Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1607025

Re: [PATCH v4 1/4] syscalls: Restore address limit after a syscall

Show all headers | View raw

On 03/22/17 13:44, Andy Lutomirski wrote:
> 
> While it's possible that silently papering over the bug is slightly
> faster than BUGging, it will allow bugs to continue to exist
> undetected.
> 

It would also allow the test to be inlined (at least on architectures
which have a one-site implementation) and have only the failure case out
of line, with a __noreturn annotation (which allows it to be jumped to
rather than called, which is usually available as a conditional
operation whereas call often isn't.)

That is...

extern void __noreturn __pre_usermode_state_invalid(void);

static void verify_pre_usermode_state(void)
{
	if (unlikely(!segment_eq(get_fs(), USER_DS))
		__pre_usermode_state_invalid();
}

	-hpa

Back to linux.kernel | Previous | Next — Previous in thread | Find similar | Unroll thread

Thread

[PATCH v4 1/4] syscalls: Restore address limit after a syscall Thomas Garnier <thgarnie@google.com> - 2017-03-22 21:40 +0100
  [PATCH v4 4/4] arm64/syscalls: Specific usage of verify_pre_usermode_state Thomas Garnier <thgarnie@google.com> - 2017-03-22 21:40 +0100
  Re: [PATCH v4 1/4] syscalls: Restore address limit after a syscall Andy Lutomirski <luto@amacapital.net> - 2017-03-22 21:50 +0100
    Re: [PATCH v4 1/4] syscalls: Restore address limit after a syscall Thomas Garnier <thgarnie@google.com> - 2017-03-22 22:00 +0100
      Re: [PATCH v4 1/4] syscalls: Restore address limit after a syscall "H. Peter Anvin" <hpa@zytor.com> - 2017-03-22 22:20 +0100
        Re: [PATCH v4 1/4] syscalls: Restore address limit after a syscall Thomas Garnier <thgarnie@google.com> - 2017-03-23 16:20 +0100
          Re: [PATCH v4 1/4] syscalls: Restore address limit after a syscall Borislav Petkov <bp@alien8.de> - 2017-03-23 16:40 +0100
            Re: [PATCH v4 1/4] syscalls: Restore address limit after a syscall Thomas Garnier <thgarnie@google.com> - 2017-03-23 16:50 +0100
    Re: [PATCH v4 1/4] syscalls: Restore address limit after a syscall "H. Peter Anvin" <hpa@zytor.com> - 2017-03-22 22:20 +0100

csiph-web