linux/arch/x86
Andy Lutomirski a493d1ca1a x86/membarrier: Get rid of a dubious optimization
sync_core_before_usermode() had an incorrect optimization.  If the kernel
returns from an interrupt, it can get to usermode without IRET. It just has
to schedule to a different task in the same mm and do SYSRET.  Fortunately,
there were no callers of sync_core_before_usermode() that could have had
in_irq() or in_nmi() equal to true, because it's only ever called from the
scheduler.

While at it, clarify a related comment.

Fixes: 70216e18e5 ("membarrier: Provide core serializing command, *_SYNC_CORE")
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/5afc7632be1422f91eaf7611aaaa1b5b8580a086.1607058304.git.luto@kernel.org
2020-12-09 09:37:42 +01:00
..
boot A set of fixes for x86: 2020-12-06 11:22:39 -08:00
configs * A defconfig fix, from Daniel Díaz. 2020-09-20 15:06:43 -07:00
crypto crypto: x86/poly1305 - add back a needed assignment 2020-10-24 09:38:32 +11:00
entry A couple of x86 fixes which missed rc1 due to my stupidity: 2020-10-27 14:39:29 -07:00
events perf/x86/intel: Check PEBS status correctly 2020-12-03 10:00:26 +01:00
hyperv hyperv-fixes for 5.10-rc3 2020-11-05 11:32:03 -08:00
ia32 x86: remove address space overrides using set_fs() 2020-09-08 22:21:36 -04:00
include x86/membarrier: Get rid of a dubious optimization 2020-12-09 09:37:42 +01:00
kernel A set of fixes for x86: 2020-12-06 11:22:39 -08:00
kvm ARM: 2020-11-27 11:04:13 -08:00
lib x86/insn-eval: Use new for_each_insn_prefix() macro to loop over prefixes bytes 2020-12-06 10:03:08 +01:00
math-emu treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
mm x86/membarrier: Get rid of a dubious optimization 2020-12-09 09:37:42 +01:00
net bpf: x64: Do not emit sub/add 0, %rsp when !stack_depth 2020-09-29 16:47:39 -07:00
oprofile
pci pci-v5.10-changes 2020-10-22 12:41:00 -07:00
platform efi/x86: Free efi_pgd with free_pages() 2020-11-10 19:18:11 +01:00
power Kbuild updates for v5.9 2020-08-09 14:10:26 -07:00
purgatory treewide: Convert macro and uses of __section(foo) to __section("foo") 2020-10-25 14:51:49 -07:00
ras
realmode x86/head/64: Don't call verify_cpu() on starting APs 2020-09-09 11:33:20 +02:00
tools x86/insn: Make inat-tables.c suitable for pre-decompression code 2020-09-07 19:45:24 +02:00
um arch/um: partially revert the conversion to __section() macro 2020-10-26 15:39:37 -07:00
video
xen xen: branch for v5.10-rc5 2020-11-20 10:30:48 -08:00
.gitignore
Kbuild
Kconfig kbuild: Hoist '--orphan-handling' into Kconfig 2020-12-01 22:45:36 +09:00
Kconfig.assembler
Kconfig.cpu
Kconfig.debug x86, powerpc: Rename memcpy_mcsafe() to copy_mc_to_{user, kernel}() 2020-10-06 11:18:04 +02:00
Makefile kbuild: Hoist '--orphan-handling' into Kconfig 2020-12-01 22:45:36 +09:00
Makefile_32.cpu
Makefile.um