diff options
| author | Paul Walmsley <pjw@kernel.org> | 2026-04-04 18:40:58 -0600 |
|---|---|---|
| committer | Paul Walmsley <pjw@kernel.org> | 2026-04-04 18:40:58 -0600 |
| commit | 08ee1559052be302f1d3752f48360b89517d9f8d (patch) | |
| tree | 75318cdfd654c53621e9e75e7b429877acc556ad /kernel | |
| parent | e5342fe2c1bb5b4fab6ed531a0122c6417e57ecf (diff) | |
prctl: cfi: change the branch landing pad prctl()s to be more descriptive
Per Linus' comments requesting the replacement of "INDIR_BR_LP" in the
indirect branch tracking prctl()s with something more readable, and
suggesting the use of the speculation control prctl()s as an exemplar,
reimplement the prctl()s and related constants that control per-task
forward-edge control flow integrity.
This primarily involves two changes. First, the prctls are
restructured to resemble the style of the speculative execution
workaround control prctls PR_{GET,SET}_SPECULATION_CTRL, to make them
easier to extend in the future. Second, the "indir_br_lp" abbrevation
is expanded to "branch_landing_pads" to be less telegraphic. The
kselftest and documentation is adjusted accordingly.
Link: https://lore.kernel.org/linux-riscv/CAHk-=whhSLGZAx3N5jJpb4GLFDqH_QvS07D+6BnkPWmCEzTAgw@mail.gmail.com/
Cc: Deepak Gupta <debug@rivosinc.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Brown <broonie@kernel.org>
Signed-off-by: Paul Walmsley <pjw@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sys.c | 23 |
1 files changed, 13 insertions, 10 deletions
diff --git a/kernel/sys.c b/kernel/sys.c index a5e0c187bbbf..62e842055cc9 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -2889,20 +2889,23 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, return -EINVAL; error = rseq_slice_extension_prctl(arg2, arg3); break; - case PR_GET_INDIR_BR_LP_STATUS: - if (arg3 || arg4 || arg5) + case PR_GET_CFI: + if (arg2 != PR_CFI_BRANCH_LANDING_PADS) return -EINVAL; - error = arch_prctl_get_branch_landing_pad_state(me, (unsigned long __user *)arg2); - break; - case PR_SET_INDIR_BR_LP_STATUS: - if (arg3 || arg4 || arg5) + if (arg4 || arg5) return -EINVAL; - error = arch_prctl_set_branch_landing_pad_state(me, arg2); + error = arch_prctl_get_branch_landing_pad_state(me, (unsigned long __user *)arg3); break; - case PR_LOCK_INDIR_BR_LP_STATUS: - if (arg2 || arg3 || arg4 || arg5) + case PR_SET_CFI: + if (arg2 != PR_CFI_BRANCH_LANDING_PADS) return -EINVAL; - error = arch_prctl_lock_branch_landing_pad_state(me); + if (arg4 || arg5) + return -EINVAL; + error = arch_prctl_set_branch_landing_pad_state(me, arg3); + if (error) + break; + if (arg3 & PR_CFI_LOCK && !(arg3 & PR_CFI_DISABLE)) + error = arch_prctl_lock_branch_landing_pad_state(me); break; default: trace_task_prctl_unknown(option, arg2, arg3, arg4, arg5); |