diff options
author | Thomas Gleixner <tglx@linutronix.de> | 2020-11-03 10:27:40 +0100 |
---|---|---|
committer | Luis Claudio R. Goncalves <lgoncalv@redhat.com> | 2023-02-18 21:28:08 -0300 |
commit | da9fa247080eb06ca486888a703aba648da83f30 (patch) | |
tree | 6b9a1a6d777b6764deacccae23d3fd5989e99464 /arch/mips | |
parent | 13a976a30267ce61647240c2fb22e2d7d9504484 (diff) | |
download | linux-rt-da9fa247080eb06ca486888a703aba648da83f30.tar.gz |
mips/crashdump: Simplify copy_oldmem_page()
Replace kmap_atomic_pfn() with kmap_local_pfn() which is preemptible and
can take page faults.
Remove the indirection of the dump page and the related cruft which is not
longer required.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: linux-mips@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Diffstat (limited to 'arch/mips')
-rw-r--r-- | arch/mips/kernel/crash_dump.c | 42 |
1 files changed, 7 insertions, 35 deletions
diff --git a/arch/mips/kernel/crash_dump.c b/arch/mips/kernel/crash_dump.c index 01b2bd95ba1f..9aba83e1eeb4 100644 --- a/arch/mips/kernel/crash_dump.c +++ b/arch/mips/kernel/crash_dump.c @@ -5,8 +5,6 @@ #include <linux/uaccess.h> #include <linux/slab.h> -static void *kdump_buf_page; - /** * copy_oldmem_page - copy one page from "oldmem" * @pfn: page frame number to be copied @@ -17,51 +15,25 @@ static void *kdump_buf_page; * @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 + * Copy a page from "oldmem". For this page, there might be no pte mapped * in the current kernel. - * - * Calling copy_to_user() in atomic context is not desirable. Hence first - * copying the data to a pre-allocated kernel page and then copying to user - * space in non-atomic context. */ -ssize_t copy_oldmem_page(unsigned long pfn, char *buf, - size_t csize, unsigned long offset, int userbuf) +ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize, + unsigned long offset, int userbuf) { void *vaddr; if (!csize) return 0; - vaddr = kmap_atomic_pfn(pfn); + vaddr = kmap_local_pfn(pfn); if (!userbuf) { - memcpy(buf, (vaddr + offset), csize); - kunmap_atomic(vaddr); + memcpy(buf, vaddr + offset, csize); } else { - if (!kdump_buf_page) { - pr_warn("Kdump: Kdump buffer page not allocated\n"); - - return -EFAULT; - } - copy_page(kdump_buf_page, vaddr); - kunmap_atomic(vaddr); - if (copy_to_user(buf, (kdump_buf_page + offset), csize)) - return -EFAULT; + if (copy_to_user(buf, vaddr + offset, csize)) + csize = -EFAULT; } return csize; } - -static int __init kdump_buf_page_init(void) -{ - int ret = 0; - - kdump_buf_page = kmalloc(PAGE_SIZE, GFP_KERNEL); - if (!kdump_buf_page) { - pr_warn("Kdump: Failed to allocate kdump buffer page\n"); - ret = -ENOMEM; - } - - return ret; -} -arch_initcall(kdump_buf_page_init); |