@@ -30,19 +30,7 @@
#include <unistd.h>
#include "jit-protocol.h"
-
-/* ElfW is coming from linux. On other platforms it does not exist.
- Let us define it here. */
-#ifndef ElfW
-# if (defined (_LP64) || defined (__LP64__))
-# define WORDSIZE 64
-# else
-# define WORDSIZE 32
-# endif /* _LP64 || __LP64__ */
-#define ElfW(type) _ElfW (Elf, WORDSIZE, type)
-#define _ElfW(e,w,t) _ElfW_1 (e, w, _##t)
-#define _ElfW_1(e,w,t) e##w##t
-#endif /* !ElfW */
+#include "jit-elf-util.h"
static void
usage ()
@@ -51,35 +39,6 @@ usage ()
exit (1);
}
-/* Rename jit_function_XXXX to match idx */
-
-static void
-update_name (const void *const addr, int idx)
-{
- const ElfW (Ehdr) *const ehdr = (ElfW (Ehdr) *)addr;
- ElfW (Shdr) *const shdr = (ElfW (Shdr) *)((char *)addr + ehdr->e_shoff);
- ElfW (Phdr) *const phdr = (ElfW (Phdr) *)((char *)addr + ehdr->e_phoff);
- int i;
-
- for (i = 0; i < ehdr->e_shnum; ++i)
- {
- if (shdr[i].sh_type == SHT_STRTAB)
- {
- /* Note: we update both .strtab and .dynstr. The latter would
- not be correct if this were a regular shared library (.hash
- would be wrong), but this is a simulation -- the library is
- never exposed to the dynamic loader, so it all ends up ok. */
- char *const strtab = (char *)((ElfW (Addr))addr + shdr[i].sh_offset);
- char *const strtab_end = strtab + shdr[i].sh_size;
- char *p;
-
- for (p = strtab; p < strtab_end; p += strlen (p) + 1)
- if (strcmp (p, "jit_function_XXXX") == 0)
- sprintf (p, "jit_function_%04d", idx);
- }
- }
-}
-
/* Defined by the .exp file if testing attach. */
#ifndef ATTACH
#define ATTACH 0
@@ -122,39 +81,20 @@ MAIN (int argc, char *argv[])
for (i = 1; i < argc; ++i)
{
- struct stat st;
- int fd;
-
- printf ("%s:%d: libname = %s, i = %d\n", __FILE__, __LINE__, argv[i], i);
- if ((fd = open (argv[i], O_RDONLY)) == -1)
- {
- fprintf (stderr, "open (\"%s\", O_RDONLY): %s\n", argv[i],
- strerror (errno));
- exit (1);
- }
-
- if (fstat (fd, &st) != 0)
- {
- fprintf (stderr, "fstat (\"%d\"): %s\n", fd, strerror (errno));
- exit (1);
- }
-
- void* load_addr = (void*) (size_t) (LOAD_ADDRESS + (i-1) * LOAD_INCREMENT);
- const void *const addr = mmap (load_addr, st.st_size, PROT_READ|PROT_WRITE,
- MAP_PRIVATE, fd, 0);
- struct jit_code_entry *const entry = calloc (1, sizeof (*entry));
-
- if (addr == MAP_FAILED)
- {
- fprintf (stderr, "mmap: %s\n", strerror (errno));
- exit (1);
- }
-
+ size_t obj_size;
+ ElfW (Addr) load_addr = LOAD_ADDRESS + (i-1) * LOAD_INCREMENT;
+ printf("Loading %s as JIT at %p\n", argv[i], (void*) load_addr);
+ ElfW (Addr) addr = load_elf (argv[i], &obj_size, load_addr);
update_name (addr, i);
+ char name[32];
+ sprintf (name, "jit_function_%04d", i);
+ int (*jit_function) () = (int (*) ()) load_symbol (addr, name);
+
/* Link entry at the end of the list. */
+ struct jit_code_entry *const entry = calloc (1, sizeof (*entry));
entry->symfile_addr = (const char *)addr;
- entry->symfile_size = st.st_size;
+ entry->symfile_size = obj_size;
entry->prev_entry = __jit_debug_descriptor.relevant_entry;
__jit_debug_descriptor.relevant_entry = entry;
@@ -166,6 +106,12 @@ MAIN (int argc, char *argv[])
/* Notify GDB. */
__jit_debug_descriptor.action_flag = JIT_REGISTER;
__jit_debug_register_code ();
+
+ if (jit_function () != 42)
+ {
+ fprintf (stderr, "unexpected return value\n");
+ exit (1);
+ }
}
WAIT_FOR_GDB; i = 0; /* gdb break here 1 */
new file mode 100644
@@ -0,0 +1,145 @@
+/* This test program is part of GDB, the GNU debugger.
+
+ Copyright 2020 Free Software Foundation, Inc.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+/* Simulates loading of JIT code by memory mapping a compiled
+ shared library binary and doing minimal post-processing. */
+
+#include <elf.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <link.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+/* ElfW is coming from linux. On other platforms it does not exist.
+ Let us define it here. */
+#ifndef ElfW
+#if (defined(_LP64) || defined(__LP64__))
+#define WORDSIZE 64
+#else
+#define WORDSIZE 32
+#endif /* _LP64 || __LP64__ */
+#define ElfW(type) _ElfW (Elf, WORDSIZE, type)
+#define _ElfW(e, w, t) _ElfW_1 (e, w, _##t)
+#define _ElfW_1(e, w, t) e##w##t
+#endif /* !ElfW */
+
+/* Looks into string tables for entry
+ "jit_function_XXXX" and updates it to use `rename_num`. */
+static void
+update_name (ElfW (Addr) addr, int rename_num)
+{
+ const ElfW (Ehdr) *const ehdr = (ElfW (Ehdr) *) addr;
+ ElfW (Shdr) *const shdr = (ElfW (Shdr) *) ((char *) addr + ehdr->e_shoff);
+ ElfW (Phdr) *const phdr = (ElfW (Phdr) *) ((char *) addr + ehdr->e_phoff);
+
+ for (int i = 0; i < ehdr->e_shnum; ++i)
+ {
+ if (shdr[i].sh_type == SHT_STRTAB)
+ {
+ /* Note: we update both .strtab and .dynstr. The latter would
+ not be correct if this were a regular shared library (.hash
+ would be wrong), but this is a simulation -- the library is
+ never exposed to the dynamic loader, so it all ends up ok. */
+ char *const strtab = (char *) (addr + shdr[i].sh_offset);
+ char *const strtab_end = strtab + shdr[i].sh_size;
+ char *p;
+
+ for (p = strtab; p < strtab_end; p += strlen (p) + 1)
+ if (strcmp (p, "jit_function_XXXX") == 0)
+ sprintf (p, "jit_function_%04d", rename_num);
+ }
+ }
+}
+
+/* Find symbol with the name `sym_name`. */
+static ElfW (Addr)
+load_symbol (ElfW (Addr) addr, const char *sym_name)
+{
+ const ElfW (Ehdr) *const ehdr = (ElfW (Ehdr) *) addr;
+ ElfW (Shdr) *const shdr = (ElfW (Shdr) *) ((char *) addr + ehdr->e_shoff);
+
+ ElfW (Addr) sym_old_addr = 0;
+ ElfW (Addr) sym_new_addr = 0;
+
+ /* Find `func_name` in symbol_table and adjust it from the addr. */
+
+ for (int i = 0; i < ehdr->e_shnum; ++i)
+ {
+ if (shdr[i].sh_type == SHT_SYMTAB)
+ {
+ ElfW (Sym) *symtab = (ElfW (Sym) *) (addr + shdr[i].sh_offset);
+ ElfW (Sym) *symtab_end
+ = (ElfW (Sym) *) (addr + shdr[i].sh_offset + shdr[i].sh_size);
+ char *const strtab
+ = (char *) (addr + shdr[shdr[i].sh_link].sh_offset);
+
+ for (ElfW (Sym) *p = symtab; p < symtab_end; ++p)
+ {
+ const char *s = strtab + p->st_name;
+ if (strcmp (s, sym_name) == 0)
+ return p->st_value;
+ }
+ }
+ }
+
+ fprintf (stderr, "symbol '%s' not found\n", sym_name);
+ exit (1);
+ return 0;
+}
+
+/* Open an elf binary file and memory map it with execution flag enabled. */
+ElfW (Addr)
+load_elf (const char *libname, size_t *size, ElfW (Addr) load_addr)
+{
+ int fd;
+ struct stat st;
+
+ if ((fd = open (libname, O_RDONLY)) == -1)
+ {
+ fprintf (stderr, "open (\"%s\", O_RDONLY): %s\n", libname,
+ strerror (errno));
+ exit (1);
+ }
+
+ if (fstat (fd, &st) != 0)
+ {
+ fprintf (stderr, "fstat (\"%d\"): %s\n", fd, strerror (errno));
+ exit (1);
+ }
+
+ void *addr = mmap ((void *) load_addr, st.st_size,
+ PROT_READ | PROT_WRITE | PROT_EXEC,
+ load_addr ? MAP_PRIVATE | MAP_FIXED : MAP_PRIVATE, fd, 0);
+ close (fd);
+
+ if (addr == MAP_FAILED)
+ {
+ fprintf (stderr, "mmap: %s\n", strerror (errno));
+ exit (1);
+ }
+
+ if (size != NULL)
+ *size = st.st_size;
+
+ return (ElfW (Addr)) addr;
+}
\ No newline at end of file