From f387d0e1027f2d13cbfc1305b54198af701ede19 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Tue, 2 Dec 2025 09:59:37 -0800 Subject: [PATCH] x86/asm: Remove ANNOTATE_DATA_SPECIAL usage Instead of manually annotating each __ex_table entry, just make the section mergeable and store the entry size in the ELF section header. Either way works for objtool create_fake_symbols(), this way produces cleaner code generation. Signed-off-by: Josh Poimboeuf Signed-off-by: Ingo Molnar Cc: Linus Torvalds Link: https://patch.msgid.link/b858cb7891c1ba0080e22a9c32595e6c302435e2.1764694625.git.jpoimboe@kernel.org --- arch/um/include/asm/Kbuild | 1 - arch/um/include/shared/common-offsets.h | 1 + arch/x86/include/asm/asm.h | 25 ++++++++++++---------- arch/x86/kernel/asm-offsets.c | 1 + arch/x86/um/shared/sysdep/kernel-offsets.h | 2 ++ kernel/bounds.c | 1 + scripts/mod/devicetable-offsets.c | 1 + 7 files changed, 20 insertions(+), 12 deletions(-) diff --git a/arch/um/include/asm/Kbuild b/arch/um/include/asm/Kbuild index b6810db24ca4d..1b9b82bbe3220 100644 --- a/arch/um/include/asm/Kbuild +++ b/arch/um/include/asm/Kbuild @@ -5,7 +5,6 @@ generic-y += device.h generic-y += dma-mapping.h generic-y += emergency-restart.h generic-y += exec.h -generic-y += extable.h generic-y += ftrace.h generic-y += hw_irq.h generic-y += irq_regs.h diff --git a/arch/um/include/shared/common-offsets.h b/arch/um/include/shared/common-offsets.h index 4e19103afd71a..a6f77cb6aa7e1 100644 --- a/arch/um/include/shared/common-offsets.h +++ b/arch/um/include/shared/common-offsets.h @@ -20,3 +20,4 @@ DEFINE(UM_KERN_GDT_ENTRY_TLS_ENTRIES, GDT_ENTRY_TLS_ENTRIES); DEFINE(UM_SECCOMP_ARCH_NATIVE, SECCOMP_ARCH_NATIVE); DEFINE(ALT_INSTR_SIZE, sizeof(struct alt_instr)); +DEFINE(EXTABLE_SIZE, sizeof(struct exception_table_entry)); diff --git a/arch/x86/include/asm/asm.h b/arch/x86/include/asm/asm.h index bd62bd87a841e..0e8c611bc9e2a 100644 --- a/arch/x86/include/asm/asm.h +++ b/arch/x86/include/asm/asm.h @@ -126,18 +126,21 @@ static __always_inline __pure void *rip_rel_ptr(void *p) #ifdef __KERNEL__ +#ifndef COMPILE_OFFSETS +#include +#endif + # include /* Exception table entry */ #ifdef __ASSEMBLER__ -# define _ASM_EXTABLE_TYPE(from, to, type) \ - .pushsection "__ex_table","a" ; \ - .balign 4 ; \ - ANNOTATE_DATA_SPECIAL ; \ - .long (from) - . ; \ - .long (to) - . ; \ - .long type ; \ +# define _ASM_EXTABLE_TYPE(from, to, type) \ + .pushsection "__ex_table", "aM", @progbits, EXTABLE_SIZE ; \ + .balign 4 ; \ + .long (from) - . ; \ + .long (to) - . ; \ + .long type ; \ .popsection # ifdef CONFIG_KPROBES @@ -180,18 +183,18 @@ static __always_inline __pure void *rip_rel_ptr(void *p) ".purgem extable_type_reg\n" # define _ASM_EXTABLE_TYPE(from, to, type) \ - " .pushsection \"__ex_table\",\"a\"\n" \ + " .pushsection __ex_table, \"aM\", @progbits, " \ + __stringify(EXTABLE_SIZE) "\n" \ " .balign 4\n" \ - ANNOTATE_DATA_SPECIAL \ " .long (" #from ") - .\n" \ " .long (" #to ") - .\n" \ " .long " __stringify(type) " \n" \ " .popsection\n" # define _ASM_EXTABLE_TYPE_REG(from, to, type, reg) \ - " .pushsection \"__ex_table\",\"a\"\n" \ + " .pushsection __ex_table, \"aM\", @progbits, " \ + __stringify(EXTABLE_SIZE) "\n" \ " .balign 4\n" \ - ANNOTATE_DATA_SPECIAL \ " .long (" #from ") - .\n" \ " .long (" #to ") - .\n" \ DEFINE_EXTABLE_TYPE_REG \ diff --git a/arch/x86/kernel/asm-offsets.c b/arch/x86/kernel/asm-offsets.c index db3bb51433294..25fcde525c68c 100644 --- a/arch/x86/kernel/asm-offsets.c +++ b/arch/x86/kernel/asm-offsets.c @@ -126,4 +126,5 @@ static void __used common(void) BLANK(); DEFINE(ALT_INSTR_SIZE, sizeof(struct alt_instr)); + DEFINE(EXTABLE_SIZE, sizeof(struct exception_table_entry)); } diff --git a/arch/x86/um/shared/sysdep/kernel-offsets.h b/arch/x86/um/shared/sysdep/kernel-offsets.h index 6fd1ed4003992..8215a0200ddd9 100644 --- a/arch/x86/um/shared/sysdep/kernel-offsets.h +++ b/arch/x86/um/shared/sysdep/kernel-offsets.h @@ -1,4 +1,5 @@ /* SPDX-License-Identifier: GPL-2.0 */ +#define COMPILE_OFFSETS #include #include #include @@ -7,6 +8,7 @@ #include #include #include +#include /* workaround for a warning with -Wmissing-prototypes */ void foo(void); diff --git a/kernel/bounds.c b/kernel/bounds.c index 29b2cd00df2cc..02b619eb61065 100644 --- a/kernel/bounds.c +++ b/kernel/bounds.c @@ -6,6 +6,7 @@ */ #define __GENERATING_BOUNDS_H +#define COMPILE_OFFSETS /* Include headers that define the enum constants of interest */ #include #include diff --git a/scripts/mod/devicetable-offsets.c b/scripts/mod/devicetable-offsets.c index d3d00e85edf73..ef2ffb68f69d1 100644 --- a/scripts/mod/devicetable-offsets.c +++ b/scripts/mod/devicetable-offsets.c @@ -1,4 +1,5 @@ // SPDX-License-Identifier: GPL-2.0 +#define COMPILE_OFFSETS #include #include -- 2.47.3