Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
arch/x86/include/asm/nospec-branch.h | 13 +-------
include/linux/objtool_types.h | 1
tools/include/linux/objtool_types.h | 1
tools/objtool/check.c | 52 ++++++++++++-----------------------
4 files changed, 22 insertions(+), 45 deletions(-)
--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -193,12 +193,7 @@
* objtool the subsequent indirect jump/call is vouched safe for retpoline
* builds.
*/
-.macro ANNOTATE_RETPOLINE_SAFE
-.Lhere_\@:
- .pushsection .discard.retpoline_safe
- .long .Lhere_\@
- .popsection
-.endm
+#define ANNOTATE_RETPOLINE_SAFE ANNOTATE type=ANNOTYPE_RETPOLINE_SAFE
/*
* (ab)use RETPOLINE_SAFE on RET to annotate away 'bare' RET instructions
@@ -317,11 +312,7 @@
#else /* __ASSEMBLY__ */
-#define ANNOTATE_RETPOLINE_SAFE \
- "999:\n\t" \
- ".pushsection .discard.retpoline_safe\n\t" \
- ".long 999b\n\t" \
- ".popsection\n\t"
+#define ANNOTATE_RETPOLINE_SAFE ASM_ANNOTATE(ANNOTYPE_RETPOLINE_SAFE)
typedef u8 retpoline_thunk_t[RETPOLINE_THUNK_SIZE];
extern retpoline_thunk_t __x86_indirect_thunk_array[];
--- a/include/linux/objtool_types.h
+++ b/include/linux/objtool_types.h
@@ -58,5 +58,6 @@ struct unwind_hint {
* Annotate types
*/
#define ANNOTYPE_NOENDBR 1
+#define ANNOTYPE_RETPOLINE_SAFE 2
#endif /* _LINUX_OBJTOOL_TYPES_H */
--- a/tools/include/linux/objtool_types.h
+++ b/tools/include/linux/objtool_types.h
@@ -58,5 +58,6 @@ struct unwind_hint {
* Annotate types
*/
#define ANNOTYPE_NOENDBR 1
+#define ANNOTYPE_RETPOLINE_SAFE 2
#endif /* _LINUX_OBJTOOL_TYPES_H */
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -2308,12 +2308,12 @@ static int read_unwind_hints(struct objt
return 0;
}
-static int read_annotate(struct objtool_file *file, void (*func)(int type, struct instruction *insn))
+static int read_annotate(struct objtool_file *file, int (*func)(int type, struct instruction *insn))
{
struct section *rsec, *sec;
struct instruction *insn;
struct reloc *reloc;
- int type;
+ int type, ret;
rsec = find_section_by_name(file->elf, ".rela.discard.annotate");
if (!rsec)
@@ -2333,53 +2333,37 @@ static int read_annotate(struct objtool_
type = *(u32 *)(sec->data->d_buf + (reloc_idx(reloc) * sec->sh.sh_entsize) + 4);
- func(type, insn);
+ ret = func(type, insn);
+ if (ret < 0)
+ return ret;
}
return 0;
}
-static void __annotate_noendbr(int type, struct instruction *insn)
+static int __annotate_noendbr(int type, struct instruction *insn)
{
if (type != ANNOTYPE_NOENDBR)
- return;
+ return 0;
insn->noendbr = 1;
+ return 0;
}
-static int read_retpoline_hints(struct objtool_file *file)
+static int __annotate_retpoline_safe(int type, struct instruction *insn)
{
- struct section *rsec;
- struct instruction *insn;
- struct reloc *reloc;
-
- rsec = find_section_by_name(file->elf, ".rela.discard.retpoline_safe");
- if (!rsec)
+ if (type != ANNOTYPE_RETPOLINE_SAFE)
return 0;
- for_each_reloc(rsec, reloc) {
- if (reloc->sym->type != STT_SECTION) {
- WARN("unexpected relocation symbol type in %s", rsec->name);
- return -1;
- }
-
- insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc));
- if (!insn) {
- WARN("bad .discard.retpoline_safe entry");
- return -1;
- }
-
- if (insn->type != INSN_JUMP_DYNAMIC &&
- insn->type != INSN_CALL_DYNAMIC &&
- insn->type != INSN_RETURN &&
- insn->type != INSN_NOP) {
- WARN_INSN(insn, "retpoline_safe hint not an indirect jump/call/ret/nop");
- return -1;
- }
-
- insn->retpoline_safe = true;
+ if (insn->type != INSN_JUMP_DYNAMIC &&
+ insn->type != INSN_CALL_DYNAMIC &&
+ insn->type != INSN_RETURN &&
+ insn->type != INSN_NOP) {
+ WARN_INSN(insn, "retpoline_safe hint not an indirect jump/call/ret/nop");
+ return -1;
}
+ insn->retpoline_safe = true;
return 0;
}
@@ -2666,7 +2650,7 @@ static int decode_sections(struct objtoo
if (ret)
return ret;
- ret = read_retpoline_hints(file);
+ ret = read_annotate(file, __annotate_retpoline_safe);
if (ret)
return ret;On Mon, Dec 04, 2023, Peter Zijlstra wrote: > > --- a/arch/x86/include/asm/nospec-branch.h > +++ b/arch/x86/include/asm/nospec-branch.h > @@ -193,12 +193,7 @@ > * objtool the subsequent indirect jump/call is vouched safe for retpoline > * builds. > */ > -.macro ANNOTATE_RETPOLINE_SAFE > -.Lhere_\@: > - .pushsection .discard.retpoline_safe > - .long .Lhere_\@ > - .popsection > -.endm > +#define ANNOTATE_RETPOLINE_SAFE ANNOTATE type=ANNOTYPE_RETPOLINE_SAFE > > /* > * (ab)use RETPOLINE_SAFE on RET to annotate away 'bare' RET instructions > @@ -317,11 +312,7 @@ > > #else /* __ASSEMBLY__ */ > > -#define ANNOTATE_RETPOLINE_SAFE \ > - "999:\n\t" \ > - ".pushsection .discard.retpoline_safe\n\t" \ > - ".long 999b\n\t" \ > - ".popsection\n\t" > +#define ANNOTATE_RETPOLINE_SAFE ASM_ANNOTATE(ANNOTYPE_RETPOLINE_SAFE) This fails for some of my builds that end up with CONFIG_OBJTOOl=n. Adding a stub for ASM_ANNOTATE() gets me past that: @@ -156,6 +171,7 @@ #define STACK_FRAME_NON_STANDARD(func) #define STACK_FRAME_NON_STANDARD_FP(func) #define ANNOTATE_NOENDBR +#define ASM_ANNOTATE(x) #define ASM_REACHABLE #else #define ANNOTATE_INTRA_FUNCTION_CALL but then I run into other issues: arch/x86/kernel/relocate_kernel_32.S: Assembler messages: arch/x86/kernel/relocate_kernel_32.S:96: Error: Parameter named `type' does not exist for macro `annotate' arch/x86/kernel/relocate_kernel_32.S:166: Error: Parameter named `type' does not exist for macro `annotate' arch/x86/kernel/relocate_kernel_32.S:174: Error: Parameter named `type' does not exist for macro `annotate' arch/x86/kernel/relocate_kernel_32.S:200: Error: Parameter named `type' does not exist for macro `annotate' arch/x86/kernel/relocate_kernel_32.S:220: Error: Parameter named `type' does not exist for macro `annotate' arch/x86/kernel/relocate_kernel_32.S:285: Error: Parameter named `type' does not exist for macro `annotate'
Hi Peter,
On Wed, 6 Dec 2023, Sean Christopherson wrote:
> On Mon, Dec 04, 2023, Peter Zijlstra wrote:
> >
> > --- a/arch/x86/include/asm/nospec-branch.h
> > +++ b/arch/x86/include/asm/nospec-branch.h
> > @@ -193,12 +193,7 @@
> > * objtool the subsequent indirect jump/call is vouched safe for retpoline
> > * builds.
> > */
> > -.macro ANNOTATE_RETPOLINE_SAFE
> > -.Lhere_\@:
> > - .pushsection .discard.retpoline_safe
> > - .long .Lhere_\@
> > - .popsection
> > -.endm
> > +#define ANNOTATE_RETPOLINE_SAFE ANNOTATE type=ANNOTYPE_RETPOLINE_SAFE
> >
> > /*
> > * (ab)use RETPOLINE_SAFE on RET to annotate away 'bare' RET instructions
> > @@ -317,11 +312,7 @@
> >
> > #else /* __ASSEMBLY__ */
> >
> > -#define ANNOTATE_RETPOLINE_SAFE \
> > - "999:\n\t" \
> > - ".pushsection .discard.retpoline_safe\n\t" \
> > - ".long 999b\n\t" \
> > - ".popsection\n\t"
> > +#define ANNOTATE_RETPOLINE_SAFE ASM_ANNOTATE(ANNOTYPE_RETPOLINE_SAFE)
>
> This fails for some of my builds that end up with CONFIG_OBJTOOl=n. Adding a
> stub for ASM_ANNOTATE() gets me past that:
>
> @@ -156,6 +171,7 @@
> #define STACK_FRAME_NON_STANDARD(func)
> #define STACK_FRAME_NON_STANDARD_FP(func)
> #define ANNOTATE_NOENDBR
> +#define ASM_ANNOTATE(x)
> #define ASM_REACHABLE
> #else
> #define ANNOTATE_INTRA_FUNCTION_CALL
>
> but then I run into other issues:
>
> arch/x86/kernel/relocate_kernel_32.S: Assembler messages:
> arch/x86/kernel/relocate_kernel_32.S:96: Error: Parameter named `type' does not exist for macro `annotate'
> arch/x86/kernel/relocate_kernel_32.S:166: Error: Parameter named `type' does not exist for macro `annotate'
> arch/x86/kernel/relocate_kernel_32.S:174: Error: Parameter named `type' does not exist for macro `annotate'
> arch/x86/kernel/relocate_kernel_32.S:200: Error: Parameter named `type' does not exist for macro `annotate'
> arch/x86/kernel/relocate_kernel_32.S:220: Error: Parameter named `type' does not exist for macro `annotate'
> arch/x86/kernel/relocate_kernel_32.S:285: Error: Parameter named `type' does not exist for macro `annotate'
Sean pointed me at this series recently. It seems like these compile errors
(and some others) go away with the following diff:
diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h
index 0bebdcad7ba1..036ab199859a 100644
--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -489,7 +489,7 @@ static inline void call_depth_return_thunk(void) {}
" .align 16\n" \
"903: lea 4(%%esp), %%esp;\n" \
" pushl %[thunk_target];\n" \
- " ret;\n" \
+ " ret;\n", \
X86_FEATURE_RETPOLINE, \
"lfence;\n" \
ANNOTATE_RETPOLINE_SAFE \
diff --git a/include/linux/objtool.h b/include/linux/objtool.h
index f6f80bfefe3b..e811b2ff3a9c 100644
--- a/include/linux/objtool.h
+++ b/include/linux/objtool.h
@@ -159,6 +159,7 @@
#define STACK_FRAME_NON_STANDARD_FP(func)
#define ANNOTATE_NOENDBR
#define ASM_REACHABLE
+#define ASM_ANNOTATE(x)
#else
#define ANNOTATE_INTRA_FUNCTION_CALL
.macro UNWIND_HINT type:req sp_reg=0 sp_offset=0 signal=0
@@ -169,7 +170,7 @@
.endm
.macro REACHABLE
.endm
-.macro ANNOTATE
+.macro ANNOTATE type:req
.endm
#endif
This series applies on top of the latest kvm-x86/next with only a few trivial
conflicts, so I hope you are able to send a new version.
I could send one for you, but I have no idea how to properly test it.
On Fri, Sep 13, 2024 at 1:47 PM James Houghton <jthoughton@google.com> wrote:
>
> On Wed, 6 Dec 2023, Sean Christopherson wrote:
> > On Mon, Dec 04, 2023, Peter Zijlstra wrote:
> > >
> > > --- a/arch/x86/include/asm/nospec-branch.h
> > > +++ b/arch/x86/include/asm/nospec-branch.h
> > > @@ -193,12 +193,7 @@
> > > * objtool the subsequent indirect jump/call is vouched safe for retpoline
> > > * builds.
> > > */
> > > -.macro ANNOTATE_RETPOLINE_SAFE
> > > -.Lhere_\@:
> > > - .pushsection .discard.retpoline_safe
> > > - .long .Lhere_\@
> > > - .popsection
> > > -.endm
> > > +#define ANNOTATE_RETPOLINE_SAFE ANNOTATE type=ANNOTYPE_RETPOLINE_SAFE
> > >
> > > /*
> > > * (ab)use RETPOLINE_SAFE on RET to annotate away 'bare' RET instructions
> > > @@ -317,11 +312,7 @@
> > >
> > > #else /* __ASSEMBLY__ */
> > >
> > > -#define ANNOTATE_RETPOLINE_SAFE \
> > > - "999:\n\t" \
> > > - ".pushsection .discard.retpoline_safe\n\t" \
> > > - ".long 999b\n\t" \
> > > - ".popsection\n\t"
> > > +#define ANNOTATE_RETPOLINE_SAFE ASM_ANNOTATE(ANNOTYPE_RETPOLINE_SAFE)
> >
> > This fails for some of my builds that end up with CONFIG_OBJTOOl=n. Adding a
> > stub for ASM_ANNOTATE() gets me past that:
> >
> > @@ -156,6 +171,7 @@
> > #define STACK_FRAME_NON_STANDARD(func)
> > #define STACK_FRAME_NON_STANDARD_FP(func)
> > #define ANNOTATE_NOENDBR
> > +#define ASM_ANNOTATE(x)
> > #define ASM_REACHABLE
> > #else
> > #define ANNOTATE_INTRA_FUNCTION_CALL
> >
> > but then I run into other issues:
> >
> > arch/x86/kernel/relocate_kernel_32.S: Assembler messages:
> > arch/x86/kernel/relocate_kernel_32.S:96: Error: Parameter named `type' does not exist for macro `annotate'
> > arch/x86/kernel/relocate_kernel_32.S:166: Error: Parameter named `type' does not exist for macro `annotate'
> > arch/x86/kernel/relocate_kernel_32.S:174: Error: Parameter named `type' does not exist for macro `annotate'
> > arch/x86/kernel/relocate_kernel_32.S:200: Error: Parameter named `type' does not exist for macro `annotate'
> > arch/x86/kernel/relocate_kernel_32.S:220: Error: Parameter named `type' does not exist for macro `annotate'
> > arch/x86/kernel/relocate_kernel_32.S:285: Error: Parameter named `type' does not exist for macro `annotate'
>
> Sean pointed me at this series recently. It seems like these compile errors
> (and some others) go away with the following diff:
>
> diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h
> index 0bebdcad7ba1..036ab199859a 100644
> --- a/arch/x86/include/asm/nospec-branch.h
> +++ b/arch/x86/include/asm/nospec-branch.h
> @@ -489,7 +489,7 @@ static inline void call_depth_return_thunk(void) {}
> " .align 16\n" \
> "903: lea 4(%%esp), %%esp;\n" \
> " pushl %[thunk_target];\n" \
> - " ret;\n" \
> + " ret;\n", \
> X86_FEATURE_RETPOLINE, \
> "lfence;\n" \
> ANNOTATE_RETPOLINE_SAFE \
> diff --git a/include/linux/objtool.h b/include/linux/objtool.h
> index f6f80bfefe3b..e811b2ff3a9c 100644
> --- a/include/linux/objtool.h
> +++ b/include/linux/objtool.h
> @@ -159,6 +159,7 @@
> #define STACK_FRAME_NON_STANDARD_FP(func)
> #define ANNOTATE_NOENDBR
> #define ASM_REACHABLE
> +#define ASM_ANNOTATE(x)
> #else
> #define ANNOTATE_INTRA_FUNCTION_CALL
> .macro UNWIND_HINT type:req sp_reg=0 sp_offset=0 signal=0
> @@ -169,7 +170,7 @@
> .endm
> .macro REACHABLE
> .endm
> -.macro ANNOTATE
> +.macro ANNOTATE type:req
> .endm
> #endif
>
> This series applies on top of the latest kvm-x86/next with only a few trivial
> conflicts, so I hope you are able to send a new version.
>
> I could send one for you, but I have no idea how to properly test it.
Hi Peter,
I'll go ahead and repost this series soon unless you tell me otherwise. :)
On Wed, Oct 30, 2024 at 01:08:28PM -0700, James Houghton wrote: > Hi Peter, > > I'll go ahead and repost this series soon unless you tell me otherwise. :) Thanks for your persistent poking. I've refreshed the queue:x86/kvm branch, and provided the robots don't scream, I'll go and post it.
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