From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 53C36C433F5 for ; Wed, 4 May 2022 17:09:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1356096AbiEDRNT (ORCPT ); Wed, 4 May 2022 13:13:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40384 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1356696AbiEDRJi (ORCPT ); Wed, 4 May 2022 13:09:38 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CBDF6DFA8; Wed, 4 May 2022 09:55:21 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 5FA5BB82737; Wed, 4 May 2022 16:55:21 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 01BD1C385AA; Wed, 4 May 2022 16:55:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1651683320; bh=hk4cHU0VdAIQ2P5i0CO7Xs40z12faF4Vc3CU85wuPtY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1woxZBcKaOonBxcTFVbqj2CXPM+cWnDoR4osDVedVarOs2yxMU/vbrvwBcT456It4 OQ1HXridFs11hzBBqOsHoUuVAuHKSXsKlKbl0CulttWjfxNK39TRt+bUmLbtPJJlFF 1vfUDQ1roPf1HYRTRLgTP5D5FpMAQE7gUwOPhQwo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alexey Kardashevskiy , Michael Ellerman , Nathan Chancellor Subject: [PATCH 5.15 177/177] powerpc/64: Add UADDR64 relocation support Date: Wed, 4 May 2022 18:46:10 +0200 Message-Id: <20220504153109.573608222@linuxfoundation.org> X-Mailer: git-send-email 2.36.0 In-Reply-To: <20220504153053.873100034@linuxfoundation.org> References: <20220504153053.873100034@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Alexey Kardashevskiy commit d799769188529abc6cbf035a10087a51f7832b6b upstream. When ld detects unaligned relocations, it emits R_PPC64_UADDR64 relocations instead of R_PPC64_RELATIVE. Currently R_PPC64_UADDR64 are detected by arch/powerpc/tools/relocs_check.sh and expected not to work. Below is a simple chunk to trigger this behaviour (this disables optimization for the demonstration purposes only, this also happens with -O1/-O2 when CONFIG_PRINTK_INDEX=y, for example): \#pragma GCC push_options \#pragma GCC optimize ("O0") struct entry { const char *file; int line; } __attribute__((packed)); static const struct entry e1 = { .file = __FILE__, .line = __LINE__ }; static const struct entry e2 = { .file = __FILE__, .line = __LINE__ }; ... prom_printf("e1=%s %lx %lx\n", e1.file, (unsigned long) e1.file, mfmsr()); prom_printf("e2=%s %lx\n", e2.file, (unsigned long) e2.file); \#pragma GCC pop_options This adds support for UADDR64 for 64bit. This reuses __dynamic_symtab from the 32bit code which supports more relocation types already. Because RELACOUNT includes only R_PPC64_RELATIVE, this replaces it with RELASZ which is the size of all relocation records. Signed-off-by: Alexey Kardashevskiy Signed-off-by: Michael Ellerman Cc: Nathan Chancellor Link: https://lore.kernel.org/r/20220309061822.168173-1-aik@ozlabs.ru Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/kernel/reloc_64.S | 67 +++++++++++++++++++++++++------------ arch/powerpc/kernel/vmlinux.lds.S | 2 - arch/powerpc/tools/relocs_check.sh | 7 --- 3 files changed, 48 insertions(+), 28 deletions(-) --- a/arch/powerpc/kernel/reloc_64.S +++ b/arch/powerpc/kernel/reloc_64.S @@ -8,8 +8,10 @@ #include RELA = 7 -RELACOUNT = 0x6ffffff9 +RELASZ = 8 +RELAENT = 9 R_PPC64_RELATIVE = 22 +R_PPC64_UADDR64 = 43 /* * r3 = desired final address of kernel @@ -25,29 +27,38 @@ _GLOBAL(relocate) add r9,r9,r12 /* r9 has runtime addr of .rela.dyn section */ ld r10,(p_st - 0b)(r12) add r10,r10,r12 /* r10 has runtime addr of _stext */ + ld r13,(p_sym - 0b)(r12) + add r13,r13,r12 /* r13 has runtime addr of .dynsym */ /* - * Scan the dynamic section for the RELA and RELACOUNT entries. + * Scan the dynamic section for the RELA, RELASZ and RELAENT entries. */ li r7,0 li r8,0 -1: ld r6,0(r11) /* get tag */ +.Ltags: + ld r6,0(r11) /* get tag */ cmpdi r6,0 - beq 4f /* end of list */ + beq .Lend_of_list /* end of list */ cmpdi r6,RELA bne 2f ld r7,8(r11) /* get RELA pointer in r7 */ - b 3f -2: addis r6,r6,(-RELACOUNT)@ha - cmpdi r6,RELACOUNT@l + b 4f +2: cmpdi r6,RELASZ bne 3f - ld r8,8(r11) /* get RELACOUNT value in r8 */ -3: addi r11,r11,16 - b 1b -4: cmpdi r7,0 /* check we have both RELA and RELACOUNT */ + ld r8,8(r11) /* get RELASZ value in r8 */ + b 4f +3: cmpdi r6,RELAENT + bne 4f + ld r12,8(r11) /* get RELAENT value in r12 */ +4: addi r11,r11,16 + b .Ltags +.Lend_of_list: + cmpdi r7,0 /* check we have RELA, RELASZ, RELAENT */ cmpdi cr1,r8,0 - beq 6f - beq cr1,6f + beq .Lout + beq cr1,.Lout + cmpdi r12,0 + beq .Lout /* * Work out linktime address of _stext and hence the @@ -62,23 +73,39 @@ _GLOBAL(relocate) /* * Run through the list of relocations and process the - * R_PPC64_RELATIVE ones. + * R_PPC64_RELATIVE and R_PPC64_UADDR64 ones. */ + divd r8,r8,r12 /* RELASZ / RELAENT */ mtctr r8 -5: ld r0,8(9) /* ELF64_R_TYPE(reloc->r_info) */ +.Lrels: ld r0,8(r9) /* ELF64_R_TYPE(reloc->r_info) */ cmpdi r0,R_PPC64_RELATIVE - bne 6f + bne .Luaddr64 ld r6,0(r9) /* reloc->r_offset */ ld r0,16(r9) /* reloc->r_addend */ + b .Lstore +.Luaddr64: + srdi r14,r0,32 /* ELF64_R_SYM(reloc->r_info) */ + clrldi r0,r0,32 + cmpdi r0,R_PPC64_UADDR64 + bne .Lnext + ld r6,0(r9) + ld r0,16(r9) + mulli r14,r14,24 /* 24 == sizeof(elf64_sym) */ + add r14,r14,r13 /* elf64_sym[ELF64_R_SYM] */ + ld r14,8(r14) + add r0,r0,r14 +.Lstore: add r0,r0,r3 stdx r0,r7,r6 - addi r9,r9,24 - bdnz 5b - -6: blr +.Lnext: + add r9,r9,r12 + bdnz .Lrels +.Lout: + blr .balign 8 p_dyn: .8byte __dynamic_start - 0b p_rela: .8byte __rela_dyn_start - 0b +p_sym: .8byte __dynamic_symtab - 0b p_st: .8byte _stext - 0b --- a/arch/powerpc/kernel/vmlinux.lds.S +++ b/arch/powerpc/kernel/vmlinux.lds.S @@ -275,9 +275,7 @@ SECTIONS . = ALIGN(8); .dynsym : AT(ADDR(.dynsym) - LOAD_OFFSET) { -#ifdef CONFIG_PPC32 __dynamic_symtab = .; -#endif *(.dynsym) } .dynstr : AT(ADDR(.dynstr) - LOAD_OFFSET) { *(.dynstr) } --- a/arch/powerpc/tools/relocs_check.sh +++ b/arch/powerpc/tools/relocs_check.sh @@ -39,6 +39,7 @@ $objdump -R "$vmlinux" | # R_PPC_NONE grep -F -w -v 'R_PPC64_RELATIVE R_PPC64_NONE +R_PPC64_UADDR64 R_PPC_ADDR16_LO R_PPC_ADDR16_HI R_PPC_ADDR16_HA @@ -54,9 +55,3 @@ fi num_bad=$(echo "$bad_relocs" | wc -l) echo "WARNING: $num_bad bad relocations" echo "$bad_relocs" - -# If we see this type of relocation it's an idication that -# we /may/ be using an old version of binutils. -if echo "$bad_relocs" | grep -q -F -w R_PPC64_UADDR64; then - echo "WARNING: You need at least binutils >= 2.19 to build a CONFIG_RELOCATABLE kernel" -fi