6.12-stable review patch. If anyone has any objections, please let me know.
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From: Benjamin Berg benjamin.berg@intel.com
[ Upstream commit 84a6fc378471fbeaf48f8604566a5a33a3d63c18 ]
There is no need to override the default version of this function anymore as UML now has proper _nofault memory access functions.
Doing this also fixes the fact that the implementation was incorrect as using mincore() will incorrectly flag pages as inaccessible if they were swapped out by the host.
Fixes: f75b1b1bedfb ("um: Implement probe_kernel_read()") Signed-off-by: Benjamin Berg benjamin.berg@intel.com Link: https://patch.msgid.link/20250210160926.420133-3-benjamin@sipsolutions.net Signed-off-by: Johannes Berg johannes.berg@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/um/include/shared/os.h | 1 - arch/um/kernel/Makefile | 2 +- arch/um/kernel/maccess.c | 19 -------------- arch/um/os-Linux/process.c | 51 ------------------------------------- 4 files changed, 1 insertion(+), 72 deletions(-) delete mode 100644 arch/um/kernel/maccess.c
diff --git a/arch/um/include/shared/os.h b/arch/um/include/shared/os.h index 9a039d6f1f748..77a8593f219a1 100644 --- a/arch/um/include/shared/os.h +++ b/arch/um/include/shared/os.h @@ -218,7 +218,6 @@ extern int os_protect_memory(void *addr, unsigned long len, extern int os_unmap_memory(void *addr, int len); extern int os_drop_memory(void *addr, int length); extern int can_drop_memory(void); -extern int os_mincore(void *addr, unsigned long len);
/* execvp.c */ extern int execvp_noalloc(char *buf, const char *file, char *const argv[]); diff --git a/arch/um/kernel/Makefile b/arch/um/kernel/Makefile index f8567b933ffaa..4df1cd0d20179 100644 --- a/arch/um/kernel/Makefile +++ b/arch/um/kernel/Makefile @@ -17,7 +17,7 @@ extra-y := vmlinux.lds obj-y = config.o exec.o exitcode.o irq.o ksyms.o mem.o \ physmem.o process.o ptrace.o reboot.o sigio.o \ signal.o sysrq.o time.o tlb.o trap.o \ - um_arch.o umid.o maccess.o kmsg_dump.o capflags.o skas/ + um_arch.o umid.o kmsg_dump.o capflags.o skas/ obj-y += load_file.o
obj-$(CONFIG_BLK_DEV_INITRD) += initrd.o diff --git a/arch/um/kernel/maccess.c b/arch/um/kernel/maccess.c deleted file mode 100644 index 8ccd56813f684..0000000000000 --- a/arch/um/kernel/maccess.c +++ /dev/null @@ -1,19 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-only -/* - * Copyright (C) 2013 Richard Weinberger richrd@nod.at - */ - -#include <linux/uaccess.h> -#include <linux/kernel.h> -#include <os.h> - -bool copy_from_kernel_nofault_allowed(const void *src, size_t size) -{ - void *psrc = (void *)rounddown((unsigned long)src, PAGE_SIZE); - - if ((unsigned long)src < PAGE_SIZE || size <= 0) - return false; - if (os_mincore(psrc, size + src - psrc) <= 0) - return false; - return true; -} diff --git a/arch/um/os-Linux/process.c b/arch/um/os-Linux/process.c index e52dd37ddadcc..2686120ab2325 100644 --- a/arch/um/os-Linux/process.c +++ b/arch/um/os-Linux/process.c @@ -223,57 +223,6 @@ int __init can_drop_memory(void) return ok; }
-static int os_page_mincore(void *addr) -{ - char vec[2]; - int ret; - - ret = mincore(addr, UM_KERN_PAGE_SIZE, vec); - if (ret < 0) { - if (errno == ENOMEM || errno == EINVAL) - return 0; - else - return -errno; - } - - return vec[0] & 1; -} - -int os_mincore(void *addr, unsigned long len) -{ - char *vec; - int ret, i; - - if (len <= UM_KERN_PAGE_SIZE) - return os_page_mincore(addr); - - vec = calloc(1, (len + UM_KERN_PAGE_SIZE - 1) / UM_KERN_PAGE_SIZE); - if (!vec) - return -ENOMEM; - - ret = mincore(addr, UM_KERN_PAGE_SIZE, vec); - if (ret < 0) { - if (errno == ENOMEM || errno == EINVAL) - ret = 0; - else - ret = -errno; - - goto out; - } - - for (i = 0; i < ((len + UM_KERN_PAGE_SIZE - 1) / UM_KERN_PAGE_SIZE); i++) { - if (!(vec[i] & 1)) { - ret = 0; - goto out; - } - } - - ret = 1; -out: - free(vec); - return ret; -} - void init_new_thread_signals(void) { set_handler(SIGSEGV);