From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 9DCE62AE78; Mon, 8 Dec 2025 05:48:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765172906; cv=none; b=nNa6MY9yhSUeJHw+gmF3Ei4jbGuzj9LROfOtLG2AwgMxO25y4/BiZm6IK3jWsnnwEhbOw/WjxNR2F14+t1vuNtdHlNGbBNgSdKdm34YDhyy7RvHianFcMm7h6eqNX65yJBUzI2Kj2bITqdV7IT+DUOtKL56CfmNGK0prZ/VeU/Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765172906; c=relaxed/simple; bh=HACHYxKtWBB35vXwiRXSHDkz/E+ty1eVulvsAx2z6Ak=; h=Message-ID:Date:MIME-Version:Subject:To:References:From: In-Reply-To:Content-Type; b=acAPC77JuxxVqejslLwRAEj/T4CoJFFYheHO8RcMRK05UIROW+XJ3HDMJr5X9UxSP/7m/OxciiWnNW6DvD/cPciwYthpzUxzr9rbL92bXXafnVJpV/m7TmuXItEE4Cnp/xA9/zLJo7s4fWGYmkxsc51eRVrNHEqgXGXWUW1a6M4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6770B1692; Sun, 7 Dec 2025 21:48:16 -0800 (PST) Received: from [10.164.18.52] (unknown [10.164.18.52]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 304C33F762; Sun, 7 Dec 2025 21:48:16 -0800 (PST) Message-ID: Date: Mon, 8 Dec 2025 11:18:14 +0530 Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v9 04/16] arm64/ptrace: Refactor syscall_trace_enter/exit() To: Jinjie Ruan , catalin.marinas@arm.com, will@kernel.org, oleg@redhat.com, tglx@linutronix.de, peterz@infradead.org, luto@kernel.org, shuah@kernel.org, kees@kernel.org, wad@chromium.org, deller@gmx.de, macro@orcam.me.uk, charlie@rivosinc.com, kevin.brodsky@arm.com, ldv@strace.io, mark.rutland@arm.com, song@kernel.org, ryan.roberts@arm.com, ada.coupriediaz@arm.com, broonie@kernel.org, pengcan@kylinos.cn, dvyukov@google.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org References: <20251204082123.2792067-1-ruanjinjie@huawei.com> <20251204082123.2792067-5-ruanjinjie@huawei.com> Content-Language: en-US From: Anshuman Khandual In-Reply-To: <20251204082123.2792067-5-ruanjinjie@huawei.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 04/12/25 1:51 PM, Jinjie Ruan wrote: > The generic syscall entry code has the following form, which use > the input syscall work flag and syscall number: > > | syscall_trace_enter(struct pt_regs *regs, long syscall, > | unsigned long work) > | > | syscall_exit_work(struct pt_regs *regs, unsigned long work) > > In preparation for moving arm64 over to the generic entry code, > refactor syscall_trace_enter/exit() to also pass thread flags, and > get syscall number by syscall_get_nr() helper. > > No functional changes. > > Reviewed-by: Kevin Brodsky > Signed-off-by: Jinjie Ruan > --- > arch/arm64/include/asm/syscall.h | 4 ++-- > arch/arm64/kernel/ptrace.c | 25 ++++++++++++++++--------- > arch/arm64/kernel/syscall.c | 5 +++-- > 3 files changed, 21 insertions(+), 13 deletions(-) > > diff --git a/arch/arm64/include/asm/syscall.h b/arch/arm64/include/asm/syscall.h > index 5e4c7fc44f73..cef1d9ce6e1b 100644 > --- a/arch/arm64/include/asm/syscall.h > +++ b/arch/arm64/include/asm/syscall.h > @@ -120,7 +120,7 @@ static inline int syscall_get_arch(struct task_struct *task) > return AUDIT_ARCH_AARCH64; > } > > -int syscall_trace_enter(struct pt_regs *regs); > -void syscall_trace_exit(struct pt_regs *regs); > +int syscall_trace_enter(struct pt_regs *regs, long syscall, unsigned long flags); > +void syscall_trace_exit(struct pt_regs *regs, unsigned long flags); > > #endif /* __ASM_SYSCALL_H */ > diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c > index 3926ce6aa268..b962cbcca11d 100644 > --- a/arch/arm64/kernel/ptrace.c > +++ b/arch/arm64/kernel/ptrace.c > @@ -2381,9 +2381,8 @@ static void report_syscall_exit(struct pt_regs *regs) > } > } > > -int syscall_trace_enter(struct pt_regs *regs) > +int syscall_trace_enter(struct pt_regs *regs, long syscall, unsigned long flags) > { > - unsigned long flags = read_thread_flags(); > int ret; > > if (flags & (_TIF_SYSCALL_EMU | _TIF_SYSCALL_TRACE)) { > @@ -2396,19 +2395,27 @@ int syscall_trace_enter(struct pt_regs *regs) > if (secure_computing() == -1) > return NO_SYSCALL; > > - if (test_thread_flag(TIF_SYSCALL_TRACEPOINT)) > - trace_sys_enter(regs, regs->syscallno); > + /* Either of the above might have changed the syscall number */ > + syscall = syscall_get_nr(current, regs); > > - audit_syscall_entry(regs->syscallno, regs->orig_x0, regs->regs[1], > + if (test_thread_flag(TIF_SYSCALL_TRACEPOINT)) { > + trace_sys_enter(regs, syscall); > + > + /* > + * Probes or BPF hooks in the tracepoint may have changed the > + * system call number as well. > + */ > + syscall = syscall_get_nr(current, regs); > + } > + > + audit_syscall_entry(syscall, regs->orig_x0, regs->regs[1], > regs->regs[2], regs->regs[3]); > > - return regs->syscallno; > + return syscall; regs->syscallno still remains unchanged even if syscall is evaluated to be different ? > } > > -void syscall_trace_exit(struct pt_regs *regs) > +void syscall_trace_exit(struct pt_regs *regs, unsigned long flags) > { > - unsigned long flags = read_thread_flags(); > - > audit_syscall_exit(regs); > > if (flags & _TIF_SYSCALL_TRACEPOINT) > diff --git a/arch/arm64/kernel/syscall.c b/arch/arm64/kernel/syscall.c > index aba7ca6bca2d..ec31f82d2e9f 100644 > --- a/arch/arm64/kernel/syscall.c > +++ b/arch/arm64/kernel/syscall.c > @@ -124,7 +124,7 @@ static void el0_svc_common(struct pt_regs *regs, int scno, int sc_nr, > */ > if (scno == NO_SYSCALL) > syscall_set_return_value(current, regs, -ENOSYS, 0); > - scno = syscall_trace_enter(regs); > + scno = syscall_trace_enter(regs, scno, flags); > if (scno == NO_SYSCALL) > goto trace_exit; > } > @@ -143,7 +143,8 @@ static void el0_svc_common(struct pt_regs *regs, int scno, int sc_nr, > } > > trace_exit: > - syscall_trace_exit(regs); > + flags = read_thread_flags(); > + syscall_trace_exit(regs, flags); > } > > void do_el0_svc(struct pt_regs *regs)