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author | David S. Miller <davem@davemloft.net> | 2019-08-06 18:44:57 -0700 |
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committer | David S. Miller <davem@davemloft.net> | 2019-08-06 18:44:57 -0700 |
commit | 13dfb3fa494361ea9a5950f27c9cd8b06d28c04f (patch) | |
tree | 1bf30874f57c6c6b21160a10282191fcd0868055 /arch/x86/entry/calling.h | |
parent | Merge branch '40GbE' of git://git.kernel.org/pub/scm/linux/kernel/git/jkirsher/next-queue (diff) | |
parent | Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net (diff) | |
download | linux-dev-13dfb3fa494361ea9a5950f27c9cd8b06d28c04f.tar.xz linux-dev-13dfb3fa494361ea9a5950f27c9cd8b06d28c04f.zip |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Just minor overlapping changes in the conflicts here.
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/x86/entry/calling.h')
-rw-r--r-- | arch/x86/entry/calling.h | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/arch/x86/entry/calling.h b/arch/x86/entry/calling.h index 830bd984182b..515c0ceeb4a3 100644 --- a/arch/x86/entry/calling.h +++ b/arch/x86/entry/calling.h @@ -314,6 +314,23 @@ For 32-bit we have the following conventions - kernel is built with #endif +/* + * Mitigate Spectre v1 for conditional swapgs code paths. + * + * FENCE_SWAPGS_USER_ENTRY is used in the user entry swapgs code path, to + * prevent a speculative swapgs when coming from kernel space. + * + * FENCE_SWAPGS_KERNEL_ENTRY is used in the kernel entry non-swapgs code path, + * to prevent the swapgs from getting speculatively skipped when coming from + * user space. + */ +.macro FENCE_SWAPGS_USER_ENTRY + ALTERNATIVE "", "lfence", X86_FEATURE_FENCE_SWAPGS_USER +.endm +.macro FENCE_SWAPGS_KERNEL_ENTRY + ALTERNATIVE "", "lfence", X86_FEATURE_FENCE_SWAPGS_KERNEL +.endm + .macro STACKLEAK_ERASE_NOCLOBBER #ifdef CONFIG_GCC_PLUGIN_STACKLEAK PUSH_AND_CLEAR_REGS |