1 files changed, 37 insertions, 2 deletions

diff --git a/Userland/Libraries/LibELF/Relocation.cpp b/Userland/Libraries/LibELF/Relocation.cpp
index b3c84e4cbf..30bac88c5f 100644
--- a/Userland/Libraries/LibELF/Relocation.cpp
+++ b/Userland/Libraries/LibELF/Relocation.cpp
@@ -26,6 +26,9 @@ bool perform_relative_relocations(FlatPtr base_address)
     FlatPtr relocation_section_addr = 0;
     size_t relocation_table_size = 0;
     size_t relocation_count = 0;
+    size_t relocation_entry_size = 0;
+    FlatPtr relr_relocation_section_addr = 0;
+    size_t relr_relocation_table_size = 0;
     bool use_addend = false;
     auto* dyns = reinterpret_cast<const ElfW(Dyn)*>(dynamic_section_addr);
     for (unsigned i = 0;; ++i) {
@@ -40,11 +43,19 @@ bool perform_relative_relocations(FlatPtr base_address)
             relocation_count = dyn.d_un.d_val;
         else if (dyn.d_tag == DT_RELSZ || dyn.d_tag == DT_RELASZ)
             relocation_table_size = dyn.d_un.d_val;
+        else if (dyn.d_tag == DT_RELENT || dyn.d_tag == DT_RELAENT)
+            relocation_entry_size = dyn.d_un.d_val;
+        else if (dyn.d_tag == DT_RELR)
+            relr_relocation_section_addr = base_address + dyn.d_un.d_ptr;
+        else if (dyn.d_tag == DT_RELRSZ)
+            relr_relocation_table_size = dyn.d_un.d_val;
+        else if (dyn.d_tag == DT_RELRENT)
+            VERIFY(dyn.d_un.d_val == sizeof(FlatPtr));
     }
-    if (!relocation_section_addr || !relocation_table_size || !relocation_count)
+
+    if ((!relocation_section_addr || !relocation_table_size || !relocation_count) && (!relr_relocation_section_addr || !relr_relocation_table_size))
         return false;
 
-    auto relocation_entry_size = relocation_table_size / relocation_count;
     for (unsigned i = 0; i < relocation_count; ++i) {
         size_t offset_in_section = i * relocation_entry_size;
         auto* relocation = (ElfW(Rela)*)(relocation_section_addr + offset_in_section);
@@ -64,6 +75,30 @@ bool perform_relative_relocations(FlatPtr base_address)
         __builtin_memcpy(patch_address, &relocated_address, sizeof(relocated_address));
     }
 
+    auto patch_relr = [base_address](FlatPtr* patch_ptr) {
+        FlatPtr relocated_address;
+        __builtin_memcpy(&relocated_address, patch_ptr, sizeof(FlatPtr));
+        relocated_address += base_address;
+        __builtin_memcpy(patch_ptr, &relocated_address, sizeof(FlatPtr));
+    };
+
+    auto* entries = reinterpret_cast<ElfW(Relr)*>(relr_relocation_section_addr);
+    FlatPtr* patch_ptr = nullptr;
+
+    for (unsigned i = 0; i < relr_relocation_table_size / sizeof(FlatPtr); ++i) {
+        if ((entries[i] & 1u) == 0) {
+            patch_ptr = reinterpret_cast<FlatPtr*>(base_address + entries[i]);
+            patch_relr(patch_ptr);
+            ++patch_ptr;
+        } else {
+            unsigned j = 0;
+            for (auto bitmap = entries[i]; (bitmap >>= 1u) != 0; ++j)
+                if (bitmap & 1u)
+                    patch_relr(patch_ptr + j);
+
+            patch_ptr += 8 * sizeof(FlatPtr) - 1;
+        }
+    }
     return true;
 }
 }