openkylin
/
linux
mirror of https://gitee.com/openkylin/linux.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity

x86/mpx: Use signed variables to compute effective addresses 

Even though memory addresses are unsigned, the operands used to compute the
effective address do have a sign. This is true for ModRM.rm, SIB.base,
SIB.index as well as the displacement bytes. Thus, signed variables shall
be used when computing the effective address from these operands. Once the
signed effective address has been computed, it is casted to an unsigned
long to determine the linear address.

Variables are renamed to better reflect the type of address being
computed.

Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Adan Hawthorn <adanhawthorn@gmail.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: ricardo.neri@intel.com
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Huang Rui <ray.huang@amd.com>
Cc: Qiaowei Ren <qiaowei.ren@intel.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Nathan Howard <liverlint@gmail.com>
Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Chen Yucong <slaoub@gmail.com>
Cc: Adam Buchbinder <adam.buchbinder@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Joe Perches <joe@perches.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.kernel.org/r/1509135945-13762-7-git-send-email-ricardo.neri-calderon@linux.intel.com
This commit is contained in:
Ricardo Neri 2017-10-27 13:25:33 -07:00 committed by Thomas Gleixner
parent b15d70df6e
commit b8d2eff3b1
1 changed files with 14 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
arch/x86/mm/mpx.c
View File

@ -138,8 +138,9 @@ static int get_reg_offset(struct insn *insn, struct pt_regs *regs,
*/
static void __user *mpx_get_addr_ref(struct insn *insn, struct pt_regs *regs)
{
unsigned long addr = -1L, base, indx;
int addr_offset, base_offset, indx_offset;
unsigned long linear_addr = -1L;
long eff_addr, base, indx;
insn_byte_t sib;
insn_get_modrm(insn);
@ -150,7 +151,8 @@ static void __user *mpx_get_addr_ref(struct insn *insn, struct pt_regs *regs)
addr_offset = get_reg_offset(insn, regs, REG_TYPE_RM);
if (addr_offset < 0)
goto out;
addr = regs_get_register(regs, addr_offset);
eff_addr = regs_get_register(regs, addr_offset);
} else {
if (insn->sib.nbytes) {
base_offset = get_reg_offset(insn, regs, REG_TYPE_BASE);
@ -163,17 +165,23 @@ static void __user *mpx_get_addr_ref(struct insn *insn, struct pt_regs *regs)
base = regs_get_register(regs, base_offset);
indx = regs_get_register(regs, indx_offset);
addr = base + indx * (1 << X86_SIB_SCALE(sib));
eff_addr = base + indx * (1 << X86_SIB_SCALE(sib));
} else {
addr_offset = get_reg_offset(insn, regs, REG_TYPE_RM);
if (addr_offset < 0)
goto out;
addr = regs_get_register(regs, addr_offset);
eff_addr = regs_get_register(regs, addr_offset);
}
addr += insn->displacement.value;
eff_addr += insn->displacement.value;
}
linear_addr = (unsigned long)eff_addr;
out:
return (void __user *)addr;
return (void __user *)linear_addr;
}
static int mpx_insn_decode(struct insn *insn,