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Message-Id: <20200327023205.881896-22-viro@ZenIV.linux.org.uk>
Date: Fri, 27 Mar 2020 02:32:05 +0000
From: Al Viro <viro@...IV.linux.org.uk>
To: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Thomas Gleixner <tglx@...utronix.de>, x86@...nel.org,
linux-kernel@...r.kernel.org
Subject: [RFC][PATCH v2 22/22] kill uaccess_try()
From: Al Viro <viro@...iv.linux.org.uk>
finally
Signed-off-by: Al Viro <viro@...iv.linux.org.uk>
---
Documentation/x86/exception-tables.rst | 6 ----
arch/x86/include/asm/asm.h | 6 ----
arch/x86/include/asm/processor.h | 1 -
arch/x86/include/asm/uaccess.h | 65 ----------------------------------
arch/x86/mm/extable.c | 12 -------
5 files changed, 90 deletions(-)
diff --git a/Documentation/x86/exception-tables.rst b/Documentation/x86/exception-tables.rst
index ed6d4b0cf62c..514f51829da7 100644
--- a/Documentation/x86/exception-tables.rst
+++ b/Documentation/x86/exception-tables.rst
@@ -337,10 +337,4 @@ pointer which points to one of:
entry->insn. It is used to distinguish page faults from machine
check.
-3) ``int ex_handler_ext(const struct exception_table_entry *fixup)``
- This case is used for uaccess_err ... we need to set a flag
- in the task structure. Before the handler functions existed this
- case was handled by adding a large offset to the fixup to tag
- it as special.
-
More functions can easily be added.
diff --git a/arch/x86/include/asm/asm.h b/arch/x86/include/asm/asm.h
index cd339b88d5d4..0f63585edf5f 100644
--- a/arch/x86/include/asm/asm.h
+++ b/arch/x86/include/asm/asm.h
@@ -138,9 +138,6 @@
# define _ASM_EXTABLE_FAULT(from, to) \
_ASM_EXTABLE_HANDLE(from, to, ex_handler_fault)
-# define _ASM_EXTABLE_EX(from, to) \
- _ASM_EXTABLE_HANDLE(from, to, ex_handler_ext)
-
# define _ASM_NOKPROBE(entry) \
.pushsection "_kprobe_blacklist","aw" ; \
_ASM_ALIGN ; \
@@ -166,9 +163,6 @@
# define _ASM_EXTABLE_FAULT(from, to) \
_ASM_EXTABLE_HANDLE(from, to, ex_handler_fault)
-# define _ASM_EXTABLE_EX(from, to) \
- _ASM_EXTABLE_HANDLE(from, to, ex_handler_ext)
-
/* For C file, we already have NOKPROBE_SYMBOL macro */
#endif
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 09705ccc393c..19718fcfdd6a 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -541,7 +541,6 @@ struct thread_struct {
mm_segment_t addr_limit;
unsigned int sig_on_uaccess_err:1;
- unsigned int uaccess_err:1; /* uaccess failed */
/* Floating point and extended processor state */
struct fpu fpu;
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index 4dc5accdd826..d11662f753d2 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -193,23 +193,12 @@ __typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL))
: : "A" (x), "r" (addr) \
: : label)
-#define __put_user_asm_ex_u64(x, addr) \
- asm volatile("\n" \
- "1: movl %%eax,0(%1)\n" \
- "2: movl %%edx,4(%1)\n" \
- "3:" \
- _ASM_EXTABLE_EX(1b, 2b) \
- _ASM_EXTABLE_EX(2b, 3b) \
- : : "A" (x), "r" (addr))
-
#define __put_user_x8(x, ptr, __ret_pu) \
asm volatile("call __put_user_8" : "=a" (__ret_pu) \
: "A" ((typeof(*(ptr)))(x)), "c" (ptr) : "ebx")
#else
#define __put_user_goto_u64(x, ptr, label) \
__put_user_goto(x, ptr, "q", "", "er", label)
-#define __put_user_asm_ex_u64(x, addr) \
- __put_user_asm_ex(x, addr, "q", "", "er")
#define __put_user_x8(x, ptr, __ret_pu) __put_user_x(8, x, ptr, __ret_pu)
#endif
@@ -289,31 +278,6 @@ do { \
} \
} while (0)
-/*
- * This doesn't do __uaccess_begin/end - the exception handling
- * around it must do that.
- */
-#define __put_user_size_ex(x, ptr, size) \
-do { \
- __chk_user_ptr(ptr); \
- switch (size) { \
- case 1: \
- __put_user_asm_ex(x, ptr, "b", "b", "iq"); \
- break; \
- case 2: \
- __put_user_asm_ex(x, ptr, "w", "w", "ir"); \
- break; \
- case 4: \
- __put_user_asm_ex(x, ptr, "l", "k", "ir"); \
- break; \
- case 8: \
- __put_user_asm_ex_u64((__typeof__(*ptr))(x), ptr); \
- break; \
- default: \
- __put_user_bad(); \
- } \
-} while (0)
-
#ifdef CONFIG_X86_32
#define __get_user_asm_u64(x, ptr, retval, errret) \
({ \
@@ -430,29 +394,6 @@ struct __large_struct { unsigned long buf[100]; };
retval = __put_user_failed(x, addr, itype, rtype, ltype, errret); \
} while (0)
-#define __put_user_asm_ex(x, addr, itype, rtype, ltype) \
- asm volatile("1: mov"itype" %"rtype"0,%1\n" \
- "2:\n" \
- _ASM_EXTABLE_EX(1b, 2b) \
- : : ltype(x), "m" (__m(addr)))
-
-/*
- * uaccess_try and catch
- */
-#define uaccess_try do { \
- current->thread.uaccess_err = 0; \
- __uaccess_begin(); \
- barrier();
-
-#define uaccess_try_nospec do { \
- current->thread.uaccess_err = 0; \
- __uaccess_begin_nospec(); \
-
-#define uaccess_catch(err) \
- __uaccess_end(); \
- (err) |= (current->thread.uaccess_err ? -EFAULT : 0); \
-} while (0)
-
/**
* __get_user - Get a simple variable from user space, with less checking.
* @x: Variable to store result.
@@ -502,12 +443,6 @@ struct __large_struct { unsigned long buf[100]; };
#define __put_user(x, ptr) \
__put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
-#define put_user_try uaccess_try
-#define put_user_catch(err) uaccess_catch(err)
-
-#define put_user_ex(x, ptr) \
- __put_user_size_ex((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
-
extern unsigned long
copy_from_user_nmi(void *to, const void __user *from, unsigned long n);
extern __must_check long
diff --git a/arch/x86/mm/extable.c b/arch/x86/mm/extable.c
index 30bb0bd3b1b8..b991aa4bdfae 100644
--- a/arch/x86/mm/extable.c
+++ b/arch/x86/mm/extable.c
@@ -80,18 +80,6 @@ __visible bool ex_handler_uaccess(const struct exception_table_entry *fixup,
}
EXPORT_SYMBOL(ex_handler_uaccess);
-__visible bool ex_handler_ext(const struct exception_table_entry *fixup,
- struct pt_regs *regs, int trapnr,
- unsigned long error_code,
- unsigned long fault_addr)
-{
- /* Special hack for uaccess_err */
- current->thread.uaccess_err = 1;
- regs->ip = ex_fixup_addr(fixup);
- return true;
-}
-EXPORT_SYMBOL(ex_handler_ext);
-
__visible bool ex_handler_rdmsr_unsafe(const struct exception_table_entry *fixup,
struct pt_regs *regs, int trapnr,
unsigned long error_code,
--
2.11.0
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