[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Guile-commits] 01/01: Revert "Add support for reading ELF symbol table
From: |
Andy Wingo |
Subject: |
[Guile-commits] 01/01: Revert "Add support for reading ELF symbol table from C" |
Date: |
Sun, 29 Jul 2018 10:12:01 -0400 (EDT) |
wingo pushed a commit to branch lightning
in repository guile.
commit 5ebe58419e43de2d512d37a1732202f29a43dd7e
Author: Andy Wingo <address@hidden>
Date: Sun Jul 29 16:11:38 2018 +0200
Revert "Add support for reading ELF symbol table from C"
This reverts commit e95f15c932650783f34253e396216c66050905f0. It's no
longer needed given the current JIT strategy.
---
libguile/loader.c | 123 ++++++++++++++++--------------------------------------
libguile/loader.h | 7 +---
2 files changed, 38 insertions(+), 92 deletions(-)
diff --git a/libguile/loader.c b/libguile/loader.c
index 8f25040..b37721c 100644
--- a/libguile/loader.c
+++ b/libguile/loader.c
@@ -61,7 +61,6 @@
#define ELFCLASS ELFCLASS32
#define Elf_Phdr Elf32_Phdr
#define Elf_Dyn Elf32_Dyn
-#define Elf_Sym Elf32_Sym
#elif SIZEOF_UINTPTR_T == 8
#define Elf_Half Elf64_Half
#define Elf_Word Elf64_Word
@@ -69,7 +68,6 @@
#define ELFCLASS ELFCLASS64
#define Elf_Phdr Elf64_Phdr
#define Elf_Dyn Elf64_Dyn
-#define Elf_Sym Elf64_Sym
#else
#error
#endif
@@ -92,8 +90,7 @@
/* The page size. */
static size_t page_size;
-static void register_elf (char *data, size_t len, char *frame_maps,
- char *symtab, char *strtab);
+static void register_elf (char *data, size_t len, char *frame_maps);
enum bytecode_kind
{
@@ -261,14 +258,12 @@ segment_flags_to_prot (Elf_Word flags)
static char*
process_dynamic_segment (char *base, Elf_Phdr *dyn_phdr,
- SCM *init_out, SCM *entry_out, char **frame_maps_out,
- char **symtab_out, char **strtab_out)
+ SCM *init_out, SCM *entry_out, char **frame_maps_out)
{
char *dyn_addr = base + dyn_phdr->p_vaddr;
Elf_Dyn *dyn = (Elf_Dyn *) dyn_addr;
size_t i, dyn_size = dyn_phdr->p_memsz / sizeof (Elf_Dyn);
char *init = 0, *gc_root = 0, *entry = 0, *frame_maps = 0;
- char *symtab = 0, *strtab = 0;
ptrdiff_t gc_root_size = 0;
enum bytecode_kind bytecode_kind = BYTECODE_KIND_NONE;
@@ -284,12 +279,6 @@ process_dynamic_segment (char *base, Elf_Phdr *dyn_phdr,
return "duplicate DT_INIT";
init = base + dyn[i].d_un.d_val;
break;
- case DT_SYMTAB:
- symtab = base + dyn[i].d_un.d_val;
- break;
- case DT_STRTAB:
- strtab = base + dyn[i].d_un.d_val;
- break;
case DT_GUILE_GC_ROOT:
if (gc_root)
return "duplicate DT_GUILE_GC_ROOT";
@@ -355,8 +344,6 @@ process_dynamic_segment (char *base, Elf_Phdr *dyn_phdr,
*init_out = init ? pointer_to_procedure (bytecode_kind, init) : SCM_BOOL_F;
*entry_out = pointer_to_procedure (bytecode_kind, entry);
*frame_maps_out = frame_maps;
- *symtab_out = symtab;
- *strtab_out = strtab;
return NULL;
}
@@ -374,7 +361,7 @@ load_thunk_from_memory (char *data, size_t len, int
is_read_only)
int i;
int dynamic_segment = -1;
SCM init = SCM_BOOL_F, entry = SCM_BOOL_F;
- char *frame_maps = 0, *symtab = 0, *strtab = 0;
+ char *frame_maps = 0;
errno = 0;
@@ -478,14 +465,13 @@ load_thunk_from_memory (char *data, size_t len, int
is_read_only)
}
if ((err_msg = process_dynamic_segment (data, &ph[dynamic_segment],
- &init, &entry, &frame_maps,
- &symtab, &strtab)))
+ &init, &entry, &frame_maps)))
goto cleanup;
if (scm_is_true (init))
scm_call_0 (init);
- register_elf (data, len, frame_maps, symtab, strtab);
+ register_elf (data, len, frame_maps);
/* Finally! Return the thunk. */
return entry;
@@ -616,11 +602,9 @@ SCM_DEFINE (scm_load_thunk_from_memory,
"load-thunk-from-memory", 1, 0, 0,
struct mapped_elf_image
{
- const char *start;
- const char *end;
- const char *frame_maps;
- const char *symtab;
- const char *strtab;
+ char *start;
+ char *end;
+ char *frame_maps;
};
static struct mapped_elf_image *mapped_elf_images = NULL;
@@ -628,7 +612,7 @@ static size_t mapped_elf_images_count = 0;
static size_t mapped_elf_images_allocated = 0;
static size_t
-find_mapped_elf_insertion_index (const char *ptr)
+find_mapped_elf_insertion_index (char *ptr)
{
/* "mapped_elf_images_count" must never be dereferenced. */
size_t start = 0, end = mapped_elf_images_count;
@@ -647,8 +631,7 @@ find_mapped_elf_insertion_index (const char *ptr)
}
static void
-register_elf (char *data, size_t len, char *frame_maps, char *symtab,
- char *strtab)
+register_elf (char *data, size_t len, char *frame_maps)
{
scm_i_pthread_mutex_lock (&scm_i_misc_mutex);
{
@@ -656,7 +639,7 @@ register_elf (char *data, size_t len, char *frame_maps,
char *symtab,
if (mapped_elf_images_count == mapped_elf_images_allocated)
{
struct mapped_elf_image *prev;
- size_t old_size, new_size;
+ size_t n;
if (mapped_elf_images_allocated)
mapped_elf_images_allocated *= 2;
@@ -664,33 +647,42 @@ register_elf (char *data, size_t len, char *frame_maps,
char *symtab,
mapped_elf_images_allocated = 16;
prev = mapped_elf_images;
- old_size = mapped_elf_images_count * sizeof (*mapped_elf_images);
- new_size = mapped_elf_images_allocated * sizeof (*mapped_elf_images);
- mapped_elf_images = scm_gc_malloc_pointerless (new_size, "mapped elf");
+ mapped_elf_images =
+ scm_gc_malloc_pointerless (sizeof (*mapped_elf_images)
+ * mapped_elf_images_allocated,
+ "mapped elf images");
- memcpy (mapped_elf_images, prev, old_size);
+ for (n = 0; n < mapped_elf_images_count; n++)
+ {
+ mapped_elf_images[n].start = prev[n].start;
+ mapped_elf_images[n].end = prev[n].end;
+ mapped_elf_images[n].frame_maps = prev[n].frame_maps;
+ }
}
{
+ size_t end;
size_t n = find_mapped_elf_insertion_index (data);
- memmove (&mapped_elf_images[n+1], &mapped_elf_images[n],
- (mapped_elf_images_count - n) * sizeof (*mapped_elf_images));
-
+ for (end = mapped_elf_images_count; n < end; end--)
+ {
+ const struct mapped_elf_image *prev = &mapped_elf_images[end - 1];
+ mapped_elf_images[end].start = prev->start;
+ mapped_elf_images[end].end = prev->end;
+ mapped_elf_images[end].frame_maps = prev->frame_maps;
+ }
mapped_elf_images_count++;
mapped_elf_images[n].start = data;
mapped_elf_images[n].end = data + len;
mapped_elf_images[n].frame_maps = frame_maps;
- mapped_elf_images[n].symtab = symtab;
- mapped_elf_images[n].strtab = strtab;
}
}
scm_i_pthread_mutex_unlock (&scm_i_misc_mutex);
}
static struct mapped_elf_image *
-find_mapped_elf_image_unlocked (const char *ptr)
+find_mapped_elf_image_unlocked (char *ptr)
{
size_t n = find_mapped_elf_insertion_index ((char *) ptr);
@@ -703,7 +695,7 @@ find_mapped_elf_image_unlocked (const char *ptr)
}
static int
-find_mapped_elf_image (const char *ptr, struct mapped_elf_image *image)
+find_mapped_elf_image (char *ptr, struct mapped_elf_image *image)
{
int result;
@@ -779,9 +771,9 @@ const uint8_t *
scm_find_slot_map_unlocked (const uint32_t *ip)
{
struct mapped_elf_image *image;
- const char *base;
- const struct frame_map_prefix *prefix;
- const struct frame_map_header *headers;
+ char *base;
+ struct frame_map_prefix *prefix;
+ struct frame_map_header *headers;
uintptr_t addr = (uintptr_t) ip;
size_t start, end;
@@ -790,8 +782,8 @@ scm_find_slot_map_unlocked (const uint32_t *ip)
return NULL;
base = image->frame_maps;
- prefix = (const struct frame_map_prefix *) base;
- headers = (const struct frame_map_header *) (base + sizeof (*prefix));
+ prefix = (struct frame_map_prefix *) base;
+ headers = (struct frame_map_header *) (base + sizeof (*prefix));
if (addr < ((uintptr_t) image->start) + prefix->text_offset)
return NULL;
@@ -818,49 +810,6 @@ scm_find_slot_map_unlocked (const uint32_t *ip)
return NULL;
}
-int
-scm_i_program_address_range (const char *code, const char **start,
- const char **end)
-{
- struct mapped_elf_image image;
- ptrdiff_t size;
- const Elf_Sym *symtab, *sym;
- ptrdiff_t lo, hi, offset;
-
- if (!find_mapped_elf_image (code, &image))
- return 0;
-
- if (!image.symtab || !image.strtab)
- return 0;
-
- /* The compiler will put the strtab directly after the symtab, which
- lets us know the symtab size without traversing the section
- table. It's hacky but it's what glibc does. */
- if (image.symtab >= image.strtab)
- abort ();
-
- size = (image.strtab - image.symtab) / sizeof (Elf_Sym);
- symtab = (const Elf_Sym *) image.symtab;
- lo = 0, hi = size, offset = code - image.start;
- while (lo < hi)
- {
- ptrdiff_t test = (lo + hi) / 2;
- sym = symtab + test;
- if (offset < sym->st_value)
- hi = test;
- else if (offset < sym->st_value + sym->st_size)
- {
- *start = image.start + sym->st_value;
- *end = *start + sym->st_size;
- return 1;
- }
- else
- lo = test + 1;
- }
-
- return 0;
-}
-
void
scm_bootstrap_loader (void)
diff --git a/libguile/loader.h b/libguile/loader.h
index 54ec9f7..d9f632d 100644
--- a/libguile/loader.h
+++ b/libguile/loader.h
@@ -55,11 +55,8 @@
SCM_API SCM scm_load_thunk_from_file (SCM filename);
SCM_API SCM scm_load_thunk_from_memory (SCM bv);
-SCM_INTERNAL const uint8_t * scm_find_slot_map_unlocked (const uint32_t *ip);
-
-SCM_INTERNAL int scm_i_program_address_range (const char *code,
- const char **start,
- const char **end);
+SCM_INTERNAL const uint8_t *
+scm_find_slot_map_unlocked (const uint32_t *ip);
SCM_INTERNAL void scm_bootstrap_loader (void);
SCM_INTERNAL void scm_init_loader (void);