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| author |   Thomas Gleixner <tglx@linutronix.de> | 2019-02-18 23:42:51 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2019-03-06 21:52:13 +0100 |
| commit | 04dcbdb8057827b043b3c71aa397c4c63e67d086 (patch) | |
| tree | ef837807f05eaf4ce6abe5d62b5ef5703931c3e5 /arch/x86/entry | |
| parent | x86/speculation/mds: Add mds_clear_cpu_buffers() (diff) | |
| download | linux-dev-04dcbdb8057827b043b3c71aa397c4c63e67d086.tar.xz linux-dev-04dcbdb8057827b043b3c71aa397c4c63e67d086.zip | |
x86/speculation/mds: Clear CPU buffers on exit to user
Add a static key which controls the invocation of the CPU buffer clear
mechanism on exit to user space and add the call into
prepare_exit_to_usermode() and do_nmi() right before actually returning.
Add documentation which kernel to user space transition this covers and
explain why some corner cases are not mitigated.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Jon Masters <jcm@redhat.com>
Tested-by: Jon Masters <jcm@redhat.com>
Diffstat (limited to 'arch/x86/entry')
| -rw-r--r-- | arch/x86/entry/common.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c index 7bc105f47d21..19f650d729f5 100644 --- a/arch/x86/entry/common.c +++ b/arch/x86/entry/common.c @@ -31,6 +31,7 @@ #include <asm/vdso.h> #include <linux/uaccess.h> #include <asm/cpufeature.h> +#include <asm/nospec-branch.h> #define CREATE_TRACE_POINTS #include <trace/events/syscalls.h> @@ -212,6 +213,8 @@ __visible inline void prepare_exit_to_usermode(struct pt_regs *regs) #endif user_enter_irqoff(); + + mds_user_clear_cpu_buffers(); } #define SYSCALL_EXIT_WORK_FLAGS \ |