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 f90edc85b50933a9df52391d041ad9f8b1a8ee66..9301a2821615b66cacd781eeba3e53d57e60fe75 100644 (file)
--- a/arch/ia64/include/asm/compat.h
+++ b/arch/ia64/include/asm/compat.h
@@ -199,7 +199,7 @@ ptr_to_compat(void __user *uptr)
 }
 
 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 613f6912dfc1d024b2aa6b28fb4215ba8b251552..dbc51065df5b3fe53611ff15e9cc259188ff0dbc 100644 (file)
--- a/arch/mips/include/asm/compat.h
+++ b/arch/mips/include/asm/compat.h
@@ -145,7 +145,7 @@ static inline compat_uptr_t ptr_to_compat(void __user *uptr)
        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 02b77baa5da69f04729013cd9b6402ffc2dc3c39..efa0b60c63fe683f22629ddd540ed036495cd896 100644 (file)
--- a/arch/parisc/include/asm/compat.h
+++ b/arch/parisc/include/asm/compat.h
@@ -147,7 +147,7 @@ static inline compat_uptr_t ptr_to_compat(void __user *uptr)
        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;
        return (void __user *)regs->gr[30];

diff --git a/arch/powerpc/include/asm/compat.h b/arch/powerpc/include/asm/compat.h
index 396d21a800587f0c8a740714a3277a743d2618cc..a11d4eac4f97f369f48866a7475696879b8be5d3 100644 (file)
--- a/arch/powerpc/include/asm/compat.h
+++ b/arch/powerpc/include/asm/compat.h
@@ -134,7 +134,7 @@ static inline compat_uptr_t ptr_to_compat(void __user *uptr)
        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 104f2007f097720b339e469d37b7732c120c8168..a875c2f542e1070a120b484c96a0d2fc10fc55cb 100644 (file)
--- a/arch/s390/include/asm/compat.h
+++ b/arch/s390/include/asm/compat.h
@@ -181,7 +181,7 @@ static inline int is_compat_task(void)
 
 #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 5016f76ea98a6f38510d3dc5a8593a1d871d4f53..6f57325bb883c5553b4781691cd699952bb90ff8 100644 (file)
--- a/arch/sparc/include/asm/compat.h
+++ b/arch/sparc/include/asm/compat.h
@@ -167,7 +167,7 @@ static inline compat_uptr_t ptr_to_compat(void __user *uptr)
        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 5a34da6cdd79a18802d437056393c41d6e2f6fba..345d81ce44bb81f51c47ebc0cdc8559a4f00b53a 100644 (file)
--- a/arch/tile/include/asm/compat.h
+++ b/arch/tile/include/asm/compat.h
@@ -195,7 +195,7 @@ static inline unsigned long ptr_to_compat_reg(void __user *uptr)
        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 b86feabed69bfe8e74f81f179c91fbe3a4b799d8..518bb99c339480820fc3995b1456d29704d67f07 100644 (file)
--- 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 @@ ENTRY(ia32_sysenter_target)
        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 @@ sysexit_from_sys_call:
        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 @@ sysenter_tracesys:
        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 @@ ENTRY(ia32_cstar_target)
        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 @@ cstar_tracesys:
        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 @@ ENTRY(ia32_syscall)
        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 @@ ia32_tracesys:
        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 306160e58b48772ccef1f65c803a3a3813ff5d1e..1d9cd27c2920a326e5ac2440ebdbd998d0b925c0 100644 (file)
--- a/arch/x86/include/asm/compat.h
+++ b/arch/x86/include/asm/compat.h
@@ -205,7 +205,7 @@ static inline compat_uptr_t ptr_to_compat(void __user *uptr)
        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 9ddc8780e8db7bfe45496587bc47e5fb00d12073..5778b559d59c3222ee825897b7430523aa96c353 100644 (file)
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -360,5 +360,8 @@ extern ssize_t compat_rw_copy_check_uvector(int type,
                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 e167efce8423e2cdaf2709412c36cc3ae642c90f..c9e2ec0b34a8cc38cda604273618a22c8d2d928c 100644 (file)
--- a/kernel/compat.c
+++ b/kernel/compat.c
@@ -1126,3 +1126,24 @@ compat_sys_sysinfo(struct compat_sysinfo __user *info)
 
        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);