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()
This commit is contained in:
Linus Torvalds 2010-09-14 17:07:51 -07:00
commit 9c03f1622a
11 changed files with 46 additions and 16 deletions

View file

@ -199,7 +199,7 @@ ptr_to_compat(void __user *uptr)
} }
static __inline__ void __user * 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); struct pt_regs *regs = task_pt_regs(current);
return (void __user *) (((regs->r12 & 0xffffffff) & -16) - len); return (void __user *) (((regs->r12 & 0xffffffff) & -16) - len);

View file

@ -145,7 +145,7 @@ static inline compat_uptr_t ptr_to_compat(void __user *uptr)
return (u32)(unsigned long)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 *) struct pt_regs *regs = (struct pt_regs *)
((unsigned long) current_thread_info() + THREAD_SIZE - 32) - 1; ((unsigned long) current_thread_info() + THREAD_SIZE - 32) - 1;

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@ -147,7 +147,7 @@ static inline compat_uptr_t ptr_to_compat(void __user *uptr)
return (u32)(unsigned long)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; struct pt_regs *regs = &current->thread.regs;
return (void __user *)regs->gr[30]; return (void __user *)regs->gr[30];

View file

@ -134,7 +134,7 @@ static inline compat_uptr_t ptr_to_compat(void __user *uptr)
return (u32)(unsigned long)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; struct pt_regs *regs = current->thread.regs;
unsigned long usp = regs->gpr[1]; unsigned long usp = regs->gpr[1];

View file

@ -181,7 +181,7 @@ static inline int is_compat_task(void)
#endif #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; unsigned long stack;

View file

@ -167,7 +167,7 @@ static inline compat_uptr_t ptr_to_compat(void __user *uptr)
return (u32)(unsigned long)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; struct pt_regs *regs = current_thread_info()->kregs;
unsigned long usp = regs->u_regs[UREG_I6]; unsigned long usp = regs->u_regs[UREG_I6];

View file

@ -195,7 +195,7 @@ static inline unsigned long ptr_to_compat_reg(void __user *uptr)
return (long)(int)(long __force)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); struct pt_regs *regs = task_pt_regs(current);
return (void __user *)regs->sp - len; return (void __user *)regs->sp - len;

View file

@ -50,7 +50,12 @@
/* /*
* Reload arg registers from stack in case ptrace changed them. * Reload arg registers from stack in case ptrace changed them.
* We don't reload %eax because syscall_trace_enter() returned * 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 .macro LOAD_ARGS32 offset, _r9=0
.if \_r9 .if \_r9
@ -60,6 +65,7 @@
movl \offset+48(%rsp),%edx movl \offset+48(%rsp),%edx
movl \offset+56(%rsp),%esi movl \offset+56(%rsp),%esi
movl \offset+64(%rsp),%edi movl \offset+64(%rsp),%edi
movl %eax,%eax /* zero extension */
.endm .endm
.macro CFI_STARTPROC32 simple .macro CFI_STARTPROC32 simple
@ -153,7 +159,7 @@ ENTRY(ia32_sysenter_target)
testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%r10) testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%r10)
CFI_REMEMBER_STATE CFI_REMEMBER_STATE
jnz sysenter_tracesys jnz sysenter_tracesys
cmpl $(IA32_NR_syscalls-1),%eax cmpq $(IA32_NR_syscalls-1),%rax
ja ia32_badsys ja ia32_badsys
sysenter_do_call: sysenter_do_call:
IA32_ARG_FIXUP IA32_ARG_FIXUP
@ -195,7 +201,7 @@ sysexit_from_sys_call:
movl $AUDIT_ARCH_I386,%edi /* 1st arg: audit arch */ movl $AUDIT_ARCH_I386,%edi /* 1st arg: audit arch */
call audit_syscall_entry call audit_syscall_entry
movl RAX-ARGOFFSET(%rsp),%eax /* reload syscall number */ movl RAX-ARGOFFSET(%rsp),%eax /* reload syscall number */
cmpl $(IA32_NR_syscalls-1),%eax cmpq $(IA32_NR_syscalls-1),%rax
ja ia32_badsys ja ia32_badsys
movl %ebx,%edi /* reload 1st syscall arg */ movl %ebx,%edi /* reload 1st syscall arg */
movl RCX-ARGOFFSET(%rsp),%esi /* reload 2nd syscall arg */ movl RCX-ARGOFFSET(%rsp),%esi /* reload 2nd syscall arg */
@ -248,7 +254,7 @@ sysenter_tracesys:
call syscall_trace_enter call syscall_trace_enter
LOAD_ARGS32 ARGOFFSET /* reload args from stack in case ptrace changed it */ LOAD_ARGS32 ARGOFFSET /* reload args from stack in case ptrace changed it */
RESTORE_REST 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) */ ja int_ret_from_sys_call /* sysenter_tracesys has set RAX(%rsp) */
jmp sysenter_do_call jmp sysenter_do_call
CFI_ENDPROC CFI_ENDPROC
@ -314,7 +320,7 @@ ENTRY(ia32_cstar_target)
testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%r10) testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%r10)
CFI_REMEMBER_STATE CFI_REMEMBER_STATE
jnz cstar_tracesys jnz cstar_tracesys
cmpl $IA32_NR_syscalls-1,%eax cmpq $IA32_NR_syscalls-1,%rax
ja ia32_badsys ja ia32_badsys
cstar_do_call: cstar_do_call:
IA32_ARG_FIXUP 1 IA32_ARG_FIXUP 1
@ -367,7 +373,7 @@ cstar_tracesys:
LOAD_ARGS32 ARGOFFSET, 1 /* reload args from stack in case ptrace changed it */ LOAD_ARGS32 ARGOFFSET, 1 /* reload args from stack in case ptrace changed it */
RESTORE_REST RESTORE_REST
xchgl %ebp,%r9d 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) */ ja int_ret_from_sys_call /* cstar_tracesys has set RAX(%rsp) */
jmp cstar_do_call jmp cstar_do_call
END(ia32_cstar_target) END(ia32_cstar_target)
@ -425,7 +431,7 @@ ENTRY(ia32_syscall)
orl $TS_COMPAT,TI_status(%r10) orl $TS_COMPAT,TI_status(%r10)
testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%r10) testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%r10)
jnz ia32_tracesys jnz ia32_tracesys
cmpl $(IA32_NR_syscalls-1),%eax cmpq $(IA32_NR_syscalls-1),%rax
ja ia32_badsys ja ia32_badsys
ia32_do_call: ia32_do_call:
IA32_ARG_FIXUP IA32_ARG_FIXUP
@ -444,7 +450,7 @@ ia32_tracesys:
call syscall_trace_enter call syscall_trace_enter
LOAD_ARGS32 ARGOFFSET /* reload args from stack in case ptrace changed it */ LOAD_ARGS32 ARGOFFSET /* reload args from stack in case ptrace changed it */
RESTORE_REST 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) */ ja int_ret_from_sys_call /* ia32_tracesys has set RAX(%rsp) */
jmp ia32_do_call jmp ia32_do_call
END(ia32_syscall) END(ia32_syscall)

View file

@ -205,7 +205,7 @@ static inline compat_uptr_t ptr_to_compat(void __user *uptr)
return (u32)(unsigned long)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); struct pt_regs *regs = task_pt_regs(current);
return (void __user *)regs->sp - len; return (void __user *)regs->sp - len;

View file

@ -360,5 +360,8 @@ extern ssize_t compat_rw_copy_check_uvector(int type,
const struct compat_iovec __user *uvector, unsigned long nr_segs, const struct compat_iovec __user *uvector, unsigned long nr_segs,
unsigned long fast_segs, struct iovec *fast_pointer, unsigned long fast_segs, struct iovec *fast_pointer,
struct iovec **ret_pointer); struct iovec **ret_pointer);
extern void __user *compat_alloc_user_space(unsigned long len);
#endif /* CONFIG_COMPAT */ #endif /* CONFIG_COMPAT */
#endif /* _LINUX_COMPAT_H */ #endif /* _LINUX_COMPAT_H */

View file

@ -1126,3 +1126,24 @@ compat_sys_sysinfo(struct compat_sysinfo __user *info)
return 0; 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);