From 11a4180c0b03e2ee0c948fd8430ee092dc1625b3 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Thu, 7 Dec 2006 02:14:06 +0100 Subject: [PATCH] [PATCH] i386: Use probe_kernel_address instead of __get_user in fault paths Makes the intention of the code cleaner to read and avoids a potential deadlock on mmap_sem. Also change the types of the arguments to not include __user because they're really not user addresses. Signed-off-by: Andi Kleen --- arch/i386/kernel/traps.c | 24 +++++++++++++----------- arch/i386/mm/fault.c | 12 ++++++------ 2 files changed, 19 insertions(+), 17 deletions(-) diff --git a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c index 237f488..7b2f9f0 100644 --- a/arch/i386/kernel/traps.c +++ b/arch/i386/kernel/traps.c @@ -380,7 +380,7 @@ void show_registers(struct pt_regs *regs) * time of the fault.. */ if (in_kernel) { - u8 __user *eip; + u8 *eip; int code_bytes = 64; unsigned char c; @@ -389,18 +389,20 @@ void show_registers(struct pt_regs *regs) printk(KERN_EMERG "Code: "); - eip = (u8 __user *)regs->eip - 43; - if (eip < (u8 __user *)PAGE_OFFSET || __get_user(c, eip)) { + eip = (u8 *)regs->eip - 43; + if (eip < (u8 *)PAGE_OFFSET || + probe_kernel_address(eip, c)) { /* try starting at EIP */ - eip = (u8 __user *)regs->eip; + eip = (u8 *)regs->eip; code_bytes = 32; } for (i = 0; i < code_bytes; i++, eip++) { - if (eip < (u8 __user *)PAGE_OFFSET || __get_user(c, eip)) { + if (eip < (u8 *)PAGE_OFFSET || + probe_kernel_address(eip, c)) { printk(" Bad EIP value."); break; } - if (eip == (u8 __user *)regs->eip) + if (eip == (u8 *)regs->eip) printk("<%02x> ", c); else printk("%02x ", c); @@ -416,7 +418,7 @@ static void handle_BUG(struct pt_regs *regs) if (eip < PAGE_OFFSET) return; - if (probe_kernel_address((unsigned short __user *)eip, ud2)) + if (probe_kernel_address((unsigned short *)eip, ud2)) return; if (ud2 != 0x0b0f) return; @@ -429,11 +431,11 @@ static void handle_BUG(struct pt_regs *regs) char *file; char c; - if (probe_kernel_address((unsigned short __user *)(eip + 2), - line)) + if (probe_kernel_address((unsigned short *)(eip + 2), line)) break; - if (__get_user(file, (char * __user *)(eip + 4)) || - (unsigned long)file < PAGE_OFFSET || __get_user(c, file)) + if (probe_kernel_address((char **)(eip + 4), file) || + (unsigned long)file < PAGE_OFFSET || + probe_kernel_address(file, c)) file = ""; printk(KERN_EMERG "kernel BUG at %s:%d!\n", file, line); diff --git a/arch/i386/mm/fault.c b/arch/i386/mm/fault.c index 2581575..aaaa4d2 100644 --- a/arch/i386/mm/fault.c +++ b/arch/i386/mm/fault.c @@ -22,9 +22,9 @@ #include #include #include +#include #include -#include #include #include #include @@ -167,7 +167,7 @@ static inline unsigned long get_segment_eip(struct pt_regs *regs, static int __is_prefetch(struct pt_regs *regs, unsigned long addr) { unsigned long limit; - unsigned long instr = get_segment_eip (regs, &limit); + unsigned char *instr = (unsigned char *)get_segment_eip (regs, &limit); int scan_more = 1; int prefetch = 0; int i; @@ -177,9 +177,9 @@ static int __is_prefetch(struct pt_regs *regs, unsigned long addr) unsigned char instr_hi; unsigned char instr_lo; - if (instr > limit) + if (instr > (unsigned char *)limit) break; - if (__get_user(opcode, (unsigned char __user *) instr)) + if (probe_kernel_address(instr, opcode)) break; instr_hi = opcode & 0xf0; @@ -204,9 +204,9 @@ static int __is_prefetch(struct pt_regs *regs, unsigned long addr) case 0x00: /* Prefetch instruction is 0x0F0D or 0x0F18 */ scan_more = 0; - if (instr > limit) + if (instr > (unsigned char *)limit) break; - if (__get_user(opcode, (unsigned char __user *) instr)) + if (probe_kernel_address(instr, opcode)) break; prefetch = (instr_lo == 0xF) && (opcode == 0x0D || opcode == 0x18); -- 2.7.4