lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Fri, 25 Apr 2008 17:59:53 +0200 From: Ingo Molnar <mingo@...e.hu> To: Mathieu Desnoyers <mathieu.desnoyers@...ymtl.ca> Cc: Linus Torvalds <torvalds@...ux-foundation.org>, Jiri Slaby <jirislaby@...il.com>, David Miller <davem@...emloft.net>, zdenek.kabelac@...il.com, rjw@...k.pl, paulmck@...ux.vnet.ibm.com, akpm@...ux-foundation.org, linux-ext4@...r.kernel.org, herbert@...dor.apana.org.au, penberg@...helsinki.fi, clameter@....com, linux-kernel@...r.kernel.org, Andi Kleen <andi@...stfloor.org>, pageexec@...email.hu, "H. Peter Anvin" <hpa@...or.com>, Jeremy Fitzhardinge <jeremy@...p.org> Subject: Re: [PATCH 1/1] x86: fix text_poke * Mathieu Desnoyers <mathieu.desnoyers@...ymtl.ca> wrote: > Woooow, just a sec here. I removed the atomicity test _because_ there > happen to be a case where it's safe to do non-atomic instruction > modification. If we do : > > 1) replace the instruction first byte by a breakpoint, execute an > instruction bypass (see the immediate values patches for detail) > 2) modify the instruction non-atomically > 3) put back the original instruction first byte. > > That's why I removed the BUG_ONs at the beginning of the function. > That's also why it's required to deal with page crossing. but the code as-is is nonsensical. It checks for: BUG_ON(len > sizeof(long)); but then deals with page crossing... it should also rename text_poke_early() to text_poke_core(), and call _that_ from text_poke() if core_kernel_text(). From that alone the whole poke_text() function would look a whole lot cleaner. Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists