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| author |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-07-31 09:39:56 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-07-31 09:39:56 +0200 |
| commit | fe3015748a905e08eb0e1750aa2928f520063d59 (patch) | |
| tree | d15524d1f7931e8e5964e9ff8368792d09282da5 /arch/x86/kernel/cpu/bugs.c | |
| parent | parport_pc: add support for ASIX AX99100 (diff) | |
| parent | Linux 6.5-rc4 (diff) | |
| download | wireguard-linux-fe3015748a905e08eb0e1750aa2928f520063d59.tar.xz wireguard-linux-fe3015748a905e08eb0e1750aa2928f520063d59.zip | |
Merge 6.5-rc4 into tty-next
We need the serial/tty fixes in here as well for testing and future
development.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86/kernel/cpu/bugs.c')
| -rw-r--r-- | arch/x86/kernel/cpu/bugs.c | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index 9e2a91830f72..95507448e781 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -1150,19 +1150,21 @@ spectre_v2_user_select_mitigation(void) } /* - * If no STIBP, enhanced IBRS is enabled, or SMT impossible, STIBP + * If no STIBP, Intel enhanced IBRS is enabled, or SMT impossible, STIBP * is not required. * - * Enhanced IBRS also protects against cross-thread branch target + * Intel's Enhanced IBRS also protects against cross-thread branch target * injection in user-mode as the IBRS bit remains always set which * implicitly enables cross-thread protections. However, in legacy IBRS * mode, the IBRS bit is set only on kernel entry and cleared on return - * to userspace. This disables the implicit cross-thread protection, - * so allow for STIBP to be selected in that case. + * to userspace. AMD Automatic IBRS also does not protect userspace. + * These modes therefore disable the implicit cross-thread protection, + * so allow for STIBP to be selected in those cases. */ if (!boot_cpu_has(X86_FEATURE_STIBP) || !smt_possible || - spectre_v2_in_eibrs_mode(spectre_v2_enabled)) + (spectre_v2_in_eibrs_mode(spectre_v2_enabled) && + !boot_cpu_has(X86_FEATURE_AUTOIBRS))) return; /* @@ -2294,7 +2296,8 @@ static ssize_t mmio_stale_data_show_state(char *buf) static char *stibp_state(void) { - if (spectre_v2_in_eibrs_mode(spectre_v2_enabled)) + if (spectre_v2_in_eibrs_mode(spectre_v2_enabled) && + !boot_cpu_has(X86_FEATURE_AUTOIBRS)) return ""; switch (spectre_v2_user_stibp) { |