diff options
38 files changed, 686 insertions, 411 deletions
diff --git a/MAINTAINERS b/MAINTAINERS index 7eecfb345806..3763cecf9394 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -12515,6 +12515,7 @@ M: Josh Poimboeuf <jpoimboe@redhat.com> 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 e7752b4038ff..86651e86289d 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 d25534940bde..fdbffec4cfde 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 7d903fdb3f43..664d4610d700 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 db8f8693ab8d..547c7abb39f5 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 15e06408f6ba..041f0b50bc27 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 a515e2d230b7..db115943e8bd 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 ec88bbe08a32..6a339ce328e0 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 91ea74ae71b8..dec6d5bc603c 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 1bb6b31eb646..19e2265956ba 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 96979c09ebd1..f0a9954c49db 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 b1418a6c0e90..41e54997d830 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 e9f448a5ebb3..15b5bde69324 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 @@ out_open: return -EINVAL; } - diff --git a/include/linux/frame.h b/include/linux/frame.h deleted file mode 100644 index 303cda600e56..000000000000 --- 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 000000000000..ab82c793c897 --- /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 ed0b3578867c..03e284873644 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 c19c0dad1ebe..c5e5e5a11535 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 d25534940bde..fdbffec4cfde 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 000000000000..ab82c793c897 --- /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 7770edcda3a0..4ea9a833dde7 100644 --- a/tools/objtool/Makefile +++ b/tools/objtool/Makefile @@ -37,7 +37,7 @@ INCLUDES := -I$(srctree)/tools/include \ -I$(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) $(KBUILD_HOSTLDFLAGS) @@ -55,6 +55,10 @@ ifeq ($(SRCARCH),x86) 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 2e2ce089b0e9..4a84c3081b8e 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 7c5004008e97..9f7869b5c5e0 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 1967370440b3..cde9c36e40ae 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 000000000000..d818b2bffa02 --- /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 000000000000..fd4af88c0ea5 --- /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 7a44174967b5..c6d199bfd0ae 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 b1dfe2007962..7b31121fa60b 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 326ac390168b..c6ab44543c92 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 36d38b9153ac..5ec00a4b891b 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 58fdda510653..9df0cd86d310 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 9a7cd0b88bd8..4125d4578b23 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 fca46e006fc2..5e6a95368d35 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 e6b2363c2e03..235663b96adc 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 e893f1e48e44..1a2420febd08 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 35061530e46e..abddf38ef334 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 aa099b21dffa..606a4b5e929f 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 @@ fi 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 942ea5e8ac36..7843e9a7a72f 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 190be4fa5c21..8137a6046a47 100644 --- a/tools/perf/Makefile.config +++ b/tools/perf/Makefile.config @@ -16,7 +16,7 @@ $(shell printf "" > $(OUTPUT).config-detected) 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 |