oss-sec mailing list archives
Re: stack buffer overflow in fbdev
From: Linus Torvalds <torvalds () linux-foundation org>
Date: Sun, 21 Jul 2019 14:04:19 -0700
On Sun, Jul 21, 2019 at 1:09 PM Daniel Vetter <daniel () ffwll ch> wrote:
PS: git log -G disappoints by not using all the cores I have here ..
Yeah, "git grep" is threaded (but if you want more than 8 threads you need to configure it). But "-G" is not. Part of it is that "-G" is actually very very different from grep. "grep" looks at all files, and is threaded over the number of files. "-G" looks at each file diff pair, does a diff of them, and then does a grep to see if the pattern is in the diff. And usually the number of file diff pairs is fairly small, and it would be non-trivial to parallelize it. I guess git could parallelize over many commits, but it doesn't. Side note: "-S" is usually faster than "-G". It skips the "create diff" part, and instead just counts the number of occurrences of the string in the diffpairs, and shows the end result is the number is different. Odd semantics, but very useful exactly for the "when did this appear or disappear" kind of thing. So "git log -G fb_edid_add_monspecs" is indeed very slow. If you limit the space that you grep over, you can speed things up enormously. So something like git log -S fb_edid_add_monspecs drivers/video/fbdev/ isn't too horrendous. Linus
Current thread:
- stack buffer overflow in fbdev Tavis Ormandy (Jul 19)
- Re: stack buffer overflow in fbdev Linus Torvalds (Jul 21)
- Re: stack buffer overflow in fbdev Daniel Vetter (Jul 22)
- Re: stack buffer overflow in fbdev Linus Torvalds (Jul 22)
- Re: stack buffer overflow in fbdev Bartlomiej Zolnierkiewicz (Jul 22)
- Re: stack buffer overflow in fbdev Daniel Vetter (Jul 23)
- Re: stack buffer overflow in fbdev Daniel Vetter (Jul 22)
- Re: stack buffer overflow in fbdev Linus Torvalds (Jul 21)
- Re: stack buffer overflow in fbdev Linus Torvalds (Jul 23)