OpenBSD: runtime fixes

After this commit we can compile and run code with some limitations. - The dlsym function is broken so this makes -run and bound checking not work all the time. Make -k test does work for most code. - You have to do: ln -s /usr/lib/libN.so.x.y /usr/lib/libN.so for all .so files in /usr/lib. OpenBSD uses opendir/readdir to find the correct so file. This is not the way other platforms do this. Also the .a versions do not have all symbols that are present in the .so files. tcc.h: - Use different dynamic loader elf.h: - Add SHT_X86_64_UNWIND tccelf.c: - Do not use -dl - Add required NOTE section - Add extra dynamic tags - Allow SHT_X86_64_UNWIND/SHT_NOTE in tcc_load_object_file tccrun.c: - Uses MAP_FIXED because without the offset between exec and data section becomes too big for x86_64 lib/bcheck.c: - Do not use __libc_freeres tests/tcctest.c: - aligned_function also disabled for __GNUC__ == 4

herman ten brugge committed 5 years ago

Commit baacb0f1 parent 19d287a6 files · +80 −7Browse files

Unified · Split

6 files

elf.h +2 −0
lib/bcheck.c +1 −1
tcc.h +5 −1
tccelf.c +56 −4
tccrun.c +15 −0
tests/tcctest.c +1 −1

elf.h+2−0

@@ -2908,6 +2908,8 @@ typedef Elf32_Addr Elf32_Conflict; · 2907 unmodified lines
2908		2908
2909	#define R_X86_64_NUM 43	2909	#define R_X86_64_NUM 43
2910		2910
		2911	/* x86-64 sh_type values. */
		2912	#define SHT_X86_64_UNWIND 0x70000001 /* Unwind information. */
2911		2913
2912	/* AM33 relocations. */	2914	/* AM33 relocations. */
2913	#define R_MN10300_NONE 0 /* No reloc. */	2915	#define R_MN10300_NONE 0 /* No reloc. */

lib/bcheck.c+1−1

@@ -1147,7 +1147,7 @@ void __attribute__((destructor)) __bound_exit(void) · 1146 unmodified lines
1147	dprintf(stderr, "%s, %s():\n", __FILE__, __FUNCTION__);	1147	dprintf(stderr, "%s, %s():\n", __FILE__, __FUNCTION__);
1148		1148
1149	if (inited) {	1149	if (inited) {
1150	#if !defined(_WIN32) && !defined(__APPLE__)	1150	#if !defined(_WIN32) && !defined(__APPLE__) && !defined(__OpenBSD__)
1151	if (print_heap) {	1151	if (print_heap) {
1152	extern void __libc_freeres (void);	1152	extern void __libc_freeres (void);
1153	__libc_freeres ();	1153	__libc_freeres ();

tcc.h+5−1

 #  if defined(TCC_MUSL)
 #   define CONFIG_TCC_ELFINTERP "/lib/ld-musl-x86_64.so.1"
 #  else
-#   define CONFIG_TCC_ELFINTERP "/lib64/ld-linux-x86-64.so.2"
+#   if defined(__OpenBSD__)
+#    define CONFIG_TCC_ELFINTERP "/usr/libexec/ld.so"
+#   else
+#    define CONFIG_TCC_ELFINTERP "/lib64/ld-linux-x86-64.so.2"
+#   endif
 #  endif
 # elif defined(TCC_TARGET_RISCV64)
 #  define CONFIG_TCC_ELFINTERP "/lib/ld-linux-riscv64-lp64d.so.1"

tccelf.c+56−4

 #ifdef CONFIG_TCC_BCHECK
         if (s1->do_bounds_check && s1->output_type != TCC_OUTPUT_DLL) {
             tcc_add_library_err(s1, "pthread");
+#if !defined(__OpenBSD__)
             tcc_add_library_err(s1, "dl");
+#endif
             tcc_add_support(s1, "bcheck.o");
         }
 #endif
 }
 static void fill_unloadable_phdr(ElfW(Phdr) *phdr, int phnum, Section *interp,
-                                 Section *dynamic)
+                                 Section *dynamic, Section *note)
 {
     ElfW(Phdr) *ph;
         ph->p_align = interp->sh_addralign;
     }
+    if (note) {
+        ph = &phdr[phnum - 2];
+        ph->p_type = PT_NOTE;
+        ph->p_offset = note->sh_offset;
+        ph->p_vaddr = note->sh_addr;
+        ph->p_paddr = ph->p_vaddr;
+        ph->p_filesz = note->sh_size;
+        ph->p_memsz = note->sh_size;
+        ph->p_flags = PF_R;
+        ph->p_align = note->sh_addralign;
+    }
     /* if dynamic section, then add corresponding program header */
     if (dynamic) {
         ph = &phdr[phnum - 1];
     put_dt(dynamic, DT_RELA, dyninf->rel_addr);
     put_dt(dynamic, DT_RELASZ, dyninf->rel_size);
     put_dt(dynamic, DT_RELAENT, sizeof(ElfW_Rel));
+#ifdef __OpenBSD__
+    put_dt(dynamic, DT_PLTGOT, s1->got->sh_addr);
+    put_dt(dynamic, DT_PLTRELSZ, dyninf->rel_size);
+    put_dt(dynamic, DT_JMPREL, dyninf->rel_addr);
+    put_dt(dynamic, DT_PLTREL, DT_RELA);
+    put_dt(dynamic, DT_BIND_NOW, 1); /* Dirty hack */
+#endif
 #else
 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
     put_dt(dynamic, DT_PLTGOT, s1->got->sh_addr);
 }
 #endif
+#ifdef __OpenBSD__
+static Section *create_openbsd_note_section(TCCState *s1)
+{
+    Section *s = find_section (s1, ".note.openbsd.ident");
+    if (s->data_offset == 0) {
+        unsigned char *ptr = section_ptr_add(s, sizeof(ElfW(Nhdr)) + 8 + 4);
+        ElfW(Nhdr) *note = (ElfW(Nhdr) *) ptr;
+        s->sh_type = SHT_NOTE;
+        note->n_namesz = 8;
+        note->n_descsz = 4;
+        note->n_type = ELF_NOTE_OS_GNU;
+	strcpy (ptr + sizeof(ElfW(Nhdr)), "OpenBSD");
+    }
+    return s;
+}
+#endif
 /* Output an elf, coff or binary file */
 /* XXX: suppress unneeded sections */
 static int elf_output_file(TCCState *s1, const char *filename)
     int ret, phnum, shnum, file_type, file_offset, *sec_order;
     struct dyn_inf dyninf = {0};
     ElfW(Phdr) *phdr;
-    Section *strsec, *interp, *dynamic, *dynstr;
+    Section *strsec, *interp, *dynamic, *dynstr, *note = NULL;
+    file_type = s1->output_type;
 #ifdef TCC_TARGET_ARM
     create_arm_attribute_section (s1);
 #endif
+#ifdef __OpenBSD__
+    if (file_type != TCC_OUTPUT_OBJ)
+        note = create_openbsd_note_section (s1);
+#endif
-    file_type = s1->output_type;
     s1->nb_errors = 0;
     ret = -1;
     phdr = NULL;
         phnum = i < s1->nb_sections ? 6 : 5;
     }
+    phnum += note != NULL;
     /* allocate program segment headers */
     phdr = tcc_mallocz(phnum * sizeof(ElfW(Phdr)));
     /* Fill remaining program header and finalize relocation related to dynamic
        linking. */
     if (file_type != TCC_OUTPUT_OBJ) {
-        fill_unloadable_phdr(phdr, phnum, interp, dynamic);
+        fill_unloadable_phdr(phdr, phnum, interp, dynamic, note);
         if (dynamic) {
             ElfW(Sym) *sym;
             dynamic->data_offset = dyninf.data_offset;
         if (sh->sh_type != SHT_PROGBITS &&
 #ifdef TCC_ARM_EABI
             sh->sh_type != SHT_ARM_EXIDX &&
+#endif
+#ifdef __OpenBSD__
+            sh->sh_type != SHT_X86_64_UNWIND &&
+            sh->sh_type != SHT_NOTE &&
 #endif
             sh->sh_type != SHT_NOBITS &&
             sh->sh_type != SHT_PREINIT_ARRAY &&

tccrun.c+15−0

@@ -88,8 +88,23 @@ LIBTCCAPI int tcc_relocate(TCCState s1, void ptr) · 87 unmodified lines
88	unlink(tmpfname);	88	unlink(tmpfname);
89	ftruncate(fd, size);	89	ftruncate(fd, size);
90		90
		91	#ifdef __OpenBSD__
		92	{ /* OpenBSD uses random 64 addresses that are far apart. This does not
		93	work for the x86_64 target.
		94	This might be a problem in the future for other targets. */
		95	static char prw = (char ) 0x100000000;
		96	char *pex = prw + 0x40000000;
		97
		98	ptr = mmap (prw, size, PROT_READ\|PROT_WRITE, MAP_SHARED \| MAP_FIXED, fd, 0);
		99	prx = mmap (pex, size, PROT_READ\|PROT_EXEC, MAP_SHARED \| MAP_FIXED, fd, 0);
		100	tcc_enter_state (s1);
		101	prw += 0x100000000;
		102	tcc_exit_state();
		103	}
		104	#else
91	ptr = mmap (NULL, size, PROT_READ\|PROT_WRITE, MAP_SHARED, fd, 0);	105	ptr = mmap (NULL, size, PROT_READ\|PROT_WRITE, MAP_SHARED, fd, 0);
92	prx = mmap (NULL, size, PROT_READ\|PROT_EXEC, MAP_SHARED, fd, 0);	106	prx = mmap (NULL, size, PROT_READ\|PROT_EXEC, MAP_SHARED, fd, 0);
		107	#endif
93	if (ptr == MAP_FAILED \|\| prx == MAP_FAILED)	108	if (ptr == MAP_FAILED \|\| prx == MAP_FAILED)
94	tcc_error("tccrun: could not map memory");	109	tcc_error("tccrun: could not map memory");
95	dynarray_add(&s1->runtime_mem, &s1->nb_runtime_mem, (void*)(addr_t)size);	110	dynarray_add(&s1->runtime_mem, &s1->nb_runtime_mem, (void*)(addr_t)size);

tests/tcctest.c+1−1

@@ -2313,7 +2313,7 @@ int fib(int n) · 2312 unmodified lines
2313	return fib(n-1) + fib(n-2);	2313	return fib(n-1) + fib(n-2);
2314	}	2314	}
2315		2315
2316	#if __GNUC__ == 3	2316	#if __GNUC__ == 3 \|\| __GNUC__ == 4
2317	# define aligned_function 0	2317	# define aligned_function 0
2318	#else	2318	#else
2319	void __attribute__((aligned(16))) aligned_function(int i) {}	2319	void __attribute__((aligned(16))) aligned_function(int i) {}

OpenBSD: runtime fixes

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