From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 713DA4431 for ; Wed, 15 Mar 2023 12:41:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EF05BC433EF; Wed, 15 Mar 2023 12:41:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678884115; bh=pCBr1gp1Lt4TOniMBhE+17n9OoubI3QD4cVa2z4Oaos=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bP8hmUogs47IipdOd/Vev/CKIkI8Kep9lZFW3XxhCyjePwvNEsYM/1JjzMxKT7b+m 2yGoJ5gHG6zVfeG8zeNkRQrY6uqesbay8ewqo5/8RdSfr7MwB2r3EiYeIo2Wv+uqQD vCX/myLiQyPT83ta1YXdSPulH8QoEB0IlewlV3NM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Guenter Roeck , Conor Dooley , Samuel Holland , Palmer Dabbelt , Sasha Levin Subject: [PATCH 6.2 113/141] RISC-V: take text_mutex during alternative patching Date: Wed, 15 Mar 2023 13:13:36 +0100 Message-Id: <20230315115743.437505798@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230315115739.932786806@linuxfoundation.org> References: <20230315115739.932786806@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit [ Upstream commit 9493e6f3ce02f44c21aa19f3cbf3b9aa05479d06 ] Guenter reported a splat during boot, that Samuel pointed out was the lockdep assertion failing in patch_insn_write(): WARNING: CPU: 0 PID: 0 at arch/riscv/kernel/patch.c:63 patch_insn_write+0x222/0x2f6 epc : patch_insn_write+0x222/0x2f6 ra : patch_insn_write+0x21e/0x2f6 epc : ffffffff800068c6 ra : ffffffff800068c2 sp : ffffffff81803df0 gp : ffffffff81a1ab78 tp : ffffffff81814f80 t0 : ffffffffffffe000 t1 : 0000000000000001 t2 : 4c45203a76637369 s0 : ffffffff81803e40 s1 : 0000000000000004 a0 : 0000000000000000 a1 : ffffffffffffffff a2 : 0000000000000004 a3 : 0000000000000000 a4 : 0000000000000001 a5 : 0000000000000000 a6 : 0000000000000000 a7 : 0000000052464e43 s2 : ffffffff80b4889c s3 : 000000000000082c s4 : ffffffff80b48828 s5 : 0000000000000828 s6 : ffffffff8131a0a0 s7 : 0000000000000fff s8 : 0000000008000200 s9 : ffffffff8131a520 s10: 0000000000000018 s11: 000000000000000b t3 : 0000000000000001 t4 : 000000000000000d t5 : ffffffffd8180000 t6 : ffffffff81803bc8 status: 0000000200000100 badaddr: 0000000000000000 cause: 0000000000000003 [] patch_insn_write+0x222/0x2f6 [] patch_text_nosync+0xc/0x2a [] riscv_cpufeature_patch_func+0x52/0x98 [] _apply_alternatives+0x46/0x86 [] apply_boot_alternatives+0x3c/0xfa [] setup_arch+0x584/0x5b8 [] start_kernel+0xa2/0x8f8 This issue was exposed by 702e64550b12 ("riscv: fpu: switch has_fpu() to riscv_has_extension_likely()"), as it is the patching in has_fpu() that triggers the splats in Guenter's report. Take the text_mutex before doing any code patching to satisfy lockdep. Fixes: ff689fd21cb1 ("riscv: add RISC-V Svpbmt extension support") Fixes: a35707c3d850 ("riscv: add memory-type errata for T-Head") Fixes: 1a0e5dbd3723 ("riscv: sifive: Add SiFive alternative ports") Reported-by: Guenter Roeck Link: https://lore.kernel.org/all/20230212154333.GA3760469@roeck-us.net/ Signed-off-by: Conor Dooley Reviewed-by: Samuel Holland Tested-by: Guenter Roeck Link: https://lore.kernel.org/r/20230212194735.491785-1-conor@kernel.org Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt Signed-off-by: Sasha Levin --- arch/riscv/errata/sifive/errata.c | 3 +++ arch/riscv/errata/thead/errata.c | 8 ++++++-- arch/riscv/kernel/cpufeature.c | 6 +++++- 3 files changed, 14 insertions(+), 3 deletions(-) diff --git a/arch/riscv/errata/sifive/errata.c b/arch/riscv/errata/sifive/errata.c index 1031038423e74..5b77d7310e391 100644 --- a/arch/riscv/errata/sifive/errata.c +++ b/arch/riscv/errata/sifive/errata.c @@ -4,6 +4,7 @@ */ #include +#include #include #include #include @@ -107,7 +108,9 @@ void __init_or_module sifive_errata_patch_func(struct alt_entry *begin, tmp = (1U << alt->errata_id); if (cpu_req_errata & tmp) { + mutex_lock(&text_mutex); patch_text_nosync(alt->old_ptr, alt->alt_ptr, alt->alt_len); + mutex_lock(&text_mutex); cpu_apply_errata |= tmp; } } diff --git a/arch/riscv/errata/thead/errata.c b/arch/riscv/errata/thead/errata.c index fac5742d1c1e6..9d71fe3d35c77 100644 --- a/arch/riscv/errata/thead/errata.c +++ b/arch/riscv/errata/thead/errata.c @@ -5,6 +5,7 @@ #include #include +#include #include #include #include @@ -97,11 +98,14 @@ void __init_or_module thead_errata_patch_func(struct alt_entry *begin, struct al tmp = (1U << alt->errata_id); if (cpu_req_errata & tmp) { /* On vm-alternatives, the mmu isn't running yet */ - if (stage == RISCV_ALTERNATIVES_EARLY_BOOT) + if (stage == RISCV_ALTERNATIVES_EARLY_BOOT) { memcpy((void *)__pa_symbol(alt->old_ptr), (void *)__pa_symbol(alt->alt_ptr), alt->alt_len); - else + } else { + mutex_lock(&text_mutex); patch_text_nosync(alt->old_ptr, alt->alt_ptr, alt->alt_len); + mutex_unlock(&text_mutex); + } } } diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c index 93e45560af307..5a82d5520a1fd 100644 --- a/arch/riscv/kernel/cpufeature.c +++ b/arch/riscv/kernel/cpufeature.c @@ -10,6 +10,7 @@ #include #include #include +#include #include #include #include @@ -339,8 +340,11 @@ void __init_or_module riscv_cpufeature_patch_func(struct alt_entry *begin, } tmp = (1U << alt->errata_id); - if (cpu_req_feature & tmp) + if (cpu_req_feature & tmp) { + mutex_lock(&text_mutex); patch_text_nosync(alt->old_ptr, alt->alt_ptr, alt->alt_len); + mutex_unlock(&text_mutex); + } } } #endif -- 2.39.2