kernel_optimize_test/arch
Sean Christopherson 3aec683ee7 x86/cpu: Initialize MSR_TSC_AUX if RDTSCP *or* RDPID is supported
commit b6b4fbd90b155a0025223df2c137af8a701d53b3 upstream.

Initialize MSR_TSC_AUX with CPU node information if RDTSCP or RDPID is
supported.  This fixes a bug where vdso_read_cpunode() will read garbage
via RDPID if RDPID is supported but RDTSCP is not.  While no known CPU
supports RDPID but not RDTSCP, both Intel's SDM and AMD's APM allow for
RDPID to exist without RDTSCP, e.g. it's technically a legal CPU model
for a virtual machine.

Note, technically MSR_TSC_AUX could be initialized if and only if RDPID
is supported since RDTSCP is currently not used to retrieve the CPU node.
But, the cost of the superfluous WRMSR is negigible, whereas leaving
MSR_TSC_AUX uninitialized is just asking for future breakage if someone
decides to utilize RDTSCP.

Fixes: a582c540ac ("x86/vdso: Use RDPID in preference to LSL when available")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210504225632.1532621-2-seanjc@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-11 14:47:37 +02:00
..
alpha
arc arc: kernel: Return -EFAULT if copy_to_user() fails 2021-04-21 13:00:51 +02:00
arm crypto: arm/curve25519 - Move '.fpu' after '.arch' 2021-05-11 14:47:35 +02:00
arm64 arm64/vdso: Discard .note.gnu.property sections in vDSO 2021-05-11 14:47:33 +02:00
c6x
csky csky: change a Kconfig symbol name to fix e1000 build error 2021-04-28 13:40:02 +02:00
h8300
hexagon
ia64 ia64: fix discontig.c section mismatches 2021-04-28 13:40:02 +02:00
m68k
microblaze
mips mips: Do not include hi and lo in clobber list for R6 2021-05-07 11:04:30 +02:00
nds32 nds32: flush_dcache_page: use page_mapping_file to avoid races with swapoff 2021-04-14 08:41:58 +02:00
nios2 nios2: fixed broken sys_clone syscall 2021-03-04 11:38:16 +01:00
openrisc
parisc parisc: avoid a warning on u8 cast for cmpxchg on u8 pointers 2021-04-14 08:41:59 +02:00
powerpc powerpc: fix EDEADLOCK redefinition error in uapi/asm/errno.h 2021-05-11 14:47:35 +02:00
riscv riscv: Fix spelling mistake "SPARSEMEM" to "SPARSMEM" 2021-04-21 13:00:55 +02:00
s390 s390/archrandom: add parameter check for s390_arch_random_generate 2021-05-11 14:47:31 +02:00
sh
sparc sparc64: Fix opcode filtering in handling of no fault loads 2021-03-30 14:31:50 +02:00
um um: defer killing userspace on page table update failures 2021-03-04 11:38:42 +01:00
x86 x86/cpu: Initialize MSR_TSC_AUX if RDTSCP *or* RDPID is supported 2021-05-11 14:47:37 +02:00
xtensa xtensa: move coprocessor_flush to the .text section 2021-04-07 15:00:09 +02:00
.gitignore
Kconfig