queue-4.19/arm64-use-the-correct-function-type-for-__arm64_sys_.patch

   1 From 7fdbf7a52757d00ff8e7fd9a19e8bfa7c5fe190b Mon Sep 17 00:00:00 2001
   2 From: Sami Tolvanen <samitolvanen@google.com>
   3 Date: Fri, 24 May 2019 15:11:18 -0700
   4 Subject: arm64: use the correct function type for __arm64_sys_ni_syscall
   5
   6 [ Upstream commit 1e29ab3186e33c77dbb2d7566172a205b59fa390 ]
   7
   8 Calling sys_ni_syscall through a syscall_fn_t pointer trips indirect
   9 call Control-Flow Integrity checking due to a function type
  10 mismatch. Use SYSCALL_DEFINE0 for __arm64_sys_ni_syscall instead and
  11 remove the now unnecessary casts.
  12
  13 Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
  14 Signed-off-by: Will Deacon <will.deacon@arm.com>
  15 Signed-off-by: Sasha Levin <sashal@kernel.org>
  16 ---
  17  arch/arm64/kernel/sys.c   | 14 +++++++++-----
  18  arch/arm64/kernel/sys32.c |  7 ++-----
  19  2 files changed, 11 insertions(+), 10 deletions(-)
  20
  21 diff --git a/arch/arm64/kernel/sys.c b/arch/arm64/kernel/sys.c
  22 index 162a95ed0881..fe20c461582a 100644
  23 --- a/arch/arm64/kernel/sys.c
  24 +++ b/arch/arm64/kernel/sys.c
  25 @@ -47,22 +47,26 @@ SYSCALL_DEFINE1(arm64_personality, unsigned int, personality)
  26         return ksys_personality(personality);
  27  }
  28
  29 +asmlinkage long sys_ni_syscall(void);
  30 +
  31 +asmlinkage long __arm64_sys_ni_syscall(const struct pt_regs *__unused)
  32 +{
  33 +       return sys_ni_syscall();
  34 +}
  35 +
  36  /*
  37   * Wrappers to pass the pt_regs argument.
  38   */
  39  #define __arm64_sys_personality                __arm64_sys_arm64_personality
  40
  41 -asmlinkage long sys_ni_syscall(const struct pt_regs *);
  42 -#define __arm64_sys_ni_syscall sys_ni_syscall
  43 -
  44  #undef __SYSCALL
  45  #define __SYSCALL(nr, sym)     asmlinkage long __arm64_##sym(const struct pt_regs *);
  46  #include <asm/unistd.h>
  47
  48  #undef __SYSCALL
  49 -#define __SYSCALL(nr, sym)     [nr] = (syscall_fn_t)__arm64_##sym,
  50 +#define __SYSCALL(nr, sym)     [nr] = __arm64_##sym,
  51
  52  const syscall_fn_t sys_call_table[__NR_syscalls] = {
  53 -       [0 ... __NR_syscalls - 1] = (syscall_fn_t)sys_ni_syscall,
  54 +       [0 ... __NR_syscalls - 1] = __arm64_sys_ni_syscall,
  55  #include <asm/unistd.h>
  56  };
  57 diff --git a/arch/arm64/kernel/sys32.c b/arch/arm64/kernel/sys32.c
  58 index 0f8bcb7de700..3c80a40c1c9d 100644
  59 --- a/arch/arm64/kernel/sys32.c
  60 +++ b/arch/arm64/kernel/sys32.c
  61 @@ -133,17 +133,14 @@ COMPAT_SYSCALL_DEFINE6(aarch32_fallocate, int, fd, int, mode,
  62         return ksys_fallocate(fd, mode, arg_u64(offset), arg_u64(len));
  63  }
  64
  65 -asmlinkage long sys_ni_syscall(const struct pt_regs *);
  66 -#define __arm64_sys_ni_syscall sys_ni_syscall
  67 -
  68  #undef __SYSCALL
  69  #define __SYSCALL(nr, sym)     asmlinkage long __arm64_##sym(const struct pt_regs *);
  70  #include <asm/unistd32.h>
  71
  72  #undef __SYSCALL
  73 -#define __SYSCALL(nr, sym)     [nr] = (syscall_fn_t)__arm64_##sym,
  74 +#define __SYSCALL(nr, sym)     [nr] = __arm64_##sym,
  75
  76  const syscall_fn_t compat_sys_call_table[__NR_compat_syscalls] = {
  77 -       [0 ... __NR_compat_syscalls - 1] = (syscall_fn_t)sys_ni_syscall,
  78 +       [0 ... __NR_compat_syscalls - 1] = __arm64_sys_ni_syscall,
  79  #include <asm/unistd32.h>
  80  };
  81 --
  82 2.20.1
  83