linux-dev/arch/x86/include/asm/archrandom.h, branch linus/master

x86/cpu: Use RDRAND and RDSEED mnemonics in archrandom.h

2020-05-18T17:50:47Z

Current minimum required version of binutils is 2.23, which supports RDRAND and RDSEED instruction mnemonics. Replace the byte-wise specification of RDRAND and RDSEED with these proper mnemonics. Signed-off-by: Uros Bizjak Signed-off-by: Borislav Petkov Reviewed-by: H. Peter Anvin (Intel) Acked-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20200508105817.207887-1-ubizjak@gmail.com

x86: Mark archrandom.h functions __must_check

2020-01-25T17:18:50Z

We must not use the pointer output without validating the success of the random read. Reviewed-by: Ard Biesheuvel Signed-off-by: Richard Henderson Signed-off-by: Mark Brown Link: https://lore.kernel.org/r/20200110145422.49141-8-broonie@kernel.org Signed-off-by: Theodore Ts'o

x86: Remove arch_has_random, arch_has_random_seed

2020-01-25T17:18:50Z

Use the expansion of these macros directly in arch_get_random_*. These symbols are currently part of the generic archrandom.h interface, but are currently unused and can be removed. Signed-off-by: Richard Henderson Signed-off-by: Mark Brown Link: https://lore.kernel.org/r/20200110145422.49141-2-broonie@kernel.org Signed-off-by: Theodore Ts'o

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 335

2019-06-05T15:37:06Z

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms and conditions of the gnu general public license version 2 as published by the free software foundation this program is distributed in the hope it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 51 franklin st fifth floor boston ma 02110 1301 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 111 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Alexios Zavras Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190530000436.567572064@linutronix.de Signed-off-by: Greg Kroah-Hartman

x86/asm: Remove unnecessary \n\t in front of CC_SET() from asm templates

2017-09-24T09:19:01Z

There is no need for \n\t in front of CC_SET(), as the macro already includes these two. Signed-off-by: Uros Bizjak Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20170906151808.5634-1-ubizjak@gmail.com Signed-off-by: Ingo Molnar

x86, asm: Use CC_SET()/CC_OUT() and static_cpu_has() in archrandom.h

2016-06-08T19:41:20Z

Use CC_SET()/CC_OUT() and static_cpu_has(). This produces code good enough to eliminate ad hoc use of alternatives in , greatly simplifying the code. While we are at it, make x86_init_rdrand() compile out completely if we don't need it. Signed-off-by: H. Peter Anvin Link: http://lkml.kernel.org/r/1465414726-197858-11-git-send-email-hpa@linux.intel.com v2: fix a conflict between and discovered by Ingo Molnar. There are a few places in x86-specific code where we need all of even when CONFIG_ARCH_RANDOM is disabled, so does not suffice.

x86, asm: use bool for bitops and other assembly outputs

2016-06-08T19:41:20Z

The gcc people have confirmed that using "bool" when combined with inline assembly always is treated as a byte-sized operand that can be assumed to be 0 or 1, which is exactly what the SET instruction emits. Change the output types and intermediate variables of as many operations as practical to "bool". Signed-off-by: H. Peter Anvin Link: http://lkml.kernel.org/r/1465414726-197858-3-git-send-email-hpa@linux.intel.com Reviewed-by: Andy Lutomirski Reviewed-by: Borislav Petkov Acked-by: Peter Zijlstra (Intel)

random: Add arch_has_random[_seed]()

2014-03-20T02:24:08Z

Add predicate functions for having arch_get_random[_seed]*(). The only current use is to avoid the loop in arch_random_refill() when arch_get_random_seed_long() is unavailable. Signed-off-by: H. Peter Anvin Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Signed-off-by: Theodore Ts'o

x86, random: Enable the RDSEED instruction

2014-03-20T02:22:06Z

Upcoming Intel silicon adds a new RDSEED instruction, which is similar to RDRAND but provides a stronger guarantee: unlike RDRAND, RDSEED will always reseed the PRNG from the true random number source between each read. Thus, the output of RDSEED is guaranteed to be 100% entropic, unlike RDRAND which is only architecturally guaranteed to be 1/512 entropic (although in practice is much more.) The RDSEED instruction takes the same time to execute as RDRAND, but RDSEED unlike RDRAND can legitimately return failure (CF=0) due to entropy exhaustion if too many threads on too many cores are hammering the RDSEED instruction at the same time. Therefore, we have to be more conservative and only use it in places where we can tolerate failures. This patch introduces the primitives arch_get_random_seed_{int,long}() but does not use it yet. Signed-off-by: H. Peter Anvin Reviewed-by: Ingo Molnar Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Signed-off-by: Theodore Ts'o

x86, kaslr: Provide randomness functions

2013-10-13T10:12:12Z

Adds potential sources of randomness: RDRAND, RDTSC, or the i8254. This moves the pre-alternatives inline rdrand function into the header so both pieces of code can use it. Availability of RDRAND is then controlled by CONFIG_ARCH_RANDOM, if someone wants to disable it even for kASLR. Signed-off-by: Kees Cook Link: http://lkml.kernel.org/r/1381450698-28710-4-git-send-email-keescook@chromium.org Signed-off-by: H. Peter Anvin