Adds a utility to exercise the prctl DEXCR inheritance in the shell.
Supports setting and clearing each aspect.
Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
[mpe: Use correct SPDX license, use execvp() for usability, print errors]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240417112325.728010-9-bgray@linux.ibm.com
Some basic tests of the prctl interface of the DEXCR.
Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
[mpe: Add missing SPDX tag]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240417112325.728010-6-bgray@linux.ibm.com
The hashchk tests want to verify that the hash key is changed over exec.
It does so by calculating hashes at the same address across an exec.
This is made simpler by disabling PIE functionality, so we can
re-execute ourselves and be using the same addresses in the child.
While -fno-pie is already added, -no-pie is also required.
Fixes: bdb07f35a5 ("selftests/powerpc/dexcr: Add hashst/hashchk test")
Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240417112325.728010-2-bgray@linux.ibm.com
Build breaks when executing make with run_tests for sub-folders
under powerpc. This is because, CFLAGS and GIT_VERSION macros are
defined in Makefile of toplevel powerpc folder.
make: Entering directory '/home/maddy/linux/tools/testing/selftests/powerpc/mm'
gcc hugetlb_vs_thp_test.c ../harness.c ../utils.c -o /home/maddy/selftest_output//hugetlb_vs_thp_test
hugetlb_vs_thp_test.c:6:10: fatal error: utils.h: No such file or directory
6 | #include "utils.h"
| ^~~~~~~~~
compilation terminated.
Fix this by adding the flags.mk in each sub-folder Makefile. Also remove
the CFLAGS and GIT_VERSION macros from powerpc/ folder Makefile since
the same is definied in flags.mk
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240229093711.581230-3-maddy@linux.ibm.com
Add a utility 'lsdexcr' to print the current DEXCR status. Useful for
quickly checking the status such as when debugging test failures or
verifying the new default DEXCR does what you want (for userspace at
least). Example output:
# ./lsdexcr
uDEXCR: 04000000 (NPHIE)
HDEXCR: 00000000
Effective: 04000000 (NPHIE)
SBHE (0): clear (Speculative branch hint enable)
IBRTPD (3): clear (Indirect branch recurrent target ...)
SRAPD (4): clear (Subroutine return address ...)
NPHIE * (5): set (Non-privileged hash instruction enable)
PHIE (6): clear (Privileged hash instruction enable)
DEXCR[NPHIE] enabled: hashst/hashchk working
Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230616034846.311705-12-bgray@linux.ibm.com
Test the kernel DEXCR[NPHIE] interface and hashchk exception handling.
Introduces with it a DEXCR utils library for common DEXCR operations.
Volatile is used to prevent the compiler optimising away the signal
tests.
Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230616034846.311705-11-bgray@linux.ibm.com
