Uwe Kleine-König <u.kleine-koe...@pengutronix.de> writes: > Hello Rusty, > > [added akpm to Cc: who took the patch back then and Julia for the > coccinelle part below] > > On Mon, Jun 03, 2013 at 11:59:15AM +0930, Rusty Russell wrote: >> >> Back in 2011, Uwe Kleine-König added the nonsensically-named >> PTR_RET(), providing a means to avoid if() statements in code (commit >> fa9ee9c4b9). >> >> Instead, just make PTR_ERR() return 0 if the pointer isn't an error >> value. This is harmless, since PTR_ERR() should have never been >> passed a non-error value. And GCC is usually smart enough to remove >> the extra test if IS_ERR() has already been called. > I wonder in which situations gcc fails to be smart enough. Did you check > this?
Good q. I just wrote a simple test to confirm that GCC usually did, then compared the text sizes. Since it was bigger, I assume GCC isn't doing it all the time. Hmm, first change is in do_debug. Ah, no surprise here: if (notify_die(DIE_DEBUG, "debug", regs, PTR_ERR(&dr6), error_code, SIGTRAP) == NOTIFY_STOP) goto exit; Huh? dr6 is on the stack? Ancient, fixed. I'll wade through the other differences after the weekend... Cheers, Rusty. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/