From 38ca670f2390b20977b21883f156276ef2e3f8cb Mon Sep 17 00:00:00 2001 From: Youling Tang Date: Sat, 10 Dec 2022 22:39:59 +0800 Subject: [PATCH] LoongArch: extable: Add `type` and `data` fields mainline inclusion from mainline-v6.2-rc1 commit 26bc82441250f2e01621f5b26606a4f6926ee3ad category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I6BWFP CVE: NA -------------------------------- This is a LoongArch port of commit d6e2cc564775 ("arm64: extable: add `type` and `data` fields"). Subsequent patches will add specialized handlers for fixups, in addition to the simple PC fixup we have today. In preparation, this patch adds a new `type` field to struct exception_table_entry, and uses this to distinguish the fixup and other cases. A `data` field is also added so that subsequent patches can associate data specific to each exception site (e.g. register numbers). Handlers are named ex_handler_*() for consistency, following the example of x86. At the same time, get_ex_fixup() is split out into a helper so that it can be used by other ex_handler_*() functions in the subsequent patches. Signed-off-by: Youling Tang Signed-off-by: Huacai Chen Change-Id: I95ac7a755a8a3389b63b92c1e98a851c1993c0aa (cherry picked from commit 82f69454de796b638ea76b7841e7e659d8de52fa) --- arch/loongarch/include/asm/asm-extable.h | 15 ++++++++--- arch/loongarch/include/asm/extable.h | 11 ++++++++ arch/loongarch/kernel/vmlinux.lds.S | 3 +-- arch/loongarch/mm/extable.c | 7 +++++- scripts/sorttable.c | 32 +++++++++++++++++++++++- 5 files changed, 60 insertions(+), 8 deletions(-) diff --git a/arch/loongarch/include/asm/asm-extable.h b/arch/loongarch/include/asm/asm-extable.h index 74f8bc75472a..634bd770e3c4 100644 --- a/arch/loongarch/include/asm/asm-extable.h +++ b/arch/loongarch/include/asm/asm-extable.h @@ -2,17 +2,22 @@ #ifndef __ASM_ASM_EXTABLE_H #define __ASM_ASM_EXTABLE_H +#define EX_TYPE_NONE 0 +#define EX_TYPE_FIXUP 1 + #ifdef __ASSEMBLY__ -#define __ASM_EXTABLE_RAW(insn, fixup) \ +#define __ASM_EXTABLE_RAW(insn, fixup, type, data) \ .pushsection __ex_table, "a"; \ .balign 4; \ .long ((insn) - .); \ .long ((fixup) - .); \ + .short (type); \ + .short (data); \ .popsection; .macro _asm_extable, insn, fixup - __ASM_EXTABLE_RAW(\insn, \fixup) + __ASM_EXTABLE_RAW(\insn, \fixup, EX_TYPE_FIXUP, 0) .endm #else /* __ASSEMBLY__ */ @@ -20,15 +25,17 @@ #include #include -#define __ASM_EXTABLE_RAW(insn, fixup) \ +#define __ASM_EXTABLE_RAW(insn, fixup, type, data) \ ".pushsection __ex_table, \"a\"\n" \ ".balign 4\n" \ ".long ((" insn ") - .)\n" \ ".long ((" fixup ") - .)\n" \ + ".short (" type ")\n" \ + ".short (" data ")\n" \ ".popsection\n" #define _ASM_EXTABLE(insn, fixup) \ - __ASM_EXTABLE_RAW(#insn, #fixup) + __ASM_EXTABLE_RAW(#insn, #fixup, __stringify(EX_TYPE_FIXUP), "0") #endif /* __ASSEMBLY__ */ diff --git a/arch/loongarch/include/asm/extable.h b/arch/loongarch/include/asm/extable.h index b571c89705d1..92612b4364a1 100644 --- a/arch/loongarch/include/asm/extable.h +++ b/arch/loongarch/include/asm/extable.h @@ -17,10 +17,21 @@ struct exception_table_entry { int insn, fixup; + short type, data; }; #define ARCH_HAS_RELATIVE_EXTABLE +#define swap_ex_entry_fixup(a, b, tmp, delta) \ +do { \ + (a)->fixup = (b)->fixup + (delta); \ + (b)->fixup = (tmp).fixup - (delta); \ + (a)->type = (b)->type; \ + (b)->type = (tmp).type; \ + (a)->data = (b)->data; \ + (b)->data = (tmp).data; \ +} while (0) + bool fixup_exception(struct pt_regs *regs); #endif diff --git a/arch/loongarch/kernel/vmlinux.lds.S b/arch/loongarch/kernel/vmlinux.lds.S index 36d042739f3c..e956e2e3c510 100644 --- a/arch/loongarch/kernel/vmlinux.lds.S +++ b/arch/loongarch/kernel/vmlinux.lds.S @@ -4,6 +4,7 @@ #include #define PAGE_SIZE _PAGE_SIZE +#define RO_EXCEPTION_TABLE_ALIGN 4 /* * Put .bss..swapper_pg_dir as the first thing in .bss. This will @@ -53,8 +54,6 @@ SECTIONS . = ALIGN(PECOFF_SEGMENT_ALIGN); _etext = .; - EXCEPTION_TABLE(16) - . = ALIGN(PECOFF_SEGMENT_ALIGN); __init_begin = .; __inittext_begin = .; diff --git a/arch/loongarch/mm/extable.c b/arch/loongarch/mm/extable.c index 08a9a7d6357a..fd2395221cff 100644 --- a/arch/loongarch/mm/extable.c +++ b/arch/loongarch/mm/extable.c @@ -30,5 +30,10 @@ bool fixup_exception(struct pt_regs *regs) if (!ex) return false; - return ex_handler_fixup(ex, regs); + switch (ex->type) { + case EX_TYPE_FIXUP: + return ex_handler_fixup(ex, regs); + } + + BUG(); } diff --git a/scripts/sorttable.c b/scripts/sorttable.c index 5ce49722d5bc..92f1951b46f6 100644 --- a/scripts/sorttable.c +++ b/scripts/sorttable.c @@ -231,6 +231,34 @@ static void sort_relative_table(char *extab_image, int image_size) } } +static void sort_relative_table_with_data(char *extab_image, int image_size) +{ + int i = 0; + + while (i < image_size) { + uint32_t *loc = (uint32_t *)(extab_image + i); + + w(r(loc) + i, loc); + w(r(loc + 1) + i + 4, loc + 1); + /* Don't touch the fixup type or data */ + + i += sizeof(uint32_t) * 3; + } + + qsort(extab_image, image_size / 12, 12, compare_relative_table); + + i = 0; + while (i < image_size) { + uint32_t *loc = (uint32_t *)(extab_image + i); + + w(r(loc) - i, loc); + w(r(loc + 1) - (i + 4), loc + 1); + /* Don't touch the fixup type or data */ + + i += sizeof(uint32_t) * 3; + } +} + static void x86_sort_relative_table(char *extab_image, int image_size) { int i = 0; @@ -339,6 +367,9 @@ static int do_file(char const *const fname, void *addr) case EM_X86_64: custom_sort = x86_sort_relative_table; break; + case EM_LOONGARCH: + custom_sort = sort_relative_table_with_data; + break; case EM_S390: custom_sort = s390_sort_relative_table; break; @@ -347,7 +378,6 @@ static int do_file(char const *const fname, void *addr) case EM_PPC: case EM_ARM: case EM_PPC64: - case EM_LOONGARCH: custom_sort = sort_relative_table; break; case EM_ARCOMPACT: -- GitLab