summaryrefslogtreecommitdiffstats
path: root/arch/x86/lib/putuser.S
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2026-09-25 15:55:03 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-09-25 15:55:03 -0700
commit75467f60a3d14f08f86f2b353298d2826382ff23 (patch)
treeacd8a7d5b5a675042449386efa5b42ec44d8bf81 /arch/x86/lib/putuser.S
downloadlinux-stable-75467f60a3d14f08f86f2b353298d2826382ff23.tar.gz
linux-stable-75467f60a3d14f08f86f2b353298d2826382ff23.zip
Merge tag 'ipe-pr-20260925' of git://git.kernel.org/pub/scm/linux/kernel/git/wufan/ipegrafted
Pull IPE fixes from Fan Wu: "Two fixes for use-after-free issues found by recent LLM-assisted code analysis. - move successful policy load auditing under the new policy directory's inode lock, preventing a concurrent policy deletion from freeing the policy while it is still being audited - protect the dm-verity root hash with RCU, preventing policy evaluation from racing with root hash replacement during preresume" * tag 'ipe-pr-20260925' of git://git.kernel.org/pub/scm/linux/kernel/git/wufan/ipe: ipe: protect the dm-verity root hash with RCU ipe: fix use-after-free when auditing a newly loaded policy
Diffstat (limited to 'arch/x86/lib/putuser.S')
-rw-r--r--arch/x86/lib/putuser.S156
1 files changed, 156 insertions, 0 deletions
diff --git a/arch/x86/lib/putuser.S b/arch/x86/lib/putuser.S
new file mode 100644
index 000000000..46d9e9b98
--- /dev/null
+++ b/arch/x86/lib/putuser.S
@@ -0,0 +1,156 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * __put_user functions.
+ *
+ * (C) Copyright 2005 Linus Torvalds
+ * (C) Copyright 2005 Andi Kleen
+ * (C) Copyright 2008 Glauber Costa
+ *
+ * These functions have a non-standard call interface
+ * to make them more efficient, especially as they
+ * return an error value in addition to the "real"
+ * return value.
+ */
+#include <linux/export.h>
+#include <linux/linkage.h>
+#include <linux/objtool.h>
+#include <asm/thread_info.h>
+#include <asm/errno.h>
+#include <asm/asm.h>
+#include <asm/smap.h>
+
+/*
+ * __put_user_X
+ *
+ * Inputs: %eax[:%edx] contains the data
+ * %ecx contains the address
+ *
+ * Outputs: %ecx is error code (0 or -EFAULT)
+ *
+ * Clobbers: %ebx needed for task pointer
+ *
+ * These functions should not modify any other registers,
+ * as they get called from within inline assembly.
+ */
+
+.macro check_range size:req
+.if IS_ENABLED(CONFIG_X86_64)
+ mov %rcx, %rbx
+ sar $63, %rbx
+ or %rbx, %rcx
+.else
+ cmp $TASK_SIZE_MAX-\size+1, %ecx
+ jae .Lbad_put_user
+.endif
+.endm
+
+.text
+SYM_FUNC_START(__put_user_1)
+ ANNOTATE_NOENDBR
+ check_range size=1
+ ASM_STAC
+1: movb %al,(%_ASM_CX)
+ xor %ecx,%ecx
+ ASM_CLAC
+ RET
+SYM_FUNC_END(__put_user_1)
+EXPORT_SYMBOL(__put_user_1)
+
+SYM_FUNC_START(__put_user_nocheck_1)
+ ANNOTATE_NOENDBR
+ ASM_STAC
+2: movb %al,(%_ASM_CX)
+ xor %ecx,%ecx
+ ASM_CLAC
+ RET
+SYM_FUNC_END(__put_user_nocheck_1)
+EXPORT_SYMBOL(__put_user_nocheck_1)
+
+SYM_FUNC_START(__put_user_2)
+ ANNOTATE_NOENDBR
+ check_range size=2
+ ASM_STAC
+3: movw %ax,(%_ASM_CX)
+ xor %ecx,%ecx
+ ASM_CLAC
+ RET
+SYM_FUNC_END(__put_user_2)
+EXPORT_SYMBOL(__put_user_2)
+
+SYM_FUNC_START(__put_user_nocheck_2)
+ ANNOTATE_NOENDBR
+ ASM_STAC
+4: movw %ax,(%_ASM_CX)
+ xor %ecx,%ecx
+ ASM_CLAC
+ RET
+SYM_FUNC_END(__put_user_nocheck_2)
+EXPORT_SYMBOL(__put_user_nocheck_2)
+
+SYM_FUNC_START(__put_user_4)
+ ANNOTATE_NOENDBR
+ check_range size=4
+ ASM_STAC
+5: movl %eax,(%_ASM_CX)
+ xor %ecx,%ecx
+ ASM_CLAC
+ RET
+SYM_FUNC_END(__put_user_4)
+EXPORT_SYMBOL(__put_user_4)
+
+SYM_FUNC_START(__put_user_nocheck_4)
+ ANNOTATE_NOENDBR
+ ASM_STAC
+6: movl %eax,(%_ASM_CX)
+ xor %ecx,%ecx
+ ASM_CLAC
+ RET
+SYM_FUNC_END(__put_user_nocheck_4)
+EXPORT_SYMBOL(__put_user_nocheck_4)
+
+SYM_FUNC_START(__put_user_8)
+ ANNOTATE_NOENDBR
+ check_range size=8
+ ASM_STAC
+7: mov %_ASM_AX,(%_ASM_CX)
+#ifdef CONFIG_X86_32
+8: movl %edx,4(%_ASM_CX)
+#endif
+ xor %ecx,%ecx
+ ASM_CLAC
+ RET
+SYM_FUNC_END(__put_user_8)
+EXPORT_SYMBOL(__put_user_8)
+
+SYM_FUNC_START(__put_user_nocheck_8)
+ ANNOTATE_NOENDBR
+ ASM_STAC
+9: mov %_ASM_AX,(%_ASM_CX)
+#ifdef CONFIG_X86_32
+10: movl %edx,4(%_ASM_CX)
+#endif
+ xor %ecx,%ecx
+ ASM_CLAC
+ RET
+SYM_FUNC_END(__put_user_nocheck_8)
+EXPORT_SYMBOL(__put_user_nocheck_8)
+
+SYM_CODE_START_LOCAL(__put_user_handle_exception)
+ ASM_CLAC
+.Lbad_put_user:
+ movl $-EFAULT,%ecx
+ RET
+SYM_CODE_END(__put_user_handle_exception)
+
+ _ASM_EXTABLE_UA(1b, __put_user_handle_exception)
+ _ASM_EXTABLE_UA(2b, __put_user_handle_exception)
+ _ASM_EXTABLE_UA(3b, __put_user_handle_exception)
+ _ASM_EXTABLE_UA(4b, __put_user_handle_exception)
+ _ASM_EXTABLE_UA(5b, __put_user_handle_exception)
+ _ASM_EXTABLE_UA(6b, __put_user_handle_exception)
+ _ASM_EXTABLE_UA(7b, __put_user_handle_exception)
+ _ASM_EXTABLE_UA(9b, __put_user_handle_exception)
+#ifdef CONFIG_X86_32
+ _ASM_EXTABLE_UA(8b, __put_user_handle_exception)
+ _ASM_EXTABLE_UA(10b, __put_user_handle_exception)
+#endif