On Mon, Mar 16, 2015 at 03:04:05PM -0400, Chris Metcalf wrote:
> To be compatible with the generic get_compat_sigevent(), the
> copy_siginfo_to_user32() and thus copy_siginfo_from_user32()
> have to use si_int instead of si_ptr. Using si_ptr means that
> for the case of ILP32 compat code running in big-endian mode,
> we would end up copying the high 32 bits of the pointer value
> into si_int instead of the desired low 32 bits.
>
> Signed-off-by: Chris Metcalf <cmetcalf@xxxxxxxxxx>
> Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
> ---
> arch/tile/kernel/compat_signal.c | 9 +++------
> 1 file changed, 3 insertions(+), 6 deletions(-)
>
> diff --git a/arch/tile/kernel/compat_signal.c b/arch/tile/kernel/compat_signal.c
> index 8c5abf2e4794..bca13054afb4 100644
> --- a/arch/tile/kernel/compat_signal.c
> +++ b/arch/tile/kernel/compat_signal.c
> @@ -68,7 +68,7 @@ int copy_siginfo_to_user32(struct compat_siginfo __user *to, const siginfo_t *fr
> if (from->si_code < 0) {
> err |= __put_user(from->si_pid, &to->si_pid);
> err |= __put_user(from->si_uid, &to->si_uid);
> - err |= __put_user(ptr_to_compat(from->si_ptr), &to->si_ptr);
> + err |= __put_user(from->si_int, &to->si_int);
> } else {
> /*
> * First 32bits of unions are always present:
> @@ -93,8 +93,7 @@ int copy_siginfo_to_user32(struct compat_siginfo __user *to, const siginfo_t *fr
> break;
> case __SI_TIMER >> 16:
> err |= __put_user(from->si_overrun, &to->si_overrun);
> - err |= __put_user(ptr_to_compat(from->si_ptr),
> - &to->si_ptr);
> + err |= __put_user(from->si_int, &to->si_int);
> break;
It's usually the __SI_TIMER and __SI_MESGQ cases that matters here (the
latter already handled). I'm not entirely sure about the si_code < 0
change.
> /* This is not generated by the kernel as of now. */
> case __SI_RT >> 16:
> @@ -110,7 +109,6 @@ int copy_siginfo_to_user32(struct compat_siginfo __user *to, const siginfo_t *fr
> int copy_siginfo_from_user32(siginfo_t *to, struct compat_siginfo __user *from)
> {
> int err;
> - u32 ptr32;
>
> if (!access_ok(VERIFY_READ, from, sizeof(struct compat_siginfo)))
> return -EFAULT;
> @@ -121,8 +119,7 @@ int copy_siginfo_from_user32(siginfo_t *to, struct compat_siginfo __user *from)
>
> err |= __get_user(to->si_pid, &from->si_pid);
> err |= __get_user(to->si_uid, &from->si_uid);
> - err |= __get_user(ptr32, &from->si_ptr);
> - to->si_ptr = compat_ptr(ptr32);
> + err |= __get_user(to->si_int, &from->si_int);
We have a memset(to, 0, sizeof(*to)) on arm64 in this function but I
can't see it on tile. Some members or even half of si_ptr would be left
uninitialised.
--
Catalin
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