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| author | Matthew Malcomson <matthew.malcomson@arm.com> | 2020-07-09 09:11:58 +0100 |
|---|---|---|
| committer | Matthew Malcomson <matthew.malcomson@arm.com> | 2020-07-09 09:11:58 +0100 |
| commit | a9ba2a9b77bec7eacaf066801f22d1c366a2bc86 (patch) | |
| tree | a9c871fba0e6c6b389f025c54aac4151540aa020 /gcc/config/aarch64/aarch64.opt | |
| parent | 2a39c42a42cdea4a8962b9e140b88e0051894f38 (diff) | |
| download | gcc-a9ba2a9b77bec7eacaf066801f22d1c366a2bc86.zip gcc-a9ba2a9b77bec7eacaf066801f22d1c366a2bc86.tar.gz gcc-a9ba2a9b77bec7eacaf066801f22d1c366a2bc86.tar.bz2 | |
aarch64: New Straight Line Speculation (SLS) mitigation flags
Here we introduce the flags that will be used for straight line speculation.
The new flag introduced is `-mharden-sls=`.
This flag can take arguments of `none`, `all`, or a comma seperated list of one
or more of `retbr` or `blr`.
`none` indicates no special mitigation of the straight line speculation
vulnerability.
`all` requests all mitigations currently implemented.
`retbr` requests that the RET and BR instructions have a speculation barrier
inserted after them.
`blr` requests that BLR instructions are replaced by a BL to a function stub
using a BR with a speculation barrier after it.
Setting this on a per-function basis using attributes or the like is not
enabled, but may be in the future.
gcc/ChangeLog:
2020-06-02 Matthew Malcomson <matthew.malcomson@arm.com>
* config/aarch64/aarch64-protos.h (aarch64_harden_sls_retbr_p):
New.
(aarch64_harden_sls_blr_p): New.
* config/aarch64/aarch64.c (enum aarch64_sls_hardening_type):
New.
(aarch64_harden_sls_retbr_p): New.
(aarch64_harden_sls_blr_p): New.
(aarch64_validate_sls_mitigation): New.
(aarch64_override_options): Parse options for SLS mitigation.
* config/aarch64/aarch64.opt (-mharden-sls): New option.
* doc/invoke.texi: Document new option.
Diffstat (limited to 'gcc/config/aarch64/aarch64.opt')
| -rw-r--r-- | gcc/config/aarch64/aarch64.opt | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/gcc/config/aarch64/aarch64.opt b/gcc/config/aarch64/aarch64.opt index d99d14c..5170361 100644 --- a/gcc/config/aarch64/aarch64.opt +++ b/gcc/config/aarch64/aarch64.opt @@ -71,6 +71,10 @@ mgeneral-regs-only Target Report RejectNegative Mask(GENERAL_REGS_ONLY) Save Generate code which uses only the general registers. +mharden-sls= +Target RejectNegative Joined Var(aarch64_harden_sls_string) +Generate code to mitigate against straight line speculation. + mfix-cortex-a53-835769 Target Report Var(aarch64_fix_a53_err835769) Init(2) Save Workaround for ARM Cortex-A53 Erratum number 835769. |