Re: [PATCH 7/7] x86/cet: Add PTRACE interface for CET
From: Andy Lutomirski <luto@amacapital.net>
Date: 2018-06-07 18:33:22
Also in:
linux-arch, linux-mm, lkml
On Thu, Jun 7, 2018 at 7:42 AM Yu-cheng Yu [off-list ref] wrote:
quoted hunk ↗ jump to hunk
Add PTRACE interface for CET MSRs. Signed-off-by: Yu-cheng Yu <redacted> --- arch/x86/include/asm/fpu/regset.h | 7 ++++--- arch/x86/kernel/fpu/regset.c | 41 +++++++++++++++++++++++++++++++++++++++ arch/x86/kernel/ptrace.c | 16 +++++++++++++++ include/uapi/linux/elf.h | 1 + 4 files changed, 62 insertions(+), 3 deletions(-)diff --git a/arch/x86/include/asm/fpu/regset.h b/arch/x86/include/asm/fpu/regset.h index d5bdffb9d27f..edad0d889084 100644 --- a/arch/x86/include/asm/fpu/regset.h +++ b/arch/x86/include/asm/fpu/regset.h@@ -7,11 +7,12 @@ #include <linux/regset.h> -extern user_regset_active_fn regset_fpregs_active, regset_xregset_fpregs_active; +extern user_regset_active_fn regset_fpregs_active, regset_xregset_fpregs_active, + cetregs_active; extern user_regset_get_fn fpregs_get, xfpregs_get, fpregs_soft_get, - xstateregs_get; + xstateregs_get, cetregs_get; extern user_regset_set_fn fpregs_set, xfpregs_set, fpregs_soft_set, - xstateregs_set; + xstateregs_set, cetregs_set; /* * xstateregs_active == regset_fpregs_active. Please refer to the commentdiff --git a/arch/x86/kernel/fpu/regset.c b/arch/x86/kernel/fpu/regset.c index bc02f5144b95..7008eb084d36 100644 --- a/arch/x86/kernel/fpu/regset.c +++ b/arch/x86/kernel/fpu/regset.c@@ -160,6 +160,47 @@ int xstateregs_set(struct task_struct *target, const struct user_regset *regset, return ret; } +int cetregs_active(struct task_struct *target, const struct user_regset *regset) +{ +#ifdef CONFIG_X86_INTEL_CET + if (target->thread.cet.shstk_enabled || target->thread.cet.ibt_enabled) + return regset->n; +#endif + return 0; +} + +int cetregs_get(struct task_struct *target, const struct user_regset *regset, + unsigned int pos, unsigned int count, + void *kbuf, void __user *ubuf) +{ + struct fpu *fpu = &target->thread.fpu; + struct cet_user_state *cetregs; + + if (!boot_cpu_has(X86_FEATURE_SHSTK)) + return -ENODEV;
This whole series has a boot_cpu_has, static_cpu_has, and cpu_feature_enabled all over. Please settle on just one, preferably static_cpu_has.
+
+ cetregs = get_xsave_addr(&fpu->state.xsave, XFEATURE_MASK_SHSTK_USER);
+
+ fpu__prepare_read(fpu);
+ return user_regset_copyout(&pos, &count, &kbuf, &ubuf, cetregs, 0, -1);
+}
+
+int cetregs_set(struct task_struct *target, const struct user_regset *regset,
+ unsigned int pos, unsigned int count,
+ const void *kbuf, const void __user *ubuf)
+{
+ struct fpu *fpu = &target->thread.fpu;
+ struct cet_user_state *cetregs;
+
+ if (!boot_cpu_has(X86_FEATURE_SHSTK))
+ return -ENODEV;
+
+ cetregs = get_xsave_addr(&fpu->state.xsave, XFEATURE_MASK_SHSTK_USER);
+
+ fpu__prepare_write(fpu);
+ return user_regset_copyin(&pos, &count, &kbuf, &ubuf, cetregs, 0, -1);Is this called for core dumping on current? If so, please make sure it's correct. (I think it is for get but maybe not for set.) -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html