From nobody Fri Dec 19 07:55:57 2025 Received: from mail-pj1-f45.google.com (mail-pj1-f45.google.com [209.85.216.45]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C50CA1CD213 for ; Wed, 22 Jan 2025 22:56:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.45 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737586621; cv=none; b=mcRRxkPtwujUsntLZbGE2NklDHXjDwRz84IBMvOxS9ZsmoTa0dzaXrYhLjBIzI1kr7EA9A+QeVwdF1MhJultSKmfAYvQM7zoLUx+wVYxh1juYFh5IZNgRBWEczk18EJWLk6fmNcvRbfGl/W51iA5jQ86LEnjQKEeBas2OnyPvbk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737586621; c=relaxed/simple; bh=IfDjpWzOkJ2hu8S0SjhggOry7IIgS+knXj7qp/i1XMU=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=Yl7MzxoSoIaWFyLB6Y2Yvxb/1Jhf2vP5rKrT9y9sLDAuTIk0+yEuniA227H/yi5izGNHuZ04BDWrUDFzj98Yq37DZA/2nj0jIr3s0BzCx+3VjLeVaRR7GHW5rkls7oyOKoqfUQ85msADICCWrTBx0Vf41vtCV165j/C3hsIvHy0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=rivosinc.com; spf=pass smtp.mailfrom=rivosinc.com; dkim=pass (2048-bit key) header.d=rivosinc-com.20230601.gappssmtp.com header.i=@rivosinc-com.20230601.gappssmtp.com header.b=AU3d/eJo; arc=none smtp.client-ip=209.85.216.45 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=rivosinc.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=rivosinc.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=rivosinc-com.20230601.gappssmtp.com header.i=@rivosinc-com.20230601.gappssmtp.com header.b="AU3d/eJo" Received: by mail-pj1-f45.google.com with SMTP id 98e67ed59e1d1-2ee76befe58so593582a91.2 for ; Wed, 22 Jan 2025 14:56:59 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rivosinc-com.20230601.gappssmtp.com; s=20230601; t=1737586619; x=1738191419; darn=vger.kernel.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=8+waL18iX0aaC1P1/K+RB0UPKm0pakylfY2Y6RIkpXQ=; b=AU3d/eJowTIa5iqA+4+TTLPqkvhZvLf2H+jdKrwp2TAvWdrJK3UEgcELgGasf4DoEC xN9UMIxYxN06dGFF6k2PGovTcT3EwEL3qewa3pUikaqdK3D0MZnQFKcyK9NxM0lAwjih BKFCWU9Bc1tufvFoq0rT5J/pmffkqqUqkTzKoTIce6YR1rbChneNWfIu/PVx5UsvKDU4 SMqIThj589BBGxpEiEcLofBZDRiquOt3PPK0NIiMlPv0nkcX/uMmfHuS672dzjehPE3A hg1U6kCrprciKYE+wwjg785I3d0oa/+3eSFgGYxVGlQIZ7xCroqvA7Of5yZ1UO79/iC0 PvCQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1737586619; x=1738191419; 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=8+waL18iX0aaC1P1/K+RB0UPKm0pakylfY2Y6RIkpXQ=; b=BNJ/aRUhWbwqjHQZ/cKuVrjvAu9METGIQuypsuAv571xZhKBoFeQ+tv2LG/8ieKt7W faLG6HCgguBhn+6EGtaXU/r1lEkfA98rfhGblmUQyZXaTGn+S+sR9BCOedjyNPbugY+k XkBkTgsH9JWk8ZJ5so8nmLJJ7W4yvADBrumEqni9kSjmx3kWOfSE6j95Gsx3Xa6O0gVi 6DNjZChw78L42RFskeqc4kXChReSfU834dpnxArKbiMWOVPymG2LrQ/4sThjLxEqd69C 8bhvSjor5JLVTveHEsnK5NFOp7TIpYPGdxCO86hMygjfJ85GTI+/AU2i0c44cW7cHVvz 5suA== X-Forwarded-Encrypted: i=1; AJvYcCXzzsNluq88ufKemRMqj4JvdWg9LGqY1ZJxFSop/aWWnkBR8xAUpP/vIY9alLWwz232c+7r+iS24MaqkA4=@vger.kernel.org X-Gm-Message-State: AOJu0YyOSGssmCTf0b8Slkt5rFc3OLpyxBV4B73ZkV75TP/GLglX37zR s+ra4H98Lwgjl1FqWlRVEarwUXNWU7REKq1xzwUJ6ZwjJe2fC5Ra4An03FkBxqQ= X-Gm-Gg: ASbGncu2s4IWBMj4d2WX+UW3p0upsveL1V02oK0FBdxEdr1ix9Yk04drwbTMsD/Akb4 SnWwi2xvlKs5l/uckAmPisXu4zL2wYTkZpBGBDxQ7LZpOWYcy0cPmuHtJIyJmgzYeXpJpFCoUpZ T1QiPko0POpe/3WaJdlp1ko154/xqsnT+rUJDzN83SZrFzaQU2sWZYaJ4mAIbQH/y8ZUUFhA0LX 3VGjsrCOtTIxIX1JNX3FpqbfpkEu1uw3Lqkk2fKcCltTMIs4kFM5+tgGiaXQl/rjgv7BdNK9e8K WhgL30gDjq06Ap2g5Tbq X-Google-Smtp-Source: AGHT+IFzzfa8LiTbTT2Dmbp7MvGOIfIV8LIzhJeiC+AzFuWK0lSK5kP59xevBlrCdbe0b52VK1rxLQ== X-Received: by 2002:a17:90b:2c83:b0:2ee:c918:cd42 with SMTP id 98e67ed59e1d1-2f782d4eea7mr29321427a91.22.1737586619150; Wed, 22 Jan 2025 14:56:59 -0800 (PST) Received: from charlie.ba.rivosinc.com ([64.71.180.162]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-2f7e6aaf3b4sm2301375a91.25.2025.01.22.14.56.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 22 Jan 2025 14:56:58 -0800 (PST) From: Charlie Jenkins Date: Wed, 22 Jan 2025 14:56:22 -0800 Subject: [PATCH 3/4] loongarch: entry: Migrate ret_from_fork() to C Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20250122-riscv_optimize_entry-v1-3-4ee95559cfd0@rivosinc.com> References: <20250122-riscv_optimize_entry-v1-0-4ee95559cfd0@rivosinc.com> In-Reply-To: <20250122-riscv_optimize_entry-v1-0-4ee95559cfd0@rivosinc.com> To: Paul Walmsley , Palmer Dabbelt , Huacai Chen , WANG Xuerui , Thomas Gleixner , Peter Zijlstra , Andy Lutomirski , Alexandre Ghiti Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, loongarch@lists.linux.dev, Charlie Jenkins X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=openpgp-sha256; l=5559; i=charlie@rivosinc.com; h=from:subject:message-id; bh=IfDjpWzOkJ2hu8S0SjhggOry7IIgS+knXj7qp/i1XMU=; b=owGbwMvMwCXWx5hUnlvL8Y3xtFoSQ/rE8i1dL+OOSYp8qL2mJrSGk+0H5+f2Kp+Pe9jq1j479 X6Zw93yjlIWBjEuBlkxRRaeaw3MrXf0y46Klk2AmcPKBDKEgYtTACbS58XwP8BkwY7+lm9r70p9 PBS5f82H6nUbnypMbNbf1X3B77b6BXlGhvWh9sl8e+4IHvqc9LB/msHdqb4Hds7b5PnpRYe+W/a WgzwA X-Developer-Key: i=charlie@rivosinc.com; a=openpgp; fpr=7D834FF11B1D8387E61C776FFB10D1F27D6B1354 Loongarch is the only architecture that calls syscall_exit_to_user_mode() from asm. Move the call into C so that this function can be inlined across all architectures. Signed-off-by: Charlie Jenkins --- arch/loongarch/include/asm/switch_to.h | 8 ++++++++ arch/loongarch/kernel/entry.S | 22 ++++++++++----------- arch/loongarch/kernel/process.c | 36 ++++++++++++++++++++++++++++--= ---- 3 files changed, 48 insertions(+), 18 deletions(-) diff --git a/arch/loongarch/include/asm/switch_to.h b/arch/loongarch/includ= e/asm/switch_to.h index 5b225aff3ba21aa06d0713bc8e73e1b941389630..a1c5576f1fd145670e13038bec6= dd390486099ab 100644 --- a/arch/loongarch/include/asm/switch_to.h +++ b/arch/loongarch/include/asm/switch_to.h @@ -26,6 +26,14 @@ extern asmlinkage struct task_struct *__switch_to(struct= task_struct *prev, struct task_struct *next, struct thread_info *next_ti, void *sched_ra, void *sched_cfa); =20 +void noinstr __no_stack_protector ret_from_kernel_thread(struct task_struc= t *prev, + struct pt_regs *regs, + int (*fn)(void *), + void *fn_arg); + +void noinstr __no_stack_protector ret_from_fork(struct task_struct *prev, + struct pt_regs *regs); + /* * For newly created kernel threads switch_to() will return to * ret_from_kernel_thread, newly created user threads to ret_from_fork. diff --git a/arch/loongarch/kernel/entry.S b/arch/loongarch/kernel/entry.S index 48e7e34e355e83eae8165957ba2eac05a8bf17df..2abc29e573810e000f2fef4646d= dca0dbb80eabe 100644 --- a/arch/loongarch/kernel/entry.S +++ b/arch/loongarch/kernel/entry.S @@ -77,24 +77,22 @@ SYM_CODE_START(handle_syscall) SYM_CODE_END(handle_syscall) _ASM_NOKPROBE(handle_syscall) =20 -SYM_CODE_START(ret_from_fork) +SYM_CODE_START(ret_from_fork_asm) UNWIND_HINT_REGS - bl schedule_tail # a0 =3D struct task_struct *prev - move a0, sp - bl syscall_exit_to_user_mode + move a1, sp + bl ret_from_fork RESTORE_STATIC RESTORE_SOME RESTORE_SP_AND_RET -SYM_CODE_END(ret_from_fork) +SYM_CODE_END(ret_from_fork_asm) =20 -SYM_CODE_START(ret_from_kernel_thread) +SYM_CODE_START(ret_from_kernel_thread_asm) UNWIND_HINT_REGS - bl schedule_tail # a0 =3D struct task_struct *prev - move a0, s1 - jirl ra, s0, 0 - move a0, sp - bl syscall_exit_to_user_mode + move a1, sp + move a2, s0 + move a3, s1 + bl ret_from_kernel_thread RESTORE_STATIC RESTORE_SOME RESTORE_SP_AND_RET -SYM_CODE_END(ret_from_kernel_thread) +SYM_CODE_END(ret_from_kernel_thread_asm) diff --git a/arch/loongarch/kernel/process.c b/arch/loongarch/kernel/proces= s.c index 6e58f65455c7ca3eae2e88ed852c8655a6701e5c..9bb069ef363fefed1f2115e6572= b31c2b76bb414 100644 --- a/arch/loongarch/kernel/process.c +++ b/arch/loongarch/kernel/process.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #include #include @@ -47,6 +48,7 @@ #include #include #include +#include #include #include =20 @@ -63,8 +65,12 @@ EXPORT_SYMBOL(__stack_chk_guard); unsigned long boot_option_idle_override =3D IDLE_NO_OVERRIDE; EXPORT_SYMBOL(boot_option_idle_override); =20 -asmlinkage void ret_from_fork(void); -asmlinkage void ret_from_kernel_thread(void); +asmlinkage void restore_and_ret(void); +asmlinkage void ret_from_fork_asm(void); +void noinstr __no_stack_protector ret_from_kernel_thread(struct task_struc= t *prev, + struct pt_regs *regs, + int (*fn)(void *), + void *fn_arg) =20 void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long sp) { @@ -138,6 +144,24 @@ int arch_dup_task_struct(struct task_struct *dst, stru= ct task_struct *src) return 0; } =20 +void noinstr __no_stack_protector ret_from_kernel_thread(struct task_struc= t *prev, + struct pt_regs *regs, + int (*fn)(void *), + void *fn_arg) +{ + schedule_tail(prev); + + fn(fn_arg); + + syscall_exit_to_user_mode(regs); +} + +void noinstr __no_stack_protector ret_from_fork(struct task_struct *prev, = struct pt_regs *regs) +{ + schedule_tail(prev); + syscall_exit_to_user_mode(regs); +} + /* * Copy architecture-specific thread state */ @@ -165,8 +189,8 @@ int copy_thread(struct task_struct *p, const struct ker= nel_clone_args *args) p->thread.reg03 =3D childksp; p->thread.reg23 =3D (unsigned long)args->fn; p->thread.reg24 =3D (unsigned long)args->fn_arg; - p->thread.reg01 =3D (unsigned long)ret_from_kernel_thread; - p->thread.sched_ra =3D (unsigned long)ret_from_kernel_thread; + p->thread.reg01 =3D (unsigned long)ret_from_kernel_thread_asm; + p->thread.sched_ra =3D (unsigned long)ret_from_kernel_thread_asm; memset(childregs, 0, sizeof(struct pt_regs)); childregs->csr_euen =3D p->thread.csr_euen; childregs->csr_crmd =3D p->thread.csr_crmd; @@ -182,8 +206,8 @@ int copy_thread(struct task_struct *p, const struct ker= nel_clone_args *args) childregs->regs[3] =3D usp; =20 p->thread.reg03 =3D (unsigned long) childregs; - p->thread.reg01 =3D (unsigned long) ret_from_fork; - p->thread.sched_ra =3D (unsigned long) ret_from_fork; + p->thread.reg01 =3D (unsigned long) ret_from_fork_asm; + p->thread.sched_ra =3D (unsigned long) ret_from_fork_asm; =20 /* * New tasks lose permission to use the fpu. This accelerates context --=20 2.43.0