From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id B44FA442F for ; Tue, 23 Jan 2024 20:39:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706042390; cv=none; b=q/8+InTHOVb5uCpiQI/U+w6Y/76Od+Hx/QVLeWhlwrGo3Bil85LXyhQ9LyJ94ApmHF0/fvUTjmUjU0mURy4PAFLYEb+I/6IJIAw9i3uAImHVy2VpANMj+r6yFMZQbmRSjvFDGCDKBSdStGaWj9IgC7Gsniahhc2ira53uFIhq6U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706042390; c=relaxed/simple; bh=i6J8JhCKUSOAUoIN6I02LYR/3LiO6VdtviWxHbght6U=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=ifa76k7SQv4MlADkoxAWkqdEUEdPGHx4Fi2ZBLrUfhKqEduaOobcFCFIyDufanpp0k+/f/C1IFEpLW+mPB0p5ZI8R9u3lAUZwzPuxwAcs+kWW8KqFuVJSsGUTKNW4+S32+fL3apkwaD3d//EwJpB//yuYv7ZfBZpjtAdlnRFWi4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=MSwjGWx2; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="MSwjGWx2" Received: from [192.168.86.69] (unknown [50.46.228.62]) by linux.microsoft.com (Postfix) with ESMTPSA id 1D37920E34C3; Tue, 23 Jan 2024 12:39:42 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 1D37920E34C3 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1706042382; bh=EzzVmcDkr4eK/twYOi2TVMk6XSbdoFxGZpRHPlXrgDk=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=MSwjGWx24G/dCiewsrAyb9DoW7Qz4VpJaetsRK60L/WjxLBZQrUhm3xVf7ttb/oGX xHSDrIlBRB9N4/pQO7hPTUEM2TdDWlaONfjQOYTuXPcRlsoIywv4LZ+vPk/b4DC9lF MWxJpTE9q0bJOoTJgqFp//IXZMeBX8cJ4T0i/4XI= Message-ID: <9c71454b-ba41-4725-9fb7-0602b1a656c1@linux.microsoft.com> Date: Tue, 23 Jan 2024 12:39:41 -0800 Precedence: bulk X-Mailing-List: linux-integrity@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 2/7] kexec: define functions to map and unmap segments Content-Language: en-US To: Stefan Berger , zohar@linux.ibm.com, roberto.sassu@huaweicloud.com, roberto.sassu@huawei.com, eric.snowberg@oracle.com, ebiederm@xmission.com, noodles@fb.com, bauermann@kolabnow.com, linux-integrity@vger.kernel.org, kexec@lists.infradead.org Cc: code@tyhicks.com, nramas@linux.microsoft.com, paul@paul-moore.com References: <20240122183804.3293904-1-tusharsu@linux.microsoft.com> <20240122183804.3293904-3-tusharsu@linux.microsoft.com> From: Tushar Sugandhi In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Thanks Stefan for taking a look. On 1/23/24 09:03, Stefan Berger wrote: > > > On 1/22/24 13:37, Tushar Sugandhi wrote: >> Implement kimage_map_segment() to enable mapping of IMA buffer source >> pages to the kimage structure post kexec 'load'.  This function, >> accepting a kimage pointer, an address, and a size, will gather the >> source pages within the specified address range, create an array of page >> pointers, and map these to a contiguous virtual address range.  The >> function returns the start of this range if successful, or NULL if >> unsuccessful. >> >> Implement kimage_unmap_segment() for unmapping segments >> using vunmap().  Relocate 'for_each_kimage_entry()' macro from >> kexec_core.c to kexec.h for broader accessibility. >> >> Signed-off-by: Tushar Sugandhi >> --- >>   include/linux/kexec.h              | 13 +++++++ >>   kernel/kexec_core.c                | 59 +++++++++++++++++++++++++++--- >>   security/integrity/ima/ima_kexec.c |  1 + >>   3 files changed, 68 insertions(+), 5 deletions(-) >> >> diff --git a/include/linux/kexec.h b/include/linux/kexec.h >> index 22b5cd24f581..e00b8101b53b 100644 >> --- a/include/linux/kexec.h >> +++ b/include/linux/kexec.h >> @@ -490,6 +490,15 @@ static inline int >> arch_kexec_post_alloc_pages(void *vaddr, unsigned int pages, g >>   static inline void arch_kexec_pre_free_pages(void *vaddr, unsigned >> int pages) { } >>   #endif >> +#define for_each_kimage_entry(image, ptr, entry) \ >> +    for (ptr = &image->head; (entry = *ptr) && !(entry & IND_DONE); \ >> +        ptr = (entry & IND_INDIRECTION) ? \ >> +            boot_phys_to_virt((entry & PAGE_MASK)) : ptr + 1) >> + >> +extern void *kimage_map_segment(struct kimage *image, >> +                unsigned long addr, unsigned long size); >> +extern void kimage_unmap_segment(void *buffer); >> + > > This series applies to v6.5. You may want to rebase to 6.7. > Will rebase. Thanks for catching this. >>   #else /* !CONFIG_KEXEC_CORE */ >>   struct pt_regs; >>   struct task_struct; >> @@ -497,6 +506,10 @@ static inline void __crash_kexec(struct pt_regs >> *regs) { } >>   static inline void crash_kexec(struct pt_regs *regs) { } >>   static inline int kexec_should_crash(struct task_struct *p) { return >> 0; } >>   static inline int kexec_crash_loaded(void) { return 0; } >> +static inline void *kimage_map_segment(struct kimage *image, >> +                       unsigned long addr, unsigned long size) >> +{ return NULL; } >> +static inline void kimage_unmap_segment(void *buffer) { } >>   #define kexec_in_progress false >>   #endif /* CONFIG_KEXEC_CORE */ >> diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c >> index 3d578c6fefee..26978ad02676 100644 >> --- a/kernel/kexec_core.c >> +++ b/kernel/kexec_core.c >> @@ -594,11 +594,6 @@ void kimage_terminate(struct kimage *image) >>       *image->entry = IND_DONE; >>   } >> -#define for_each_kimage_entry(image, ptr, entry) \ >> -    for (ptr = &image->head; (entry = *ptr) && !(entry & IND_DONE); \ >> -        ptr = (entry & IND_INDIRECTION) ? \ >> -            boot_phys_to_virt((entry & PAGE_MASK)) : ptr + 1) >> - >>   static void kimage_free_entry(kimage_entry_t entry) >>   { >>       struct page *page; >> @@ -921,6 +916,60 @@ int kimage_load_segment(struct kimage *image, >>       return result; >>   } >> +void *kimage_map_segment(struct kimage *image, >> +             unsigned long addr, unsigned long size) >> +{ >> +    unsigned long eaddr = addr + size; >> +    unsigned long src_page_addr, dest_page_addr; >> +    unsigned int npages; >> +    struct page **src_pages; >> +    int i; >> +    kimage_entry_t *ptr, entry; >> +    void *vaddr = NULL; >> + >> +    /* >> +     * Collect the source pages and map them in a contiguous VA range. >> +     */ >> +    npages = PFN_UP(eaddr) - PFN_DOWN(addr); >> +    src_pages = kmalloc_array(npages, sizeof(*src_pages), GFP_KERNEL); >> +    if (!src_pages) { >> +        pr_err("%s: Could not allocate ima pages array.\n", __func__); >> +        return NULL; >> +    } >> + >> +    i = 0; >> +    for_each_kimage_entry(image, ptr, entry) { >> +        if (entry & IND_DESTINATION) >> +            dest_page_addr = entry & PAGE_MASK; >> +        else if (entry & IND_SOURCE) { >> +            if (dest_page_addr >= addr && dest_page_addr < eaddr) { >> +                src_page_addr = entry & PAGE_MASK; >> +                src_pages[i++] = >> +                    virt_to_page(__va(src_page_addr)); >> +                if (i == npages) >> +                    break; >> +                dest_page_addr += PAGE_SIZE; >> +            } >> +        } >> +    } >> + >> +    /* Sanity check. */ >> +    WARN_ON(i < npages); >> + >> +    vaddr = vmap(src_pages, npages, VM_MAP, PAGE_KERNEL); >> +    kfree(src_pages); >> + >> +    if (!vaddr) >> +        pr_err("%s: Could not map imap buffer.\n", __func__); > > imap -> ima > Good eye catching this. Will fix. >> + >> +    return vaddr; >> +} >> + >> +void kimage_unmap_segment(void *segment_buffer) >> +{ >> +    vunmap(segment_buffer); >> +} >> + >>   struct kexec_load_limit { >>       /* Mutex protects the limit count. */ >>       struct mutex mutex; >> diff --git a/security/integrity/ima/ima_kexec.c >> b/security/integrity/ima/ima_kexec.c >> index 99daac355c70..4f944c9b4168 100644 >> --- a/security/integrity/ima/ima_kexec.c >> +++ b/security/integrity/ima/ima_kexec.c >> @@ -170,6 +170,7 @@ void ima_add_kexec_buffer(struct kimage *image) >>       pr_debug("kexec measurement buffer for the loaded kernel at >> 0x%lx.\n", >>            kbuf.mem); >>   } >> + > > remove > Will do. ~Tushar >>   #endif /* IMA_KEXEC */ >>   /*