RE: [PATCH v2 3/3] treewide: use get_random_u32_between() when possible

2022-11-17 Thread David Laight
From: Theodore Ts'o > Sent: 17 November 2022 15:43 ... > The problem with "between", "ranged", "spanning" is that they don't > tell the reader whether we're dealing with an "open interval" or a > "closed interval". They are just different ways of saying that it's a > range between, say, 0 and 20.

Re: [PATCH v2 3/3] treewide: use get_random_u32_between() when possible

2022-11-17 Thread Jason A. Donenfeld
On Thu, Nov 17, 2022 at 10:42:37AM -0500, Theodore Ts'o wrote: > On Wed, Nov 16, 2022 at 04:47:27PM -0800, Kees Cook wrote: > > >> > - between > > >> > - ranged > > >> > - spanning > > >> > > > >> > https://www.thefreedictionary.com/List-of-prepositions.htm > > >> > - amid > > >> > > > >> >

Re: [PATCH v2 3/3] treewide: use get_random_u32_between() when possible

2022-11-17 Thread Theodore Ts'o
On Wed, Nov 16, 2022 at 04:47:27PM -0800, Kees Cook wrote: > >> > - between > >> > - ranged > >> > - spanning > >> > > >> > https://www.thefreedictionary.com/List-of-prepositions.htm > >> > - amid > >> > > >> > Sigh, names. > >> > >> I think "inclusive" is best. > > > >I find it not very

Re: [PATCH v2 3/3] treewide: use get_random_u32_between() when possible

2022-11-17 Thread Russell King (Oracle)
On Thu, Nov 17, 2022 at 03:05:14AM +0100, Jason A. Donenfeld wrote: > On Thu, Nov 17, 2022 at 12:55:47AM +0100, Jason A. Donenfeld wrote: > > 1) How/whether to make f(0, UR2_MAX) safe, > >- without additional 64-bit arithmetic, > >- minimizing the number of branches. > >I have a few

Re: [PATCH v2 3/3] treewide: use get_random_u32_between() when possible

2022-11-17 Thread Kees Cook
On November 16, 2022 4:43:54 PM PST, "Jason A. Donenfeld" wrote: >On Wed, Nov 16, 2022 at 04:31:18PM -0800, Kees Cook wrote: >> On Thu, Nov 17, 2022 at 01:03:14AM +0100, Jason A. Donenfeld wrote: >> > On Thu, Nov 17, 2022 at 12:55:47AM +0100, Jason A. Donenfeld wrote: >> > > 2) What to call it:

Re: [PATCH v2 3/3] treewide: use get_random_u32_between() when possible

2022-11-16 Thread Jason A. Donenfeld
On Thu, Nov 17, 2022 at 12:55:47AM +0100, Jason A. Donenfeld wrote: > 1) How/whether to make f(0, UR2_MAX) safe, >- without additional 64-bit arithmetic, >- minimizing the number of branches. >I have a few ideas I'll code golf for a bit. > I think I can make progress with (1) alone by

Re: [PATCH v2 3/3] treewide: use get_random_u32_between() when possible

2022-11-16 Thread Jason A. Donenfeld
On Wed, Nov 16, 2022 at 04:31:18PM -0800, Kees Cook wrote: > On Thu, Nov 17, 2022 at 01:03:14AM +0100, Jason A. Donenfeld wrote: > > On Thu, Nov 17, 2022 at 12:55:47AM +0100, Jason A. Donenfeld wrote: > > > 2) What to call it: > > >- between I still like, because it mirrors "I'm thinking of a

Re: [PATCH v2 3/3] treewide: use get_random_u32_between() when possible

2022-11-16 Thread Kees Cook
On Thu, Nov 17, 2022 at 01:03:14AM +0100, Jason A. Donenfeld wrote: > On Thu, Nov 17, 2022 at 12:55:47AM +0100, Jason A. Donenfeld wrote: > > 2) What to call it: > >- between I still like, because it mirrors "I'm thinking of a number > > between 1 and 10 and..." that everybody knows, > >

Re: [PATCH v2 3/3] treewide: use get_random_u32_between() when possible

2022-11-16 Thread Jason A. Donenfeld
On Thu, Nov 17, 2022 at 12:55:47AM +0100, Jason A. Donenfeld wrote: > 2) What to call it: >- between I still like, because it mirrors "I'm thinking of a number > between 1 and 10 and..." that everybody knows, >- inclusive I guess works, but it's not a preposition, >- bikeshed

Re: [PATCH v2 3/3] treewide: use get_random_u32_between() when possible

2022-11-16 Thread Jason A. Donenfeld
On Wed, Nov 16, 2022 at 02:43:13PM -0800, Kees Cook wrote: > On Mon, Nov 14, 2022 at 05:45:58PM +0100, Jason A. Donenfeld wrote: > > - (get_random_u32_below(1024) + 1) * PAGE_SIZE; > > + get_random_u32_between(1, 1024 + 1) * PAGE_SIZE; > > I

Re: [PATCH v2 3/3] treewide: use get_random_u32_between() when possible

2022-11-16 Thread Kees Cook
On Mon, Nov 14, 2022 at 05:45:58PM +0100, Jason A. Donenfeld wrote: > - (get_random_u32_below(1024) + 1) * PAGE_SIZE; > + get_random_u32_between(1, 1024 + 1) * PAGE_SIZE; I really don't like "between". Can't this be named "inclusive" (and

[PATCH v2 3/3] treewide: use get_random_u32_between() when possible

2022-11-14 Thread Jason A. Donenfeld
These cases were done with this Coccinelle: @@ expression H; expression L; @@ - (get_random_u32_below(H) + L) + get_random_u32_between(L, H + L) @@ expression H; expression L; expression E; @@ get_random_u32_between(L, H - + E - - E ) @@ expression H; expression L; expression E; @@