From: Mark Brown broonie@kernel.org
mainline inclusion from mainline-v5.19-rc2 commit 2e990e63220bb01e2755b55b93878ce7c8cbe747 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8E73O CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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The EFI save/restore code is confused. When saving the check for saving FFR is inverted due to confusion with the streaming mode check, and when restoring we check if we need to restore FFR by checking the percpu efi_sm_state without the required wrapper rather than based on the combination of FA64 support and streaming mode.
Fixes: e0838f6373e5 ("arm64/sme: Save and restore streaming mode over EFI runtime calls") Reported-by: kernel test robot lkp@intel.com Reviewed-by: Catalin Marinas catalin.marinas@arm.com Signed-off-by: Mark Brown broonie@kernel.org Link: https://lore.kernel.org/r/20220602124132.3528951-1-broonie@kernel.org Signed-off-by: Catalin Marinas catalin.marinas@arm.com Signed-off-by: Wang ShaoBo bobo.shaobowang@huawei.com --- arch/arm64/kernel/fpsimd.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index 649b6653a5701..18b7603885406 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -1877,10 +1877,15 @@ void __efi_fpsimd_begin(void) if (system_supports_sme()) { svcr = read_sysreg_s(SYS_SVCR);
- if (!system_supports_fa64()) - ffr = svcr & SVCR_SM_MASK; + __this_cpu_write(efi_sm_state, + svcr & SVCR_SM_MASK);
- __this_cpu_write(efi_sm_state, ffr); + /* + * Unless we have FA64 FFR does not + * exist in streaming mode. + */ + if (!system_supports_fa64()) + ffr = !(svcr & SVCR_SM_MASK); }
sve_save_state(sve_state + sve_ffr_offset(sve_max_vl()), @@ -1925,8 +1930,13 @@ void __efi_fpsimd_end(void) sysreg_clear_set_s(SYS_SVCR, 0, SVCR_SM_MASK); + + /* + * Unless we have FA64 FFR does not + * exist in streaming mode. + */ if (!system_supports_fa64()) - ffr = efi_sm_state; + ffr = false; } }