From 4d3b0664a0d0c0dc7501cfbd067f74226aeca510 Mon Sep 17 00:00:00 2001 From: Michael Holzheu Date: Fri, 27 Sep 2013 15:41:43 +0200 Subject: [PATCH] s390: Allow vmalloc target buffers for copy_from_oldmem() Currently copy_from_oldmem() is not able to copy to virtual memory. When using kexec pre-allocated ELF header, copy_from_oldmem() is used to copy the ELF notes information to vmalloc buffers. So fix this and use the new function copy_from_realmem() that allows copying also to vmalloc memory. Signed-off-by: Michael Holzheu Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/crash_dump.c | 42 +++++++++++++++++------------------ 1 file changed, 20 insertions(+), 22 deletions(-) diff --git a/arch/s390/kernel/crash_dump.c b/arch/s390/kernel/crash_dump.c index c84f33d51f7b..7dd21720e5b0 100644 --- a/arch/s390/kernel/crash_dump.c +++ b/arch/s390/kernel/crash_dump.c @@ -40,28 +40,26 @@ static inline void *load_real_addr(void *addr) } /* - * Copy up to one page to vmalloc or real memory + * Copy real to virtual or real memory */ -static ssize_t copy_page_real(void *buf, void *src, size_t csize) +static int copy_from_realmem(void *dest, void *src, size_t count) { - size_t size; + unsigned long size; + int rc; - if (is_vmalloc_addr(buf)) { - BUG_ON(csize >= PAGE_SIZE); - /* If buf is not page aligned, copy first part */ - size = min(roundup(__pa(buf), PAGE_SIZE) - __pa(buf), csize); - if (size) { - if (memcpy_real(load_real_addr(buf), src, size)) - return -EFAULT; - buf += size; - src += size; - } - /* Copy second part */ - size = csize - size; - return (size) ? memcpy_real(load_real_addr(buf), src, size) : 0; - } else { - return memcpy_real(buf, src, csize); - } + if (!count) + return 0; + if (!is_vmalloc_or_module_addr(dest)) + return memcpy_real(dest, src, count); + do { + size = min(count, PAGE_SIZE - (__pa(dest) & ~PAGE_MASK)); + if (memcpy_real(load_real_addr(dest), src, size)) + return -EFAULT; + count -= size; + dest += size; + src += size; + } while (count); + return 0; } /* @@ -114,7 +112,7 @@ static ssize_t copy_oldmem_page_kdump(char *buf, size_t csize, rc = copy_to_user_real((void __force __user *) buf, (void *) src, csize); else - rc = copy_page_real(buf, (void *) src, csize); + rc = copy_from_realmem(buf, (void *) src, csize); return (rc == 0) ? rc : csize; } @@ -210,7 +208,7 @@ int copy_from_oldmem(void *dest, void *src, size_t count) if (OLDMEM_BASE) { if ((unsigned long) src < OLDMEM_SIZE) { copied = min(count, OLDMEM_SIZE - (unsigned long) src); - rc = memcpy_real(dest, src + OLDMEM_BASE, copied); + rc = copy_from_realmem(dest, src + OLDMEM_BASE, copied); if (rc) return rc; } @@ -223,7 +221,7 @@ int copy_from_oldmem(void *dest, void *src, size_t count) return rc; } } - return memcpy_real(dest + copied, src + copied, count - copied); + return copy_from_realmem(dest + copied, src + copied, count - copied); } /* -- 2.20.1