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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 19BE8C369AB for ; Thu, 24 Apr 2025 07:21:12 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A16B46B0032; Thu, 24 Apr 2025 03:21:09 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 99F3D6B007B; Thu, 24 Apr 2025 03:21:09 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7F2EC6B0082; Thu, 24 Apr 2025 03:21:09 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 5D1376B0032 for ; Thu, 24 Apr 2025 03:21:09 -0400 (EDT) Received: from smtpin20.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 10EACB7141 for ; Thu, 24 Apr 2025 07:21:11 +0000 (UTC) X-FDA: 83368091142.20.63937EE Received: from mail-pl1-f181.google.com (mail-pl1-f181.google.com [209.85.214.181]) by imf10.hostedemail.com (Postfix) with ESMTP id 309B8C0009 for ; Thu, 24 Apr 2025 07:21:08 +0000 (UTC) Authentication-Results: imf10.hostedemail.com; dkim=pass header.d=rivosinc-com.20230601.gappssmtp.com header.s=20230601 header.b=KmUBKf6i; dmarc=none; spf=pass (imf10.hostedemail.com: domain of debug@rivosinc.com designates 209.85.214.181 as permitted sender) smtp.mailfrom=debug@rivosinc.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1745479269; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=9asBpltvPplgv3SFS9sFJV/rAaW0N72SDtlluYCBpfI=; b=tCEgu9yMAe36JGT4C1vzFZGoiyhB6L1uC7p6OW2p8yK8//1QVpDpaxZNQ7ZTGIhQorc4W8 ygfSAa/IGdoiHFYSYlKRlXGoDQIaVgLGUjNCCfQWoIq1lqH44i7fXtAGyF65UzmObuRYaO T86cTvmXJj7pnYyvNFeHF2uHrfmHK58= ARC-Authentication-Results: i=1; imf10.hostedemail.com; dkim=pass header.d=rivosinc-com.20230601.gappssmtp.com header.s=20230601 header.b=KmUBKf6i; dmarc=none; spf=pass (imf10.hostedemail.com: domain of debug@rivosinc.com designates 209.85.214.181 as permitted sender) smtp.mailfrom=debug@rivosinc.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1745479269; a=rsa-sha256; cv=none; b=pzgFEqzyX+c2MinJtOurjzxDhXiCvenBjaCLoCp2KkA7AXD5yoZHbg/UCERbgrhpbO+R1U sk8fOyuNUgwXT8/BEhAQtm4YO4Nib/4rhcGJ/uT385+4IeR1M0ARCTaMkWShlvnQcqLxxL 4F2IneSe//xvHOd9/+iq5LdNKVbsma8= Received: by mail-pl1-f181.google.com with SMTP id d9443c01a7336-2295d78b45cso10165445ad.0 for ; Thu, 24 Apr 2025 00:21:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rivosinc-com.20230601.gappssmtp.com; s=20230601; t=1745479268; x=1746084068; darn=kvack.org; h=cc:to:in-reply-to:references:message-id:content-transfer-encoding :mime-version:subject:date:from:from:to:cc:subject:date:message-id :reply-to; bh=9asBpltvPplgv3SFS9sFJV/rAaW0N72SDtlluYCBpfI=; b=KmUBKf6i4fwaoLljiiD4JWSk9BIO/5f5IfAIU84/MAqf59xdnuL6tetPC8nSpuLD1I 2H6+QPERXdkqFqlRX07+ObedJQPv+0LLl/PWSQukamaqgTJs1GbG5z0WslKKDsr9G0LY eDHbGR5PBJEhOyBiovygHAug9/brPBwHIQuddVN8CmWTMvZXtcU3cyLkRZnwo82gwQVb I72dubJevMyVFz+1A/SZ+CKvPWahaAcP0NWINqlvAZSfrPeiSqyv+T2EDMa775sHO+rE Tkz3aonQnyo7RNZuc57vFMZTgVkD2f4TsRgfp8Ied+lcbW88TReU3jTC96gxljWKZ6SN WNEA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1745479268; x=1746084068; h=cc:to:in-reply-to:references:message-id:content-transfer-encoding :mime-version:subject:date:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=9asBpltvPplgv3SFS9sFJV/rAaW0N72SDtlluYCBpfI=; b=E8ioUEAoLMHuQSCNeONr7ExKLW8FReYetYIdtSps+vfZNC/BLEsY8RKI0mYZfWAkZ2 VefRh00sdvOFceAWbDBb6bFQ2wJk5Ed7C/NvjbIU9lSHr1eQnXFtiJQ+DnZmPFSLLAOh DKf+LE5n8PW+g6hy0U3C2aSh4SZ2PhmZrnBdi+TJifUzrtlZd1DbwRkdc8rSsEYe6Vf1 WZ8Y2ISLnS9LUW7LZRgNZ06DFS5qd7+u6WKK8K3NLwSF4s5rvUpWORDCpXLKOGvGtHhX H4jgakJPhPQzuAz+fIKl9pwMTcuBoV43oyDRIshVBOl5MIughHIiV1NcmFBTOrrHrpTn vLZA== X-Forwarded-Encrypted: i=1; AJvYcCUglB5TEIPp5oiy6TVpT3x2FuPxmPl+lZzuKNAQ9/c/6GHRypg5JGLuapBbx2KCRDIryvRDVfdXfw==@kvack.org X-Gm-Message-State: AOJu0Yy6ppYlIbvVq/63FR/Sz9syI/v7Fcrgs3j+8cLom5tz4jO/Pey5 /wse3F3NHp1rxHFv0+BewWGz/5oW2UZCBjIJriH70hDZbkvvkvs+mBG3ViP+858= X-Gm-Gg: ASbGncsvIQqrWcDxjFE0V/k518hRGoLVGnPKu4lGGlNcaSveDEHYm8vEzAMU+N7lQd4 reQzGxT/6E61pWzNH5ZdPtOBAvcmwd7dPp1ZJF44Cny+Etm68TscjOj5VXg9Hz9lentHMKUcomF +CAz2RVFcsn1Xn0Z+pWRSwqpeD9o4ZCAt4skzcZ/n6uqFhiSVlxT5vTtwvJMKcN15cwFFFC5vS0 byCjiiCi4gPTwM6bsfKo0v+Gtum4W6nKpxWFXLUAORkZMcnaVzqK/xx/cLCgPqmJoSb/WRaLxU/ +AqJ7VyKs40DSmYr6L4yN5DIaE9BC3AoXUTdKgwMtQB4aBUuIfD1R2TUCJ1law== X-Google-Smtp-Source: AGHT+IGE5P7Mnj4RlD9mm2Eq7UA4FDxZU535xr45jeSciDmZlNOSzyfSJbfq0qrWmBUkxDiIGQQdyw== X-Received: by 2002:a17:902:ecca:b0:227:e6fe:2908 with SMTP id d9443c01a7336-22db3d9a1efmr22822445ad.48.1745479268021; Thu, 24 Apr 2025 00:21:08 -0700 (PDT) Received: from debug.ba.rivosinc.com ([64.71.180.162]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-22db52163d6sm6240765ad.214.2025.04.24.00.21.04 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 24 Apr 2025 00:21:07 -0700 (PDT) From: Deepak Gupta Date: Thu, 24 Apr 2025 00:20:29 -0700 Subject: [PATCH v13 14/28] riscv: Implements arch agnostic indirect branch tracking prctls MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20250424-v5_user_cfi_series-v13-14-971437de586a@rivosinc.com> References: <20250424-v5_user_cfi_series-v13-0-971437de586a@rivosinc.com> In-Reply-To: <20250424-v5_user_cfi_series-v13-0-971437de586a@rivosinc.com> To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Andrew Morton , "Liam R. Howlett" , Vlastimil Babka , Lorenzo Stoakes , Paul Walmsley , Palmer Dabbelt , Albert Ou , Conor Dooley , Rob Herring , Krzysztof Kozlowski , Arnd Bergmann , Christian Brauner , Peter Zijlstra , Oleg Nesterov , Eric Biederman , Kees Cook , Jonathan Corbet , Shuah Khan , Jann Horn , Conor Dooley , Miguel Ojeda , Alex Gaynor , Boqun Feng , Gary Guo , =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-riscv@lists.infradead.org, devicetree@vger.kernel.org, linux-arch@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, alistair.francis@wdc.com, richard.henderson@linaro.org, jim.shu@sifive.com, andybnac@gmail.com, kito.cheng@sifive.com, charlie@rivosinc.com, atishp@rivosinc.com, evan@rivosinc.com, cleger@rivosinc.com, alexghiti@rivosinc.com, samitolvanen@google.com, broonie@kernel.org, rick.p.edgecombe@intel.com, rust-for-linux@vger.kernel.org, Zong Li , Deepak Gupta X-Mailer: b4 0.13.0 X-Stat-Signature: wikxk4mpkypdgu85rj3m8m1bsiuizdno X-Rspamd-Queue-Id: 309B8C0009 X-Rspam-User: X-Rspamd-Server: rspam05 X-HE-Tag: 1745479268-819089 X-HE-Meta: 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 WijRbtDr 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: prctls implemented are: PR_SET_INDIR_BR_LP_STATUS, PR_GET_INDIR_BR_LP_STATUS and PR_LOCK_INDIR_BR_LP_STATUS Reviewed-by: Zong Li Signed-off-by: Deepak Gupta --- arch/riscv/include/asm/usercfi.h | 16 +++++++- arch/riscv/kernel/entry.S | 2 +- arch/riscv/kernel/process.c | 5 +++ arch/riscv/kernel/usercfi.c | 79 ++++++++++++++++++++++++++++++++++++++++ 4 files changed, 100 insertions(+), 2 deletions(-) diff --git a/arch/riscv/include/asm/usercfi.h b/arch/riscv/include/asm/usercfi.h index c4dcd256f19a..a8cec7c14d1d 100644 --- a/arch/riscv/include/asm/usercfi.h +++ b/arch/riscv/include/asm/usercfi.h @@ -16,7 +16,9 @@ struct kernel_clone_args; struct cfi_status { unsigned long ubcfi_en : 1; /* Enable for backward cfi. */ unsigned long ubcfi_locked : 1; - unsigned long rsvd : ((sizeof(unsigned long) * 8) - 2); + unsigned long ufcfi_en : 1; /* Enable for forward cfi. Note that ELP goes in sstatus */ + unsigned long ufcfi_locked : 1; + unsigned long rsvd : ((sizeof(unsigned long) * 8) - 4); unsigned long user_shdw_stk; /* Current user shadow stack pointer */ unsigned long shdw_stk_base; /* Base address of shadow stack */ unsigned long shdw_stk_size; /* size of shadow stack */ @@ -33,6 +35,10 @@ bool is_shstk_locked(struct task_struct *task); bool is_shstk_allocated(struct task_struct *task); void set_shstk_lock(struct task_struct *task); void set_shstk_status(struct task_struct *task, bool enable); +bool is_indir_lp_enabled(struct task_struct *task); +bool is_indir_lp_locked(struct task_struct *task); +void set_indir_lp_status(struct task_struct *task, bool enable); +void set_indir_lp_lock(struct task_struct *task); #define PR_SHADOW_STACK_SUPPORTED_STATUS_MASK (PR_SHADOW_STACK_ENABLE) @@ -58,6 +64,14 @@ void set_shstk_status(struct task_struct *task, bool enable); #define set_shstk_status(task, enable) +#define is_indir_lp_enabled(task) false + +#define is_indir_lp_locked(task) false + +#define set_indir_lp_status(task, enable) + +#define set_indir_lp_lock(task) + #endif /* CONFIG_RISCV_USER_CFI */ #endif /* __ASSEMBLY__ */ diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S index f5531d82f7e7..02442f8ad91a 100644 --- a/arch/riscv/kernel/entry.S +++ b/arch/riscv/kernel/entry.S @@ -143,7 +143,7 @@ SYM_CODE_START(handle_exception) * Disable the FPU/Vector to detect illegal usage of floating point * or vector in kernel space. */ - li t0, SR_SUM | SR_FS_VS + li t0, SR_SUM | SR_FS_VS | SR_ELP REG_L s0, TASK_TI_USER_SP(tp) csrrc s1, CSR_STATUS, t0 diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c index cd11667593fe..4587201dd81d 100644 --- a/arch/riscv/kernel/process.c +++ b/arch/riscv/kernel/process.c @@ -160,6 +160,11 @@ void start_thread(struct pt_regs *regs, unsigned long pc, set_shstk_status(current, false); set_shstk_base(current, 0, 0); set_active_shstk(current, 0); + /* + * disable indirect branch tracking on exec. + * libc will enable it later via prctl. + */ + set_indir_lp_status(current, false); #ifdef CONFIG_64BIT regs->status &= ~SR_UXL; diff --git a/arch/riscv/kernel/usercfi.c b/arch/riscv/kernel/usercfi.c index 08620bdae696..2ebe789caa6b 100644 --- a/arch/riscv/kernel/usercfi.c +++ b/arch/riscv/kernel/usercfi.c @@ -72,6 +72,35 @@ void set_shstk_lock(struct task_struct *task) task->thread_info.user_cfi_state.ubcfi_locked = 1; } +bool is_indir_lp_enabled(struct task_struct *task) +{ + return task->thread_info.user_cfi_state.ufcfi_en; +} + +bool is_indir_lp_locked(struct task_struct *task) +{ + return task->thread_info.user_cfi_state.ufcfi_locked; +} + +void set_indir_lp_status(struct task_struct *task, bool enable) +{ + if (!cpu_supports_indirect_br_lp_instr()) + return; + + task->thread_info.user_cfi_state.ufcfi_en = enable ? 1 : 0; + + if (enable) + task->thread.envcfg |= ENVCFG_LPE; + else + task->thread.envcfg &= ~ENVCFG_LPE; + + csr_write(CSR_ENVCFG, task->thread.envcfg); +} + +void set_indir_lp_lock(struct task_struct *task) +{ + task->thread_info.user_cfi_state.ufcfi_locked = 1; +} /* * If size is 0, then to be compatible with regular stack we want it to be as big as * regular stack. Else PAGE_ALIGN it and return back @@ -371,3 +400,53 @@ int arch_lock_shadow_stack_status(struct task_struct *task, return 0; } + +int arch_get_indir_br_lp_status(struct task_struct *t, unsigned long __user *status) +{ + unsigned long fcfi_status = 0; + + if (!cpu_supports_indirect_br_lp_instr()) + return -EINVAL; + + /* indirect branch tracking is enabled on the task or not */ + fcfi_status |= (is_indir_lp_enabled(t) ? PR_INDIR_BR_LP_ENABLE : 0); + + return copy_to_user(status, &fcfi_status, sizeof(fcfi_status)) ? -EFAULT : 0; +} + +int arch_set_indir_br_lp_status(struct task_struct *t, unsigned long status) +{ + bool enable_indir_lp = false; + + if (!cpu_supports_indirect_br_lp_instr()) + return -EINVAL; + + /* indirect branch tracking is locked and further can't be modified by user */ + if (is_indir_lp_locked(t)) + return -EINVAL; + + /* Reject unknown flags */ + if (status & ~PR_INDIR_BR_LP_ENABLE) + return -EINVAL; + + enable_indir_lp = (status & PR_INDIR_BR_LP_ENABLE); + set_indir_lp_status(t, enable_indir_lp); + + return 0; +} + +int arch_lock_indir_br_lp_status(struct task_struct *task, + unsigned long arg) +{ + /* + * If indirect branch tracking is not supported or not enabled on task, + * nothing to lock here + */ + if (!cpu_supports_indirect_br_lp_instr() || + !is_indir_lp_enabled(task) || arg != 0) + return -EINVAL; + + set_indir_lp_lock(task); + + return 0; +} -- 2.43.0