* PowerPC64: stub debug dump
@ 2022-06-22 3:08 Alan Modra
0 siblings, 0 replies; 2+ messages in thread
From: Alan Modra @ 2022-06-22 3:08 UTC (permalink / raw)
To: binutils
powerpc64le-linux-ld is failing the assertion in ppc_build_one_stub,
again apparently, which means a stub will overwrite the tail of a
previous stub. The difficulty with debugging these issues is that
it's not a problem with the stub that triggers the assertion, but the
previous stub in that section. This patch keeps track of the last
stub and adds a debug dump. Hopefully that will help.
* elf64-ppc.c (enum _ppc64_sec_type): Add sec_stub.
(struct _ppc64_elf_section_data): Add u.last_ent.
(dump_previous_stub): New function.
(ppc_build_one_stub): Keep track of previous stub, and dump it
when finding an overlapping stub.
diff --git a/bfd/elf64-ppc.c b/bfd/elf64-ppc.c
index 6e2016c150d..c69b07435a1 100644
--- a/bfd/elf64-ppc.c
+++ b/bfd/elf64-ppc.c
@@ -1996,7 +1996,8 @@ static const struct bfd_elf_special_section ppc64_elf_special_sections[] =
enum _ppc64_sec_type {
sec_normal = 0,
sec_opd = 1,
- sec_toc = 2
+ sec_toc = 2,
+ sec_stub = 3
};
struct _ppc64_elf_section_data
@@ -2026,6 +2027,9 @@ struct _ppc64_elf_section_data
/* And the relocation addend. */
bfd_vma *add;
} toc;
+
+ /* Stub debugging. */
+ struct ppc_stub_hash_entry *last_ent;
} u;
enum _ppc64_sec_type sec_type:2;
@@ -11636,6 +11640,47 @@ get_r2off (struct bfd_link_info *info,
return r2off;
}
+/* Debug dump. */
+
+static void
+dump_previous_stub (struct ppc_stub_hash_entry *stub_entry)
+{
+ asection *stub_sec = stub_entry->group->stub_sec;
+ struct _ppc64_elf_section_data *esd = ppc64_elf_section_data (stub_sec);
+ if (esd->sec_type == sec_stub)
+ {
+ fprintf (stderr, "Previous stub: type = ");
+ switch (esd->u.last_ent->type.main)
+ {
+ case ppc_stub_none: fprintf (stderr, "none"); break;
+ case ppc_stub_long_branch: fprintf (stderr, "long_branch"); break;
+ case ppc_stub_plt_branch: fprintf (stderr, "plt_branch"); break;
+ case ppc_stub_plt_call: fprintf (stderr, "plt_call"); break;
+ case ppc_stub_global_entry: fprintf (stderr, "global_entry"); break;
+ case ppc_stub_save_res: fprintf (stderr, "save_res"); break;
+ default: fprintf (stderr, "???"); break;
+ }
+ switch (esd->u.last_ent->type.sub)
+ {
+ case ppc_stub_toc: fprintf (stderr, ":toc"); break;
+ case ppc_stub_notoc: fprintf (stderr, ":notoc"); break;
+ case ppc_stub_p9notoc: fprintf (stderr, ":p9notoc"); break;
+ default: fprintf (stderr, ":???"); break;
+ }
+ if (esd->u.last_ent->type.r2save)
+ fprintf (stderr, ":r2save");
+ fprintf (stderr, "\nname = %s", esd->u.last_ent->root.string);
+ fprintf (stderr, "\noffset = %#lx:", esd->u.last_ent->stub_offset);
+ for (size_t i = esd->u.last_ent->stub_offset;
+ i < stub_entry->stub_offset; i += 4)
+ {
+ uint32_t *p = (uint32_t *) (stub_sec->contents + i);
+ fprintf (stderr, " %08x", *p);
+ }
+ fprintf (stderr, "\n");
+ }
+}
+
static bool
ppc_build_one_stub (struct bfd_hash_entry *gen_entry, void *in_arg)
{
@@ -11680,7 +11725,11 @@ ppc_build_one_stub (struct bfd_hash_entry *gen_entry, void *in_arg)
if (htab == NULL)
return false;
- BFD_ASSERT (stub_entry->stub_offset >= stub_entry->group->stub_sec->size);
+ if (stub_entry->stub_offset < stub_entry->group->stub_sec->size)
+ {
+ BFD_ASSERT (0);
+ dump_previous_stub (stub_entry);
+ }
loc = stub_entry->group->stub_sec->contents + stub_entry->stub_offset;
htab->stub_count[stub_entry->type.main - 1] += 1;
@@ -12122,6 +12171,12 @@ ppc_build_one_stub (struct bfd_hash_entry *gen_entry, void *in_arg)
}
stub_entry->group->stub_sec->size = stub_entry->stub_offset + (p - loc);
+ struct _ppc64_elf_section_data *esd
+ = ppc64_elf_section_data (stub_entry->group->stub_sec);
+ if (esd->sec_type == sec_normal)
+ esd->sec_type = sec_stub;
+ if (esd->sec_type == sec_stub)
+ esd->u.last_ent = stub_entry;
if (htab->params->emit_stub_syms)
{
--
Alan Modra
Australia Development Lab, IBM
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: PowerPC64: stub debug dump
@ 2022-06-23 8:34 Alan Modra
0 siblings, 0 replies; 2+ messages in thread
From: Alan Modra @ 2022-06-23 8:34 UTC (permalink / raw)
To: binutils
Let's show the current stub as well as the previous one. Of interest
is the current offset and a new field, id. Check that the build
hash table traversal is in the same order as sizing traversal too.
* elf64-ppc.c (struct ppc_stub_hash_entry): Add id.
(struct ppc_link_hash_table): Add stub_id.
(stub_hash_newfunc): Init id and symtype.
(dump_stub): New function, extracted from..
(dump_previous_stub): ..here. Deleted.
(ppc_build_one_stub): Sanity check stub id as well as offset.
Show current stub as well as previous.
(ppc_size_one_stub): Set stub id.
(ppc64_elf_size_stubs): Init stub_id before traversal.
(ppc64_elf_build_stubs): Likewise.
diff --git a/bfd/elf64-ppc.c b/bfd/elf64-ppc.c
index c69b07435a1..6af33d883b3 100644
--- a/bfd/elf64-ppc.c
+++ b/bfd/elf64-ppc.c
@@ -3083,6 +3083,9 @@ struct ppc_stub_hash_entry
/* Symbol st_other. */
unsigned char other;
+
+ /* Debug: Track hash table traversal. */
+ unsigned int id;
};
struct ppc_branch_hash_entry
@@ -3321,6 +3324,9 @@ struct ppc_link_hash_table
/* Whether any code linked seems to be Power10. */
unsigned int has_power10_relocs:1;
+ /* Incremented once for each stub sized. */
+ unsigned int stub_id;
+
/* Incremented every time we size stubs. */
unsigned int stub_iteration;
@@ -3401,7 +3407,9 @@ stub_hash_newfunc (struct bfd_hash_entry *entry,
eh->target_section = NULL;
eh->h = NULL;
eh->plt_ent = NULL;
+ eh->symtype = 0;
eh->other = 0;
+ eh->id = 0;
}
return entry;
@@ -11643,42 +11651,40 @@ get_r2off (struct bfd_link_info *info,
/* Debug dump. */
static void
-dump_previous_stub (struct ppc_stub_hash_entry *stub_entry)
+dump_stub (const char *header,
+ struct ppc_stub_hash_entry *stub_entry,
+ size_t end_offset)
{
- asection *stub_sec = stub_entry->group->stub_sec;
- struct _ppc64_elf_section_data *esd = ppc64_elf_section_data (stub_sec);
- if (esd->sec_type == sec_stub)
+ const char *t1, *t2, *t3;
+ switch (stub_entry->type.main)
{
- fprintf (stderr, "Previous stub: type = ");
- switch (esd->u.last_ent->type.main)
- {
- case ppc_stub_none: fprintf (stderr, "none"); break;
- case ppc_stub_long_branch: fprintf (stderr, "long_branch"); break;
- case ppc_stub_plt_branch: fprintf (stderr, "plt_branch"); break;
- case ppc_stub_plt_call: fprintf (stderr, "plt_call"); break;
- case ppc_stub_global_entry: fprintf (stderr, "global_entry"); break;
- case ppc_stub_save_res: fprintf (stderr, "save_res"); break;
- default: fprintf (stderr, "???"); break;
- }
- switch (esd->u.last_ent->type.sub)
- {
- case ppc_stub_toc: fprintf (stderr, ":toc"); break;
- case ppc_stub_notoc: fprintf (stderr, ":notoc"); break;
- case ppc_stub_p9notoc: fprintf (stderr, ":p9notoc"); break;
- default: fprintf (stderr, ":???"); break;
- }
- if (esd->u.last_ent->type.r2save)
- fprintf (stderr, ":r2save");
- fprintf (stderr, "\nname = %s", esd->u.last_ent->root.string);
- fprintf (stderr, "\noffset = %#lx:", esd->u.last_ent->stub_offset);
- for (size_t i = esd->u.last_ent->stub_offset;
- i < stub_entry->stub_offset; i += 4)
- {
- uint32_t *p = (uint32_t *) (stub_sec->contents + i);
- fprintf (stderr, " %08x", *p);
- }
- fprintf (stderr, "\n");
+ case ppc_stub_none: t1 = "none"; break;
+ case ppc_stub_long_branch: t1 = "long_branch"; break;
+ case ppc_stub_plt_branch: t1 = "plt_branch"; break;
+ case ppc_stub_plt_call: t1 = "plt_call"; break;
+ case ppc_stub_global_entry: t1 = "global_entry"; break;
+ case ppc_stub_save_res: t1 = "save_res"; break;
+ default: t1 = "???"; break;
+ }
+ switch (stub_entry->type.sub)
+ {
+ case ppc_stub_toc: t2 = "toc"; break;
+ case ppc_stub_notoc: t2 = "notoc"; break;
+ case ppc_stub_p9notoc: t2 = "p9notoc"; break;
+ default: t2 = "???"; break;
+ }
+ t3 = stub_entry->type.r2save ? "r2save" : "";
+ fprintf (stderr, "%s id = %u type = %s:%s:%s\n",
+ header, stub_entry->id, t1, t2, t3);
+ fprintf (stderr, "name = %s\n", stub_entry->root.string);
+ fprintf (stderr, "offset = %#lx:", stub_entry->stub_offset);
+ for (size_t i = stub_entry->stub_offset; i < end_offset; i += 4)
+ {
+ asection *stub_sec = stub_entry->group->stub_sec;
+ uint32_t *p = (uint32_t *) (stub_sec->contents + i);
+ fprintf (stderr, " %08x", (uint32_t) bfd_get_32 (stub_sec->owner, p));
}
+ fprintf (stderr, "\n");
}
static bool
@@ -11725,11 +11731,28 @@ ppc_build_one_stub (struct bfd_hash_entry *gen_entry, void *in_arg)
if (htab == NULL)
return false;
- if (stub_entry->stub_offset < stub_entry->group->stub_sec->size)
+ struct _ppc64_elf_section_data *esd
+ = ppc64_elf_section_data (stub_entry->group->stub_sec);
+ ++htab->stub_id;
+ if (stub_entry->id != htab->stub_id
+ || stub_entry->stub_offset < stub_entry->group->stub_sec->size)
{
BFD_ASSERT (0);
- dump_previous_stub (stub_entry);
+ if (stub_entry->id != htab->stub_id)
+ fprintf (stderr, "Expected id %u, got %u\n",
+ htab->stub_id, stub_entry->id);
+ if (stub_entry->stub_offset < stub_entry->group->stub_sec->size)
+ fprintf (stderr, "Expected offset >= %" BFD_VMA_FMT "x, got %"
+ BFD_VMA_FMT "x\n", stub_entry->group->stub_sec->size,
+ stub_entry->stub_offset);
+ if (esd->sec_type == sec_stub)
+ dump_stub ("Previous:", esd->u.last_ent, stub_entry->stub_offset);
+ dump_stub ("Current:", stub_entry, 0);
}
+ if (esd->sec_type == sec_normal)
+ esd->sec_type = sec_stub;
+ if (esd->sec_type == sec_stub)
+ esd->u.last_ent = stub_entry;
loc = stub_entry->group->stub_sec->contents + stub_entry->stub_offset;
htab->stub_count[stub_entry->type.main - 1] += 1;
@@ -12171,12 +12194,6 @@ ppc_build_one_stub (struct bfd_hash_entry *gen_entry, void *in_arg)
}
stub_entry->group->stub_sec->size = stub_entry->stub_offset + (p - loc);
- struct _ppc64_elf_section_data *esd
- = ppc64_elf_section_data (stub_entry->group->stub_sec);
- if (esd->sec_type == sec_normal)
- esd->sec_type = sec_stub;
- if (esd->sec_type == sec_stub)
- esd->u.last_ent = stub_entry;
if (htab->params->emit_stub_syms)
{
@@ -12262,6 +12279,7 @@ ppc_size_one_stub (struct bfd_hash_entry *gen_entry, void *in_arg)
if (htab->stub_iteration > STUB_SHRINK_ITER
&& stub_entry->stub_offset > stub_offset)
stub_offset = stub_entry->stub_offset;
+ stub_entry->id = ++htab->stub_id;
if (stub_entry->h != NULL
&& stub_entry->h->save_res
@@ -14218,6 +14236,7 @@ ppc64_elf_size_stubs (struct bfd_link_info *info)
}
htab->stub_changed = false;
+ htab->stub_id = 0;
bfd_hash_traverse (&htab->stub_hash_table, ppc_size_one_stub, info);
for (group = htab->group; group != NULL; group = group->next)
@@ -15153,6 +15172,7 @@ ppc64_elf_build_stubs (struct bfd_link_info *info,
}
/* Build the stubs as directed by the stub hash table. */
+ htab->stub_id = 0;
bfd_hash_traverse (&htab->stub_hash_table, ppc_build_one_stub, info);
for (group = htab->group; group != NULL; group = group->next)
--
Alan Modra
Australia Development Lab, IBM
^ permalink raw reply [flat|nested] 2+ messages in thread
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