mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-08 14:20:07 +00:00
doc: Add plain text readme for using GCS
TODO: this is just for the arm/gcs branch while it is being developed
This commit is contained in:
parent
435305562e
commit
9ccf7a55c5
69
README
69
README
@ -1,3 +1,72 @@
|
||||
this branch contains experimental GCS support (not ABI stable)
|
||||
|
||||
source and branches
|
||||
-------------------
|
||||
|
||||
binutils-gdb: upstream-git users/ARM/gcs-binutils-gdb-master
|
||||
gcc (trunk): upstream-git vendors/ARM/gcs
|
||||
gcc (gcc-13): upstream-git vendors/ARM/gcs-13
|
||||
note: gcc vendor branches need setup https://gcc.gnu.org/gitwrite.html#vendor
|
||||
glibc: upstream-git arm/gcs
|
||||
linux: https://git.kernel.org/pub/scm/linux/kernel/git/broonie/misc.git arm64-gcs
|
||||
fvp fast model can be used for testing.
|
||||
|
||||
toolchain build
|
||||
---------------
|
||||
|
||||
two options:
|
||||
|
||||
(1) branch-protect by default
|
||||
configure gcc with --enable-standard-branch-protection
|
||||
and build glibc normally
|
||||
|
||||
(2) do not branch-protect by default, require explicit cflags
|
||||
configure gcc with
|
||||
CFLAGS_FOR_TARGET='-O2 -mbranch-protection=standard'
|
||||
CXXFLAGS_FOR_TARGET='-O2 -mbranch-protection=standard'
|
||||
and configure glibc with
|
||||
CFLAGS='-g -O2 -mbranch-protection=standard'
|
||||
build user code with
|
||||
CFLAGS+=-mbranch-protection=standard
|
||||
(equivalent to -mbranch-protection=bti+pac+gcs)
|
||||
|
||||
linking
|
||||
-------
|
||||
|
||||
use ldflags:
|
||||
|
||||
-z experimental-gcs={always,never,implicit}
|
||||
always: force GCS marking on
|
||||
never: force GCS marking off
|
||||
implicit: mark output if all inputs are marked (default)
|
||||
|
||||
-z experimental-gcs-report={none,warning,error}
|
||||
none: silent (default)
|
||||
warning: when output is marked, unmarked input is a warning
|
||||
error: when output is marked, unmarked input is an error
|
||||
|
||||
runtime
|
||||
-------
|
||||
|
||||
run with environment var
|
||||
|
||||
GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=1:glibc.cpu.aarch64_gcs_policy=2
|
||||
|
||||
by default both tunables are 0, the meaning is
|
||||
|
||||
glibc.cpu.aarch64_gcs_policy=0:
|
||||
GCS is enabled if glibc.cpu.aarch64_gcs is set
|
||||
glibc.cpu.aarch64_gcs_policy=1:
|
||||
GCS is enabled if glibc.cpu.aarch64_gcs is set and binary is marked
|
||||
if GCS is enabled an incompatible dlopen is an error
|
||||
glibc.cpu.aarch64_gcs_policy=2:
|
||||
GCS is enabled if glibc.cpu.aarch64_gcs is set
|
||||
if GCS is enabled any incompatible binary is an error
|
||||
|
||||
|
||||
original readme
|
||||
---------------
|
||||
|
||||
This directory contains the sources of the GNU C Library.
|
||||
See the file "version.h" for what release version you have.
|
||||
|
||||
|
Loading…
Reference in New Issue
Block a user