Messages in this thread | | | Date | Mon, 15 Feb 2010 17:17:52 +0100 | From | Oleg Nesterov <> | Subject | Re: x86: get rid of the insane TIF_ABI_PENDING bit |
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commit 05d43ed8a89c159ff641d472f970e3f1baa66318 Author: H. Peter Anvin <hpa@zytor.com> Date: Thu Jan 28 22:14:43 2010 -0800
> --- a/arch/x86/include/asm/elf.h > +++ b/arch/x86/include/asm/elf.h > @@ -181,14 +181,8 @@ do { \ > void start_thread_ia32(struct pt_regs *regs, u32 new_ip, u32 new_sp); > #define compat_start_thread start_thread_ia32 > > -#define COMPAT_SET_PERSONALITY(ex) \ > -do { \ > - if (test_thread_flag(TIF_IA32)) \ > - clear_thread_flag(TIF_ABI_PENDING); \ > - else \ > - set_thread_flag(TIF_ABI_PENDING); \ > - current->personality |= force_personality32; \ > -} while (0) > +void set_personality_ia32(void); > +#define COMPAT_SET_PERSONALITY(ex) set_personality_ia32()
OK, but what about force_personality32? With this patch it becomes unused?
> +void set_personality_ia32(void) > +{ > + /* inherit personality from parent */ > + > + /* Make sure to be in 32bit mode */ > + set_thread_flag(TIF_IA32); > + > + /* Prepare the first "return" to user space */ > + current_thread_info()->status |= TS_COMPAT;
Can't understand why we need TS_COMPAT. I assume this is correct, this was copied from flush_thread().
What TS_COMPAT actually means? I thought it just means "the task is inside 32-bit syscall".
If a 64bit task execs a 32bit app, can't this TS_COMPAT break, say, syscall_get_arguments() ?
Just curious, I don't really understand COMPAT issues anyway.
Oleg.
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