Re: [PATCH v2 2/9] ARM: traps: use get_kernel_nofault instead of set_fs()

From: Christoph Hellwig
Date: Sat Sep 19 2020 - 01:27:52 EST


On Fri, Sep 18, 2020 at 02:46:17PM +0200, Arnd Bergmann wrote:
> ARM uses set_fs() and __get_user() to allow the stack dumping code to
> access possibly invalid pointers carefully. These can be changed to the
> simpler get_kernel_nofault(), and allow the eventual removal of set_fs().
>
> dump_instr() will print either kernel or user space pointers,
> depending on how it was called. For dump_mem(), I assume we are only
> interested in kernel pointers, and the only time that this is called
> with user_mode(regs)==true is when the regs themselves are unreliable
> as a result of the condition that caused the trap.
>
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>

Looks good,

Reviewed-by: Christoph Hellwig <hch@xxxxxx>