diff options
| author | Dimitris Papastamos <dimitris.papastamos@arm.com> | 2018-05-16 11:36:14 +0100 |
|---|---|---|
| committer | Dimitris Papastamos <dimitris.papastamos@arm.com> | 2018-05-23 12:45:48 +0100 |
| commit | fe007b2e15ec7b569c07fedbd9bfccb5ed742eec (patch) | |
| tree | 5a4273d0322ec9567c2bb472a10d9d9c3cb9908a /lib/el3_runtime | |
| parent | e0865708155826a70e2199a54cab8e90e8d07a32 (diff) | |
Add support for dynamic mitigation for CVE-2018-3639
Some CPUS may benefit from using a dynamic mitigation approach for
CVE-2018-3639. A new SMC interface is defined to allow software
executing in lower ELs to enable or disable the mitigation for their
execution context.
It should be noted that regardless of the state of the mitigation for
lower ELs, code executing in EL3 is always mitigated against
CVE-2018-3639.
NOTE: This change is a compatibility break for any platform using
the declare_cpu_ops_workaround_cve_2017_5715 macro. Migrate to
the declare_cpu_ops_wa macro instead.
Change-Id: I3509a9337ad217bbd96de9f380c4ff8bf7917013
Signed-off-by: Dimitris Papastamos <dimitris.papastamos@arm.com>
Diffstat (limited to 'lib/el3_runtime')
| -rw-r--r-- | lib/el3_runtime/aarch64/context.S | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/lib/el3_runtime/aarch64/context.S b/lib/el3_runtime/aarch64/context.S index 121ca4d3..707e6dbd 100644 --- a/lib/el3_runtime/aarch64/context.S +++ b/lib/el3_runtime/aarch64/context.S @@ -404,6 +404,15 @@ func el3_exit msr spsr_el3, x16 msr elr_el3, x17 +#if IMAGE_BL31 && DYNAMIC_WORKAROUND_CVE_2018_3639 + /* Restore mitigation state as it was on entry to EL3 */ + ldr x17, [sp, #CTX_CVE_2018_3639_OFFSET + CTX_CVE_2018_3639_DISABLE] + cmp x17, xzr + beq 1f + blr x17 +#endif + +1: /* Restore saved general purpose registers and return */ b restore_gp_registers_eret endfunc el3_exit |