From e232333be69ee9ccd4281032af0d2416940cb98d Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Mon, 8 Nov 2021 11:42:20 +0000 Subject: scripts/sorttable: Unify arm64 & x86 sort functions The format of the arm64 and x86 exception table entries is essentially the same as of commits: 46d28947d9876fc0 ("x86/extable: Rework the exception table mechanics") d6e2cc5647753825 ("arm64: extable: add `type` and `data` fields") Both use a 12-byte entry consisting of two 32-bit relative offsets and 32 bits of (absolute) data, and their sort functions are identical aside from commentary, with arm64 saying: /* Don't touch the fixup type or data */ ... and x86 saying: /* Don't touch the fixup type */ Unify the two behind a common sort_relative_table_with_data() function, retaining the arm64 commentary. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland Cc: Ard Biesheuvel Cc: Borislav Petkov Cc: Catalin Marinas Cc: Thomas Gleixner Cc: Will Deacon Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Palmer Dabbelt --- scripts/sorttable.c | 36 +++--------------------------------- 1 file changed, 3 insertions(+), 33 deletions(-) (limited to 'scripts/sorttable.c') diff --git a/scripts/sorttable.c b/scripts/sorttable.c index b7c2ad71f9cf..ca9db62bf766 100644 --- a/scripts/sorttable.c +++ b/scripts/sorttable.c @@ -231,7 +231,7 @@ static void sort_relative_table(char *extab_image, int image_size) } } -static void arm64_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; @@ -259,34 +259,6 @@ static void arm64_sort_relative_table(char *extab_image, int image_size) } } -static void x86_sort_relative_table(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 */ - - 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 */ - - i += sizeof(uint32_t) * 3; - } -} - static void s390_sort_relative_table(char *extab_image, int image_size) { int i; @@ -364,15 +336,13 @@ static int do_file(char const *const fname, void *addr) switch (r2(&ehdr->e_machine)) { case EM_386: + case EM_AARCH64: case EM_X86_64: - custom_sort = x86_sort_relative_table; + custom_sort = sort_relative_table_with_data; break; case EM_S390: custom_sort = s390_sort_relative_table; break; - case EM_AARCH64: - custom_sort = arm64_sort_relative_table; - break; case EM_PARISC: case EM_PPC: case EM_PPC64: -- cgit v1.2.3 From bb1f85d6046f0db757ac52ed60a5eba5df394819 Mon Sep 17 00:00:00 2001 From: Jisheng Zhang Date: Thu, 18 Nov 2021 19:22:51 +0800 Subject: riscv: switch to relative exception tables Similar as other architectures such as arm64, x86 and so on, use offsets relative to the exception table entry values rather than absolute addresses for both the exception locationand the fixup. However, RISCV label difference will actually produce two relocations, a pair of R_RISCV_ADD32 and R_RISCV_SUB32. Take below simple code for example: $ cat test.S .section .text 1: nop .section __ex_table,"a" .balign 4 .long (1b - .) .previous $ riscv64-linux-gnu-gcc -c test.S $ riscv64-linux-gnu-readelf -r test.o Relocation section '.rela__ex_table' at offset 0x100 contains 2 entries: Offset Info Type Sym. Value Sym. Name + Addend 000000000000 000600000023 R_RISCV_ADD32 0000000000000000 .L1^B1 + 0 000000000000 000500000027 R_RISCV_SUB32 0000000000000000 .L0 + 0 The modpost will complain the R_RISCV_SUB32 relocation, so we need to patch modpost.c to skip this relocation for .rela__ex_table section. After this patch, the __ex_table section size of defconfig vmlinux is reduced from 7072 Bytes to 3536 Bytes. Signed-off-by: Jisheng Zhang Reviewed-by: Kefeng Wang Signed-off-by: Palmer Dabbelt --- scripts/sorttable.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'scripts/sorttable.c') diff --git a/scripts/sorttable.c b/scripts/sorttable.c index ca9db62bf766..f4a8255036b5 100644 --- a/scripts/sorttable.c +++ b/scripts/sorttable.c @@ -346,6 +346,7 @@ static int do_file(char const *const fname, void *addr) case EM_PARISC: case EM_PPC: case EM_PPC64: + case EM_RISCV: custom_sort = sort_relative_table; break; case EM_ARCOMPACT: @@ -353,7 +354,6 @@ static int do_file(char const *const fname, void *addr) case EM_ARM: case EM_MICROBLAZE: case EM_MIPS: - case EM_RISCV: case EM_XTENSA: break; default: -- cgit v1.2.3 From 2bf847db0c7437c28b10fba2981b9a7db4b4e0e2 Mon Sep 17 00:00:00 2001 From: Jisheng Zhang Date: Thu, 18 Nov 2021 19:26:05 +0800 Subject: riscv: extable: add `type` and `data` fields This is a riscv port of commit d6e2cc564775 ("arm64: extable: add `type` and `data` fields"). Signed-off-by: Jisheng Zhang Signed-off-by: Palmer Dabbelt --- scripts/sorttable.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'scripts/sorttable.c') diff --git a/scripts/sorttable.c b/scripts/sorttable.c index f4a8255036b5..82b162b3941b 100644 --- a/scripts/sorttable.c +++ b/scripts/sorttable.c @@ -337,6 +337,7 @@ static int do_file(char const *const fname, void *addr) switch (r2(&ehdr->e_machine)) { case EM_386: case EM_AARCH64: + case EM_RISCV: case EM_X86_64: custom_sort = sort_relative_table_with_data; break; @@ -346,7 +347,6 @@ static int do_file(char const *const fname, void *addr) case EM_PARISC: case EM_PPC: case EM_PPC64: - case EM_RISCV: custom_sort = sort_relative_table; break; case EM_ARCOMPACT: -- cgit v1.2.3