as per ARMv8-M Security Extensions. */
int cmse_implib;
+ /* The import library whose symbols' address must remain stable in
+ the import library generated. */
+ bfd *in_implib_bfd;
+
/* The index of the next unused R_ARM_TLS_DESC slot in .rel.plt. */
bfd_vma next_tls_desc_index;
/* Input stub section holding secure gateway veneers. */
asection *cmse_stub_sec;
+ /* Offset in cmse_stub_sec where new SG veneers (not in input import library)
+ start to be allocated. */
+ bfd_vma new_cmse_stub_offset;
+
/* Number of elements in stub_group. */
unsigned int top_id;
/* Initialize the local fields. */
eh = (struct elf32_arm_stub_hash_entry *) entry;
eh->stub_sec = NULL;
- eh->stub_offset = 0;
+ eh->stub_offset = (bfd_vma) -1;
eh->source_value = 0;
eh->target_value = 0;
eh->target_section = NULL;
eh->stub_type = arm_stub_none;
eh->stub_size = 0;
eh->stub_template = NULL;
- eh->stub_template_size = 0;
+ eh->stub_template_size = -1;
eh->h = NULL;
eh->id_sec = NULL;
eh->output_name = NULL;
}
stub_entry->stub_sec = stub_sec;
- stub_entry->stub_offset = 0;
+ stub_entry->stub_offset = (bfd_vma) -1;
stub_entry->id_sec = link_sec;
return stub_entry;
abort (); /* Should be unreachable. */
}
+/* If veneers of type STUB_TYPE should go in a dedicated output section,
+ returns the address of the hash table field in HTAB holding the offset at
+ which new veneers should be layed out in the stub section. */
+
+static bfd_vma*
+arm_new_stubs_start_offset_ptr (struct elf32_arm_link_hash_table *htab,
+ enum elf32_arm_stub_type stub_type)
+{
+ switch (stub_type)
+ {
+ case arm_stub_cmse_branch_thumb_only:
+ return &htab->new_cmse_stub_offset;
+
+ default:
+ BFD_ASSERT (!arm_dedicated_stub_output_section_required (stub_type));
+ return NULL;
+ }
+}
+
static bfd_boolean
arm_build_one_stub (struct bfd_hash_entry *gen_entry,
void * in_arg)
{
#define MAXRELOCS 3
+ bfd_boolean removed_sg_veneer;
struct elf32_arm_stub_hash_entry *stub_entry;
struct elf32_arm_link_hash_table *globals;
struct bfd_link_info *info;
int stub_reloc_idx[MAXRELOCS] = {-1, -1};
int stub_reloc_offset[MAXRELOCS] = {0, 0};
int nrelocs = 0;
+ int just_allocated = 0;
/* Massage our args to the form they really have. */
stub_entry = (struct elf32_arm_stub_hash_entry *) gen_entry;
/* We have to do less-strictly-aligned fixes last. */
return TRUE;
- /* Make a note of the offset within the stubs for this entry. */
- stub_entry->stub_offset = stub_sec->size;
+ /* Assign a slot at the end of section if none assigned yet. */
+ if (stub_entry->stub_offset == (bfd_vma) -1)
+ {
+ stub_entry->stub_offset = stub_sec->size;
+ just_allocated = 1;
+ }
loc = stub_sec->contents + stub_entry->stub_offset;
stub_bfd = stub_sec->owner;
}
}
- stub_sec->size += size;
+ if (just_allocated)
+ stub_sec->size += size;
/* Stub size has already been computed in arm_size_one_stub. Check
consistency. */
if (stub_entry->branch_type == ST_BRANCH_TO_THUMB)
sym_value |= 1;
- /* Assume there is at least one and at most MAXRELOCS entries to relocate
- in each stub. */
- BFD_ASSERT (nrelocs != 0 && nrelocs <= MAXRELOCS);
+ /* Assume non empty slots have at least one and at most MAXRELOCS entries
+ to relocate in each stub. */
+ removed_sg_veneer =
+ (size == 0 && stub_entry->stub_type == arm_stub_cmse_branch_thumb_only);
+ BFD_ASSERT (removed_sg_veneer || (nrelocs != 0 && nrelocs <= MAXRELOCS));
for (i = 0; i < nrelocs; i++)
{
size = find_stub_size_and_template (stub_entry->stub_type, &template_sequence,
&template_size);
- stub_entry->stub_size = size;
- stub_entry->stub_template = template_sequence;
- stub_entry->stub_template_size = template_size;
+ /* Initialized to -1. Null size indicates an empty slot full of zeros. */
+ if (stub_entry->stub_template_size)
+ {
+ stub_entry->stub_size = size;
+ stub_entry->stub_template = template_sequence;
+ stub_entry->stub_template_size = template_size;
+ }
+
+ /* Already accounted for. */
+ if (stub_entry->stub_offset != (bfd_vma) -1)
+ return TRUE;
size = (size + 7) & ~7;
stub_entry->stub_sec->size += size;
and *NEW_STUB is set to FALSE. Otherwise, *NEW_STUB is set to
TRUE and the stub entry is initialized.
- Returns whether the stub could be successfully created or updated, or FALSE
- if an error occured. */
+ Returns the stub that was created or updated, or NULL if an error
+ occurred. */
-static bfd_boolean
+static struct elf32_arm_stub_hash_entry *
elf32_arm_create_stub (struct elf32_arm_link_hash_table *htab,
enum elf32_arm_stub_type stub_type, asection *section,
Elf_Internal_Rela *irela, asection *sym_sec,
stub_name = elf32_arm_stub_name (id_sec, sym_sec, hash, irela,
stub_type);
if (!stub_name)
- return FALSE;
+ return NULL;
}
stub_entry = arm_stub_hash_lookup (&htab->stub_hash_table, stub_name, FALSE,
if (!sym_claimed)
free (stub_name);
stub_entry->target_value = sym_value;
- return TRUE;
+ return stub_entry;
}
stub_entry = elf32_arm_add_stub (stub_name, section, htab, stub_type);
{
if (!sym_claimed)
free (stub_name);
- return FALSE;
+ return NULL;
}
stub_entry->target_value = sym_value;
if (stub_entry->output_name == NULL)
{
free (stub_name);
- return FALSE;
+ return NULL;
}
/* For historical reasons, use the existing names for ARM-to-Thumb and
}
*new_stub = TRUE;
- return TRUE;
+ return stub_entry;
}
/* Scan symbols in INPUT_BFD to identify secure entry functions needing a
OUT_ATTR gives the output attributes, SYM_HASHES the symbol index to hash
entry mapping while HTAB gives the name to hash entry mapping.
+ *CMSE_STUB_CREATED is increased by the number of secure gateway veneer
+ created.
- If any secure gateway veneer is created, *STUB_CHANGED is set to TRUE. The
- return value gives whether a stub failed to be allocated. */
+ The return value gives whether a stub failed to be allocated. */
static bfd_boolean
cmse_scan (bfd *input_bfd, struct elf32_arm_link_hash_table *htab,
obj_attribute *out_attr, struct elf_link_hash_entry **sym_hashes,
- bfd_boolean *stub_changed)
+ int *cmse_stub_created)
{
const struct elf_backend_data *bed;
Elf_Internal_Shdr *symtab_hdr;
char *sym_name, *lsym_name;
bfd_vma sym_value;
asection *section;
- bfd_boolean is_v8m, new_stub, created_stub, cmse_invalid, ret = TRUE;
+ struct elf32_arm_stub_hash_entry *stub_entry;
+ bfd_boolean is_v8m, new_stub, cmse_invalid, ret = TRUE;
bed = get_elf_backend_data (input_bfd);
symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
if (!ret)
continue;
branch_type = ARM_GET_SYM_BRANCH_TYPE (hash->root.target_internal);
- created_stub
+ stub_entry
= elf32_arm_create_stub (htab, arm_stub_cmse_branch_thumb_only,
NULL, NULL, section, hash, sym_name,
sym_value, branch_type, &new_stub);
- if (!created_stub)
+ if (stub_entry == NULL)
ret = FALSE;
else
{
BFD_ASSERT (new_stub);
- *stub_changed = TRUE;
+ (*cmse_stub_created)++;
}
}
return ret;
}
+/* Return TRUE iff a symbol identified by its linker HASH entry is a secure
+ code entry function, ie can be called from non secure code without using a
+ veneer. */
+
+static bfd_boolean
+cmse_entry_fct_p (struct elf32_arm_link_hash_entry *hash)
+{
+ uint32_t first_insn;
+ asection *section;
+ file_ptr offset;
+ bfd *abfd;
+
+ /* Defined symbol of function type. */
+ if (hash->root.root.type != bfd_link_hash_defined
+ && hash->root.root.type != bfd_link_hash_defweak)
+ return FALSE;
+ if (hash->root.type != STT_FUNC)
+ return FALSE;
+
+ /* Read first instruction. */
+ section = hash->root.root.u.def.section;
+ abfd = section->owner;
+ offset = hash->root.root.u.def.value - section->vma;
+ if (!bfd_get_section_contents (abfd, section, &first_insn, offset,
+ sizeof (first_insn)))
+ return FALSE;
+
+ /* Start by SG instruction. */
+ return first_insn == 0xe97fe97f;
+}
+
+/* Output the name (in symbol table) of the veneer GEN_ENTRY if it is a new
+ secure gateway veneers (ie. the veneers was not in the input import library)
+ and there is no output import library (GEN_INFO->out_implib_bfd is NULL. */
+
+static bfd_boolean
+arm_list_new_cmse_stub (struct bfd_hash_entry *gen_entry, void *gen_info)
+{
+ struct elf32_arm_stub_hash_entry *stub_entry;
+ struct bfd_link_info *info;
+
+ /* Massage our args to the form they really have. */
+ stub_entry = (struct elf32_arm_stub_hash_entry *) gen_entry;
+ info = (struct bfd_link_info *) gen_info;
+
+ if (info->out_implib_bfd)
+ return TRUE;
+
+ if (stub_entry->stub_type != arm_stub_cmse_branch_thumb_only)
+ return TRUE;
+
+ if (stub_entry->stub_offset == (bfd_vma) -1)
+ (*_bfd_error_handler) (" %s", stub_entry->output_name);
+
+ return TRUE;
+}
+
+/* Set offset of each secure gateway veneers so that its address remain
+ identical to the one in the input import library referred by
+ HTAB->in_implib_bfd. A warning is issued for veneers that disappeared
+ (present in input import library but absent from the executable being
+ linked) or if new veneers appeared and there is no output import library
+ (INFO->out_implib_bfd is NULL and *CMSE_STUB_CREATED is bigger than the
+ number of secure gateway veneers found in the input import library.
+
+ The function returns whether an error occurred. If no error occurred,
+ *CMSE_STUB_CREATED gives the number of SG veneers created by both cmse_scan
+ and this function and HTAB->new_cmse_stub_offset is set to the biggest
+ veneer observed set for new veneers to be layed out after. */
+
+static bfd_boolean
+set_cmse_veneer_addr_from_implib (struct bfd_link_info *info,
+ struct elf32_arm_link_hash_table *htab,
+ int *cmse_stub_created)
+{
+ long symsize;
+ char *sym_name;
+ flagword flags;
+ long i, symcount;
+ bfd *in_implib_bfd;
+ asection *stub_out_sec;
+ bfd_boolean ret = TRUE;
+ Elf_Internal_Sym *intsym;
+ const char *out_sec_name;
+ bfd_size_type cmse_stub_size;
+ asymbol **sympp = NULL, *sym;
+ struct elf32_arm_link_hash_entry *hash;
+ const insn_sequence *cmse_stub_template;
+ struct elf32_arm_stub_hash_entry *stub_entry;
+ int cmse_stub_template_size, new_cmse_stubs_created = *cmse_stub_created;
+ bfd_vma veneer_value, stub_offset, next_cmse_stub_offset;
+ bfd_vma cmse_stub_array_start = (bfd_vma) -1, cmse_stub_sec_vma = 0;
+
+ /* No input secure gateway import library. */
+ if (!htab->in_implib_bfd)
+ return TRUE;
+
+ in_implib_bfd = htab->in_implib_bfd;
+ if (!htab->cmse_implib)
+ {
+ (*_bfd_error_handler) (_("%B: --in-implib only supported for Secure "
+ "Gateway import libraries."), in_implib_bfd);
+ return FALSE;
+ }
+
+ /* Get symbol table size. */
+ symsize = bfd_get_symtab_upper_bound (in_implib_bfd);
+ if (symsize < 0)
+ return FALSE;
+
+ /* Read in the input secure gateway import library's symbol table. */
+ sympp = (asymbol **) xmalloc (symsize);
+ symcount = bfd_canonicalize_symtab (in_implib_bfd, sympp);
+ if (symcount < 0)
+ {
+ ret = FALSE;
+ goto free_sym_buf;
+ }
+
+ htab->new_cmse_stub_offset = 0;
+ cmse_stub_size =
+ find_stub_size_and_template (arm_stub_cmse_branch_thumb_only,
+ &cmse_stub_template,
+ &cmse_stub_template_size);
+ out_sec_name =
+ arm_dedicated_stub_output_section_name (arm_stub_cmse_branch_thumb_only);
+ stub_out_sec =
+ bfd_get_section_by_name (htab->obfd, out_sec_name);
+ if (stub_out_sec != NULL)
+ cmse_stub_sec_vma = stub_out_sec->vma;
+
+ /* Set addresses of veneers mentionned in input secure gateway import
+ library's symbol table. */
+ for (i = 0; i < symcount; i++)
+ {
+ sym = sympp[i];
+ flags = sym->flags;
+ sym_name = (char *) bfd_asymbol_name (sym);
+ intsym = &((elf_symbol_type *) sym)->internal_elf_sym;
+
+ if (sym->section != bfd_abs_section_ptr
+ || !(flags & (BSF_GLOBAL | BSF_WEAK))
+ || (flags & BSF_FUNCTION) != BSF_FUNCTION
+ || (ARM_GET_SYM_BRANCH_TYPE (intsym->st_target_internal)
+ != ST_BRANCH_TO_THUMB))
+ {
+ (*_bfd_error_handler) (_("%B: invalid import library entry: `%s'."),
+ in_implib_bfd, sym_name);
+ (*_bfd_error_handler) (_("Symbol should be absolute, global and "
+ "refer to Thumb functions."));
+ ret = FALSE;
+ continue;
+ }
+
+ veneer_value = bfd_asymbol_value (sym);
+ stub_offset = veneer_value - cmse_stub_sec_vma;
+ stub_entry = arm_stub_hash_lookup (&htab->stub_hash_table, sym_name,
+ FALSE, FALSE);
+ hash = (struct elf32_arm_link_hash_entry *)
+ elf_link_hash_lookup (&(htab)->root, sym_name, FALSE, FALSE, TRUE);
+
+ /* Stub entry should have been created by cmse_scan or the symbol be of
+ a secure function callable from non secure code. */
+ if (!stub_entry && !hash)
+ {
+ bfd_boolean new_stub;
+
+ (*_bfd_error_handler)
+ (_("Entry function `%s' disappeared from secure code."), sym_name);
+ hash = (struct elf32_arm_link_hash_entry *)
+ elf_link_hash_lookup (&(htab)->root, sym_name, TRUE, TRUE, TRUE);
+ stub_entry
+ = elf32_arm_create_stub (htab, arm_stub_cmse_branch_thumb_only,
+ NULL, NULL, bfd_abs_section_ptr, hash,
+ sym_name, veneer_value,
+ ST_BRANCH_TO_THUMB, &new_stub);
+ if (stub_entry == NULL)
+ ret = FALSE;
+ else
+ {
+ BFD_ASSERT (new_stub);
+ new_cmse_stubs_created++;
+ (*cmse_stub_created)++;
+ }
+ stub_entry->stub_template_size = stub_entry->stub_size = 0;
+ stub_entry->stub_offset = stub_offset;
+ }
+ /* Symbol found is not callable from non secure code. */
+ else if (!stub_entry)
+ {
+ if (!cmse_entry_fct_p (hash))
+ {
+ (*_bfd_error_handler) (_("`%s' refers to a non entry function."),
+ sym_name);
+ ret = FALSE;
+ }
+ continue;
+ }
+ else
+ {
+ /* Only stubs for SG veneers should have been created. */
+ BFD_ASSERT (stub_entry->stub_type == arm_stub_cmse_branch_thumb_only);
+
+ /* Check visibility hasn't changed. */
+ if (!!(flags & BSF_GLOBAL)
+ != (hash->root.root.type == bfd_link_hash_defined))
+ (*_bfd_error_handler)
+ (_("%B: visibility of symbol `%s' has changed."), in_implib_bfd,
+ sym_name);
+
+ stub_entry->stub_offset = stub_offset;
+ }
+
+ /* Size should match that of a SG veneer. */
+ if (intsym->st_size != cmse_stub_size)
+ {
+ (*_bfd_error_handler) (_("%B: incorrect size for symbol `%s'."),
+ in_implib_bfd, sym_name);
+ ret = FALSE;
+ }
+
+ /* Previous veneer address is before current SG veneer section. */
+ if (veneer_value < cmse_stub_sec_vma)
+ {
+ /* Avoid offset underflow. */
+ if (stub_entry)
+ stub_entry->stub_offset = 0;
+ stub_offset = 0;
+ ret = FALSE;
+ }
+
+ /* Complain if stub offset not a multiple of stub size. */
+ if (stub_offset % cmse_stub_size)
+ {
+ (*_bfd_error_handler)
+ (_("Offset of veneer for entry function `%s' not a multiple of "
+ "its size."), sym_name);
+ ret = FALSE;
+ }
+
+ if (!ret)
+ continue;
+
+ new_cmse_stubs_created--;
+ if (veneer_value < cmse_stub_array_start)
+ cmse_stub_array_start = veneer_value;
+ next_cmse_stub_offset = stub_offset + ((cmse_stub_size + 7) & ~7);
+ if (next_cmse_stub_offset > htab->new_cmse_stub_offset)
+ htab->new_cmse_stub_offset = next_cmse_stub_offset;
+ }
+
+ if (!info->out_implib_bfd && new_cmse_stubs_created != 0)
+ {
+ BFD_ASSERT (new_cmse_stubs_created > 0);
+ (*_bfd_error_handler)
+ (_("new entry function(s) introduced but no output import library "
+ "specified:"));
+ bfd_hash_traverse (&htab->stub_hash_table, arm_list_new_cmse_stub, info);
+ }
+
+ if (cmse_stub_array_start != cmse_stub_sec_vma)
+ {
+ (*_bfd_error_handler)
+ (_("Start address of `%s' is different from previous link."),
+ out_sec_name);
+ ret = FALSE;
+ }
+
+free_sym_buf:
+ free (sympp);
+ return ret;
+}
+
/* Determine and set the size of the stub section for a final link.
The basic idea here is to examine all the relocations looking for
unsigned int),
void (*layout_sections_again) (void))
{
+ bfd_boolean ret = TRUE;
obj_attribute *out_attr;
+ int cmse_stub_created = 0;
bfd_size_type stub_group_size;
bfd_boolean m_profile, stubs_always_after_branch, first_veneer_scan = TRUE;
struct elf32_arm_link_hash_table *htab = elf32_arm_hash_table (info);
out_attr = elf_known_obj_attributes_proc (output_bfd);
m_profile = out_attr[Tag_CPU_arch_profile].i == 'M';
+
/* The Cortex-A8 erratum fix depends on stubs not being in the same 4K page
as the first half of a 32-bit branch straddling two 4K pages. This is a
crude way of enforcing that. */
sym_hashes = elf_sym_hashes (input_bfd);
if (!cmse_scan (input_bfd, htab, out_attr, sym_hashes,
- &stub_changed))
+ &cmse_stub_created))
goto error_ret_free_local;
+
+ if (cmse_stub_created != 0)
+ stub_changed = TRUE;
}
/* Walk over each section attached to the input bfd. */
do
{
bfd_boolean new_stub;
+ struct elf32_arm_stub_hash_entry *stub_entry;
/* Determine what (if any) linker stub is needed. */
stub_type = arm_type_of_stub (info, section, irela,
/* We've either created a stub for this reloc already,
or we are about to. */
- created_stub =
+ stub_entry =
elf32_arm_create_stub (htab, stub_type, section, irela,
sym_sec, hash,
(char *) sym_name, sym_value,
branch_type, &new_stub);
+ created_stub = stub_entry != NULL;
if (!created_stub)
goto error_ret_free_internal;
else if (!new_stub)
}
}
+ if (first_veneer_scan
+ && !set_cmse_veneer_addr_from_implib (info, htab,
+ &cmse_stub_created))
+ ret = FALSE;
+
if (prev_num_a8_fixes != num_a8_fixes)
stub_changed = TRUE;
stub_sec->size = 0;
}
+ /* Add new SG veneers after those already in the input import
+ library. */
+ for (stub_type = arm_stub_none + 1; stub_type < max_stub_type;
+ stub_type++)
+ {
+ bfd_vma *start_offset_p;
+ asection **stub_sec_p;
+
+ start_offset_p = arm_new_stubs_start_offset_ptr (htab, stub_type);
+ stub_sec_p = arm_dedicated_stub_input_section_ptr (htab, stub_type);
+ if (start_offset_p == NULL)
+ continue;
+
+ BFD_ASSERT (stub_sec_p != NULL);
+ if (*stub_sec_p != NULL)
+ (*stub_sec_p)->size = *start_offset_p;
+ }
+
/* Compute stub section size, considering padding. */
bfd_hash_traverse (&htab->stub_hash_table, arm_size_one_stub, htab);
for (stub_type = arm_stub_none + 1; stub_type < max_stub_type;
}
stub_entry->stub_sec = stub_sec;
- stub_entry->stub_offset = 0;
+ stub_entry->stub_offset = (bfd_vma) -1;
stub_entry->id_sec = link_sec;
stub_entry->stub_type = a8_fixes[i].stub_type;
stub_entry->source_value = a8_fixes[i].offset;
htab->a8_erratum_fixes = NULL;
htab->num_a8_erratum_fixes = 0;
}
- return TRUE;
+ return ret;
}
/* Build all the stubs associated with the current output file. The
{
asection *stub_sec;
struct bfd_hash_table *table;
+ enum elf32_arm_stub_type stub_type;
struct elf32_arm_link_hash_table *htab;
htab = elf32_arm_hash_table (info);
continue;
/* Allocate memory to hold the linker stubs. Zeroing the stub sections
- must at least be done for stub section requiring padding. */
+ must at least be done for stub section requiring padding and for SG
+ veneers to ensure that a non secure code branching to a removed SG
+ veneer causes an error. */
size = stub_sec->size;
stub_sec->contents = (unsigned char *) bfd_zalloc (htab->stub_bfd, size);
if (stub_sec->contents == NULL && size != 0)
return FALSE;
+
stub_sec->size = 0;
}
+ /* Add new SG veneers after those already in the input import library. */
+ for (stub_type = arm_stub_none + 1; stub_type < max_stub_type; stub_type++)
+ {
+ bfd_vma *start_offset_p;
+ asection **stub_sec_p;
+
+ start_offset_p = arm_new_stubs_start_offset_ptr (htab, stub_type);
+ stub_sec_p = arm_dedicated_stub_input_section_ptr (htab, stub_type);
+ if (start_offset_p == NULL)
+ continue;
+
+ BFD_ASSERT (stub_sec_p != NULL);
+ if (*stub_sec_p != NULL)
+ (*stub_sec_p)->size = *start_offset_p;
+ }
+
/* Build the stubs as directed by the stub hash table. */
table = &htab->stub_hash_table;
bfd_hash_traverse (table, arm_build_one_stub, info);
bfd_arm_stm32l4xx_fix stm32l4xx_fix,
int no_enum_warn, int no_wchar_warn,
int pic_veneer, int fix_cortex_a8,
- int fix_arm1176, int cmse_implib)
+ int fix_arm1176, int cmse_implib,
+ bfd *in_implib_bfd)
{
struct elf32_arm_link_hash_table *globals;
globals->fix_cortex_a8 = fix_cortex_a8;
globals->fix_arm1176 = fix_arm1176;
globals->cmse_implib = cmse_implib;
+ globals->in_implib_bfd = in_implib_bfd;
BFD_ASSERT (is_arm_elf (output_bfd));
elf_arm_tdata (output_bfd)->no_enum_size_warning = no_enum_warn;
projects / binutils-gdb.git / commitdiff