Merge ssh://master.kernel.org/home/hpa/tree/sec
* ssh://master.kernel.org/home/hpa/tree/sec:
x86-64, compat: Retruncate rax after ia32 syscall entry tracing
x86-64, compat: Test %rax for the syscall number, not %eax
compat: Make compat_alloc_user_space() incorporate the access_ok()
diff --git a/arch/ia64/include/asm/compat.h b/arch/ia64/include/asm/compat.h
index f90edc8..9301a28 100644
--- a/arch/ia64/include/asm/compat.h
+++ b/arch/ia64/include/asm/compat.h
@@ -199,7 +199,7 @@
}
static __inline__ void __user *
-compat_alloc_user_space (long len)
+arch_compat_alloc_user_space (long len)
{
struct pt_regs *regs = task_pt_regs(current);
return (void __user *) (((regs->r12 & 0xffffffff) & -16) - len);
diff --git a/arch/mips/include/asm/compat.h b/arch/mips/include/asm/compat.h
index 613f691..dbc5106 100644
--- a/arch/mips/include/asm/compat.h
+++ b/arch/mips/include/asm/compat.h
@@ -145,7 +145,7 @@
return (u32)(unsigned long)uptr;
}
-static inline void __user *compat_alloc_user_space(long len)
+static inline void __user *arch_compat_alloc_user_space(long len)
{
struct pt_regs *regs = (struct pt_regs *)
((unsigned long) current_thread_info() + THREAD_SIZE - 32) - 1;
diff --git a/arch/parisc/include/asm/compat.h b/arch/parisc/include/asm/compat.h
index 02b77ba..efa0b60c 100644
--- a/arch/parisc/include/asm/compat.h
+++ b/arch/parisc/include/asm/compat.h
@@ -147,7 +147,7 @@
return (u32)(unsigned long)uptr;
}
-static __inline__ void __user *compat_alloc_user_space(long len)
+static __inline__ void __user *arch_compat_alloc_user_space(long len)
{
struct pt_regs *regs = ¤t->thread.regs;
return (void __user *)regs->gr[30];
diff --git a/arch/powerpc/include/asm/compat.h b/arch/powerpc/include/asm/compat.h
index 396d21a..a11d4ea 100644
--- a/arch/powerpc/include/asm/compat.h
+++ b/arch/powerpc/include/asm/compat.h
@@ -134,7 +134,7 @@
return (u32)(unsigned long)uptr;
}
-static inline void __user *compat_alloc_user_space(long len)
+static inline void __user *arch_compat_alloc_user_space(long len)
{
struct pt_regs *regs = current->thread.regs;
unsigned long usp = regs->gpr[1];
diff --git a/arch/s390/include/asm/compat.h b/arch/s390/include/asm/compat.h
index 104f200..a875c2f 100644
--- a/arch/s390/include/asm/compat.h
+++ b/arch/s390/include/asm/compat.h
@@ -181,7 +181,7 @@
#endif
-static inline void __user *compat_alloc_user_space(long len)
+static inline void __user *arch_compat_alloc_user_space(long len)
{
unsigned long stack;
diff --git a/arch/sparc/include/asm/compat.h b/arch/sparc/include/asm/compat.h
index 5016f76..6f57325 100644
--- a/arch/sparc/include/asm/compat.h
+++ b/arch/sparc/include/asm/compat.h
@@ -167,7 +167,7 @@
return (u32)(unsigned long)uptr;
}
-static inline void __user *compat_alloc_user_space(long len)
+static inline void __user *arch_compat_alloc_user_space(long len)
{
struct pt_regs *regs = current_thread_info()->kregs;
unsigned long usp = regs->u_regs[UREG_I6];
diff --git a/arch/tile/include/asm/compat.h b/arch/tile/include/asm/compat.h
index 5a34da6..345d81c 100644
--- a/arch/tile/include/asm/compat.h
+++ b/arch/tile/include/asm/compat.h
@@ -195,7 +195,7 @@
return (long)(int)(long __force)uptr;
}
-static inline void __user *compat_alloc_user_space(long len)
+static inline void __user *arch_compat_alloc_user_space(long len)
{
struct pt_regs *regs = task_pt_regs(current);
return (void __user *)regs->sp - len;
diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S
index b86feab..518bb99 100644
--- a/arch/x86/ia32/ia32entry.S
+++ b/arch/x86/ia32/ia32entry.S
@@ -50,7 +50,12 @@
/*
* Reload arg registers from stack in case ptrace changed them.
* We don't reload %eax because syscall_trace_enter() returned
- * the value it wants us to use in the table lookup.
+ * the %rax value we should see. Instead, we just truncate that
+ * value to 32 bits again as we did on entry from user mode.
+ * If it's a new value set by user_regset during entry tracing,
+ * this matches the normal truncation of the user-mode value.
+ * If it's -1 to make us punt the syscall, then (u32)-1 is still
+ * an appropriately invalid value.
*/
.macro LOAD_ARGS32 offset, _r9=0
.if \_r9
@@ -60,6 +65,7 @@
movl \offset+48(%rsp),%edx
movl \offset+56(%rsp),%esi
movl \offset+64(%rsp),%edi
+ movl %eax,%eax /* zero extension */
.endm
.macro CFI_STARTPROC32 simple
@@ -153,7 +159,7 @@
testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%r10)
CFI_REMEMBER_STATE
jnz sysenter_tracesys
- cmpl $(IA32_NR_syscalls-1),%eax
+ cmpq $(IA32_NR_syscalls-1),%rax
ja ia32_badsys
sysenter_do_call:
IA32_ARG_FIXUP
@@ -195,7 +201,7 @@
movl $AUDIT_ARCH_I386,%edi /* 1st arg: audit arch */
call audit_syscall_entry
movl RAX-ARGOFFSET(%rsp),%eax /* reload syscall number */
- cmpl $(IA32_NR_syscalls-1),%eax
+ cmpq $(IA32_NR_syscalls-1),%rax
ja ia32_badsys
movl %ebx,%edi /* reload 1st syscall arg */
movl RCX-ARGOFFSET(%rsp),%esi /* reload 2nd syscall arg */
@@ -248,7 +254,7 @@
call syscall_trace_enter
LOAD_ARGS32 ARGOFFSET /* reload args from stack in case ptrace changed it */
RESTORE_REST
- cmpl $(IA32_NR_syscalls-1),%eax
+ cmpq $(IA32_NR_syscalls-1),%rax
ja int_ret_from_sys_call /* sysenter_tracesys has set RAX(%rsp) */
jmp sysenter_do_call
CFI_ENDPROC
@@ -314,7 +320,7 @@
testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%r10)
CFI_REMEMBER_STATE
jnz cstar_tracesys
- cmpl $IA32_NR_syscalls-1,%eax
+ cmpq $IA32_NR_syscalls-1,%rax
ja ia32_badsys
cstar_do_call:
IA32_ARG_FIXUP 1
@@ -367,7 +373,7 @@
LOAD_ARGS32 ARGOFFSET, 1 /* reload args from stack in case ptrace changed it */
RESTORE_REST
xchgl %ebp,%r9d
- cmpl $(IA32_NR_syscalls-1),%eax
+ cmpq $(IA32_NR_syscalls-1),%rax
ja int_ret_from_sys_call /* cstar_tracesys has set RAX(%rsp) */
jmp cstar_do_call
END(ia32_cstar_target)
@@ -425,7 +431,7 @@
orl $TS_COMPAT,TI_status(%r10)
testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%r10)
jnz ia32_tracesys
- cmpl $(IA32_NR_syscalls-1),%eax
+ cmpq $(IA32_NR_syscalls-1),%rax
ja ia32_badsys
ia32_do_call:
IA32_ARG_FIXUP
@@ -444,7 +450,7 @@
call syscall_trace_enter
LOAD_ARGS32 ARGOFFSET /* reload args from stack in case ptrace changed it */
RESTORE_REST
- cmpl $(IA32_NR_syscalls-1),%eax
+ cmpq $(IA32_NR_syscalls-1),%rax
ja int_ret_from_sys_call /* ia32_tracesys has set RAX(%rsp) */
jmp ia32_do_call
END(ia32_syscall)
diff --git a/arch/x86/include/asm/compat.h b/arch/x86/include/asm/compat.h
index 306160e..1d9cd27 100644
--- a/arch/x86/include/asm/compat.h
+++ b/arch/x86/include/asm/compat.h
@@ -205,7 +205,7 @@
return (u32)(unsigned long)uptr;
}
-static inline void __user *compat_alloc_user_space(long len)
+static inline void __user *arch_compat_alloc_user_space(long len)
{
struct pt_regs *regs = task_pt_regs(current);
return (void __user *)regs->sp - len;
diff --git a/include/linux/compat.h b/include/linux/compat.h
index 9ddc878..5778b55 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -360,5 +360,8 @@
const struct compat_iovec __user *uvector, unsigned long nr_segs,
unsigned long fast_segs, struct iovec *fast_pointer,
struct iovec **ret_pointer);
+
+extern void __user *compat_alloc_user_space(unsigned long len);
+
#endif /* CONFIG_COMPAT */
#endif /* _LINUX_COMPAT_H */
diff --git a/kernel/compat.c b/kernel/compat.c
index e167efc..c9e2ec0 100644
--- a/kernel/compat.c
+++ b/kernel/compat.c
@@ -1126,3 +1126,24 @@
return 0;
}
+
+/*
+ * Allocate user-space memory for the duration of a single system call,
+ * in order to marshall parameters inside a compat thunk.
+ */
+void __user *compat_alloc_user_space(unsigned long len)
+{
+ void __user *ptr;
+
+ /* If len would occupy more than half of the entire compat space... */
+ if (unlikely(len > (((compat_uptr_t)~0) >> 1)))
+ return NULL;
+
+ ptr = arch_compat_alloc_user_space(len);
+
+ if (unlikely(!access_ok(VERIFY_WRITE, ptr, len)))
+ return NULL;
+
+ return ptr;
+}
+EXPORT_SYMBOL_GPL(compat_alloc_user_space);
