On Fri, Jan 17, 2014 at 09:00:09AM +0000, Jean Pihet wrote:
On 16 January 2014 14:47, Jean Pihet jean.pihet@linaro.org wrote:
So the simplest thing would be to make compat_user_stack_pointer expand to user_stack_pointer(current_pt_regs()) on arm64 and merge that in with your original patch fixing user_stack_pointer.
I see 2 issues in your proposal:
- user_stack_pointer(regs) calls compat_user_stack_pointer if
compat_user_mode(regs)) and compat_user_stack_pointer expands to user_stack_pointer. I see a circular dependency in the macros.
Not today it doesn't, so you just need to avoid writing the circular dependency and instead make user_stack_pointer access (regs)->compat_sp instead.
- current_pt_regs() returns the current task regs although perf
passes a regs struct that had been recorded previously.
Yes, but compat_user_stack_pointer doesn't take a regs paramater anyway, so there's no change in behaviour here.
Will