LibELF: Ignore RISC-V attribute section program header

We have to skip our usual validations, as the checks might not hold for
this program header type (and the checks wouldn't really make sense for
PT_RISCV_ATTRIBUTES either).

PT_RISCV_ATTRIBUTES is defined here:
https://github.com/riscv-non-isa/riscv-elf-psabi-doc/blob/v1.0/riscv-elf.adoc#program-header-table

Userland/Libraries/LibELF/ELFABI.h

@@ -482,18 +482,20 @@ typedef struct {
 } Elf64_Phdr;
 
 /* Segment types - p_type */
-#define PT_NULL 0            /* unused */
-#define PT_LOAD 1            /* loadable segment */
-#define PT_DYNAMIC 2         /* dynamic linking section */
-#define PT_INTERP 3          /* the RTLD */
-#define PT_NOTE 4            /* auxiliary information */
-#define PT_SHLIB 5           /* reserved - purpose undefined */
-#define PT_PHDR 6            /* program header */
-#define PT_TLS 7             /* thread local storage */
-#define PT_LOOS 0x60000000   /* reserved range for OS */
-#define PT_HIOS 0x6fffffff   /*  specific segment types */
-#define PT_LOPROC 0x70000000 /* reserved range for processor */
-#define PT_HIPROC 0x7fffffff /*  specific segment types */
+#define PT_NULL 0          /* unused */
+#define PT_LOAD 1          /* loadable segment */
+#define PT_DYNAMIC 2       /* dynamic linking section */
+#define PT_INTERP 3        /* the RTLD */
+#define PT_NOTE 4          /* auxiliary information */
+#define PT_SHLIB 5         /* reserved - purpose undefined */
+#define PT_PHDR 6          /* program header */
+#define PT_TLS 7           /* thread local storage */
+#define PT_LOOS 0x60000000 /* reserved range for OS */
+#define PT_HIOS 0x6fffffff /* specific segment types */
+
+#define PT_LOPROC 0x70000000           /* start of reserved range for processor specific segment types */
+#define PT_RISCV_ATTRIBUTES 0x70000003 /* RISC-V ELF attribute section */
+#define PT_HIPROC 0x7fffffff           /* end of reserved range for processor specific segment types */
 
 #define PT_GNU_EH_FRAME 0x6474e550 /* Exception handling info */
 #define PT_GNU_RELRO 0x6474e552    /* Read-only after relocation */

Userland/Libraries/LibELF/Validation.cpp

@@ -231,6 +231,12 @@ ErrorOr<bool> validate_program_headers(Elf_Ehdr const& elf_header, size_t file_s
     for (size_t header_index = 0; header_index < num_program_headers; ++header_index) {
         auto& program_header = program_header_begin[header_index];
 
+        if (elf_header.e_machine == EM_RISCV && program_header.p_type == PT_RISCV_ATTRIBUTES) {
+            // TODO: Handle RISC-V attribute section.
+            //       We have to continue here, as `p_memsz` is 0 when using the GNU toolchain
+            continue;
+        }
+
         if (program_header.p_filesz > program_header.p_memsz) {
             if (verbose)
                 dbgln("Program header ({}) has p_filesz ({}) larger than p_memsz ({})", header_index, program_header.p_filesz, program_header.p_memsz);