Merge tag 'objtool-core-2020-10-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull objtool updates from Ingo Molnar:
"Most of the changes are cleanups and reorganization to make the
objtool code more arch-agnostic. This is in preparation for non-x86
support.
Other changes:
- KASAN fixes
- Handle unreachable trap after call to noreturn functions better
- Ignore unreachable fake jumps
- Misc smaller fixes & cleanups"
* tag 'objtool-core-2020-10-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits)
perf build: Allow nested externs to enable BUILD_BUG() usage
objtool: Allow nested externs to enable BUILD_BUG()
objtool: Permit __kasan_check_{read,write} under UACCESS
objtool: Ignore unreachable trap after call to noreturn functions
objtool: Handle calling non-function symbols in other sections
objtool: Ignore unreachable fake jumps
objtool: Remove useless tests before save_reg()
objtool: Decode unwind hint register depending on architecture
objtool: Make unwind hint definitions available to other architectures
objtool: Only include valid definitions depending on source file type
objtool: Rename frame.h -> objtool.h
objtool: Refactor jump table code to support other architectures
objtool: Make relocation in alternative handling arch dependent
objtool: Abstract alternative special case handling
objtool: Move macros describing structures to arch-dependent code
objtool: Make sync-check consider the target architecture
objtool: Group headers to check in a single list
objtool: Define 'struct orc_entry' only when needed
objtool: Skip ORC entry creation for non-text sections
objtool: Move ORC logic out of check()
...
diff --git a/MAINTAINERS b/MAINTAINERS
index 7eecfb3..3763cec 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12515,6 +12515,7 @@
M: Peter Zijlstra <peterz@infradead.org>
S: Supported
F: tools/objtool/
+F: include/linux/objtool.h
OCELOT ETHERNET SWITCH DRIVER
M: Microchip Linux Driver Support <UNGLinuxDriver@microchip.com>
diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h
index e7752b4..86651e8 100644
--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -4,7 +4,7 @@
#define _ASM_X86_NOSPEC_BRANCH_H_
#include <linux/static_key.h>
-#include <linux/frame.h>
+#include <linux/objtool.h>
#include <asm/alternative.h>
#include <asm/alternative-asm.h>
diff --git a/arch/x86/include/asm/orc_types.h b/arch/x86/include/asm/orc_types.h
index d255349..fdbffec 100644
--- a/arch/x86/include/asm/orc_types.h
+++ b/arch/x86/include/asm/orc_types.h
@@ -39,27 +39,6 @@
#define ORC_REG_SP_INDIRECT 9
#define ORC_REG_MAX 15
-/*
- * ORC_TYPE_CALL: Indicates that sp_reg+sp_offset resolves to PREV_SP (the
- * caller's SP right before it made the call). Used for all callable
- * functions, i.e. all C code and all callable asm functions.
- *
- * ORC_TYPE_REGS: Used in entry code to indicate that sp_reg+sp_offset points
- * to a fully populated pt_regs from a syscall, interrupt, or exception.
- *
- * ORC_TYPE_REGS_IRET: Used in entry code to indicate that sp_reg+sp_offset
- * points to the iret return frame.
- *
- * The UNWIND_HINT macros are used only for the unwind_hint struct. They
- * aren't used in struct orc_entry due to size and complexity constraints.
- * Objtool converts them to real types when it converts the hints to orc
- * entries.
- */
-#define ORC_TYPE_CALL 0
-#define ORC_TYPE_REGS 1
-#define ORC_TYPE_REGS_IRET 2
-#define UNWIND_HINT_TYPE_RET_OFFSET 3
-
#ifndef __ASSEMBLY__
/*
* This struct is more or less a vastly simplified version of the DWARF Call
@@ -78,19 +57,6 @@ struct orc_entry {
unsigned end:1;
} __packed;
-/*
- * This struct is used by asm and inline asm code to manually annotate the
- * location of registers on the stack for the ORC unwinder.
- *
- * Type can be either ORC_TYPE_* or UNWIND_HINT_TYPE_*.
- */
-struct unwind_hint {
- u32 ip;
- s16 sp_offset;
- u8 sp_reg;
- u8 type;
- u8 end;
-};
#endif /* __ASSEMBLY__ */
#endif /* _ORC_TYPES_H */
diff --git a/arch/x86/include/asm/unwind_hints.h b/arch/x86/include/asm/unwind_hints.h
index 7d903fd..664d461 100644
--- a/arch/x86/include/asm/unwind_hints.h
+++ b/arch/x86/include/asm/unwind_hints.h
@@ -1,51 +1,17 @@
#ifndef _ASM_X86_UNWIND_HINTS_H
#define _ASM_X86_UNWIND_HINTS_H
+#include <linux/objtool.h>
+
#include "orc_types.h"
#ifdef __ASSEMBLY__
-/*
- * In asm, there are two kinds of code: normal C-type callable functions and
- * the rest. The normal callable functions can be called by other code, and
- * don't do anything unusual with the stack. Such normal callable functions
- * are annotated with the ENTRY/ENDPROC macros. Most asm code falls in this
- * category. In this case, no special debugging annotations are needed because
- * objtool can automatically generate the ORC data for the ORC unwinder to read
- * at runtime.
- *
- * Anything which doesn't fall into the above category, such as syscall and
- * interrupt handlers, tends to not be called directly by other functions, and
- * often does unusual non-C-function-type things with the stack pointer. Such
- * code needs to be annotated such that objtool can understand it. The
- * following CFI hint macros are for this type of code.
- *
- * These macros provide hints to objtool about the state of the stack at each
- * instruction. Objtool starts from the hints and follows the code flow,
- * making automatic CFI adjustments when it sees pushes and pops, filling out
- * the debuginfo as necessary. It will also warn if it sees any
- * inconsistencies.
- */
-.macro UNWIND_HINT sp_reg=ORC_REG_SP sp_offset=0 type=ORC_TYPE_CALL end=0
-#ifdef CONFIG_STACK_VALIDATION
-.Lunwind_hint_ip_\@:
- .pushsection .discard.unwind_hints
- /* struct unwind_hint */
- .long .Lunwind_hint_ip_\@ - .
- .short \sp_offset
- .byte \sp_reg
- .byte \type
- .byte \end
- .balign 4
- .popsection
-#endif
-.endm
-
.macro UNWIND_HINT_EMPTY
- UNWIND_HINT sp_reg=ORC_REG_UNDEFINED end=1
+ UNWIND_HINT sp_reg=ORC_REG_UNDEFINED type=UNWIND_HINT_TYPE_CALL end=1
.endm
-.macro UNWIND_HINT_REGS base=%rsp offset=0 indirect=0 extra=1 iret=0
+.macro UNWIND_HINT_REGS base=%rsp offset=0 indirect=0 extra=1 partial=0
.if \base == %rsp
.if \indirect
.set sp_reg, ORC_REG_SP_INDIRECT
@@ -66,24 +32,24 @@
.set sp_offset, \offset
- .if \iret
- .set type, ORC_TYPE_REGS_IRET
+ .if \partial
+ .set type, UNWIND_HINT_TYPE_REGS_PARTIAL
.elseif \extra == 0
- .set type, ORC_TYPE_REGS_IRET
+ .set type, UNWIND_HINT_TYPE_REGS_PARTIAL
.set sp_offset, \offset + (16*8)
.else
- .set type, ORC_TYPE_REGS
+ .set type, UNWIND_HINT_TYPE_REGS
.endif
UNWIND_HINT sp_reg=sp_reg sp_offset=sp_offset type=type
.endm
.macro UNWIND_HINT_IRET_REGS base=%rsp offset=0
- UNWIND_HINT_REGS base=\base offset=\offset iret=1
+ UNWIND_HINT_REGS base=\base offset=\offset partial=1
.endm
.macro UNWIND_HINT_FUNC sp_offset=8
- UNWIND_HINT sp_offset=\sp_offset
+ UNWIND_HINT sp_reg=ORC_REG_SP sp_offset=\sp_offset type=UNWIND_HINT_TYPE_CALL
.endm
/*
@@ -92,7 +58,7 @@
* initial_func_cfi.
*/
.macro UNWIND_HINT_RET_OFFSET sp_offset=8
- UNWIND_HINT type=UNWIND_HINT_TYPE_RET_OFFSET sp_offset=\sp_offset
+ UNWIND_HINT sp_reg=ORC_REG_SP type=UNWIND_HINT_TYPE_RET_OFFSET sp_offset=\sp_offset
.endm
#endif /* __ASSEMBLY__ */
diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c
index db8f869..547c7ab 100644
--- a/arch/x86/kernel/kprobes/core.c
+++ b/arch/x86/kernel/kprobes/core.c
@@ -38,9 +38,9 @@
#include <linux/kdebug.h>
#include <linux/kallsyms.h>
#include <linux/ftrace.h>
-#include <linux/frame.h>
#include <linux/kasan.h>
#include <linux/moduleloader.h>
+#include <linux/objtool.h>
#include <linux/vmalloc.h>
#include <linux/pgtable.h>
diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c
index 15e0640..041f0b5 100644
--- a/arch/x86/kernel/kprobes/opt.c
+++ b/arch/x86/kernel/kprobes/opt.c
@@ -16,7 +16,7 @@
#include <linux/kdebug.h>
#include <linux/kallsyms.h>
#include <linux/ftrace.h>
-#include <linux/frame.h>
+#include <linux/objtool.h>
#include <linux/pgtable.h>
#include <linux/static_call.h>
diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c
index a515e2d..db115943 100644
--- a/arch/x86/kernel/reboot.c
+++ b/arch/x86/kernel/reboot.c
@@ -10,7 +10,7 @@
#include <linux/sched.h>
#include <linux/tboot.h>
#include <linux/delay.h>
-#include <linux/frame.h>
+#include <linux/objtool.h>
#include <linux/pgtable.h>
#include <acpi/reboot.h>
#include <asm/io.h>
diff --git a/arch/x86/kernel/unwind_orc.c b/arch/x86/kernel/unwind_orc.c
index ec88bbe..6a339ce 100644
--- a/arch/x86/kernel/unwind_orc.c
+++ b/arch/x86/kernel/unwind_orc.c
@@ -1,4 +1,5 @@
// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/objtool.h>
#include <linux/module.h>
#include <linux/sort.h>
#include <asm/ptrace.h>
@@ -127,12 +128,12 @@ static struct orc_entry null_orc_entry = {
.sp_offset = sizeof(long),
.sp_reg = ORC_REG_SP,
.bp_reg = ORC_REG_UNDEFINED,
- .type = ORC_TYPE_CALL
+ .type = UNWIND_HINT_TYPE_CALL
};
/* Fake frame pointer entry -- used as a fallback for generated code */
static struct orc_entry orc_fp_entry = {
- .type = ORC_TYPE_CALL,
+ .type = UNWIND_HINT_TYPE_CALL,
.sp_reg = ORC_REG_BP,
.sp_offset = 16,
.bp_reg = ORC_REG_PREV_SP,
@@ -531,7 +532,7 @@ bool unwind_next_frame(struct unwind_state *state)
/* Find IP, SP and possibly regs: */
switch (orc->type) {
- case ORC_TYPE_CALL:
+ case UNWIND_HINT_TYPE_CALL:
ip_p = sp - sizeof(long);
if (!deref_stack_reg(state, ip_p, &state->ip))
@@ -546,7 +547,7 @@ bool unwind_next_frame(struct unwind_state *state)
state->signal = false;
break;
- case ORC_TYPE_REGS:
+ case UNWIND_HINT_TYPE_REGS:
if (!deref_stack_regs(state, sp, &state->ip, &state->sp)) {
orc_warn_current("can't access registers at %pB\n",
(void *)orig_ip);
@@ -559,7 +560,7 @@ bool unwind_next_frame(struct unwind_state *state)
state->signal = true;
break;
- case ORC_TYPE_REGS_IRET:
+ case UNWIND_HINT_TYPE_REGS_PARTIAL:
if (!deref_stack_iret_regs(state, sp, &state->ip, &state->sp)) {
orc_warn_current("can't access iret registers at %pB\n",
(void *)orig_ip);
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 91ea74a..dec6d5b 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -19,7 +19,7 @@
#include <linux/trace_events.h>
#include <linux/slab.h>
#include <linux/hashtable.h>
-#include <linux/frame.h>
+#include <linux/objtool.h>
#include <linux/psp-sev.h>
#include <linux/file.h>
#include <linux/pagemap.h>
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 1bb6b31..19e2265 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -1,6 +1,6 @@
// SPDX-License-Identifier: GPL-2.0
-#include <linux/frame.h>
+#include <linux/objtool.h>
#include <linux/percpu.h>
#include <asm/debugreg.h>
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 96979c0..f0a9954 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -13,7 +13,6 @@
* Yaniv Kamay <yaniv@qumranet.com>
*/
-#include <linux/frame.h>
#include <linux/highmem.h>
#include <linux/hrtimer.h>
#include <linux/kernel.h>
@@ -22,6 +21,7 @@
#include <linux/moduleparam.h>
#include <linux/mod_devicetable.h>
#include <linux/mm.h>
+#include <linux/objtool.h>
#include <linux/sched.h>
#include <linux/sched/smt.h>
#include <linux/slab.h>
diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index b1418a6..41e5499 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -32,7 +32,7 @@
#include <linux/pci.h>
#include <linux/gfp.h>
#include <linux/edd.h>
-#include <linux/frame.h>
+#include <linux/objtool.h>
#include <xen/xen.h>
#include <xen/events.h>
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c b/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c
index e9f448a..15b5bde 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c
@@ -24,7 +24,7 @@
*
*/
-#include <linux/frame.h>
+#include <linux/objtool.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
@@ -599,4 +599,3 @@ int vmw_msg_ioctl(struct drm_device *dev, void *data,
return -EINVAL;
}
-
diff --git a/include/linux/frame.h b/include/linux/frame.h
deleted file mode 100644
index 303cda6..0000000
--- a/include/linux/frame.h
+++ /dev/null
@@ -1,35 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _LINUX_FRAME_H
-#define _LINUX_FRAME_H
-
-#ifdef CONFIG_STACK_VALIDATION
-/*
- * This macro marks the given function's stack frame as "non-standard", which
- * tells objtool to ignore the function when doing stack metadata validation.
- * It should only be used in special cases where you're 100% sure it won't
- * affect the reliability of frame pointers and kernel stack traces.
- *
- * For more information, see tools/objtool/Documentation/stack-validation.txt.
- */
-#define STACK_FRAME_NON_STANDARD(func) \
- static void __used __section(.discard.func_stack_frame_non_standard) \
- *__func_stack_frame_non_standard_##func = func
-
-/*
- * This macro indicates that the following intra-function call is valid.
- * Any non-annotated intra-function call will cause objtool to issue a warning.
- */
-#define ANNOTATE_INTRA_FUNCTION_CALL \
- 999: \
- .pushsection .discard.intra_function_calls; \
- .long 999b; \
- .popsection;
-
-#else /* !CONFIG_STACK_VALIDATION */
-
-#define STACK_FRAME_NON_STANDARD(func)
-#define ANNOTATE_INTRA_FUNCTION_CALL
-
-#endif /* CONFIG_STACK_VALIDATION */
-
-#endif /* _LINUX_FRAME_H */
diff --git a/include/linux/objtool.h b/include/linux/objtool.h
new file mode 100644
index 0000000..ab82c79
--- /dev/null
+++ b/include/linux/objtool.h
@@ -0,0 +1,129 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_OBJTOOL_H
+#define _LINUX_OBJTOOL_H
+
+#ifndef __ASSEMBLY__
+
+#include <linux/types.h>
+
+/*
+ * This struct is used by asm and inline asm code to manually annotate the
+ * location of registers on the stack.
+ */
+struct unwind_hint {
+ u32 ip;
+ s16 sp_offset;
+ u8 sp_reg;
+ u8 type;
+ u8 end;
+};
+#endif
+
+/*
+ * UNWIND_HINT_TYPE_CALL: Indicates that sp_reg+sp_offset resolves to PREV_SP
+ * (the caller's SP right before it made the call). Used for all callable
+ * functions, i.e. all C code and all callable asm functions.
+ *
+ * UNWIND_HINT_TYPE_REGS: Used in entry code to indicate that sp_reg+sp_offset
+ * points to a fully populated pt_regs from a syscall, interrupt, or exception.
+ *
+ * UNWIND_HINT_TYPE_REGS_PARTIAL: Used in entry code to indicate that
+ * sp_reg+sp_offset points to the iret return frame.
+ */
+#define UNWIND_HINT_TYPE_CALL 0
+#define UNWIND_HINT_TYPE_REGS 1
+#define UNWIND_HINT_TYPE_REGS_PARTIAL 2
+#define UNWIND_HINT_TYPE_RET_OFFSET 3
+
+#ifdef CONFIG_STACK_VALIDATION
+
+#ifndef __ASSEMBLY__
+
+#define UNWIND_HINT(sp_reg, sp_offset, type, end) \
+ "987: \n\t" \
+ ".pushsection .discard.unwind_hints\n\t" \
+ /* struct unwind_hint */ \
+ ".long 987b - .\n\t" \
+ ".short " __stringify(sp_offset) "\n\t" \
+ ".byte " __stringify(sp_reg) "\n\t" \
+ ".byte " __stringify(type) "\n\t" \
+ ".byte " __stringify(end) "\n\t" \
+ ".balign 4 \n\t" \
+ ".popsection\n\t"
+
+/*
+ * This macro marks the given function's stack frame as "non-standard", which
+ * tells objtool to ignore the function when doing stack metadata validation.
+ * It should only be used in special cases where you're 100% sure it won't
+ * affect the reliability of frame pointers and kernel stack traces.
+ *
+ * For more information, see tools/objtool/Documentation/stack-validation.txt.
+ */
+#define STACK_FRAME_NON_STANDARD(func) \
+ static void __used __section(.discard.func_stack_frame_non_standard) \
+ *__func_stack_frame_non_standard_##func = func
+
+#else /* __ASSEMBLY__ */
+
+/*
+ * This macro indicates that the following intra-function call is valid.
+ * Any non-annotated intra-function call will cause objtool to issue a warning.
+ */
+#define ANNOTATE_INTRA_FUNCTION_CALL \
+ 999: \
+ .pushsection .discard.intra_function_calls; \
+ .long 999b; \
+ .popsection;
+
+/*
+ * In asm, there are two kinds of code: normal C-type callable functions and
+ * the rest. The normal callable functions can be called by other code, and
+ * don't do anything unusual with the stack. Such normal callable functions
+ * are annotated with the ENTRY/ENDPROC macros. Most asm code falls in this
+ * category. In this case, no special debugging annotations are needed because
+ * objtool can automatically generate the ORC data for the ORC unwinder to read
+ * at runtime.
+ *
+ * Anything which doesn't fall into the above category, such as syscall and
+ * interrupt handlers, tends to not be called directly by other functions, and
+ * often does unusual non-C-function-type things with the stack pointer. Such
+ * code needs to be annotated such that objtool can understand it. The
+ * following CFI hint macros are for this type of code.
+ *
+ * These macros provide hints to objtool about the state of the stack at each
+ * instruction. Objtool starts from the hints and follows the code flow,
+ * making automatic CFI adjustments when it sees pushes and pops, filling out
+ * the debuginfo as necessary. It will also warn if it sees any
+ * inconsistencies.
+ */
+.macro UNWIND_HINT sp_reg:req sp_offset=0 type:req end=0
+.Lunwind_hint_ip_\@:
+ .pushsection .discard.unwind_hints
+ /* struct unwind_hint */
+ .long .Lunwind_hint_ip_\@ - .
+ .short \sp_offset
+ .byte \sp_reg
+ .byte \type
+ .byte \end
+ .balign 4
+ .popsection
+.endm
+
+#endif /* __ASSEMBLY__ */
+
+#else /* !CONFIG_STACK_VALIDATION */
+
+#ifndef __ASSEMBLY__
+
+#define UNWIND_HINT(sp_reg, sp_offset, type, end) \
+ "\n\t"
+#define STACK_FRAME_NON_STANDARD(func)
+#else
+#define ANNOTATE_INTRA_FUNCTION_CALL
+.macro UNWIND_HINT sp_reg:req sp_offset=0 type:req end=0
+.endm
+#endif
+
+#endif /* CONFIG_STACK_VALIDATION */
+
+#endif /* _LINUX_OBJTOOL_H */
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index ed0b357..03e2848 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -25,7 +25,7 @@
#include <linux/moduleloader.h>
#include <linux/bpf.h>
#include <linux/btf.h>
-#include <linux/frame.h>
+#include <linux/objtool.h>
#include <linux/rbtree_latch.h>
#include <linux/kallsyms.h>
#include <linux/rcupdate.h>
diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
index c19c0da..c5e5e5a 100644
--- a/kernel/kexec_core.c
+++ b/kernel/kexec_core.c
@@ -36,7 +36,7 @@
#include <linux/syscore_ops.h>
#include <linux/compiler.h>
#include <linux/hugetlb.h>
-#include <linux/frame.h>
+#include <linux/objtool.h>
#include <asm/page.h>
#include <asm/sections.h>
diff --git a/tools/arch/x86/include/asm/orc_types.h b/tools/arch/x86/include/asm/orc_types.h
index d255349..fdbffec 100644
--- a/tools/arch/x86/include/asm/orc_types.h
+++ b/tools/arch/x86/include/asm/orc_types.h
@@ -39,27 +39,6 @@
#define ORC_REG_SP_INDIRECT 9
#define ORC_REG_MAX 15
-/*
- * ORC_TYPE_CALL: Indicates that sp_reg+sp_offset resolves to PREV_SP (the
- * caller's SP right before it made the call). Used for all callable
- * functions, i.e. all C code and all callable asm functions.
- *
- * ORC_TYPE_REGS: Used in entry code to indicate that sp_reg+sp_offset points
- * to a fully populated pt_regs from a syscall, interrupt, or exception.
- *
- * ORC_TYPE_REGS_IRET: Used in entry code to indicate that sp_reg+sp_offset
- * points to the iret return frame.
- *
- * The UNWIND_HINT macros are used only for the unwind_hint struct. They
- * aren't used in struct orc_entry due to size and complexity constraints.
- * Objtool converts them to real types when it converts the hints to orc
- * entries.
- */
-#define ORC_TYPE_CALL 0
-#define ORC_TYPE_REGS 1
-#define ORC_TYPE_REGS_IRET 2
-#define UNWIND_HINT_TYPE_RET_OFFSET 3
-
#ifndef __ASSEMBLY__
/*
* This struct is more or less a vastly simplified version of the DWARF Call
@@ -78,19 +57,6 @@ struct orc_entry {
unsigned end:1;
} __packed;
-/*
- * This struct is used by asm and inline asm code to manually annotate the
- * location of registers on the stack for the ORC unwinder.
- *
- * Type can be either ORC_TYPE_* or UNWIND_HINT_TYPE_*.
- */
-struct unwind_hint {
- u32 ip;
- s16 sp_offset;
- u8 sp_reg;
- u8 type;
- u8 end;
-};
#endif /* __ASSEMBLY__ */
#endif /* _ORC_TYPES_H */
diff --git a/tools/include/linux/objtool.h b/tools/include/linux/objtool.h
new file mode 100644
index 0000000..ab82c79
--- /dev/null
+++ b/tools/include/linux/objtool.h
@@ -0,0 +1,129 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_OBJTOOL_H
+#define _LINUX_OBJTOOL_H
+
+#ifndef __ASSEMBLY__
+
+#include <linux/types.h>
+
+/*
+ * This struct is used by asm and inline asm code to manually annotate the
+ * location of registers on the stack.
+ */
+struct unwind_hint {
+ u32 ip;
+ s16 sp_offset;
+ u8 sp_reg;
+ u8 type;
+ u8 end;
+};
+#endif
+
+/*
+ * UNWIND_HINT_TYPE_CALL: Indicates that sp_reg+sp_offset resolves to PREV_SP
+ * (the caller's SP right before it made the call). Used for all callable
+ * functions, i.e. all C code and all callable asm functions.
+ *
+ * UNWIND_HINT_TYPE_REGS: Used in entry code to indicate that sp_reg+sp_offset
+ * points to a fully populated pt_regs from a syscall, interrupt, or exception.
+ *
+ * UNWIND_HINT_TYPE_REGS_PARTIAL: Used in entry code to indicate that
+ * sp_reg+sp_offset points to the iret return frame.
+ */
+#define UNWIND_HINT_TYPE_CALL 0
+#define UNWIND_HINT_TYPE_REGS 1
+#define UNWIND_HINT_TYPE_REGS_PARTIAL 2
+#define UNWIND_HINT_TYPE_RET_OFFSET 3
+
+#ifdef CONFIG_STACK_VALIDATION
+
+#ifndef __ASSEMBLY__
+
+#define UNWIND_HINT(sp_reg, sp_offset, type, end) \
+ "987: \n\t" \
+ ".pushsection .discard.unwind_hints\n\t" \
+ /* struct unwind_hint */ \
+ ".long 987b - .\n\t" \
+ ".short " __stringify(sp_offset) "\n\t" \
+ ".byte " __stringify(sp_reg) "\n\t" \
+ ".byte " __stringify(type) "\n\t" \
+ ".byte " __stringify(end) "\n\t" \
+ ".balign 4 \n\t" \
+ ".popsection\n\t"
+
+/*
+ * This macro marks the given function's stack frame as "non-standard", which
+ * tells objtool to ignore the function when doing stack metadata validation.
+ * It should only be used in special cases where you're 100% sure it won't
+ * affect the reliability of frame pointers and kernel stack traces.
+ *
+ * For more information, see tools/objtool/Documentation/stack-validation.txt.
+ */
+#define STACK_FRAME_NON_STANDARD(func) \
+ static void __used __section(.discard.func_stack_frame_non_standard) \
+ *__func_stack_frame_non_standard_##func = func
+
+#else /* __ASSEMBLY__ */
+
+/*
+ * This macro indicates that the following intra-function call is valid.
+ * Any non-annotated intra-function call will cause objtool to issue a warning.
+ */
+#define ANNOTATE_INTRA_FUNCTION_CALL \
+ 999: \
+ .pushsection .discard.intra_function_calls; \
+ .long 999b; \
+ .popsection;
+
+/*
+ * In asm, there are two kinds of code: normal C-type callable functions and
+ * the rest. The normal callable functions can be called by other code, and
+ * don't do anything unusual with the stack. Such normal callable functions
+ * are annotated with the ENTRY/ENDPROC macros. Most asm code falls in this
+ * category. In this case, no special debugging annotations are needed because
+ * objtool can automatically generate the ORC data for the ORC unwinder to read
+ * at runtime.
+ *
+ * Anything which doesn't fall into the above category, such as syscall and
+ * interrupt handlers, tends to not be called directly by other functions, and
+ * often does unusual non-C-function-type things with the stack pointer. Such
+ * code needs to be annotated such that objtool can understand it. The
+ * following CFI hint macros are for this type of code.
+ *
+ * These macros provide hints to objtool about the state of the stack at each
+ * instruction. Objtool starts from the hints and follows the code flow,
+ * making automatic CFI adjustments when it sees pushes and pops, filling out
+ * the debuginfo as necessary. It will also warn if it sees any
+ * inconsistencies.
+ */
+.macro UNWIND_HINT sp_reg:req sp_offset=0 type:req end=0
+.Lunwind_hint_ip_\@:
+ .pushsection .discard.unwind_hints
+ /* struct unwind_hint */
+ .long .Lunwind_hint_ip_\@ - .
+ .short \sp_offset
+ .byte \sp_reg
+ .byte \type
+ .byte \end
+ .balign 4
+ .popsection
+.endm
+
+#endif /* __ASSEMBLY__ */
+
+#else /* !CONFIG_STACK_VALIDATION */
+
+#ifndef __ASSEMBLY__
+
+#define UNWIND_HINT(sp_reg, sp_offset, type, end) \
+ "\n\t"
+#define STACK_FRAME_NON_STANDARD(func)
+#else
+#define ANNOTATE_INTRA_FUNCTION_CALL
+.macro UNWIND_HINT sp_reg:req sp_offset=0 type:req end=0
+.endm
+#endif
+
+#endif /* CONFIG_STACK_VALIDATION */
+
+#endif /* _LINUX_OBJTOOL_H */
diff --git a/tools/objtool/Makefile b/tools/objtool/Makefile
index 7770edc..4ea9a83 100644
--- a/tools/objtool/Makefile
+++ b/tools/objtool/Makefile
@@ -37,7 +37,7 @@
-I$(srctree)/tools/arch/$(HOSTARCH)/include/uapi \
-I$(srctree)/tools/arch/$(SRCARCH)/include \
-I$(srctree)/tools/objtool/arch/$(SRCARCH)/include
-WARNINGS := $(EXTRA_WARNINGS) -Wno-switch-default -Wno-switch-enum -Wno-packed
+WARNINGS := $(EXTRA_WARNINGS) -Wno-switch-default -Wno-switch-enum -Wno-packed -Wno-nested-externs
CFLAGS := -Werror $(WARNINGS) $(KBUILD_HOSTCFLAGS) -g $(INCLUDES) $(LIBELF_FLAGS)
LDFLAGS += $(LIBELF_LIBS) $(LIBSUBCMD) $(KBUILD_HOSTLDFLAGS)
@@ -55,6 +55,10 @@
SUBCMD_ORC := y
endif
+ifeq ($(SUBCMD_ORC),y)
+ CFLAGS += -DINSN_USE_ORC
+endif
+
export SUBCMD_CHECK SUBCMD_ORC
export srctree OUTPUT CFLAGS SRCARCH AWK
include $(srctree)/tools/build/Makefile.include
diff --git a/tools/objtool/arch.h b/tools/objtool/arch.h
index 2e2ce08..4a84c308 100644
--- a/tools/objtool/arch.h
+++ b/tools/objtool/arch.h
@@ -11,7 +11,9 @@
#include "objtool.h"
#include "cfi.h"
+#ifdef INSN_USE_ORC
#include <asm/orc_types.h>
+#endif
enum insn_type {
INSN_JUMP_CONDITIONAL,
@@ -86,4 +88,6 @@ unsigned long arch_dest_reloc_offset(int addend);
const char *arch_nop_insn(int len);
+int arch_decode_hint_reg(struct instruction *insn, u8 sp_reg);
+
#endif /* _ARCH_H */
diff --git a/tools/objtool/arch/x86/Build b/tools/objtool/arch/x86/Build
index 7c50040..9f7869b 100644
--- a/tools/objtool/arch/x86/Build
+++ b/tools/objtool/arch/x86/Build
@@ -1,3 +1,4 @@
+objtool-y += special.o
objtool-y += decode.o
inat_tables_script = ../arch/x86/tools/gen-insn-attr-x86.awk
diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c
index 1967370..cde9c36 100644
--- a/tools/objtool/arch/x86/decode.c
+++ b/tools/objtool/arch/x86/decode.c
@@ -15,6 +15,7 @@
#include "../../elf.h"
#include "../../arch.h"
#include "../../warn.h"
+#include <asm/orc_types.h>
static unsigned char op_to_cfi_reg[][2] = {
{CFI_AX, CFI_R8},
@@ -583,3 +584,39 @@ const char *arch_nop_insn(int len)
return nops[len-1];
}
+
+int arch_decode_hint_reg(struct instruction *insn, u8 sp_reg)
+{
+ struct cfi_reg *cfa = &insn->cfi.cfa;
+
+ switch (sp_reg) {
+ case ORC_REG_UNDEFINED:
+ cfa->base = CFI_UNDEFINED;
+ break;
+ case ORC_REG_SP:
+ cfa->base = CFI_SP;
+ break;
+ case ORC_REG_BP:
+ cfa->base = CFI_BP;
+ break;
+ case ORC_REG_SP_INDIRECT:
+ cfa->base = CFI_SP_INDIRECT;
+ break;
+ case ORC_REG_R10:
+ cfa->base = CFI_R10;
+ break;
+ case ORC_REG_R13:
+ cfa->base = CFI_R13;
+ break;
+ case ORC_REG_DI:
+ cfa->base = CFI_DI;
+ break;
+ case ORC_REG_DX:
+ cfa->base = CFI_DX;
+ break;
+ default:
+ return -1;
+ }
+
+ return 0;
+}
diff --git a/tools/objtool/arch/x86/include/arch_special.h b/tools/objtool/arch/x86/include/arch_special.h
new file mode 100644
index 0000000..d818b2b
--- /dev/null
+++ b/tools/objtool/arch/x86/include/arch_special.h
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef _X86_ARCH_SPECIAL_H
+#define _X86_ARCH_SPECIAL_H
+
+#define EX_ENTRY_SIZE 12
+#define EX_ORIG_OFFSET 0
+#define EX_NEW_OFFSET 4
+
+#define JUMP_ENTRY_SIZE 16
+#define JUMP_ORIG_OFFSET 0
+#define JUMP_NEW_OFFSET 4
+
+#define ALT_ENTRY_SIZE 13
+#define ALT_ORIG_OFFSET 0
+#define ALT_NEW_OFFSET 4
+#define ALT_FEATURE_OFFSET 8
+#define ALT_ORIG_LEN_OFFSET 10
+#define ALT_NEW_LEN_OFFSET 11
+
+#endif /* _X86_ARCH_SPECIAL_H */
diff --git a/tools/objtool/arch/x86/special.c b/tools/objtool/arch/x86/special.c
new file mode 100644
index 0000000..fd4af88
--- /dev/null
+++ b/tools/objtool/arch/x86/special.c
@@ -0,0 +1,145 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#include <string.h>
+
+#include "../../special.h"
+#include "../../builtin.h"
+
+#define X86_FEATURE_POPCNT (4 * 32 + 23)
+#define X86_FEATURE_SMAP (9 * 32 + 20)
+
+void arch_handle_alternative(unsigned short feature, struct special_alt *alt)
+{
+ switch (feature) {
+ case X86_FEATURE_SMAP:
+ /*
+ * If UACCESS validation is enabled; force that alternative;
+ * otherwise force it the other way.
+ *
+ * What we want to avoid is having both the original and the
+ * alternative code flow at the same time, in that case we can
+ * find paths that see the STAC but take the NOP instead of
+ * CLAC and the other way around.
+ */
+ if (uaccess)
+ alt->skip_orig = true;
+ else
+ alt->skip_alt = true;
+ break;
+ case X86_FEATURE_POPCNT:
+ /*
+ * It has been requested that we don't validate the !POPCNT
+ * feature path which is a "very very small percentage of
+ * machines".
+ */
+ alt->skip_orig = true;
+ break;
+ default:
+ break;
+ }
+}
+
+bool arch_support_alt_relocation(struct special_alt *special_alt,
+ struct instruction *insn,
+ struct reloc *reloc)
+{
+ /*
+ * The x86 alternatives code adjusts the offsets only when it
+ * encounters a branch instruction at the very beginning of the
+ * replacement group.
+ */
+ return insn->offset == special_alt->new_off &&
+ (insn->type == INSN_CALL || is_static_jump(insn));
+}
+
+/*
+ * There are 3 basic jump table patterns:
+ *
+ * 1. jmpq *[rodata addr](,%reg,8)
+ *
+ * This is the most common case by far. It jumps to an address in a simple
+ * jump table which is stored in .rodata.
+ *
+ * 2. jmpq *[rodata addr](%rip)
+ *
+ * This is caused by a rare GCC quirk, currently only seen in three driver
+ * functions in the kernel, only with certain obscure non-distro configs.
+ *
+ * As part of an optimization, GCC makes a copy of an existing switch jump
+ * table, modifies it, and then hard-codes the jump (albeit with an indirect
+ * jump) to use a single entry in the table. The rest of the jump table and
+ * some of its jump targets remain as dead code.
+ *
+ * In such a case we can just crudely ignore all unreachable instruction
+ * warnings for the entire object file. Ideally we would just ignore them
+ * for the function, but that would require redesigning the code quite a
+ * bit. And honestly that's just not worth doing: unreachable instruction
+ * warnings are of questionable value anyway, and this is such a rare issue.
+ *
+ * 3. mov [rodata addr],%reg1
+ * ... some instructions ...
+ * jmpq *(%reg1,%reg2,8)
+ *
+ * This is a fairly uncommon pattern which is new for GCC 6. As of this
+ * writing, there are 11 occurrences of it in the allmodconfig kernel.
+ *
+ * As of GCC 7 there are quite a few more of these and the 'in between' code
+ * is significant. Esp. with KASAN enabled some of the code between the mov
+ * and jmpq uses .rodata itself, which can confuse things.
+ *
+ * TODO: Once we have DWARF CFI and smarter instruction decoding logic,
+ * ensure the same register is used in the mov and jump instructions.
+ *
+ * NOTE: RETPOLINE made it harder still to decode dynamic jumps.
+ */
+struct reloc *arch_find_switch_table(struct objtool_file *file,
+ struct instruction *insn)
+{
+ struct reloc *text_reloc, *rodata_reloc;
+ struct section *table_sec;
+ unsigned long table_offset;
+
+ /* look for a relocation which references .rodata */
+ text_reloc = find_reloc_by_dest_range(file->elf, insn->sec,
+ insn->offset, insn->len);
+ if (!text_reloc || text_reloc->sym->type != STT_SECTION ||
+ !text_reloc->sym->sec->rodata)
+ return NULL;
+
+ table_offset = text_reloc->addend;
+ table_sec = text_reloc->sym->sec;
+
+ if (text_reloc->type == R_X86_64_PC32)
+ table_offset += 4;
+
+ /*
+ * Make sure the .rodata address isn't associated with a
+ * symbol. GCC jump tables are anonymous data.
+ *
+ * Also support C jump tables which are in the same format as
+ * switch jump tables. For objtool to recognize them, they
+ * need to be placed in the C_JUMP_TABLE_SECTION section. They
+ * have symbols associated with them.
+ */
+ if (find_symbol_containing(table_sec, table_offset) &&
+ strcmp(table_sec->name, C_JUMP_TABLE_SECTION))
+ return NULL;
+
+ /*
+ * Each table entry has a rela associated with it. The rela
+ * should reference text in the same function as the original
+ * instruction.
+ */
+ rodata_reloc = find_reloc_by_dest(file->elf, table_sec, table_offset);
+ if (!rodata_reloc)
+ return NULL;
+
+ /*
+ * Use of RIP-relative switch jumps is quite rare, and
+ * indicates a rare GCC quirk/bug which can leave dead
+ * code behind.
+ */
+ if (text_reloc->type == R_X86_64_PC32)
+ file->ignore_unreachables = true;
+
+ return rodata_reloc;
+}
diff --git a/tools/objtool/builtin-check.c b/tools/objtool/builtin-check.c
index 7a44174..c6d199b 100644
--- a/tools/objtool/builtin-check.c
+++ b/tools/objtool/builtin-check.c
@@ -41,6 +41,8 @@ const struct option check_options[] = {
int cmd_check(int argc, const char **argv)
{
const char *objname, *s;
+ struct objtool_file *file;
+ int ret;
argc = parse_options(argc, argv, check_options, check_usage, 0);
@@ -53,5 +55,16 @@ int cmd_check(int argc, const char **argv)
if (s && !s[9])
vmlinux = true;
- return check(objname, false);
+ file = objtool_open_read(objname);
+ if (!file)
+ return 1;
+
+ ret = check(file);
+ if (ret)
+ return ret;
+
+ if (file->elf->changed)
+ return elf_write(file->elf);
+
+ return 0;
}
diff --git a/tools/objtool/builtin-orc.c b/tools/objtool/builtin-orc.c
index b1dfe20..7b31121 100644
--- a/tools/objtool/builtin-orc.c
+++ b/tools/objtool/builtin-orc.c
@@ -31,13 +31,38 @@ int cmd_orc(int argc, const char **argv)
usage_with_options(orc_usage, check_options);
if (!strncmp(argv[0], "gen", 3)) {
+ struct objtool_file *file;
+ int ret;
+
argc = parse_options(argc, argv, check_options, orc_usage, 0);
if (argc != 1)
usage_with_options(orc_usage, check_options);
objname = argv[0];
- return check(objname, true);
+ file = objtool_open_read(objname);
+ if (!file)
+ return 1;
+
+ ret = check(file);
+ if (ret)
+ return ret;
+
+ if (list_empty(&file->insn_list))
+ return 0;
+
+ ret = create_orc(file);
+ if (ret)
+ return ret;
+
+ ret = create_orc_sections(file);
+ if (ret)
+ return ret;
+
+ if (!file->elf->changed)
+ return 0;
+
+ return elf_write(file->elf);
}
if (!strcmp(argv[0], "dump")) {
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 326ac390..c6ab445 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -14,21 +14,19 @@
#include "warn.h"
#include "arch_elf.h"
+#include <linux/objtool.h>
#include <linux/hashtable.h>
#include <linux/kernel.h>
#include <linux/static_call_types.h>
#define FAKE_JUMP_OFFSET -1
-#define C_JUMP_TABLE_SECTION ".rodata..c_jump_table"
-
struct alternative {
struct list_head list;
struct instruction *insn;
bool skip_orig;
};
-const char *objname;
struct cfi_init_state initial_func_cfi;
struct instruction *find_insn(struct objtool_file *file,
@@ -111,12 +109,6 @@ static struct instruction *prev_insn_same_sym(struct objtool_file *file,
for (insn = next_insn_same_sec(file, insn); insn; \
insn = next_insn_same_sec(file, insn))
-static bool is_static_jump(struct instruction *insn)
-{
- return insn->type == INSN_JUMP_CONDITIONAL ||
- insn->type == INSN_JUMP_UNCONDITIONAL;
-}
-
static bool is_sibling_call(struct instruction *insn)
{
/* An indirect jump is either a sibling call or a jump to a table. */
@@ -591,6 +583,8 @@ static const char *uaccess_safe_builtin[] = {
"__asan_store4_noabort",
"__asan_store8_noabort",
"__asan_store16_noabort",
+ "__kasan_check_read",
+ "__kasan_check_write",
/* KASAN in-line */
"__asan_report_load_n_noabort",
"__asan_report_load1_noabort",
@@ -879,6 +873,17 @@ static void remove_insn_ops(struct instruction *insn)
}
}
+static struct symbol *find_call_destination(struct section *sec, unsigned long offset)
+{
+ struct symbol *call_dest;
+
+ call_dest = find_func_by_offset(sec, offset);
+ if (!call_dest)
+ call_dest = find_symbol_by_offset(sec, offset);
+
+ return call_dest;
+}
+
/*
* Find the destination instructions for all calls.
*/
@@ -896,9 +901,7 @@ static int add_call_destinations(struct objtool_file *file)
insn->offset, insn->len);
if (!reloc) {
dest_off = arch_jump_destination(insn);
- insn->call_dest = find_func_by_offset(insn->sec, dest_off);
- if (!insn->call_dest)
- insn->call_dest = find_symbol_by_offset(insn->sec, dest_off);
+ insn->call_dest = find_call_destination(insn->sec, dest_off);
if (insn->ignore)
continue;
@@ -916,8 +919,8 @@ static int add_call_destinations(struct objtool_file *file)
} else if (reloc->sym->type == STT_SECTION) {
dest_off = arch_dest_reloc_offset(reloc->addend);
- insn->call_dest = find_func_by_offset(reloc->sym->sec,
- dest_off);
+ insn->call_dest = find_call_destination(reloc->sym->sec,
+ dest_off);
if (!insn->call_dest) {
WARN_FUNC("can't find call dest symbol at %s+0x%lx",
insn->sec, insn->offset,
@@ -1029,6 +1032,8 @@ static int handle_group_alt(struct objtool_file *file,
alt_group = alt_group_next_index++;
insn = *new_insn;
sec_for_each_insn_from(file, insn) {
+ struct reloc *alt_reloc;
+
if (insn->offset >= special_alt->new_off + special_alt->new_len)
break;
@@ -1045,14 +1050,11 @@ static int handle_group_alt(struct objtool_file *file,
* .altinstr_replacement section, unless the arch's
* alternatives code can adjust the relative offsets
* accordingly.
- *
- * The x86 alternatives code adjusts the offsets only when it
- * encounters a branch instruction at the very beginning of the
- * replacement group.
*/
- if ((insn->offset != special_alt->new_off ||
- (insn->type != INSN_CALL && !is_static_jump(insn))) &&
- find_reloc_by_dest_range(file->elf, insn->sec, insn->offset, insn->len)) {
+ alt_reloc = find_reloc_by_dest_range(file->elf, insn->sec,
+ insn->offset, insn->len);
+ if (alt_reloc &&
+ !arch_support_alt_relocation(special_alt, insn, alt_reloc)) {
WARN_FUNC("unsupported relocation in alternatives section",
insn->sec, insn->offset);
@@ -1254,56 +1256,15 @@ static int add_jump_table(struct objtool_file *file, struct instruction *insn,
}
/*
- * find_jump_table() - Given a dynamic jump, find the switch jump table in
- * .rodata associated with it.
- *
- * There are 3 basic patterns:
- *
- * 1. jmpq *[rodata addr](,%reg,8)
- *
- * This is the most common case by far. It jumps to an address in a simple
- * jump table which is stored in .rodata.
- *
- * 2. jmpq *[rodata addr](%rip)
- *
- * This is caused by a rare GCC quirk, currently only seen in three driver
- * functions in the kernel, only with certain obscure non-distro configs.
- *
- * As part of an optimization, GCC makes a copy of an existing switch jump
- * table, modifies it, and then hard-codes the jump (albeit with an indirect
- * jump) to use a single entry in the table. The rest of the jump table and
- * some of its jump targets remain as dead code.
- *
- * In such a case we can just crudely ignore all unreachable instruction
- * warnings for the entire object file. Ideally we would just ignore them
- * for the function, but that would require redesigning the code quite a
- * bit. And honestly that's just not worth doing: unreachable instruction
- * warnings are of questionable value anyway, and this is such a rare issue.
- *
- * 3. mov [rodata addr],%reg1
- * ... some instructions ...
- * jmpq *(%reg1,%reg2,8)
- *
- * This is a fairly uncommon pattern which is new for GCC 6. As of this
- * writing, there are 11 occurrences of it in the allmodconfig kernel.
- *
- * As of GCC 7 there are quite a few more of these and the 'in between' code
- * is significant. Esp. with KASAN enabled some of the code between the mov
- * and jmpq uses .rodata itself, which can confuse things.
- *
- * TODO: Once we have DWARF CFI and smarter instruction decoding logic,
- * ensure the same register is used in the mov and jump instructions.
- *
- * NOTE: RETPOLINE made it harder still to decode dynamic jumps.
+ * find_jump_table() - Given a dynamic jump, find the switch jump table
+ * associated with it.
*/
static struct reloc *find_jump_table(struct objtool_file *file,
struct symbol *func,
struct instruction *insn)
{
- struct reloc *text_reloc, *table_reloc;
+ struct reloc *table_reloc;
struct instruction *dest_insn, *orig_insn = insn;
- struct section *table_sec;
- unsigned long table_offset;
/*
* Backward search using the @first_jump_src links, these help avoid
@@ -1324,52 +1285,13 @@ static struct reloc *find_jump_table(struct objtool_file *file,
insn->jump_dest->offset > orig_insn->offset))
break;
- /* look for a relocation which references .rodata */
- text_reloc = find_reloc_by_dest_range(file->elf, insn->sec,
- insn->offset, insn->len);
- if (!text_reloc || text_reloc->sym->type != STT_SECTION ||
- !text_reloc->sym->sec->rodata)
- continue;
-
- table_offset = text_reloc->addend;
- table_sec = text_reloc->sym->sec;
-
- if (text_reloc->type == R_X86_64_PC32)
- table_offset += 4;
-
- /*
- * Make sure the .rodata address isn't associated with a
- * symbol. GCC jump tables are anonymous data.
- *
- * Also support C jump tables which are in the same format as
- * switch jump tables. For objtool to recognize them, they
- * need to be placed in the C_JUMP_TABLE_SECTION section. They
- * have symbols associated with them.
- */
- if (find_symbol_containing(table_sec, table_offset) &&
- strcmp(table_sec->name, C_JUMP_TABLE_SECTION))
- continue;
-
- /*
- * Each table entry has a reloc associated with it. The reloc
- * should reference text in the same function as the original
- * instruction.
- */
- table_reloc = find_reloc_by_dest(file->elf, table_sec, table_offset);
+ table_reloc = arch_find_switch_table(file, insn);
if (!table_reloc)
continue;
dest_insn = find_insn(file, table_reloc->sym->sec, table_reloc->addend);
if (!dest_insn || !dest_insn->func || dest_insn->func->pfunc != func)
continue;
- /*
- * Use of RIP-relative switch jumps is quite rare, and
- * indicates a rare GCC quirk/bug which can leave dead code
- * behind.
- */
- if (text_reloc->type == R_X86_64_PC32)
- file->ignore_unreachables = true;
-
return table_reloc;
}
@@ -1512,32 +1434,7 @@ static int read_unwind_hints(struct objtool_file *file)
insn->hint = true;
- switch (hint->sp_reg) {
- case ORC_REG_UNDEFINED:
- cfa->base = CFI_UNDEFINED;
- break;
- case ORC_REG_SP:
- cfa->base = CFI_SP;
- break;
- case ORC_REG_BP:
- cfa->base = CFI_BP;
- break;
- case ORC_REG_SP_INDIRECT:
- cfa->base = CFI_SP_INDIRECT;
- break;
- case ORC_REG_R10:
- cfa->base = CFI_R10;
- break;
- case ORC_REG_R13:
- cfa->base = CFI_R13;
- break;
- case ORC_REG_DI:
- cfa->base = CFI_DI;
- break;
- case ORC_REG_DX:
- cfa->base = CFI_DX;
- break;
- default:
+ if (arch_decode_hint_reg(insn, hint->sp_reg)) {
WARN_FUNC("unsupported unwind_hint sp base reg %d",
insn->sec, insn->offset, hint->sp_reg);
return -1;
@@ -1951,7 +1848,8 @@ static int update_cfi_state(struct instruction *insn, struct cfi_state *cfi,
return 0;
}
- if (cfi->type == ORC_TYPE_REGS || cfi->type == ORC_TYPE_REGS_IRET)
+ if (cfi->type == UNWIND_HINT_TYPE_REGS ||
+ cfi->type == UNWIND_HINT_TYPE_REGS_PARTIAL)
return update_cfi_state_regs(insn, cfi, op);
switch (op->dest.type) {
@@ -2199,7 +2097,7 @@ static int update_cfi_state(struct instruction *insn, struct cfi_state *cfi,
/* drap: push %rbp */
cfi->stack_size = 0;
- } else if (regs[op->src.reg].base == CFI_UNDEFINED) {
+ } else {
/* drap: push %reg */
save_reg(cfi, op->src.reg, CFI_BP, -cfi->stack_size);
@@ -2228,9 +2126,7 @@ static int update_cfi_state(struct instruction *insn, struct cfi_state *cfi,
/* save drap offset so we know when to restore it */
cfi->drap_offset = op->dest.offset;
- }
-
- else if (regs[op->src.reg].base == CFI_UNDEFINED) {
+ } else {
/* drap: mov reg, disp(%rbp) */
save_reg(cfi, op->src.reg, CFI_BP, op->dest.offset);
@@ -2800,9 +2696,10 @@ static bool is_ubsan_insn(struct instruction *insn)
"__ubsan_handle_builtin_unreachable"));
}
-static bool ignore_unreachable_insn(struct instruction *insn)
+static bool ignore_unreachable_insn(struct objtool_file *file, struct instruction *insn)
{
int i;
+ struct instruction *prev_insn;
if (insn->ignore || insn->type == INSN_NOP)
return true;
@@ -2819,6 +2716,9 @@ static bool ignore_unreachable_insn(struct instruction *insn)
!strcmp(insn->sec->name, ".altinstr_aux"))
return true;
+ if (insn->type == INSN_JUMP_UNCONDITIONAL && insn->offset == FAKE_JUMP_OFFSET)
+ return true;
+
if (!insn->func)
return false;
@@ -2827,8 +2727,11 @@ static bool ignore_unreachable_insn(struct instruction *insn)
* __builtin_unreachable(). The BUG() macro has an unreachable() after
* the UD2, which causes GCC's undefined trap logic to emit another UD2
* (or occasionally a JMP to UD2).
+ *
+ * It may also insert a UD2 after calling a __noreturn function.
*/
- if (list_prev_entry(insn, list)->dead_end &&
+ prev_insn = list_prev_entry(insn, list);
+ if ((prev_insn->dead_end || dead_end_function(file, prev_insn->call_dest)) &&
(insn->type == INSN_BUG ||
(insn->type == INSN_JUMP_UNCONDITIONAL &&
insn->jump_dest && insn->jump_dest->type == INSN_BUG)))
@@ -2955,7 +2858,7 @@ static int validate_reachable_instructions(struct objtool_file *file)
return 0;
for_each_insn(file, insn) {
- if (insn->visited || ignore_unreachable_insn(insn))
+ if (insn->visited || ignore_unreachable_insn(file, insn))
continue;
WARN_FUNC("unreachable instruction", insn->sec, insn->offset);
@@ -2965,37 +2868,22 @@ static int validate_reachable_instructions(struct objtool_file *file)
return 0;
}
-static struct objtool_file file;
-
-int check(const char *_objname, bool orc)
+int check(struct objtool_file *file)
{
int ret, warnings = 0;
- objname = _objname;
-
- file.elf = elf_open_read(objname, O_RDWR);
- if (!file.elf)
- return 1;
-
- INIT_LIST_HEAD(&file.insn_list);
- hash_init(file.insn_hash);
- INIT_LIST_HEAD(&file.static_call_list);
- file.c_file = !vmlinux && find_section_by_name(file.elf, ".comment");
- file.ignore_unreachables = no_unreachable;
- file.hints = false;
-
arch_initial_func_cfi_state(&initial_func_cfi);
- ret = decode_sections(&file);
+ ret = decode_sections(file);
if (ret < 0)
goto out;
warnings += ret;
- if (list_empty(&file.insn_list))
+ if (list_empty(&file->insn_list))
goto out;
if (vmlinux && !validate_dup) {
- ret = validate_vmlinux_functions(&file);
+ ret = validate_vmlinux_functions(file);
if (ret < 0)
goto out;
@@ -3004,50 +2892,34 @@ int check(const char *_objname, bool orc)
}
if (retpoline) {
- ret = validate_retpoline(&file);
+ ret = validate_retpoline(file);
if (ret < 0)
return ret;
warnings += ret;
}
- ret = validate_functions(&file);
+ ret = validate_functions(file);
if (ret < 0)
goto out;
warnings += ret;
- ret = validate_unwind_hints(&file, NULL);
+ ret = validate_unwind_hints(file, NULL);
if (ret < 0)
goto out;
warnings += ret;
if (!warnings) {
- ret = validate_reachable_instructions(&file);
+ ret = validate_reachable_instructions(file);
if (ret < 0)
goto out;
warnings += ret;
}
- ret = create_static_call_sections(&file);
+ ret = create_static_call_sections(file);
if (ret < 0)
goto out;
warnings += ret;
- if (orc) {
- ret = create_orc(&file);
- if (ret < 0)
- goto out;
-
- ret = create_orc_sections(&file);
- if (ret < 0)
- goto out;
- }
-
- if (file.elf->changed) {
- ret = elf_write(file.elf);
- if (ret < 0)
- goto out;
- }
-
out:
if (ret < 0) {
/*
diff --git a/tools/objtool/check.h b/tools/objtool/check.h
index 36d38b9..5ec00a4 100644
--- a/tools/objtool/check.h
+++ b/tools/objtool/check.h
@@ -43,9 +43,17 @@ struct instruction {
struct symbol *func;
struct list_head stack_ops;
struct cfi_state cfi;
+#ifdef INSN_USE_ORC
struct orc_entry orc;
+#endif
};
+static inline bool is_static_jump(struct instruction *insn)
+{
+ return insn->type == INSN_JUMP_CONDITIONAL ||
+ insn->type == INSN_JUMP_UNCONDITIONAL;
+}
+
struct instruction *find_insn(struct objtool_file *file,
struct section *sec, unsigned long offset);
@@ -58,5 +66,4 @@ struct instruction *find_insn(struct objtool_file *file,
insn->sec == sec; \
insn = list_next_entry(insn, list))
-
#endif /* _CHECK_H */
diff --git a/tools/objtool/objtool.c b/tools/objtool/objtool.c
index 58fdda5..9df0cd8 100644
--- a/tools/objtool/objtool.c
+++ b/tools/objtool/objtool.c
@@ -22,6 +22,8 @@
#include <linux/kernel.h>
#include "builtin.h"
+#include "objtool.h"
+#include "warn.h"
struct cmd_struct {
const char *name;
@@ -39,6 +41,34 @@ static struct cmd_struct objtool_cmds[] = {
bool help;
+const char *objname;
+static struct objtool_file file;
+
+struct objtool_file *objtool_open_read(const char *_objname)
+{
+ if (objname) {
+ if (strcmp(objname, _objname)) {
+ WARN("won't handle more than one file at a time");
+ return NULL;
+ }
+ return &file;
+ }
+ objname = _objname;
+
+ file.elf = elf_open_read(objname, O_RDWR);
+ if (!file.elf)
+ return NULL;
+
+ INIT_LIST_HEAD(&file.insn_list);
+ hash_init(file.insn_hash);
+ INIT_LIST_HEAD(&file.static_call_list);
+ file.c_file = !vmlinux && find_section_by_name(file.elf, ".comment");
+ file.ignore_unreachables = no_unreachable;
+ file.hints = false;
+
+ return &file;
+}
+
static void cmd_usage(void)
{
unsigned int i, longest = 0;
diff --git a/tools/objtool/objtool.h b/tools/objtool/objtool.h
index 9a7cd0b..4125d45 100644
--- a/tools/objtool/objtool.h
+++ b/tools/objtool/objtool.h
@@ -12,6 +12,8 @@
#include "elf.h"
+#define __weak __attribute__((weak))
+
struct objtool_file {
struct elf *elf;
struct list_head insn_list;
@@ -20,7 +22,9 @@ struct objtool_file {
bool ignore_unreachables, c_file, hints, rodata;
};
-int check(const char *objname, bool orc);
+struct objtool_file *objtool_open_read(const char *_objname);
+
+int check(struct objtool_file *file);
int orc_dump(const char *objname);
int create_orc(struct objtool_file *file);
int create_orc_sections(struct objtool_file *file);
diff --git a/tools/objtool/orc_dump.c b/tools/objtool/orc_dump.c
index fca46e0..5e6a953 100644
--- a/tools/objtool/orc_dump.c
+++ b/tools/objtool/orc_dump.c
@@ -4,6 +4,7 @@
*/
#include <unistd.h>
+#include <linux/objtool.h>
#include <asm/orc_types.h>
#include "objtool.h"
#include "warn.h"
@@ -37,12 +38,12 @@ static const char *reg_name(unsigned int reg)
static const char *orc_type_name(unsigned int type)
{
switch (type) {
- case ORC_TYPE_CALL:
+ case UNWIND_HINT_TYPE_CALL:
return "call";
- case ORC_TYPE_REGS:
+ case UNWIND_HINT_TYPE_REGS:
return "regs";
- case ORC_TYPE_REGS_IRET:
- return "iret";
+ case UNWIND_HINT_TYPE_REGS_PARTIAL:
+ return "regs (partial)";
default:
return "?";
}
diff --git a/tools/objtool/orc_gen.c b/tools/objtool/orc_gen.c
index e6b2363..235663b 100644
--- a/tools/objtool/orc_gen.c
+++ b/tools/objtool/orc_gen.c
@@ -6,6 +6,9 @@
#include <stdlib.h>
#include <string.h>
+#include <linux/objtool.h>
+#include <asm/orc_types.h>
+
#include "check.h"
#include "warn.h"
@@ -18,6 +21,9 @@ int create_orc(struct objtool_file *file)
struct cfi_reg *cfa = &insn->cfi.cfa;
struct cfi_reg *bp = &insn->cfi.regs[CFI_BP];
+ if (!insn->sec->text)
+ continue;
+
orc->end = insn->cfi.end;
if (cfa->base == CFI_UNDEFINED) {
@@ -143,7 +149,7 @@ int create_orc_sections(struct objtool_file *file)
struct orc_entry empty = {
.sp_reg = ORC_REG_UNDEFINED,
.bp_reg = ORC_REG_UNDEFINED,
- .type = ORC_TYPE_CALL,
+ .type = UNWIND_HINT_TYPE_CALL,
};
sec = find_section_by_name(file->elf, ".orc_unwind");
diff --git a/tools/objtool/special.c b/tools/objtool/special.c
index e893f1e..1a2420f 100644
--- a/tools/objtool/special.c
+++ b/tools/objtool/special.c
@@ -14,24 +14,7 @@
#include "builtin.h"
#include "special.h"
#include "warn.h"
-
-#define EX_ENTRY_SIZE 12
-#define EX_ORIG_OFFSET 0
-#define EX_NEW_OFFSET 4
-
-#define JUMP_ENTRY_SIZE 16
-#define JUMP_ORIG_OFFSET 0
-#define JUMP_NEW_OFFSET 4
-
-#define ALT_ENTRY_SIZE 13
-#define ALT_ORIG_OFFSET 0
-#define ALT_NEW_OFFSET 4
-#define ALT_FEATURE_OFFSET 8
-#define ALT_ORIG_LEN_OFFSET 10
-#define ALT_NEW_LEN_OFFSET 11
-
-#define X86_FEATURE_POPCNT (4*32+23)
-#define X86_FEATURE_SMAP (9*32+20)
+#include "arch_special.h"
struct special_entry {
const char *sec;
@@ -68,6 +51,10 @@ struct special_entry entries[] = {
{},
};
+void __weak arch_handle_alternative(unsigned short feature, struct special_alt *alt)
+{
+}
+
static int get_alt_entry(struct elf *elf, struct special_entry *entry,
struct section *sec, int idx,
struct special_alt *alt)
@@ -92,30 +79,7 @@ static int get_alt_entry(struct elf *elf, struct special_entry *entry,
feature = *(unsigned short *)(sec->data->d_buf + offset +
entry->feature);
-
- /*
- * It has been requested that we don't validate the !POPCNT
- * feature path which is a "very very small percentage of
- * machines".
- */
- if (feature == X86_FEATURE_POPCNT)
- alt->skip_orig = true;
-
- /*
- * If UACCESS validation is enabled; force that alternative;
- * otherwise force it the other way.
- *
- * What we want to avoid is having both the original and the
- * alternative code flow at the same time, in that case we can
- * find paths that see the STAC but take the NOP instead of
- * CLAC and the other way around.
- */
- if (feature == X86_FEATURE_SMAP) {
- if (uaccess)
- alt->skip_orig = true;
- else
- alt->skip_alt = true;
- }
+ arch_handle_alternative(feature, alt);
}
orig_reloc = find_reloc_by_dest(elf, sec, offset + entry->orig);
diff --git a/tools/objtool/special.h b/tools/objtool/special.h
index 3506153..abddf38 100644
--- a/tools/objtool/special.h
+++ b/tools/objtool/special.h
@@ -7,8 +7,11 @@
#define _SPECIAL_H
#include <stdbool.h>
+#include "check.h"
#include "elf.h"
+#define C_JUMP_TABLE_SECTION ".rodata..c_jump_table"
+
struct special_alt {
struct list_head list;
@@ -28,4 +31,11 @@ struct special_alt {
int special_get_alts(struct elf *elf, struct list_head *alts);
+void arch_handle_alternative(unsigned short feature, struct special_alt *alt);
+
+bool arch_support_alt_relocation(struct special_alt *special_alt,
+ struct instruction *insn,
+ struct reloc *reloc);
+struct reloc *arch_find_switch_table(struct objtool_file *file,
+ struct instruction *insn);
#endif /* _SPECIAL_H */
diff --git a/tools/objtool/sync-check.sh b/tools/objtool/sync-check.sh
index aa099b2..606a4b5 100755
--- a/tools/objtool/sync-check.sh
+++ b/tools/objtool/sync-check.sh
@@ -1,14 +1,27 @@
#!/bin/sh
# SPDX-License-Identifier: GPL-2.0
-FILES='
+if [ -z "$SRCARCH" ]; then
+ echo 'sync-check.sh: error: missing $SRCARCH environment variable' >&2
+ exit 1
+fi
+
+FILES="include/linux/objtool.h"
+
+if [ "$SRCARCH" = "x86" ]; then
+FILES="$FILES
arch/x86/include/asm/inat_types.h
arch/x86/include/asm/orc_types.h
arch/x86/include/asm/emulate_prefix.h
arch/x86/lib/x86-opcode-map.txt
arch/x86/tools/gen-insn-attr-x86.awk
include/linux/static_call_types.h
-'
+arch/x86/include/asm/inat.h -I '^#include [\"<]\(asm/\)*inat_types.h[\">]'
+arch/x86/include/asm/insn.h -I '^#include [\"<]\(asm/\)*inat.h[\">]'
+arch/x86/lib/inat.c -I '^#include [\"<]\(../include/\)*asm/insn.h[\">]'
+arch/x86/lib/insn.c -I '^#include [\"<]\(../include/\)*asm/in\(at\|sn\).h[\">]' -I '^#include [\"<]\(../include/\)*asm/emulate_prefix.h[\">]'
+"
+fi
check_2 () {
file1=$1
@@ -41,11 +54,12 @@
cd ../..
-for i in $FILES; do
- check $i
-done
+while read -r file_entry; do
+ if [ -z "$file_entry" ]; then
+ continue
+ fi
-check arch/x86/include/asm/inat.h '-I "^#include [\"<]\(asm/\)*inat_types.h[\">]"'
-check arch/x86/include/asm/insn.h '-I "^#include [\"<]\(asm/\)*inat.h[\">]"'
-check arch/x86/lib/inat.c '-I "^#include [\"<]\(../include/\)*asm/insn.h[\">]"'
-check arch/x86/lib/insn.c '-I "^#include [\"<]\(../include/\)*asm/in\(at\|sn\).h[\">]" -I "^#include [\"<]\(../include/\)*asm/emulate_prefix.h[\">]"'
+ check $file_entry
+done <<EOF
+$FILES
+EOF
diff --git a/tools/objtool/weak.c b/tools/objtool/weak.c
index 942ea5e..7843e9a 100644
--- a/tools/objtool/weak.c
+++ b/tools/objtool/weak.c
@@ -9,17 +9,13 @@
#include <errno.h>
#include "objtool.h"
-#define __weak __attribute__((weak))
-
#define UNSUPPORTED(name) \
({ \
fprintf(stderr, "error: objtool: " name " not implemented\n"); \
return ENOSYS; \
})
-const char __weak *objname;
-
-int __weak check(const char *_objname, bool orc)
+int __weak check(struct objtool_file *file)
{
UNSUPPORTED("check subcommand");
}
diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index 190be4f..8137a60 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -16,7 +16,7 @@
detected = $(shell echo "$(1)=y" >> $(OUTPUT).config-detected)
detected_var = $(shell echo "$(1)=$($(1))" >> $(OUTPUT).config-detected)
-CFLAGS := $(EXTRA_CFLAGS) $(EXTRA_WARNINGS)
+CFLAGS := $(EXTRA_CFLAGS) $(filter-out -Wnested-externs,$(EXTRA_WARNINGS))
include $(srctree)/tools/scripts/Makefile.arch