Commit c354ec9c authored by Dmitry V. Levin's avatar Dmitry V. Levin Committed by Andrew Morton
Browse files

ptrace_get_syscall_info: factor out ptrace_get_syscall_info_op 

Move the code that calculates the type of the system call stop out of
ptrace_get_syscall_info() into a separate function
ptrace_get_syscall_info_op() which is going to be used later to implement
PTRACE_SET_SYSCALL_INFO API.

Link: https://lkml.kernel.org/r/20250303112038.GE24170@strace.io


Signed-off-by: default avatarDmitry V. Levin <ldv@strace.io>
Reviewed-by: default avatarOleg Nesterov <oleg@redhat.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexey Gladkov (Intel) <legion@kernel.org>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: anton ivanov <anton.ivanov@cambridgegreys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Brian Cain <bcain@quicinc.com>
Cc: Charlie Jenkins <charlie@rivosinc.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christian Zankel <chris@zankel.net>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Davide Berardi <berardi.dav@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Eugene Syromiatnikov <esyr@redhat.com>
Cc: Eugene Syromyatnikov <evgsyr@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Maciej W. Rozycki <macro@orcam.me.uk>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Naveen N Rao <naveen@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Renzo Davoi <renzo@cs.unibo.it>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russel King <linux@armlinux.org.uk>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent cc662273

kernel/ptrace.c

+34 −24
Original line number Diff line number Diff line
@@ -921,7 +921,6 @@ ptrace_get_syscall_info_entry(struct task_struct *child, struct pt_regs *regs, 
	unsigned long args[ARRAY_SIZE(info->entry.args)];

	int i;



	info->op = PTRACE_SYSCALL_INFO_ENTRY;

	info->entry.nr = syscall_get_nr(child, regs);

	syscall_get_arguments(child, regs, args);

	for (i = 0; i < ARRAY_SIZE(args); i++)
@@ -943,7 +942,6 @@ ptrace_get_syscall_info_seccomp(struct task_struct *child, struct pt_regs *regs, 
	 * diverge significantly enough.

	 */

	ptrace_get_syscall_info_entry(child, regs, info);

	info->op = PTRACE_SYSCALL_INFO_SECCOMP;

	info->seccomp.ret_data = child->ptrace_message;



	/* ret_data is the last field in struct ptrace_syscall_info.seccomp */
@@ -954,7 +952,6 @@ static unsigned long 
ptrace_get_syscall_info_exit(struct task_struct *child, struct pt_regs *regs,

			     struct ptrace_syscall_info *info)

{

	info->op = PTRACE_SYSCALL_INFO_EXIT;

	info->exit.rval = syscall_get_error(child, regs);

	info->exit.is_error = !!info->exit.rval;

	if (!info->exit.is_error)
@@ -965,19 +962,8 @@ ptrace_get_syscall_info_exit(struct task_struct *child, struct pt_regs *regs, 
}



static int

ptrace_get_syscall_info(struct task_struct *child, unsigned long user_size,

			void __user *datavp)

ptrace_get_syscall_info_op(struct task_struct *child)

{

	struct pt_regs *regs = task_pt_regs(child);

	struct ptrace_syscall_info info = {

		.op = PTRACE_SYSCALL_INFO_NONE,

		.arch = syscall_get_arch(child),

		.instruction_pointer = instruction_pointer(regs),

		.stack_pointer = user_stack_pointer(regs),

	};

	unsigned long actual_size = offsetof(struct ptrace_syscall_info, entry);

	unsigned long write_size;



	/*

	 * This does not need lock_task_sighand() to access

	 * child->last_siginfo because ptrace_freeze_traced()
@@ -988,18 +974,42 @@ ptrace_get_syscall_info(struct task_struct *child, unsigned long user_size, 
	case SIGTRAP | 0x80:

		switch (child->ptrace_message) {

		case PTRACE_EVENTMSG_SYSCALL_ENTRY:

			actual_size = ptrace_get_syscall_info_entry(child, regs,

								    &info);

			break;

			return PTRACE_SYSCALL_INFO_ENTRY;

		case PTRACE_EVENTMSG_SYSCALL_EXIT:

			actual_size = ptrace_get_syscall_info_exit(child, regs,

								   &info);

			break;

			return PTRACE_SYSCALL_INFO_EXIT;

		default:

			return PTRACE_SYSCALL_INFO_NONE;

		}

		break;

	case SIGTRAP | (PTRACE_EVENT_SECCOMP << 8):

		actual_size = ptrace_get_syscall_info_seccomp(child, regs,

							      &info);

		return PTRACE_SYSCALL_INFO_SECCOMP;

	default:

		return PTRACE_SYSCALL_INFO_NONE;

	}

}



static int

ptrace_get_syscall_info(struct task_struct *child, unsigned long user_size,

			void __user *datavp)

{

	struct pt_regs *regs = task_pt_regs(child);

	struct ptrace_syscall_info info = {

		.op = ptrace_get_syscall_info_op(child),

		.arch = syscall_get_arch(child),

		.instruction_pointer = instruction_pointer(regs),

		.stack_pointer = user_stack_pointer(regs),

	};

	unsigned long actual_size = offsetof(struct ptrace_syscall_info, entry);

	unsigned long write_size;



	switch (info.op) {

	case PTRACE_SYSCALL_INFO_ENTRY:

		actual_size = ptrace_get_syscall_info_entry(child, regs, &info);

		break;

	case PTRACE_SYSCALL_INFO_EXIT:

		actual_size = ptrace_get_syscall_info_exit(child, regs, &info);

		break;

	case PTRACE_SYSCALL_INFO_SECCOMP:

		actual_size = ptrace_get_syscall_info_seccomp(child, regs, &info);

		break;

	}