[PATCH v15 5/7] x86/cet/ibt: Update arch_prctl functions for Indirect Branch Tracking
From: Yu-cheng Yu <hidden>
Date: 2020-11-10 16:25:14
Also in:
linux-api, linux-arch, linux-mm, lkml
Subsystem:
the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
From: "H.J. Lu" <redacted> Update ARCH_X86_CET_STATUS and ARCH_X86_CET_DISABLE for Indirect Branch Tracking. Signed-off-by: H.J. Lu <redacted> Signed-off-by: Yu-cheng Yu <redacted> --- arch/x86/kernel/cet_prctl.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/cet_prctl.c b/arch/x86/kernel/cet_prctl.c
index bd5ad11763e4..0af1ec5d028f 100644
--- a/arch/x86/kernel/cet_prctl.c
+++ b/arch/x86/kernel/cet_prctl.c@@ -22,6 +22,9 @@ static int copy_status_to_user(struct cet_status *cet, u64 arg2) buf[2] = (u64)cet->shstk_size; } + if (cet->ibt_enabled) + buf[0] |= GNU_PROPERTY_X86_FEATURE_1_IBT; + return copy_to_user((u64 __user *)arg2, buf, sizeof(buf)); }
@@ -42,7 +45,8 @@ int prctl_cet(int option, u64 arg2) if (option == ARCH_X86_CET_STATUS) return copy_status_to_user(cet, arg2); - if (!static_cpu_has(X86_FEATURE_SHSTK)) + if (!static_cpu_has(X86_FEATURE_SHSTK) && + !static_cpu_has(X86_FEATURE_IBT)) return -EOPNOTSUPP; switch (option) {
@@ -56,6 +60,8 @@ int prctl_cet(int option, u64 arg2) return -EINVAL; if (features & GNU_PROPERTY_X86_FEATURE_1_SHSTK) cet_disable_shstk(); + if (features & GNU_PROPERTY_X86_FEATURE_1_IBT) + cet_disable_ibt(); return 0; case ARCH_X86_CET_LOCK:
--
2.21.0