From 64d6e3e3b62523b7c33d7206413b2f7c892ce047 Mon Sep 17 00:00:00 2001
From: Dave Tucker <dave@dtucker.co.uk>
Date: Wed, 2 Aug 2023 18:33:13 +0100
Subject: [PATCH] aya: Fix (func|line)_info multiple progs in section

This commit fixes the (func|line)_info when we have multiple programs in
the same section. The integration test reloc.bpf.c serves as our test
case here. This required filtering down the (func|line)_info to only
that in scope of the current symbol + then adjusting the offets to
appease the kernel.

Signed-off-by: Dave Tucker <dave@dtucker.co.uk>
---
 aya-obj/src/obj.rs                    | 20 ++++++++++++++++++--
 test/integration-test/bpf/reloc.bpf.c | 26 +++++++-------------------
 2 files changed, 25 insertions(+), 21 deletions(-)

diff --git a/aya-obj/src/obj.rs b/aya-obj/src/obj.rs
index eb16ba47..1daaa09d 100644
--- a/aya-obj/src/obj.rs
+++ b/aya-obj/src/obj.rs
@@ -614,10 +614,26 @@ impl Object {
         name: String,
         symbol: &Symbol,
     ) -> Result<(Program, Function), ParseError> {
+        let offset = symbol.address as usize - section.address as usize;
         let (func_info, line_info, func_info_rec_size, line_info_rec_size) =
             if let Some(btf_ext) = &self.btf_ext {
-                let func_info = btf_ext.func_info.get(section.name);
-                let line_info = btf_ext.line_info.get(section.name);
+                let bytes_offset = offset as u32 / INS_SIZE as u32;
+                let section_size_bytes = symbol.size as u32 / INS_SIZE as u32;
+
+                let mut func_info = btf_ext.func_info.get(section.name);
+                func_info.func_info.retain(|f| f.insn_off == bytes_offset);
+                func_info.func_info.iter_mut().for_each(|f| {
+                    f.insn_off -= bytes_offset;
+                });
+
+                let mut line_info = btf_ext.line_info.get(section.name);
+                line_info.line_info.retain(|l| {
+                    l.insn_off >= bytes_offset && l.insn_off < (bytes_offset + section_size_bytes)
+                });
+                line_info.line_info.iter_mut().for_each(|f| {
+                    f.insn_off -= bytes_offset;
+                });
+
                 (
                     func_info,
                     line_info,
diff --git a/test/integration-test/bpf/reloc.bpf.c b/test/integration-test/bpf/reloc.bpf.c
index 510406dd..dbc464a4 100644
--- a/test/integration-test/bpf/reloc.bpf.c
+++ b/test/integration-test/bpf/reloc.bpf.c
@@ -29,9 +29,7 @@ __attribute__((noinline)) int field_global() {
   return set_output(__builtin_preserve_access_index(s.b));
 }
 
-SEC("uprobe/field") int field(void *ctx) {
-  return field_global();
-}
+SEC("uprobe") int field(void *ctx) { return field_global(); }
 
 struct relocated_struct_with_pointer {
   struct relocated_struct_with_pointer *first;
@@ -46,9 +44,7 @@ __attribute__((noinline)) int pointer_global() {
   return set_output((__u64)__builtin_preserve_access_index(s.first));
 }
 
-SEC("uprobe/pointer") int pointer(void *ctx) {
-  return pointer_global();
-}
+SEC("uprobe") int pointer(void *ctx) { return pointer_global(); }
 
 __attribute__((noinline)) int struct_flavors_global() {
   struct relocated_struct_with_scalars s = {1, 2, 3};
@@ -59,9 +55,7 @@ __attribute__((noinline)) int struct_flavors_global() {
   }
 }
 
-SEC("uprobe/struct_flavors") int struct_flavors(void *ctx) {
-  return struct_flavors_global();
-}
+SEC("uprobe") int struct_flavors(void *ctx) { return struct_flavors_global(); }
 
 enum relocated_enum_unsigned_32 { U32 = 0xAAAAAAAA };
 
@@ -69,8 +63,7 @@ __attribute__((noinline)) int enum_unsigned_32_global() {
   return set_output(bpf_core_enum_value(enum relocated_enum_unsigned_32, U32));
 }
 
-SEC("uprobe/enum_unsigned_32")
-int enum_unsigned_32(void *ctx) {
+SEC("uprobe") int enum_unsigned_32(void *ctx) {
   return enum_unsigned_32_global();
 }
 
@@ -80,9 +73,7 @@ __attribute__((noinline)) int enum_signed_32_global() {
   return set_output(bpf_core_enum_value(enum relocated_enum_signed_32, S32));
 }
 
-SEC("uprobe/enum_signed_32") int enum_signed_32(void *ctx) {
-  return enum_signed_32_global();
-}
+SEC("uprobe") int enum_signed_32(void *ctx) { return enum_signed_32_global(); }
 
 enum relocated_enum_unsigned_64 { U64 = 0xAAAAAAAABBBBBBBB };
 
@@ -90,8 +81,7 @@ __attribute__((noinline)) int enum_unsigned_64_global() {
   return set_output(bpf_core_enum_value(enum relocated_enum_unsigned_64, U64));
 }
 
-SEC("uprobe/enum_unsigned_64")
-int enum_unsigned_64(void *ctx) {
+SEC("uprobe") int enum_unsigned_64(void *ctx) {
   return enum_unsigned_64_global();
 }
 
@@ -101,6 +91,4 @@ __attribute__((noinline)) int enum_signed_64_global() {
   return set_output(bpf_core_enum_value(enum relocated_enum_signed_64, u64));
 }
 
-SEC("uprobe/enum_signed_64") int enum_signed_64(void *ctx) {
-  return enum_signed_64_global();
-}
+SEC("uprobe") int enum_signed_64(void *ctx) { return enum_signed_64_global(); }