perf jit: Include program header in ELF files

The missing header makes it hard for programs like elfutils to open
these files.

Fixes: 2d86612 ("perf symbol: Correct address for bss symbols")
Reviewed-by: Leo Yan <[email protected]>
Signed-off-by: Lieven Hey <[email protected]>
Tested-by: Leo Yan <[email protected]>
Cc: Leo Yan <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

Author: lievenhey

tools/perf/util/genelf.c

@@ -253,6 +253,7 @@ jit_write_elf(int fd, uint64_t load_addr, const char *sym,
 	Elf_Data *d;
 	Elf_Scn *scn;
 	Elf_Ehdr *ehdr;
+	Elf_Phdr *phdr;
 	Elf_Shdr *shdr;
 	uint64_t eh_frame_base_offset;
 	char *strsym = NULL;
@@ -287,6 +288,19 @@ jit_write_elf(int fd, uint64_t load_addr, const char *sym,
 	ehdr->e_version = EV_CURRENT;
 	ehdr->e_shstrndx= unwinding ? 4 : 2; /* shdr index for section name */
 
+	/*
+	 * setup program header
+	 */
+	phdr = elf_newphdr(e, 1);
+	phdr[0].p_type = PT_LOAD;
+	phdr[0].p_offset = 0;
+	phdr[0].p_vaddr = 0;
+	phdr[0].p_paddr = 0;
+	phdr[0].p_filesz = csize;
+	phdr[0].p_memsz = csize;
+	phdr[0].p_flags = PF_X | PF_R;
+	phdr[0].p_align = 8;
+
 	/*
 	 * setup text section
 	 */

tools/perf/util/genelf.h

@@ -53,17 +53,21 @@ int jit_add_debug_info(Elf *e, uint64_t code_addr, void *debug, int nr_debug_ent
 
 #if GEN_ELF_CLASS == ELFCLASS64
 #define elf_newehdr	elf64_newehdr
+#define elf_newphdr	elf64_newphdr
 #define elf_getshdr	elf64_getshdr
 #define Elf_Ehdr	Elf64_Ehdr
+#define Elf_Phdr	Elf64_Phdr
 #define Elf_Shdr	Elf64_Shdr
 #define Elf_Sym		Elf64_Sym
 #define ELF_ST_TYPE(a)	ELF64_ST_TYPE(a)
 #define ELF_ST_BIND(a)	ELF64_ST_BIND(a)
 #define ELF_ST_VIS(a)	ELF64_ST_VISIBILITY(a)
 #else
 #define elf_newehdr	elf32_newehdr
+#define elf_newphdr	elf32_newphdr
 #define elf_getshdr	elf32_getshdr
 #define Elf_Ehdr	Elf32_Ehdr
+#define Elf_Phdr	Elf32_Phdr
 #define Elf_Shdr	Elf32_Shdr
 #define Elf_Sym		Elf32_Sym
 #define ELF_ST_TYPE(a)	ELF32_ST_TYPE(a)