Firefox does refuse to start, with strace, there are many lines like this: mmap2(0xe8d00000, 2097152, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xffffffffe8d14000 munmap(0xe8d14000, 2097152) = 0 mmap2(NULL, 3145728, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xffffffffe8c14000 munmap(0xe8c14000, 3145728) = 0 mmap2(0xe8d00000, 2097152, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xffffffffe8d14000 munmap(0xe8d14000, 2097152) = 0 mmap2(NULL, 3145728, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xffffffffe8c14000 munmap(0xe8c14000, 3145728) = 0 mmap2(0xe8d00000, 2097152, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xffffffffe8d14000 munmap(0xe8d14000, 2097152) = 0 mmap2(NULL, 3145728, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xffffffffe8c14000 munmap(0xe8c14000, 3145728) = 0 mmap2(0xe8d00000, 2097152, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xffffffffe8d14000 munmap(0xe8d14000, 2097152) = 0 mmap2(NULL, 3145728, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xffffffffe8c14000 munmap(0xe8c14000, 3145728) = 0 mmap2(0xe8d00000, 2097152, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xffffffffe8d14000 munmap(0xe8d14000, 2097152) = 0 mmap2(NULL, 3145728, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xffffffffe8c14000 munmap(0xe8c14000, 3145728) setting paxctl -r (disabling RANDMMAP) on the binary does allow firefox to start and run. Here some lines from #gentoo-hardened: <ncopa> i saw you have issues with firefox 3.5 <ncopa> like i have with webkit and midori <ncopa> its the jit feature i think <ncopa> that generates executable code on the fly <ncopa> which pax by design does not allow <ncopa> so looks like we have to choose between disable pax (reduce security) or disable jit (slow) <Tommy[D]> ncopa: paxctl -r /usr/lib/mozilla-firefox/firefox is another possible workaround <Tommy[D]> at least firefox does work with it <ncopa> thats turning off pax features <ncopa> = reduces security <ncopa> for the entire firefox binary <ncopa> i was thinking that it would be nice to have the jit part running as a separate process <ncopa> separate executable <ncopa> that way we could paxctl -r /path/to/jit-executable <ncopa> and most of the browser code would still run with randmmap
*** This bug has been marked as a duplicate of bug 278698 ***