xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

objtool: Keep track of retpoline call sites

Browse Source 
commit 43d5430ad74ef5156353af7aec352426ec7a8e57 upstream.

Provide infrastructure for architectures to rewrite/augment compiler
generated retpoline calls. Similar to what we do for static_call()s,
keep track of the instructions that are retpoline calls.

Use the same list_head, since a retpoline call cannot also be a
static_call.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lkml.kernel.org/r/20210326151300.130805730@infradead.org
[bwh: Backported to 5.10: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Peter Zijlstra
2021-03-26 16:12:12 +01:00
committed by Greg Kroah-Hartman
parent 8a6d73f7db
commit 33092b4866
5 changed files with 34 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files

34
tools/objtool/check.c
View File

@@ -451,7 +451,7 @@ static int create_static_call_sections(struct objtool_file *file)
return 0;
idx = 0;
list_for_each_entry(insn, &file->static_call_list, static_call_node)
list_for_each_entry(insn, &file->static_call_list, call_node)
idx++;
sec = elf_create_section(file->elf, ".static_call_sites", SHF_WRITE,
@@ -460,7 +460,7 @@ static int create_static_call_sections(struct objtool_file *file)
return -1;
idx = 0;
list_for_each_entry(insn, &file->static_call_list, static_call_node) {
list_for_each_entry(insn, &file->static_call_list, call_node) {
site = (struct static_call_site *)sec->data->d_buf + idx;
memset(site, 0, sizeof(struct static_call_site));
@@ -786,13 +786,16 @@ static int add_jump_destinations(struct objtool_file *file)
else
insn->type = INSN_JUMP_DYNAMIC_CONDITIONAL;
list_add_tail(&insn->call_node,
&file->retpoline_call_list);
insn->retpoline_safe = true;
continue;
} else if (insn->func) {
/* internal or external sibling call (with reloc) */
insn->call_dest = reloc->sym;
if (insn->call_dest->static_call_tramp) {
list_add_tail(&insn->static_call_node,
list_add_tail(&insn->call_node,
&file->static_call_list);
}
continue;
@@ -854,7 +857,7 @@ static int add_jump_destinations(struct objtool_file *file)
/* internal sibling call (without reloc) */
insn->call_dest = insn->jump_dest->func;
if (insn->call_dest->static_call_tramp) {
list_add_tail(&insn->static_call_node,
list_add_tail(&insn->call_node,
&file->static_call_list);
}
}
@@ -938,6 +941,9 @@ static int add_call_destinations(struct objtool_file *file)
insn->type = INSN_CALL_DYNAMIC;
insn->retpoline_safe = true;
list_add_tail(&insn->call_node,
&file->retpoline_call_list);
remove_insn_ops(insn);
continue;
@@ -945,7 +951,7 @@ static int add_call_destinations(struct objtool_file *file)
insn->call_dest = reloc->sym;
if (insn->call_dest && insn->call_dest->static_call_tramp) {
list_add_tail(&insn->static_call_node,
list_add_tail(&insn->call_node,
&file->static_call_list);
}
@@ -1655,6 +1661,11 @@ static void mark_rodata(struct objtool_file *file)
file->rodata = found;
}
__weak int arch_rewrite_retpolines(struct objtool_file *file)
{
return 0;
}
static int decode_sections(struct objtool_file *file)
{
int ret;
@@ -1683,6 +1694,10 @@ static int decode_sections(struct objtool_file *file)
if (ret)
return ret;
/*
* Must be before add_special_section_alts() as that depends on
* jump_dest being set.
*/
ret = add_jump_destinations(file);
if (ret)
return ret;
@@ -1719,6 +1734,15 @@ static int decode_sections(struct objtool_file *file)
if (ret)
return ret;
/*
* Must be after add_special_section_alts(), since this will emit
* alternatives. Must be after add_{jump,call}_destination(), since
* those create the call insn lists.
*/
ret = arch_rewrite_retpolines(file);
if (ret)
return ret;
return 0;
}