aboutsummaryrefslogtreecommitdiff
path: root/include/asm-i386/i387.h
AgeCommit message (Collapse)Author
2006-04-29[PATCH] i386: fix broken FP exception handlingChuck Ebbert
The FXSAVE information leak patch introduced a bug in FP exception handling: it clears FP exceptions only when there are already none outstanding. Mikael Pettersson reported that causes problems with the Erlang runtime and has tested this fix. Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com> Acked-by: Mikael Pettersson <mikpe@it.uu.se> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-20[PATCH] i386/x86-64: Fix x87 information leak between processesAndi Kleen
AMD K7/K8 CPUs only save/restore the FOP/FIP/FDP x87 registers in FXSAVE when an exception is pending. This means the value leak through context switches and allow processes to observe some x87 instruction state of other processes. This was actually documented by AMD, but nobody recognized it as being different from Intel before. The fix first adds an optimization: instead of unconditionally calling FNCLEX after each FXSAVE test if ES is pending and skip it when not needed. Then do a x87 load from a kernel variable to clear FOP/FIP/FDP. This means other processes always will only see a constant value defined by the kernel in their FP state. I took some pain to make sure to chose a variable that's already in L1 during context switch to make the overhead of this low. Also alternative() is used to patch away the new code on CPUs who don't need it. Patch for both i386/x86-64. The problem was discovered originally by Jan Beulich. Richard Brunner provided the basic code for the workarounds, with contribution from Jan. This is CVE-2006-1056 Cc: richard.brunner@amd.com Cc: jbeulich@novell.com Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-12[PATCH] i386: task_thread_info()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-22x86: use alternative instructions for fnsave/fxsave tooLinus Torvalds
This one ends up using an inline asm format that claims to read memory and then clobber it (rather than just write it directly), which made it easier to use the existing "alternative_input()" infrastructure support. Now the fxsave code matches the fxrstor.
2005-07-22x86: make restore_fpu() use alternative assembler instructionsLinus Torvalds
It's really just a single instruction, conditional on whether the CPU supports FXSR or not, so implement it as such instead of making it a function that queries FXSR dynamically. This means that the instruction just gets automatically rewritten to the correct one at boot-time.
2005-04-16Linux-2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!