-/* Copyright (C) 2001-2018 Free Software Foundation, Inc.
+/* Copyright (C) 2001-2024 Free Software Foundation, Inc.
Contributed by Jakub Jelinek <jakub@redhat.com>.
This file is part of GCC.
#endif
#if !defined(inhibit_libc) && defined(HAVE_LD_EH_FRAME_HDR) \
+ && defined(TARGET_DL_ITERATE_PHDR) \
&& (defined(__OpenBSD__) || defined(__NetBSD__))
# define ElfW(type) Elf_##type
# define USE_PT_GNU_EH_FRAME
#define PT_GNU_EH_FRAME (PT_LOOS + 0x474e550)
#endif
+#ifdef CRT_GET_RFIB_DATA
+#define NEED_DBASE_MEMBER 1
+#else
+#define NEED_DBASE_MEMBER 0
+#endif
+
struct unw_eh_callback_data
{
_Unwind_Ptr pc;
- void *tbase;
+#if NEED_DBASE_MEMBER
void *dbase;
- void *func;
- const fde *ret;
+#endif
+ const struct unw_eh_frame_hdr *hdr;
int check_cache;
};
+/* Returns DATA->dbase if available, else NULL. */
+static inline _Unwind_Ptr
+unw_eh_callback_data_dbase (const struct unw_eh_callback_data *data
+ __attribute__ ((unused)))
+{
+#if NEED_DBASE_MEMBER
+ return (_Unwind_Ptr) data->dbase;
+#else
+ return 0;
+#endif
+}
+
struct unw_eh_frame_hdr
{
unsigned char version;
/* Like base_of_encoded_value, but take the base from a struct
unw_eh_callback_data instead of an _Unwind_Context. */
-static _Unwind_Ptr
-base_from_cb_data (unsigned char encoding, struct unw_eh_callback_data *data)
+static inline _Unwind_Ptr
+base_from_cb_data (unsigned char encoding __attribute__ ((unused)),
+ _Unwind_Ptr dbase __attribute__ ((unused)))
{
+#if NEED_DBASE_MEMBER
if (encoding == DW_EH_PE_omit)
return 0;
return 0;
case DW_EH_PE_textrel:
- return (_Unwind_Ptr) data->tbase;
+ return 0;
case DW_EH_PE_datarel:
- return (_Unwind_Ptr) data->dbase;
+ return dbase;
default:
gcc_unreachable ();
}
+#else /* !NEED_DBASE_MEMBER */
+ return 0;
+#endif
}
static int
#else
_Unwind_Ptr load_base;
#endif
- const unsigned char *p;
- const struct unw_eh_frame_hdr *hdr;
- _Unwind_Ptr eh_frame;
- struct object ob;
_Unwind_Ptr pc_low = 0, pc_high = 0;
struct ext_dl_phdr_info
return 0;
/* Read .eh_frame_hdr header. */
- hdr = (const struct unw_eh_frame_hdr *)
+ data->hdr = (const struct unw_eh_frame_hdr *)
__RELOC_POINTER (p_eh_frame_hdr->p_vaddr, load_base);
- if (hdr->version != 1)
- return 1;
#ifdef CRT_GET_RFIB_DATA
-# ifdef __i386__
+# if defined __i386__ || defined __nios2__
data->dbase = NULL;
if (p_dynamic)
{
# endif
#endif
- p = read_encoded_value_with_base (hdr->eh_frame_ptr_enc,
- base_from_cb_data (hdr->eh_frame_ptr_enc,
- data),
- (const unsigned char *) (hdr + 1),
- &eh_frame);
+ return 1;
+}
+
+/* Find the FDE for the program counter PC, in a previously located
+ PT_GNU_EH_FRAME data region. *BASES is updated if an FDE to return is
+ found. */
+
+static const fde *
+find_fde_tail (_Unwind_Ptr pc,
+ const struct unw_eh_frame_hdr *hdr,
+ _Unwind_Ptr dbase,
+ struct dwarf_eh_bases *bases)
+{
+ const unsigned char *p = (const unsigned char *) (hdr + 1);
+ _Unwind_Ptr eh_frame;
+ struct object ob;
+
+ if (hdr->version != 1)
+ return NULL;
+
+ if (__builtin_expect (hdr->eh_frame_ptr_enc == (DW_EH_PE_sdata4
+ | DW_EH_PE_pcrel), 1))
+ {
+ /* Specialized version of read_encoded_value_with_base, based on what
+ BFD ld generates. */
+ signed value __attribute__ ((mode (SI)));
+ memcpy (&value, p, sizeof (value));
+ eh_frame = (_Unwind_Ptr) (p + value);
+ p += sizeof (value);
+ }
+ else
+ p = read_encoded_value_with_base (hdr->eh_frame_ptr_enc,
+ base_from_cb_data (hdr->eh_frame_ptr_enc,
+ dbase),
+ p, &eh_frame);
/* We require here specific table encoding to speed things up.
Also, DW_EH_PE_datarel here means using PT_GNU_EH_FRAME start
{
_Unwind_Ptr fde_count;
- p = read_encoded_value_with_base (hdr->fde_count_enc,
- base_from_cb_data (hdr->fde_count_enc,
- data),
- p, &fde_count);
+ if (__builtin_expect (hdr->fde_count_enc == DW_EH_PE_udata4, 1))
+ {
+ /* Specialized version of read_encoded_value_with_base, based on
+ what BFD ld generates. */
+ unsigned value __attribute__ ((mode (SI)));
+ memcpy (&value, p, sizeof (value));
+ p += sizeof (value);
+ fde_count = value;
+ }
+ else
+ p = read_encoded_value_with_base (hdr->fde_count_enc,
+ base_from_cb_data (hdr->fde_count_enc,
+ dbase),
+ p, &fde_count);
/* Shouldn't happen. */
if (fde_count == 0)
- return 1;
+ return NULL;
if ((((_Unwind_Ptr) p) & 3) == 0)
{
struct fde_table {
_Unwind_Ptr range;
mid = fde_count - 1;
- if (data->pc < table[0].initial_loc + data_base)
- return 1;
- else if (data->pc < table[mid].initial_loc + data_base)
+ if (pc < table[0].initial_loc + data_base)
+ return NULL;
+ else if (pc < table[mid].initial_loc + data_base)
{
lo = 0;
hi = mid;
while (lo < hi)
{
mid = (lo + hi) / 2;
- if (data->pc < table[mid].initial_loc + data_base)
+ if (pc < table[mid].initial_loc + data_base)
hi = mid;
- else if (data->pc >= table[mid + 1].initial_loc + data_base)
+ else if (pc >= table[mid + 1].initial_loc + data_base)
lo = mid + 1;
else
break;
f = (fde *) (table[mid].fde + data_base);
f_enc = get_fde_encoding (f);
f_enc_size = size_of_encoded_value (f_enc);
- read_encoded_value_with_base (f_enc & 0x0f, 0,
- &f->pc_begin[f_enc_size], &range);
- if (data->pc < table[mid].initial_loc + data_base + range)
- data->ret = f;
- data->func = (void *) (table[mid].initial_loc + data_base);
- return 1;
+
+ /* BFD ld uses DW_EH_PE_sdata4 | DW_EH_PE_pcrel on non-FDPIC targets,
+ so optimize for that.
+
+ This optimization is not valid for FDPIC targets. f_enc & 0x0f as
+ passed to read_encoded_value_with_base masks away the base flags,
+ but they are implicit for FDPIC. */
+#ifndef __FDPIC__
+ if (__builtin_expect (f_enc == (DW_EH_PE_sdata4 | DW_EH_PE_pcrel),
+ 1))
+ {
+ signed value __attribute__ ((mode (SI)));
+ memcpy (&value, &f->pc_begin[f_enc_size], sizeof (value));
+ range = value;
+ }
+ else
+#endif
+ read_encoded_value_with_base (f_enc & 0x0f, 0,
+ &f->pc_begin[f_enc_size], &range);
+ _Unwind_Ptr func = table[mid].initial_loc + data_base;
+ if (pc < table[mid].initial_loc + data_base + range)
+ {
+ bases->tbase = NULL;
+ bases->dbase = (void *) dbase;
+ bases->func = (void *) func;
+ return f;
+ }
+ else
+ return NULL;
}
}
As soon as GLIBC will provide API so to notify that a library has been
removed, we could cache this (and thus use search_object). */
ob.pc_begin = NULL;
- ob.tbase = data->tbase;
- ob.dbase = data->dbase;
+ ob.tbase = NULL;
+ ob.dbase = (void *) dbase;
ob.u.single = (fde *) eh_frame;
ob.s.i = 0;
ob.s.b.mixed_encoding = 1; /* Need to assume worst case. */
- data->ret = linear_search_fdes (&ob, (fde *) eh_frame, (void *) data->pc);
- if (data->ret != NULL)
+ const fde *entry = linear_search_fdes (&ob, (fde *) eh_frame, (void *) pc);
+ if (entry != NULL)
{
_Unwind_Ptr func;
- unsigned int encoding = get_fde_encoding (data->ret);
+ unsigned int encoding = get_fde_encoding (entry);
read_encoded_value_with_base (encoding,
- base_from_cb_data (encoding, data),
- data->ret->pc_begin, &func);
- data->func = (void *) func;
+ base_from_cb_data (encoding, dbase),
+ entry->pc_begin, &func);
+ bases->tbase = NULL;
+ bases->dbase = (void *) dbase;
+ bases->func = (void *) func;
}
- return 1;
+ return entry;
}
const fde *
if (ret != NULL)
return ret;
+ /* Use DLFO_STRUCT_HAS_EH_DBASE as a proxy for the existence of a glibc-style
+ _dl_find_object function. However, do not use _dl_find_object on nios2,
+ which uses the GOT address as the base for DW_EH_PE_datarel instead. */
+#if defined(DLFO_STRUCT_HAS_EH_DBASE) && !defined(__nios2__)
+ {
+ struct dl_find_object dlfo;
+ if (_dl_find_object (pc, &dlfo) == 0 && dlfo.dlfo_eh_frame != NULL)
+ return find_fde_tail ((_Unwind_Ptr) pc, dlfo.dlfo_eh_frame,
+# if DLFO_STRUCT_HAS_EH_DBASE
+ (_Unwind_Ptr) dlfo.dlfo_eh_dbase,
+# else
+ 0,
+# endif
+ bases);
+ else
+ return NULL;
+ }
+#endif /* DLFO_STRUCT_HAS_EH_DBASE */
+
data.pc = (_Unwind_Ptr) pc;
- data.tbase = NULL;
+#if NEED_DBASE_MEMBER
data.dbase = NULL;
- data.func = NULL;
- data.ret = NULL;
+#endif
data.check_cache = 1;
- if (dl_iterate_phdr (_Unwind_IteratePhdrCallback, &data) < 0)
+ if (dl_iterate_phdr (_Unwind_IteratePhdrCallback, &data) <= 0)
return NULL;
- if (data.ret)
- {
- bases->tbase = data.tbase;
- bases->dbase = data.dbase;
- bases->func = data.func;
- }
- return data.ret;
+ _Unwind_Ptr dbase = unw_eh_callback_data_dbase (&data);
+ return find_fde_tail ((_Unwind_Ptr) pc, data.hdr, dbase, bases);
}
#else
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