| Message ID | 20240122183804.3293904-3-tusharsu@linux.microsoft.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | ima: kexec: measure events between kexec load and execute | expand |
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 <tusharsu@linux.microsoft.com> > --- > 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. > #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 > + > + 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 > #endif /* IMA_KEXEC */ > > /*
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 <tusharsu@linux.microsoft.com> >> --- >> 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 */ >> /*
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); + #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__); + + 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); } + #endif /* IMA_KEXEC */ /*
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 <tusharsu@linux.microsoft.com> --- include/linux/kexec.h | 13 +++++++ kernel/kexec_core.c | 59 +++++++++++++++++++++++++++--- security/integrity/ima/ima_kexec.c | 1 + 3 files changed, 68 insertions(+), 5 deletions(-)