diff options
| -rw-r--r-- | arch/parisc/kernel/sys_parisc.c | 15 | ||||
| -rw-r--r-- | io_uring/io_uring.c | 42 |
2 files changed, 27 insertions, 30 deletions
diff --git a/arch/parisc/kernel/sys_parisc.c b/arch/parisc/kernel/sys_parisc.c index 39acccabf2ed..465b7cb9d44f 100644 --- a/arch/parisc/kernel/sys_parisc.c +++ b/arch/parisc/kernel/sys_parisc.c @@ -26,12 +26,17 @@ #include <linux/compat.h> /* - * Construct an artificial page offset for the mapping based on the physical + * Construct an artificial page offset for the mapping based on the virtual * address of the kernel file mapping variable. + * If filp is zero the calculated pgoff value aliases the memory of the given + * address. This is useful for io_uring where the mapping shall alias a kernel + * address and a userspace adress where both the kernel and the userspace + * access the same memory region. */ -#define GET_FILP_PGOFF(filp) \ - (filp ? (((unsigned long) filp->f_mapping) >> 8) \ - & ((SHM_COLOUR-1) >> PAGE_SHIFT) : 0UL) +#define GET_FILP_PGOFF(filp, addr) \ + ((filp ? (((unsigned long) filp->f_mapping) >> 8) \ + & ((SHM_COLOUR-1) >> PAGE_SHIFT) : 0UL) \ + + (addr >> PAGE_SHIFT)) static unsigned long shared_align_offset(unsigned long filp_pgoff, unsigned long pgoff) @@ -111,7 +116,7 @@ static unsigned long arch_get_unmapped_area_common(struct file *filp, do_color_align = 0; if (filp || (flags & MAP_SHARED)) do_color_align = 1; - filp_pgoff = GET_FILP_PGOFF(filp); + filp_pgoff = GET_FILP_PGOFF(filp, addr); if (flags & MAP_FIXED) { /* Even MAP_FIXED mappings must reside within TASK_SIZE */ diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index 5e97235a82d6..89a611541bc4 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -3437,8 +3437,6 @@ static unsigned long io_uring_mmu_get_unmapped_area(struct file *filp, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags) { - const unsigned long mmap_end = arch_get_mmap_end(addr, len, flags); - struct vm_unmapped_area_info info; void *ptr; /* @@ -3453,32 +3451,26 @@ static unsigned long io_uring_mmu_get_unmapped_area(struct file *filp, if (IS_ERR(ptr)) return -ENOMEM; - info.flags = VM_UNMAPPED_AREA_TOPDOWN; - info.length = len; - info.low_limit = max(PAGE_SIZE, mmap_min_addr); - info.high_limit = arch_get_mmap_base(addr, current->mm->mmap_base); + /* + * Some architectures have strong cache aliasing requirements. + * For such architectures we need a coherent mapping which aliases + * kernel memory *and* userspace memory. To achieve that: + * - use a NULL file pointer to reference physical memory, and + * - use the kernel virtual address of the shared io_uring context + * (instead of the userspace-provided address, which has to be 0UL + * anyway). + * For architectures without such aliasing requirements, the + * architecture will return any suitable mapping because addr is 0. + */ + filp = NULL; + flags |= MAP_SHARED; + pgoff = 0; /* has been translated to ptr above */ #ifdef SHM_COLOUR - info.align_mask = PAGE_MASK & (SHM_COLOUR - 1UL); + addr = (uintptr_t) ptr; #else - info.align_mask = PAGE_MASK & (SHMLBA - 1UL); + addr = 0UL; #endif - info.align_offset = (unsigned long) ptr; - - /* - * A failed mmap() very likely causes application failure, - * so fall back to the bottom-up function here. This scenario - * can happen with large stack limits and large mmap() - * allocations. - */ - addr = vm_unmapped_area(&info); - if (offset_in_page(addr)) { - info.flags = 0; - info.low_limit = TASK_UNMAPPED_BASE; - info.high_limit = mmap_end; - addr = vm_unmapped_area(&info); - } - - return addr; + return current->mm->get_unmapped_area(filp, addr, len, pgoff, flags); } #else /* !CONFIG_MMU */ |