From c354ec9cee909136e168f4f4900d56a491c4d6c5 Mon Sep 17 00:00:00 2001 From: "Dmitry V. Levin" Date: Mon, 3 Mar 2025 13:20:38 +0200 Subject: [PATCH] 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: Dmitry V. Levin Reviewed-by: Oleg Nesterov Cc: Alexander Gordeev Cc: Alexey Gladkov (Intel) Cc: Andreas Larsson Cc: anton ivanov Cc: Arnd Bergmann Cc: Borislav Betkov Cc: Brian Cain Cc: Charlie Jenkins Cc: Christian Borntraeger Cc: Christian Zankel Cc: Christophe Leroy Cc: Dave Hansen Cc: Davide Berardi Cc: David S. Miller Cc: Dinh Nguyen Cc: Eugene Syromiatnikov Cc: Eugene Syromyatnikov Cc: Geert Uytterhoeven Cc: Guo Ren Cc: Heiko Carstens Cc: Helge Deller Cc: "H. Peter Anvin" Cc: Huacai Chen Cc: Ingo Molnar Cc: Johannes Berg Cc: John Paul Adrian Glaubitz Cc: Jonas Bonn Cc: Maciej W. Rozycki Cc: Madhavan Srinivasan Cc: Max Filippov Cc: Michael Ellerman Cc: Michal Simek Cc: Mike Frysinger Cc: Naveen N Rao Cc: Nicholas Piggin Cc: Renzo Davoi Cc: Richard Weinberger Cc: Rich Felker Cc: Russel King Cc: Shuah Khan Cc: Stafford Horne Cc: Stefan Kristiansson Cc: Sven Schnelle Cc: Thomas Gleinxer Cc: Vasily Gorbik Cc: Vineet Gupta Cc: WANG Xuerui Cc: Will Deacon Cc: Yoshinori Sato Signed-off-by: Andrew Morton --- kernel/ptrace.c | 58 +++++++++++++++++++++++++++++-------------------- 1 file changed, 34 insertions(+), 24 deletions(-) diff --git a/kernel/ptrace.c b/kernel/ptrace.c index d5f89f9ef29f..22e7d74cf4cd 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -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; } -- 2.50.1