From 5d8de293c224896a4da99763fce4f9794308caf4 Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Fri, 29 Apr 2022 14:37:59 -0700 Subject: vmcore: convert copy_oldmem_page() to take an iov_iter Patch series "Convert vmcore to use an iov_iter", v5. For some reason several people have been sending bad patches to fix compiler warnings in vmcore recently. Here's how it should be done. Compile-tested only on x86. As noted in the first patch, s390 should take this conversion a bit further, but I'm not inclined to do that work myself. This patch (of 3): Instead of passing in a 'buf' and 'userbuf' argument, pass in an iov_iter. s390 needs more work to pass the iov_iter down further, or refactor, but I'd be more comfortable if someone who can test on s390 did that work. It's more convenient to convert the whole of read_from_oldmem() to take an iov_iter at the same time, so rename it to read_from_oldmem_iter() and add a temporary read_from_oldmem() wrapper that creates an iov_iter. Link: https://lkml.kernel.org/r/20220408090636.560886-1-bhe@redhat.com Link: https://lkml.kernel.org/r/20220408090636.560886-2-bhe@redhat.com Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Baoquan He Reviewed-by: Christoph Hellwig Cc: Heiko Carstens Signed-off-by: Andrew Morton --- arch/powerpc/kernel/crash_dump.c | 35 +++++------------------------------ 1 file changed, 5 insertions(+), 30 deletions(-) (limited to 'arch/powerpc') diff --git a/arch/powerpc/kernel/crash_dump.c b/arch/powerpc/kernel/crash_dump.c index 5693e1c67c2b..32b4a97f1b79 100644 --- a/arch/powerpc/kernel/crash_dump.c +++ b/arch/powerpc/kernel/crash_dump.c @@ -16,7 +16,7 @@ #include #include #include -#include +#include #include #include @@ -68,33 +68,8 @@ void __init setup_kdump_trampoline(void) } #endif /* CONFIG_NONSTATIC_KERNEL */ -static size_t copy_oldmem_vaddr(void *vaddr, char *buf, size_t csize, - unsigned long offset, int userbuf) -{ - if (userbuf) { - if (copy_to_user((char __user *)buf, (vaddr + offset), csize)) - return -EFAULT; - } else - memcpy(buf, (vaddr + offset), csize); - - return csize; -} - -/** - * copy_oldmem_page - copy one page from "oldmem" - * @pfn: page frame number to be copied - * @buf: target memory address for the copy; this can be in kernel address - * space or user address space (see @userbuf) - * @csize: number of bytes to copy - * @offset: offset in bytes into the page (based on pfn) to begin the copy - * @userbuf: if set, @buf is in user address space, use copy_to_user(), - * otherwise @buf is in kernel address space, use memcpy(). - * - * Copy a page from "oldmem". For this page, there is no pte mapped - * in the current kernel. We stitch up a pte, similar to kmap_atomic. - */ -ssize_t copy_oldmem_page(unsigned long pfn, char *buf, - size_t csize, unsigned long offset, int userbuf) +ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, + size_t csize, unsigned long offset) { void *vaddr; phys_addr_t paddr; @@ -107,10 +82,10 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf, if (memblock_is_region_memory(paddr, csize)) { vaddr = __va(paddr); - csize = copy_oldmem_vaddr(vaddr, buf, csize, offset, userbuf); + csize = copy_to_iter(vaddr + offset, csize, iter); } else { vaddr = ioremap_cache(paddr, PAGE_SIZE); - csize = copy_oldmem_vaddr(vaddr, buf, csize, offset, userbuf); + csize = copy_to_iter(vaddr + offset, csize, iter); iounmap(vaddr); } -- cgit v1.2.3 From 6308499b5e99c0c903fde2c605e41d9a86c4be6c Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 29 Apr 2022 14:37:59 -0700 Subject: net: unexport csum_and_copy_{from,to}_user csum_and_copy_from_user and csum_and_copy_to_user are exported by a few architectures, but not actually used in modular code. Drop the exports. Link: https://lkml.kernel.org/r/20220421070440.1282704-1-hch@lst.de Signed-off-by: Christoph Hellwig Acked-by: Jakub Kicinski Acked-by: Geert Uytterhoeven Acked-by: Arnd Bergmann Acked-by: Michael Ellerman (powerpc) Cc: David Miller Signed-off-by: Andrew Morton --- arch/alpha/lib/csum_partial_copy.c | 1 - arch/m68k/lib/checksum.c | 2 -- arch/powerpc/lib/checksum_wrappers.c | 2 -- arch/x86/lib/csum-wrappers_64.c | 2 -- 4 files changed, 7 deletions(-) (limited to 'arch/powerpc') diff --git a/arch/alpha/lib/csum_partial_copy.c b/arch/alpha/lib/csum_partial_copy.c index 1931a04af85a..4d180d96f09e 100644 --- a/arch/alpha/lib/csum_partial_copy.c +++ b/arch/alpha/lib/csum_partial_copy.c @@ -353,7 +353,6 @@ csum_and_copy_from_user(const void __user *src, void *dst, int len) return 0; return __csum_and_copy(src, dst, len); } -EXPORT_SYMBOL(csum_and_copy_from_user); __wsum csum_partial_copy_nocheck(const void *src, void *dst, int len) diff --git a/arch/m68k/lib/checksum.c b/arch/m68k/lib/checksum.c index 7e6afeae6217..5acb821849d3 100644 --- a/arch/m68k/lib/checksum.c +++ b/arch/m68k/lib/checksum.c @@ -265,8 +265,6 @@ csum_and_copy_from_user(const void __user *src, void *dst, int len) return sum; } -EXPORT_SYMBOL(csum_and_copy_from_user); - /* * copy from kernel space while checksumming, otherwise like csum_partial diff --git a/arch/powerpc/lib/checksum_wrappers.c b/arch/powerpc/lib/checksum_wrappers.c index f3999cbb2fcc..1a14c8780278 100644 --- a/arch/powerpc/lib/checksum_wrappers.c +++ b/arch/powerpc/lib/checksum_wrappers.c @@ -24,7 +24,6 @@ __wsum csum_and_copy_from_user(const void __user *src, void *dst, user_read_access_end(); return csum; } -EXPORT_SYMBOL(csum_and_copy_from_user); __wsum csum_and_copy_to_user(const void *src, void __user *dst, int len) { @@ -38,4 +37,3 @@ __wsum csum_and_copy_to_user(const void *src, void __user *dst, int len) user_write_access_end(); return csum; } -EXPORT_SYMBOL(csum_and_copy_to_user); diff --git a/arch/x86/lib/csum-wrappers_64.c b/arch/x86/lib/csum-wrappers_64.c index 189344924a2b..145f9a0bde29 100644 --- a/arch/x86/lib/csum-wrappers_64.c +++ b/arch/x86/lib/csum-wrappers_64.c @@ -32,7 +32,6 @@ csum_and_copy_from_user(const void __user *src, void *dst, int len) user_access_end(); return sum; } -EXPORT_SYMBOL(csum_and_copy_from_user); /** * csum_and_copy_to_user - Copy and checksum to user space. @@ -57,7 +56,6 @@ csum_and_copy_to_user(const void *src, void __user *dst, int len) user_access_end(); return sum; } -EXPORT_SYMBOL(csum_and_copy_to_user); /** * csum_partial_copy_nocheck - Copy and checksum. -- cgit v1.2.3