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 5/6] kexec: Share logic to copy segment page contents. Date: Mon, 20 Jun 2016 22:44:35 -0300 [thread overview] Message-ID: <1466473476-10104-6-git-send-email-bauerman@linux.vnet.ibm.com> (raw) In-Reply-To: <1466473476-10104-1-git-send-email-bauerman@linux.vnet.ibm.com> Make kimage_load_normal_segment and kexec_update_segment share code which they currently duplicate. Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com> --- kernel/kexec_core.c | 159 +++++++++++++++++++++++++++++++--------------------- 1 file changed, 95 insertions(+), 64 deletions(-) diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c index 8781d3e4479d..281d8b961fb4 100644 --- a/kernel/kexec_core.c +++ b/kernel/kexec_core.c @@ -700,6 +700,65 @@ static struct page *kimage_alloc_page(struct kimage *image, return page; } +struct kimage_update_buffer_state { + /* Destination memory address currently being copied to. */ + unsigned long maddr; + + /* Bytes in buffer still left to copy. */ + size_t ubytes; + + /* Bytes in memory still left to copy. */ + size_t mbytes; + + /* If true, copy from kbuf. */ + bool from_kernel; + + /* Clear pages before copying? */ + bool clear_pages; + + /* Buffer position to continue copying from. */ + const unsigned char *kbuf; + const unsigned char __user *buf; +}; + +static int kimage_update_page(struct page *page, + struct kimage_update_buffer_state *state) +{ + char *ptr; + int result = 0; + size_t uchunk, mchunk; + + ptr = kmap(page); + + /* Start with a clear page */ + if (state->clear_pages) + clear_page(ptr); + + ptr += state->maddr & ~PAGE_MASK; + mchunk = min_t(size_t, state->mbytes, + PAGE_SIZE - (state->maddr & ~PAGE_MASK)); + uchunk = min(state->ubytes, mchunk); + + if (state->from_kernel) + memcpy(ptr, state->kbuf, uchunk); + else + result = copy_from_user(ptr, state->buf, uchunk); + + kunmap(page); + if (result) + return -EFAULT; + + state->ubytes -= uchunk; + state->maddr += mchunk; + if (state->from_kernel) + state->kbuf += mchunk; + else + state->buf += mchunk; + state->mbytes -= mchunk; + + return 0; +} + /** * kexec_update_segment - update the contents of a kimage segment * @buffer: New contents of the segment. @@ -718,6 +777,7 @@ int kexec_update_segment(const char *buffer, unsigned long bufsz, unsigned long entry; unsigned long *ptr = NULL; void *dest = NULL; + struct kimage_update_buffer_state state; for (i = 0; i < kexec_image->nr_segments; i++) /* We only support updating whole segments. */ @@ -736,8 +796,15 @@ int kexec_update_segment(const char *buffer, unsigned long bufsz, return -EINVAL; } - for (entry = kexec_image->head; !(entry & IND_DONE) && memsz; - entry = *ptr++) { + state.maddr = load_addr; + state.ubytes = bufsz; + state.mbytes = memsz; + state.kbuf = buffer; + state.from_kernel = true; + state.clear_pages = false; + + for (entry = kexec_image->head; !(entry & IND_DONE) && + state.mbytes; entry = *ptr++) { void *addr = (void *) (entry & PAGE_MASK); switch (entry & IND_FLAGS) { @@ -754,26 +821,13 @@ int kexec_update_segment(const char *buffer, unsigned long bufsz, 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); + if (dest == (void *) state.maddr) { + int ret; - bufsz -= uchunk; - load_addr += mchunk; - buffer += mchunk; - memsz -= mchunk; + ret = kimage_update_page(kmap_to_page(addr), + &state); + if (ret) + return ret; } dest += PAGE_SIZE; } @@ -791,31 +845,30 @@ int kexec_update_segment(const char *buffer, unsigned long bufsz, static int kimage_load_normal_segment(struct kimage *image, struct kexec_segment *segment) { - unsigned long maddr; - size_t ubytes, mbytes; - int result; - unsigned char __user *buf = NULL; - unsigned char *kbuf = NULL; - - result = 0; - if (image->file_mode) - kbuf = segment->kbuf; - else - buf = segment->buf; - ubytes = segment->bufsz; - mbytes = segment->memsz; - maddr = segment->mem; + int result = 0; + struct kimage_update_buffer_state state; + + /* For file based kexec, source pages are in kernel memory */ + if (image->file_mode) { + state.kbuf = segment->kbuf; + state.from_kernel = true; + } else { + state.buf = segment->buf; + state.from_kernel = false; + } + state.ubytes = segment->bufsz; + state.mbytes = segment->memsz; + state.maddr = segment->mem; + state.clear_pages = true; - result = kimage_set_destination(image, maddr); + result = kimage_set_destination(image, state.maddr); if (result < 0) goto out; - while (mbytes) { + while (state.mbytes) { struct page *page; - char *ptr; - size_t uchunk, mchunk; - page = kimage_alloc_page(image, GFP_HIGHUSER, maddr); + page = kimage_alloc_page(image, GFP_HIGHUSER, state.maddr); if (!page) { result = -ENOMEM; goto out; @@ -825,31 +878,9 @@ static int kimage_load_normal_segment(struct kimage *image, if (result < 0) goto out; - ptr = kmap(page); - /* Start with a clear page */ - clear_page(ptr); - ptr += maddr & ~PAGE_MASK; - mchunk = min_t(size_t, mbytes, - PAGE_SIZE - (maddr & ~PAGE_MASK)); - uchunk = min(ubytes, mchunk); - - /* For file based kexec, source pages are in kernel memory */ - if (image->file_mode) - memcpy(ptr, kbuf, uchunk); - else - result = copy_from_user(ptr, buf, uchunk); - kunmap(page); - if (result) { - result = -EFAULT; + result = kimage_update_page(page, &state); + if (result) goto out; - } - ubytes -= uchunk; - maddr += mchunk; - if (image->file_mode) - kbuf += mchunk; - else - buf += mchunk; - mbytes -= mchunk; } out: return result; -- 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 5/6] kexec: Share logic to copy segment page contents. Date: Mon, 20 Jun 2016 22:44:35 -0300 [thread overview] Message-ID: <1466473476-10104-6-git-send-email-bauerman@linux.vnet.ibm.com> (raw) In-Reply-To: <1466473476-10104-1-git-send-email-bauerman@linux.vnet.ibm.com> Make kimage_load_normal_segment and kexec_update_segment share code which they currently duplicate. Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com> --- kernel/kexec_core.c | 159 +++++++++++++++++++++++++++++++--------------------- 1 file changed, 95 insertions(+), 64 deletions(-) diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c index 8781d3e4479d..281d8b961fb4 100644 --- a/kernel/kexec_core.c +++ b/kernel/kexec_core.c @@ -700,6 +700,65 @@ static struct page *kimage_alloc_page(struct kimage *image, return page; } +struct kimage_update_buffer_state { + /* Destination memory address currently being copied to. */ + unsigned long maddr; + + /* Bytes in buffer still left to copy. */ + size_t ubytes; + + /* Bytes in memory still left to copy. */ + size_t mbytes; + + /* If true, copy from kbuf. */ + bool from_kernel; + + /* Clear pages before copying? */ + bool clear_pages; + + /* Buffer position to continue copying from. */ + const unsigned char *kbuf; + const unsigned char __user *buf; +}; + +static int kimage_update_page(struct page *page, + struct kimage_update_buffer_state *state) +{ + char *ptr; + int result = 0; + size_t uchunk, mchunk; + + ptr = kmap(page); + + /* Start with a clear page */ + if (state->clear_pages) + clear_page(ptr); + + ptr += state->maddr & ~PAGE_MASK; + mchunk = min_t(size_t, state->mbytes, + PAGE_SIZE - (state->maddr & ~PAGE_MASK)); + uchunk = min(state->ubytes, mchunk); + + if (state->from_kernel) + memcpy(ptr, state->kbuf, uchunk); + else + result = copy_from_user(ptr, state->buf, uchunk); + + kunmap(page); + if (result) + return -EFAULT; + + state->ubytes -= uchunk; + state->maddr += mchunk; + if (state->from_kernel) + state->kbuf += mchunk; + else + state->buf += mchunk; + state->mbytes -= mchunk; + + return 0; +} + /** * kexec_update_segment - update the contents of a kimage segment * @buffer: New contents of the segment. @@ -718,6 +777,7 @@ int kexec_update_segment(const char *buffer, unsigned long bufsz, unsigned long entry; unsigned long *ptr = NULL; void *dest = NULL; + struct kimage_update_buffer_state state; for (i = 0; i < kexec_image->nr_segments; i++) /* We only support updating whole segments. */ @@ -736,8 +796,15 @@ int kexec_update_segment(const char *buffer, unsigned long bufsz, return -EINVAL; } - for (entry = kexec_image->head; !(entry & IND_DONE) && memsz; - entry = *ptr++) { + state.maddr = load_addr; + state.ubytes = bufsz; + state.mbytes = memsz; + state.kbuf = buffer; + state.from_kernel = true; + state.clear_pages = false; + + for (entry = kexec_image->head; !(entry & IND_DONE) && + state.mbytes; entry = *ptr++) { void *addr = (void *) (entry & PAGE_MASK); switch (entry & IND_FLAGS) { @@ -754,26 +821,13 @@ int kexec_update_segment(const char *buffer, unsigned long bufsz, 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); + if (dest == (void *) state.maddr) { + int ret; - bufsz -= uchunk; - load_addr += mchunk; - buffer += mchunk; - memsz -= mchunk; + ret = kimage_update_page(kmap_to_page(addr), + &state); + if (ret) + return ret; } dest += PAGE_SIZE; } @@ -791,31 +845,30 @@ int kexec_update_segment(const char *buffer, unsigned long bufsz, static int kimage_load_normal_segment(struct kimage *image, struct kexec_segment *segment) { - unsigned long maddr; - size_t ubytes, mbytes; - int result; - unsigned char __user *buf = NULL; - unsigned char *kbuf = NULL; - - result = 0; - if (image->file_mode) - kbuf = segment->kbuf; - else - buf = segment->buf; - ubytes = segment->bufsz; - mbytes = segment->memsz; - maddr = segment->mem; + int result = 0; + struct kimage_update_buffer_state state; + + /* For file based kexec, source pages are in kernel memory */ + if (image->file_mode) { + state.kbuf = segment->kbuf; + state.from_kernel = true; + } else { + state.buf = segment->buf; + state.from_kernel = false; + } + state.ubytes = segment->bufsz; + state.mbytes = segment->memsz; + state.maddr = segment->mem; + state.clear_pages = true; - result = kimage_set_destination(image, maddr); + result = kimage_set_destination(image, state.maddr); if (result < 0) goto out; - while (mbytes) { + while (state.mbytes) { struct page *page; - char *ptr; - size_t uchunk, mchunk; - page = kimage_alloc_page(image, GFP_HIGHUSER, maddr); + page = kimage_alloc_page(image, GFP_HIGHUSER, state.maddr); if (!page) { result = -ENOMEM; goto out; @@ -825,31 +878,9 @@ static int kimage_load_normal_segment(struct kimage *image, if (result < 0) goto out; - ptr = kmap(page); - /* Start with a clear page */ - clear_page(ptr); - ptr += maddr & ~PAGE_MASK; - mchunk = min_t(size_t, mbytes, - PAGE_SIZE - (maddr & ~PAGE_MASK)); - uchunk = min(ubytes, mchunk); - - /* For file based kexec, source pages are in kernel memory */ - if (image->file_mode) - memcpy(ptr, kbuf, uchunk); - else - result = copy_from_user(ptr, buf, uchunk); - kunmap(page); - if (result) { - result = -EFAULT; + result = kimage_update_page(page, &state); + if (result) goto out; - } - ubytes -= uchunk; - maddr += mchunk; - if (image->file_mode) - kbuf += mchunk; - else - buf += mchunk; - mbytes -= mchunk; } out: return result; -- 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 3:46 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 ` [PATCH 4/6] kexec_file: Add mechanism to update kexec 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 5/6] kexec: Share logic to copy segment page contents 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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