linux-kernel - [PATCH RFC v2 02/28] ARM: ptrace: Split report

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20241029-arm-generic-entry-v2-2-573519abef38@linaro.org>
Date: Tue, 29 Oct 2024 11:52:42 +0100
From: Linus Walleij <linus.walleij@...aro.org>
To: Oleg Nesterov <oleg@...hat.com>, Russell King <linux@...linux.org.uk>, 
 Kees Cook <kees@...nel.org>, Andy Lutomirski <luto@...capital.net>, 
 Will Drewry <wad@...omium.org>, Frederic Weisbecker <frederic@...nel.org>, 
 "Paul E. McKenney" <paulmck@...nel.org>, 
 Jinjie Ruan <ruanjinjie@...wei.com>, Arnd Bergmann <arnd@...db.de>, 
 Ard Biesheuvel <ardb@...nel.org>, Al Viro <viro@...iv.linux.org.uk>
Cc: linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org, 
 Linus Walleij <linus.walleij@...aro.org>
Subject: [PATCH RFC v2 02/28] ARM: ptrace: Split report_syscall()

The generic entry code requires that report_syscall() be provided
in two parts: report_syscall_enter() and report_syscall_exit()
so split the combined function in two.

Signed-off-by: Linus Walleij <linus.walleij@...aro.org>
---
 arch/arm/kernel/ptrace.c | 30 ++++++++++++++++++++++--------
 1 file changed, 22 insertions(+), 8 deletions(-)

diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c
index c421a899fc84..07b0daf47441 100644
--- a/arch/arm/kernel/ptrace.c
+++ b/arch/arm/kernel/ptrace.c
@@ -827,31 +827,45 @@ enum ptrace_syscall_dir {
 	PTRACE_SYSCALL_EXIT,
 };

-static void report_syscall(struct pt_regs *regs, enum ptrace_syscall_dir dir)
+static void report_syscall_enter(struct pt_regs *regs)
 {
 	unsigned long ip;

 	/*
 	 * IP is used to denote syscall entry/exit:
-	 * IP = 0 -> entry, =1 -> exit
+	 * IP = 0 -> entry
 	 */
 	ip = regs->ARM_ip;
-	regs->ARM_ip = dir;
+	regs->ARM_ip = PTRACE_SYSCALL_ENTER;

-	if (dir == PTRACE_SYSCALL_EXIT)
-		ptrace_report_syscall_exit(regs, 0);
-	else if (ptrace_report_syscall_entry(regs))
+	if (ptrace_report_syscall_entry(regs))
 		current_thread_info()->abi_syscall = -1;

 	regs->ARM_ip = ip;
 }

+static void report_syscall_exit(struct pt_regs *regs)
+{
+	unsigned long ip;
+
+	/*
+	 * IP is used to denote syscall entry/exit:
+	 * IP = 1 -> exit
+	 */
+	ip = regs->ARM_ip;
+	regs->ARM_ip = PTRACE_SYSCALL_EXIT;
+
+	ptrace_report_syscall_exit(regs, 0);
+
+	regs->ARM_ip = ip;
+}
+
 asmlinkage int syscall_trace_enter(struct pt_regs *regs)
 {
 	int scno;

 	if (test_thread_flag(TIF_SYSCALL_TRACE))
-		report_syscall(regs, PTRACE_SYSCALL_ENTER);
+		report_syscall_enter(regs);

 	/* Do seccomp after ptrace; syscall may have changed. */
 #ifdef CONFIG_HAVE_ARCH_SECCOMP_FILTER
@@ -892,5 +906,5 @@ asmlinkage void syscall_trace_exit(struct pt_regs *regs)
 		trace_sys_exit(regs, regs_return_value(regs));

 	if (test_thread_flag(TIF_SYSCALL_TRACE))
-		report_syscall(regs, PTRACE_SYSCALL_EXIT);
+		report_syscall_exit(regs);
 }

-- 
2.46.2