Messages in this thread Patch in this message | | | From | "H. Peter Anvin, Intel" <> | Subject | [PATCH v3 3/7] x86: move fill_user_desc() from tls.c to desc.h and add validity check | Date | Thu, 21 Jun 2018 14:17:50 -0700 |
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From: "H. Peter Anvin" <hpa@linux.intel.com>
This is generic code which is potentially useful in other contexts. Unfortunately modify_ldt() is kind of stupid in that it returns a descriptor in CPU format but takes a different format, but regsets *have* to operate differently.
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Chang S. Bae <chang.seok.bae@intel.com> Cc: Markus T. Metzger <markus.t.metzger@intel.com> --- arch/x86/include/asm/desc.h | 22 ++++++++++++++++++++++ arch/x86/kernel/tls.c | 19 ------------------- 2 files changed, 22 insertions(+), 19 deletions(-)
diff --git a/arch/x86/include/asm/desc.h b/arch/x86/include/asm/desc.h index 13c5ee878a47..5e69f993c9ff 100644 --- a/arch/x86/include/asm/desc.h +++ b/arch/x86/include/asm/desc.h @@ -386,6 +386,28 @@ static inline void set_desc_limit(struct desc_struct *desc, unsigned long limit) desc->limit1 = (limit >> 16) & 0xf; } + +static inline void fill_user_desc(struct user_desc *info, int idx, + const struct desc_struct *desc) + +{ + memset(info, 0, sizeof(*info)); + info->entry_number = idx; + if (desc->s && desc->dpl == 3) { + info->base_addr = get_desc_base(desc); + info->limit = get_desc_limit(desc); + info->seg_32bit = desc->d; + info->contents = desc->type >> 2; + info->read_exec_only = !(desc->type & 2); + info->limit_in_pages = desc->g; + info->seg_not_present = !desc->p; + info->useable = desc->avl; +#ifdef CONFIG_X86_64 + info->lm = desc->l; +#endif + } +} + void update_intr_gate(unsigned int n, const void *addr); void alloc_intr_gate(unsigned int n, const void *addr); diff --git a/arch/x86/kernel/tls.c b/arch/x86/kernel/tls.c index a5b802a12212..7b8ecb760707 100644 --- a/arch/x86/kernel/tls.c +++ b/arch/x86/kernel/tls.c @@ -197,25 +197,6 @@ SYSCALL_DEFINE1(set_thread_area, struct user_desc __user *, u_info) * Get the current Thread-Local Storage area: */ -static void fill_user_desc(struct user_desc *info, int idx, - const struct desc_struct *desc) - -{ - memset(info, 0, sizeof(*info)); - info->entry_number = idx; - info->base_addr = get_desc_base(desc); - info->limit = get_desc_limit(desc); - info->seg_32bit = desc->d; - info->contents = desc->type >> 2; - info->read_exec_only = !(desc->type & 2); - info->limit_in_pages = desc->g; - info->seg_not_present = !desc->p; - info->useable = desc->avl; -#ifdef CONFIG_X86_64 - info->lm = desc->l; -#endif -} - int do_get_thread_area(struct task_struct *p, int idx, struct user_desc __user *u_info) { -- 2.14.4
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