Re: [PATCH 1/6 v3] ptrace: Remove maxargs from task_current_syscall()

[Thomas Gleixner]

On Mon, 1 Apr 2019, Steven Rostedt wrote:

> From: "Steven Rostedt (Red Hat)" <rostedt@xxxxxxxxxxx>
> 
> task_current_syscall() has a single user that passes in 6 for maxargs, which
> is the maximum arguments that can be used to get system calls from
> syscall_get_arguments(). Instead of passing in a number of arguments to
> grab, just get 6 arguments. The args argument even specifies that it's an
> array of 6 items.
> 
> This will also allow changing syscall_get_arguments() to not get a variable
> number of arguments, but always grab 6.
> 
> Linus also suggested not passing in a bunch of arguments to
> task_current_syscall() but to instead pass in a pointer to a structure, and
> just fill the structure. struct seccomp_data has almost all the parameters
> that is needed except for the stack pointer (sp). As seccomp_data is part of
> uapi, and I'm afraid to change it, a new structure was created
> "syscall_info", which includes seccomp_data and adds the "sp" field.
> 
> Link: http://lkml.kernel.org/r/20161107213233.466776454@xxxxxxxxxxx
> 
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Andy Lutomirski <luto@xxxxxxxxxx>
> Cc: Alexey Dobriyan <adobriyan@xxxxxxxxx>
> Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
> Cc: Kees Cook <keescook@xxxxxxxxxxxx>
> Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
> Cc: linux-fsdevel@xxxxxxxxxxxxxxx
> Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>

Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>