From: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com> To: linuxppc-dev@lists.ozlabs.org Cc: kexec@lists.infradead.org, x86@kernel.org, linux-kernel@vger.kernel.org, Eric Biederman <ebiederm@xmission.com>, Dave Young <dyoung@redhat.com>, Michael Ellerman <mpe@ellerman.id.au>, Mimi Zohar <zohar@linux.vnet.ibm.com>, Eric Richter <erichte@linux.vnet.ibm.com>, Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com> Subject: [PATCH 4/6] kexec_file: Add mechanism to update kexec segments. Date: Mon, 20 Jun 2016 22:44:34 -0300 [thread overview] Message-ID: <1466473476-10104-5-git-send-email-bauerman@linux.vnet.ibm.com> (raw) In-Reply-To: <1466473476-10104-1-git-send-email-bauerman@linux.vnet.ibm.com> kexec_update_segment allows a given segment in kexec_image to have its contents updated. This is useful if the current kernel wants to send information to the next kernel that is up-to-date at the time of reboot. Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com> --- include/linux/kexec.h | 2 ++ kernel/kexec_core.c | 88 +++++++++++++++++++++++++++++++++++++++++++++++++++ kernel/kexec_file.c | 1 + 3 files changed, 91 insertions(+) diff --git a/include/linux/kexec.h b/include/linux/kexec.h index 131b1fc7820e..14d4ac070a8c 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -222,6 +222,8 @@ extern int kexec_add_buffer(struct kimage *image, char *buffer, unsigned long buf_align, unsigned long buf_min, unsigned long buf_max, bool top_down, bool checksum, unsigned long *load_addr); +int kexec_update_segment(const char *buffer, unsigned long bufsz, + unsigned long load_addr, unsigned long memsz); extern struct page *kimage_alloc_control_pages(struct kimage *image, unsigned int order); extern int kexec_load_purgatory(struct kimage *image, unsigned long min, diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c index 56b3ed0927b0..8781d3e4479d 100644 --- a/kernel/kexec_core.c +++ b/kernel/kexec_core.c @@ -700,6 +700,94 @@ static struct page *kimage_alloc_page(struct kimage *image, return page; } +/** + * kexec_update_segment - update the contents of a kimage segment + * @buffer: New contents of the segment. + * @bufsz: @buffer size. + * @load_addr: Segment's physical address in the next kernel. + * @memsz: Segment size. + * + * This function assumes kexec_mutex is held. + * + * Return: 0 on success, negative errno on error. + */ +int kexec_update_segment(const char *buffer, unsigned long bufsz, + unsigned long load_addr, unsigned long memsz) +{ + int i; + unsigned long entry; + unsigned long *ptr = NULL; + void *dest = NULL; + + for (i = 0; i < kexec_image->nr_segments; i++) + /* We only support updating whole segments. */ + if (load_addr == kexec_image->segment[i].mem && + memsz == kexec_image->segment[i].memsz) { + if (kexec_image->segment[i].do_checksum) { + pr_err("Trying to update non-modifiable segment.\n"); + return -EINVAL; + } + + break; + } + if (i == kexec_image->nr_segments) { + pr_err("Couldn't find segment to update: 0x%lx, size 0x%lx\n", + load_addr, memsz); + return -EINVAL; + } + + for (entry = kexec_image->head; !(entry & IND_DONE) && memsz; + entry = *ptr++) { + void *addr = (void *) (entry & PAGE_MASK); + + switch (entry & IND_FLAGS) { + case IND_DESTINATION: + dest = addr; + break; + case IND_INDIRECTION: + ptr = __va(addr); + break; + case IND_SOURCE: + /* Shouldn't happen, but verify just to be safe. */ + if (dest == NULL) { + pr_err("Invalid kexec entries list."); + return -EINVAL; + } + + if (dest == (void *) load_addr) { + struct page *page; + char *ptr; + size_t uchunk, mchunk; + + page = kmap_to_page(addr); + + ptr = kmap(page); + ptr += load_addr & ~PAGE_MASK; + mchunk = min_t(size_t, memsz, + PAGE_SIZE - (load_addr & ~PAGE_MASK)); + uchunk = min(bufsz, mchunk); + memcpy(ptr, buffer, uchunk); + + kunmap(page); + + bufsz -= uchunk; + load_addr += mchunk; + buffer += mchunk; + memsz -= mchunk; + } + dest += PAGE_SIZE; + } + + /* Shouldn't happen, but verify just to be safe. */ + if (ptr == NULL) { + pr_err("Invalid kexec entries list."); + return -EINVAL; + } + } + + return 0; +} + static int kimage_load_normal_segment(struct kimage *image, struct kexec_segment *segment) { diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c index 3aa829a78f50..79d09a7784d8 100644 --- a/kernel/kexec_file.c +++ b/kernel/kexec_file.c @@ -15,6 +15,7 @@ #include <linux/mm.h> #include <linux/file.h> #include <linux/slab.h> +#include <linux/highmem.h> #include <linux/kexec.h> #include <linux/mutex.h> #include <linux/list.h> -- 1.9.1
WARNING: multiple messages have this Message-ID (diff)
From: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com> To: linuxppc-dev@lists.ozlabs.org Cc: Michael Ellerman <mpe@ellerman.id.au>, x86@kernel.org, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, Eric Biederman <ebiederm@xmission.com>, Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>, Mimi Zohar <zohar@linux.vnet.ibm.com>, Dave Young <dyoung@redhat.com>, Eric Richter <erichte@linux.vnet.ibm.com> Subject: [PATCH 4/6] kexec_file: Add mechanism to update kexec segments. Date: Mon, 20 Jun 2016 22:44:34 -0300 [thread overview] Message-ID: <1466473476-10104-5-git-send-email-bauerman@linux.vnet.ibm.com> (raw) In-Reply-To: <1466473476-10104-1-git-send-email-bauerman@linux.vnet.ibm.com> kexec_update_segment allows a given segment in kexec_image to have its contents updated. This is useful if the current kernel wants to send information to the next kernel that is up-to-date at the time of reboot. Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com> --- include/linux/kexec.h | 2 ++ kernel/kexec_core.c | 88 +++++++++++++++++++++++++++++++++++++++++++++++++++ kernel/kexec_file.c | 1 + 3 files changed, 91 insertions(+) diff --git a/include/linux/kexec.h b/include/linux/kexec.h index 131b1fc7820e..14d4ac070a8c 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -222,6 +222,8 @@ extern int kexec_add_buffer(struct kimage *image, char *buffer, unsigned long buf_align, unsigned long buf_min, unsigned long buf_max, bool top_down, bool checksum, unsigned long *load_addr); +int kexec_update_segment(const char *buffer, unsigned long bufsz, + unsigned long load_addr, unsigned long memsz); extern struct page *kimage_alloc_control_pages(struct kimage *image, unsigned int order); extern int kexec_load_purgatory(struct kimage *image, unsigned long min, diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c index 56b3ed0927b0..8781d3e4479d 100644 --- a/kernel/kexec_core.c +++ b/kernel/kexec_core.c @@ -700,6 +700,94 @@ static struct page *kimage_alloc_page(struct kimage *image, return page; } +/** + * kexec_update_segment - update the contents of a kimage segment + * @buffer: New contents of the segment. + * @bufsz: @buffer size. + * @load_addr: Segment's physical address in the next kernel. + * @memsz: Segment size. + * + * This function assumes kexec_mutex is held. + * + * Return: 0 on success, negative errno on error. + */ +int kexec_update_segment(const char *buffer, unsigned long bufsz, + unsigned long load_addr, unsigned long memsz) +{ + int i; + unsigned long entry; + unsigned long *ptr = NULL; + void *dest = NULL; + + for (i = 0; i < kexec_image->nr_segments; i++) + /* We only support updating whole segments. */ + if (load_addr == kexec_image->segment[i].mem && + memsz == kexec_image->segment[i].memsz) { + if (kexec_image->segment[i].do_checksum) { + pr_err("Trying to update non-modifiable segment.\n"); + return -EINVAL; + } + + break; + } + if (i == kexec_image->nr_segments) { + pr_err("Couldn't find segment to update: 0x%lx, size 0x%lx\n", + load_addr, memsz); + return -EINVAL; + } + + for (entry = kexec_image->head; !(entry & IND_DONE) && memsz; + entry = *ptr++) { + void *addr = (void *) (entry & PAGE_MASK); + + switch (entry & IND_FLAGS) { + case IND_DESTINATION: + dest = addr; + break; + case IND_INDIRECTION: + ptr = __va(addr); + break; + case IND_SOURCE: + /* Shouldn't happen, but verify just to be safe. */ + if (dest == NULL) { + pr_err("Invalid kexec entries list."); + return -EINVAL; + } + + if (dest == (void *) load_addr) { + struct page *page; + char *ptr; + size_t uchunk, mchunk; + + page = kmap_to_page(addr); + + ptr = kmap(page); + ptr += load_addr & ~PAGE_MASK; + mchunk = min_t(size_t, memsz, + PAGE_SIZE - (load_addr & ~PAGE_MASK)); + uchunk = min(bufsz, mchunk); + memcpy(ptr, buffer, uchunk); + + kunmap(page); + + bufsz -= uchunk; + load_addr += mchunk; + buffer += mchunk; + memsz -= mchunk; + } + dest += PAGE_SIZE; + } + + /* Shouldn't happen, but verify just to be safe. */ + if (ptr == NULL) { + pr_err("Invalid kexec entries list."); + return -EINVAL; + } + } + + return 0; +} + static int kimage_load_normal_segment(struct kimage *image, struct kexec_segment *segment) { diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c index 3aa829a78f50..79d09a7784d8 100644 --- a/kernel/kexec_file.c +++ b/kernel/kexec_file.c @@ -15,6 +15,7 @@ #include <linux/mm.h> #include <linux/file.h> #include <linux/slab.h> +#include <linux/highmem.h> #include <linux/kexec.h> #include <linux/mutex.h> #include <linux/list.h> -- 1.9.1 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec
next prev parent reply other threads:[~2016-06-21 3:51 UTC|newest] Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top 2016-06-21 1:44 [PATCH 0/6] kexec_file: Add buffer hand-over for the next kernel Thiago Jung Bauermann 2016-06-21 1:44 ` Thiago Jung Bauermann 2016-06-21 1:44 ` [PATCH 1/6] kexec_file: Add buffer hand-over support " Thiago Jung Bauermann 2016-06-21 1:44 ` Thiago Jung Bauermann 2016-06-21 1:44 ` [PATCH 2/6] powerpc: " Thiago Jung Bauermann 2016-06-21 1:44 ` Thiago Jung Bauermann 2016-06-21 1:44 ` [PATCH 3/6] kexec_file: Allow skipping checksum calculation for some segments Thiago Jung Bauermann 2016-06-21 1:44 ` Thiago Jung Bauermann 2016-06-21 1:44 ` Thiago Jung Bauermann [this message] 2016-06-21 1:44 ` [PATCH 4/6] kexec_file: Add mechanism to update kexec segments Thiago Jung Bauermann 2016-06-21 1:44 ` [PATCH 5/6] kexec: Share logic to copy segment page contents Thiago Jung Bauermann 2016-06-21 1:44 ` Thiago Jung Bauermann 2016-06-21 1:44 ` [PATCH 6/6] IMA: Demonstration code for kexec buffer passing Thiago Jung Bauermann 2016-06-21 1:44 ` Thiago Jung Bauermann 2016-06-22 1:20 ` [PATCH 0/6] kexec_file: Add buffer hand-over for the next kernel Dave Young 2016-06-22 1:20 ` Dave Young 2016-06-22 13:19 ` Mimi Zohar 2016-06-22 13:19 ` Mimi Zohar 2016-06-22 16:34 ` Thiago Jung Bauermann 2016-06-22 16:34 ` Thiago Jung Bauermann
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