_sec *tmp = btf_ext;
+  if (tmp != NULL)
+  while (tmp != NULL)
+    {
+      /* Size computation does 8 bytes per section entry plus num_info of the
+       * respective structure size:
+	  - 8 bytes for func_info,
+	  - 16 bytes for both line_info and core_info.  */
+      if (tmp->func_info.num_info > 0)
+	*fi_len +=  8 + (8 * tmp->func_info.num_info);
+      if (tmp->line_info.num_info > 0)
+	*li_len +=  8 + (16 * tmp->line_info.num_info);
+      if (tmp->core_info.num_info > 0)
+	*cr_len +=  8 + (16 * tmp->core_info.num_info);
+      tmp = tmp->next;
+    }
+
+  /* If there are entries within the regions, add 4 bytes to set the header of
+     the respective sections that contains the size for each of the entry.  */
+  *fi_len += *fi_len != 0 ? 4 : 0;
+  *li_len += *li_len != 0 ? 4 : 0;
+  *cr_len += *cr_len != 0 ? 4 : 0;
+}
+
 /* Compute and output the header of a .BTF.ext debug info section.  */
 
 static void
@@ -256,23 +474,19 @@  output_btfext_header (void)
   dw2_asm_output_data (1, 0, "btfext_flags");
   dw2_asm_output_data (4, sizeof (struct btf_ext_header), "btfext_hdr_len");
 
-  uint32_t func_info_off = 0, func_info_len = 0;
-  uint32_t line_info_off = 0, line_info_len = 0;
-  uint32_t core_relo_off = 0, core_relo_len = 0;
+  btf_validate_funcinfo (btf_ext);
 
-  /* Header core_relo_len is the sum total length in bytes of all CO-RE
-     relocation sections, plus the 4 byte record size.  */
-  size_t i;
-  bpf_core_section_ref sec;
-  core_relo_len += vec_safe_length (bpf_core_sections)
-    * sizeof (struct btf_ext_section_header);
+  uint32_t func_info_len = 0;
+  uint32_t line_info_len = 0;
+  uint32_t core_info_len = 0;
+  btf_ext_info_len (&func_info_len, &line_info_len, &core_info_len);
 
-  FOR_EACH_VEC_ELT (*bpf_core_sections, i, sec)
-    core_relo_len +=
-      vec_safe_length (sec->relocs) * sizeof (struct btf_ext_reloc);
+  if (!TARGET_BPF_CORE)
+    core_info_len = 0;
 
-  if (core_relo_len)
-    core_relo_len += sizeof (uint32_t);
+  uint32_t func_info_off = 0;
+  uint32_t line_info_off = func_info_len;
+  uint32_t core_info_off = line_info_off + line_info_len;
 
   dw2_asm_output_data (4, func_info_off, "func_info_offset");
   dw2_asm_output_data (4, func_info_len, "func_info_len");
@@ -280,47 +494,47 @@  output_btfext_header (void)
   dw2_asm_output_data (4, line_info_off, "line_info_offset");
   dw2_asm_output_data (4, line_info_len, "line_info_len");
 
-  dw2_asm_output_data (4, core_relo_off, "core_relo_offset");
-  dw2_asm_output_data (4, core_relo_len, "core_relo_len");
+  dw2_asm_output_data (4, core_info_off, "core_relo_offset");
+  dw2_asm_output_data (4, core_info_len, "core_relo_len");
 }
 
-/* Output a single CO-RE relocation record.  */
+/* Outputs func_info region on .BTF.ext.  */
 
 static void
-output_asm_btfext_core_reloc (bpf_core_reloc_ref bpfcr)
+output_btfext_func_info (struct btf_ext_info_sec *sec)
 {
-  bpf_core_extra_ref *info = bpf_comment_info->get (bpfcr);
-  gcc_assert (info != NULL);
-
-  bpfcr->bpfcr_astr_off += ctfc_get_strtab_len (ctf_get_tu_ctfc (),
-						CTF_STRTAB);
-
-  dw2_assemble_integer (4, gen_rtx_LABEL_REF (Pmode, bpfcr->bpfcr_insn_label));
-  fprintf (asm_out_file, "\t%s%s\n",
-	   flag_debug_asm ? ASM_COMMENT_START : "",
-	   (flag_debug_asm ? " bpfcr_insn" : ""));
-
-  /* Extract the pretty print for the type expression.  */
-  pretty_printer pp;
-  dump_generic_node (&pp, (*info)->type, 0, TDF_VOPS|TDF_MEMSYMS|TDF_SLIM,
-		     false);
-  char *str = xstrdup (pp_formatted_text (&pp));
-
-  dw2_asm_output_data (4, bpfcr->bpfcr_type, "bpfcr_type (%s)", str);
-  dw2_asm_output_data (4, bpfcr->bpfcr_astr_off, "bpfcr_astr_off (\"%s\")",
-			  (*info)->accessor_str);
-  dw2_asm_output_data (4, bpfcr->bpfcr_kind, "bpfcr_kind");
-}
-
-/* Output all CO-RE relocation records for a section.  */
-
-static void
-output_btfext_core_relocs (bpf_core_section_ref sec)
-{
-  size_t i;
-  bpf_core_reloc_ref bpfcr;
-  FOR_EACH_VEC_ELT (*(sec->relocs), i, bpfcr)
-    output_asm_btfext_core_reloc (bpfcr);
+  unsigned int str_aux_off = ctfc_get_strtab_len (ctf_get_tu_ctfc (),
+						  CTF_STRTAB);
+  bool executed = false;
+  while (sec != NULL)
+    {
+      uint32_t count = 0;
+      if (sec->func_info.num_info > 0)
+	{
+	  if (executed == false && (executed = true))
+	    dw2_asm_output_data (4, 8, "FuncInfo entry size");
+	  dw2_asm_output_data (4, sec->sec_name_off + str_aux_off,
+			       "FuncInfo section string for %s",
+			       sec->sec_name);
+	  dw2_asm_output_data (4, sec->func_info.num_info, "Number of entries");
+
+	  struct btf_ext_funcinfo *elem = sec->func_info.head;
+	  while (elem != NULL)
+	    {
+	      if (elem->label != NULL)
+		{
+		  count += 1;
+		  dw2_asm_output_offset (4, elem->label,
+		       NULL, "label for function %s", elem->fnname);
+		  dw2_asm_output_data (4, elem->type, "btf_type_id");
+		}
+	      elem = elem->next;
+	    }
+	}
+
+      gcc_assert (count == sec->func_info.num_info);
+      sec = sec->next;
+    }
 }
 
 /* Output all CO-RE relocation sections.  */
@@ -328,28 +542,51 @@  output_btfext_core_relocs (bpf_core_section_ref sec)
 static void
 output_btfext_core_sections (void)
 {
-  size_t i;
-  bpf_core_section_ref sec;
-
-  /* BTF Ext section info. */
-  dw2_asm_output_data (4, sizeof (struct btf_ext_reloc),
-		       "btfext_core_info_rec_size");
-
-  FOR_EACH_VEC_ELT (*bpf_core_sections, i, sec)
+  struct btf_ext_info_sec *sec = btf_ext;
+  unsigned int str_aux_off = ctfc_get_strtab_len (ctf_get_tu_ctfc (),
+						  CTF_STRTAB);
+  bool executed = false;
+  while (sec != NULL)
     {
-      /* Section name offset, refers to the offset of a string with the name of
-	 the section to which these CORE relocations refer, e.g. '.text'.
-	 The string is buffered in the BTF strings table.  */
-
-      /* BTF specific strings are in CTF_AUX_STRTAB, which is concatenated
-	 after CTF_STRTAB. Add the length of STRTAB to the final offset.  */
-      sec->name_offset += ctfc_get_strtab_len (ctf_get_tu_ctfc (), CTF_STRTAB);
-
-      dw2_asm_output_data (4, sec->name_offset,  "btfext_secinfo_sec_name_off");
-      dw2_asm_output_data (4, vec_safe_length (sec->relocs),
-			   "btfext_secinfo_num_recs");
-
-      output_btfext_core_relocs (sec);
+      uint32_t count = 0;
+      if (sec->core_info.num_info > 0)
+	{
+	  if (executed == false && (executed = true))
+	    dw2_asm_output_data (4, 16, "CoreInfo entry size");
+	  dw2_asm_output_data (4, sec->sec_name_off + str_aux_off,
+			       "CoreInfo section string for %s",
+			       sec->sec_name);
+	  dw2_asm_output_data (4, sec->core_info.num_info, "Number of entries");
+
+	  struct btf_ext_core_reloc *bpfcr = sec->core_info.head;
+	  while (bpfcr != NULL)
+	    {
+	      count += 1;
+	      dw2_assemble_integer (4,
+			gen_rtx_LABEL_REF (Pmode, bpfcr->bpfcr_insn_label));
+	      fprintf (asm_out_file, "\t%s%s\n",
+		       flag_debug_asm ? ASM_COMMENT_START : "",
+		       (flag_debug_asm ? " bpfcr_insn" : ""));
+
+	      /* Extract the pretty print for the type expression.  */
+	      pretty_printer pp;
+	      dump_generic_node (&pp, bpfcr->info.type, 0,
+				 TDF_VOPS|TDF_MEMSYMS|TDF_SLIM,
+				 false);
+	      char *str = xstrdup (pp_formatted_text (&pp));
+
+	      dw2_asm_output_data (4, bpfcr->bpfcr_type, "bpfcr_type (%s)",
+				   str);
+	      dw2_asm_output_data (4, bpfcr->bpfcr_astr_off + str_aux_off,
+				   "bpfcr_astr_off (\"%s\")",
+				   bpfcr->info.accessor_str);
+	      dw2_asm_output_data (4, bpfcr->bpfcr_kind, "bpfcr_kind");
+	      bpfcr = bpfcr->next;
+	    }
+	}
+
+      gcc_assert (count == sec->core_info.num_info);
+      sec = sec->next;
     }
 }
 
@@ -362,22 +599,23 @@  btf_ext_init (void)
 				      BTF_EXT_INFO_SECTION_FLAGS, NULL);
 
   ASM_GENERATE_INTERNAL_LABEL (btf_ext_info_section_label,
-			       BTF_EXT_INFO_SECTION_LABEL,
-			       btf_ext_label_num++);
-
-  vec_alloc (bpf_core_sections, 1);
-  bpf_comment_info = hash_map<bpf_core_reloc_ref, bpf_core_extra_ref>::create_ggc ();
+			       "Lbtfext", 0);
 }
 
+
 /* Output the entire .BTF.ext section.  */
 
 void
 btf_ext_output (void)
 {
   output_btfext_header ();
-  output_btfext_core_sections ();
+  output_btfext_func_info (btf_ext);
+  if (TARGET_BPF_CORE)
+    output_btfext_core_sections ();
 
-  bpf_core_sections = NULL;
+  /* Extra padding required by BPF code, just in case all structures are empty.
+  */
+  dw2_asm_output_data (4, 0, "Required padding by libbpf structs");
 }
 
 #include "gt-coreout.h"
diff --git a/gcc/config/bpf/coreout.h b/gcc/config/bpf/coreout.h
index 8a209f26e94b..1c26b9274739 100644
--- a/gcc/config/bpf/coreout.h
+++ b/gcc/config/bpf/coreout.h
@@ -38,22 +38,6 @@  struct btf_ext_section_header
   uint32_t num_records;
 };
 
-/* A funcinfo record, in the .BTF.ext funcinfo section.  */
-struct btf_ext_funcinfo
-{
-  uint32_t insn_off; /* Offset of the first instruction of the function.  */
-  uint32_t type;     /* Type ID of a BTF_KIND_FUNC type.  */
-};
-
-/* A lineinfo record, in the .BTF.ext lineinfo section.  */
-struct btf_ext_lineinfo
-{
-  uint32_t insn_off;      /* Offset of the instruction.  */
-  uint32_t file_name_off; /* Offset of file name in BTF string table.  */
-  uint32_t line_off;      /* Offset of source line in BTF string table.  */
-  uint32_t line_col;      /* Line number (bits 31-11) and column (11-0).  */
-};
-
 enum btf_core_reloc_kind
 {
   BPF_RELO_INVALID = -1,
@@ -113,6 +97,10 @@  bpf_core_reloc_add (const tree type, const char * section_name,
 
 extern int bpf_core_get_sou_member_index (ctf_container_ref, const tree);
 
+struct btf_ext_funcinfo *btf_add_func_info_for (tree decl,
+						const char *label);
+unsigned int btf_ext_add_string (const char *str);
+
 #ifdef	__cplusplus
 }
 #endif
diff --git a/gcc/testsuite/gcc.target/bpf/btfext-funcinfo-nocore.c b/gcc/testsuite/gcc.target/bpf/btfext-funcinfo-nocore.c
new file mode 100644
index 000000000000..09d3acc8c2d4
--- /dev/null
+++ b/gcc/testsuite/gcc.target/bpf/btfext-funcinfo-nocore.c
@@ -0,0 +1,42 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O2 -dA -gbtf -mno-co-re" } */
+
+struct T {
+  int a;
+  int b;
+  struct U {
+    int c;
+    struct V {
+      int d;
+      int e[4];
+      int f;
+    } v;
+  } u;
+} __attribute__((preserve_access_index));
+
+__attribute__((section("foo_sec"), used))
+int foo_func (struct T *t)
+{
+  t->u.c = 5;
+  return t->u.v.e[3];
+}
+
+__attribute__((section("bar_sec"), used))
+int bar_func (struct T *t)
+{
+  int *x = &(t->u.v.f);
+  int old = *x;
+  *x = 4;
+  return old;
+}
+
+/* { dg-final { scan-assembler-times "FuncInfo section string for foo_sec" 1 } } */
+/* { dg-final { scan-assembler-times "FuncInfo section string for bar_sec" 1 } } */
+/* { dg-final { scan-assembler-times "label for function foo_func" 1 } } */
+/* { dg-final { scan-assembler-times "label for function bar_func" 1 } } */
+/* { dg-final { scan-assembler-times ".4byte\t0x1\t# Number of entries" 2 } } */
+/* { dg-final { scan-assembler-times "Required padding" 1 } } */
+
+/* { dg-final { scan-assembler-times "ascii \"foo_sec.0\"\[\t \]+\[^\n\]*btf_aux_string" 1 } } */
+/* { dg-final { scan-assembler-times "ascii \"bar_sec.0\"\[\t \]+\[^\n\]*btf_aux_string" 1 } } */
+
diff --git a/gcc/testsuite/gcc.target/bpf/btfext-funcinfo.c b/gcc/testsuite/gcc.target/bpf/btfext-funcinfo.c
new file mode 100644
index 000000000000..a59c5bd37eb9
--- /dev/null
+++ b/gcc/testsuite/gcc.target/bpf/btfext-funcinfo.c
@@ -0,0 +1,46 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O2 -dA -gbtf" } */
+
+struct T {
+  int a;
+  int b;
+  struct U {
+    int c;
+    struct V {
+      int d;
+      int e[4];
+      int f;
+    } v;
+  } u;
+} __attribute__((preserve_access_index));
+
+__attribute__((section("foo_sec"), used))
+int foo_func (struct T *t)
+{
+  t->u.c = 5;
+  return t->u.v.e[3];
+}
+
+__attribute__((section("bar_sec"), used))
+int bar_func (struct T *t)
+{
+  int *x = &(t->u.v.f);
+  int old = *x;
+  *x = 4;
+  return old;
+}
+
+/* { dg-final { scan-assembler-times "FuncInfo section string for foo_sec" 1 } } */
+/* { dg-final { scan-assembler-times "FuncInfo section string for bar_sec" 1 } } */
+/* { dg-final { scan-assembler-times "label for function foo_func" 1 } } */
+/* { dg-final { scan-assembler-times "label for function bar_func" 1 } } */
+
+/* { dg-final { scan-assembler-times "ascii \"0:2:1:1:3.0\"\[\t \]+\[^\n\]*btf_aux_string" 1 } } */
+/* { dg-final { scan-assembler-times "ascii \"0:2:1:2.0\"\[\t \]+\[^\n\]*btf_aux_string" 1 } } */
+/* { dg-final { scan-assembler-times "ascii \"foo_sec.0\"\[\t \]+\[^\n\]*btf_aux_string" 1 } } */
+/* { dg-final { scan-assembler-times "ascii \"bar_sec.0\"\[\t \]+\[^\n\]*btf_aux_string" 1 } } */
+/* { dg-final { scan-assembler-times "FuncInfo entry size" 1 } } */
+
+/* { dg-final { scan-assembler-times ".4byte\t0x1\t# Number of entries" 3 } } */
+/* { dg-final { scan-assembler-times ".4byte\t0x2\t# Number of entries" 1 } } */
+/* { dg-final { scan-assembler-times "Required padding" 1 } } */
diff --git a/gcc/testsuite/gcc.target/bpf/core-attr-5.c b/gcc/testsuite/gcc.target/bpf/core-attr-5.c
index c0dc15fbb271..e71901d0d4d1 100644
--- a/gcc/testsuite/gcc.target/bpf/core-attr-5.c
+++ b/gcc/testsuite/gcc.target/bpf/core-attr-5.c
@@ -55,8 +55,13 @@  func (struct T *t, int i)
 /* { dg-final { scan-assembler-times "ascii \"0:4.0\"\[\t \]+\[^\n\]*btf_aux_string" 1 } } */
 /* { dg-final { scan-assembler-times "ascii \"0:1:1:3.0\"\[\t \]+\[^\n\]*btf_aux_string" 1 } } */
 /* { dg-final { scan-assembler-times "ascii \"0:1:1:1.0\"\[\t \]+\[^\n\]*btf_aux_string" 1 } } */
-/* { dg-final { scan-assembler-times "ascii \"0:3.0\"\[\t \]+\[^\n\]*btf_aux_string" 2 } } */
+/* { dg-final { scan-assembler-times "ascii \"0:3.0\"\[\t \]+\[^\n\]*btf_aux_string" 1 } } */
 /* { dg-final { scan-assembler-times "ascii \"0:0.0\"\[\t \]+\[^\n\]*btf_aux_string" 1 } } */
+/* { dg-final { scan-assembler-times "bpfcr_astr_off \\(\"0:1:1:3\"\\)" 1 } } */
+/* { dg-final { scan-assembler-times "bpfcr_astr_off \\(\"0:4\"\\)" 1 } } */
+/* { dg-final { scan-assembler-times "bpfcr_astr_off \\(\"0:3\"\\)" 2 } } */
+/* { dg-final { scan-assembler-times "bpfcr_astr_off \\(\"0:1:2\"\\)" 1 } } */
+/* { dg-final { scan-assembler-times "bpfcr_astr_off \\(\"0:1:1:1\"\\)" 1 } } */
+/* { dg-final { scan-assembler-times "bpfcr_astr_off \\(\"0:0\"\\)" 1 } } */
 /* { dg-final { scan-assembler-times "bpfcr_type \\(struct T \\*\\)" 4 } } */
 /* { dg-final { scan-assembler-times "bpfcr_type \\(struct U \\*\\)" 4 { xfail *-*-* } } } */
-
diff --git a/gcc/testsuite/gcc.target/bpf/core-attr-6.c b/gcc/testsuite/gcc.target/bpf/core-attr-6.c
index 858ae627cb8b..34a4c367e528 100644
--- a/gcc/testsuite/gcc.target/bpf/core-attr-6.c
+++ b/gcc/testsuite/gcc.target/bpf/core-attr-6.c
@@ -37,10 +37,14 @@  func (struct T *t, int i)
   mset (&t->a);
 }
 
-/* { dg-final { scan-assembler-times "ascii \"0:3.0\"\[\t \]+\[^\n\]*btf_aux_string" 2 } } */
+/* { dg-final { scan-assembler-times "ascii \"0:3.0\"\[\t \]+\[^\n\]*btf_aux_string" 1 } } */
 /* { dg-final { scan-assembler-times "ascii \"0:1:1:1.0\"\[\t \]+\[^\n\]*btf_aux_string" 1 } } */
 /* { dg-final { scan-assembler-times "ascii \"0:1:2.0\"\[\t \]+\[^\n\]*btf_aux_string" 1 } } */
 /* { dg-final { scan-assembler-times "ascii \"0:0.0\"\[\t \]+\[^\n\]*btf_aux_string" 1 } } */
+/* { dg-final { scan-assembler-times "bpfcr_astr_off \\(\"0:1:1:1\"\\)" 1 } } */
+/* { dg-final { scan-assembler-times "bpfcr_astr_off \\(\"0:3\"\\)" 2 } } */
+/* { dg-final { scan-assembler-times "bpfcr_astr_off \\(\"0:1:2\"\\)" 1 } } */
+/* { dg-final { scan-assembler-times "bpfcr_astr_off \\(\"0:0\"\\)" 1 } } */
 /* { dg-final { scan-assembler-times "bpfcr_type \\(struct T \\*\\)" 3 } } */
 /* { dg-final { scan-assembler-times "bpfcr_type \\(struct U \\*\\)" 2 } } */
 
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 a4af9a53282a..27654205287d 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
@@ -52,9 +52,18 @@  unsigned int foo (struct T *t)
 /* { dg-final { scan-assembler-times "ascii \"0:1:0:3.0\"\[\t \]+\[^\n\]*btf_aux_string" 1 } } */
 /* { dg-final { scan-assembler-times "ascii \"0:1:0:4.0\"\[\t \]+\[^\n\]*btf_aux_string" 1 } } */
 /* { dg-final { scan-assembler-times "ascii \"0:1:1:0.0\"\[\t \]+\[^\n\]*btf_aux_string" 1 } } */
-/* { dg-final { scan-assembler-times "ascii \"0:1:1:3.0\"\[\t \]+\[^\n\]*btf_aux_string" 2 } } */
+/* { dg-final { scan-assembler-times "ascii \"0:1:1:3.0\"\[\t \]+\[^\n\]*btf_aux_string" 1 } } */
 /* { dg-final { scan-assembler-times "ascii \"0:1:1:4.0\"\[\t \]+\[^\n\]*btf_aux_string" 1 } } */
 /* { dg-final { scan-assembler-times "ascii \"0:2.0\"\[\t \]+\[^\n\]*btf_aux_string" 1 } } */
-/* { dg-final { scan-assembler-times "ascii \"0:3.0\"\[\t \]+\[^\n\]*btf_aux_string" 2 } } */
+/* { dg-final { scan-assembler-times "ascii \"0:3.0\"\[\t \]+\[^\n\]*btf_aux_string" 1 } } */
+
+/* { dg-final { scan-assembler-times "bpfcr_astr_off \\(\"0:1:0:0\"\\)" 1 } } */
+/* { dg-final { scan-assembler-times "bpfcr_astr_off \\(\"0:1:0:3\"\\)" 1 } } */
+/* { dg-final { scan-assembler-times "bpfcr_astr_off \\(\"0:1:0:4\"\\)" 1 } } */
+/* { dg-final { scan-assembler-times "bpfcr_astr_off \\(\"0:1:1:0\"\\)" 1 } } */
+/* { dg-final { scan-assembler-times "bpfcr_astr_off \\(\"0:1:1:3\"\\)" 2 } } */
+/* { 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 "0\[\t \]+\[^\n\]*bpfcr_kind" 10 } } */
diff --git a/gcc/testsuite/gcc.target/bpf/core-section-1.c b/gcc/testsuite/gcc.target/bpf/core-section-1.c
index 4f16b087c1a2..c2bac46cee78 100644
--- a/gcc/testsuite/gcc.target/bpf/core-section-1.c
+++ b/gcc/testsuite/gcc.target/bpf/core-section-1.c
@@ -35,4 +35,4 @@  int bar_func (struct T *t)
 /* { dg-final { scan-assembler-times "ascii \"foo_sec.0\"\[\t \]+\[^\n\]*btf_aux_string" 1 } } */
 /* { dg-final { scan-assembler-times "ascii \"bar_sec.0\"\[\t \]+\[^\n\]*btf_aux_string" 1 } } */
 /* { dg-final { scan-assembler-times "bpfcr_type" 2 } } */
-/* { dg-final { scan-assembler-times "btfext_core_info_rec_size" 1 } } */
+/* { dg-final { scan-assembler-times "CoreInfo entry size" 1 } } */