diff options
| author | Greg Kurz <gkurz@linux.vnet.ibm.com> | 2014-03-19 17:02:51 +0100 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2014-03-24 09:48:36 +1100 |
| commit | 599d2870425dcde3bf2a7d969d5977baa57feb8b (patch) | |
| tree | 4afbecdcb10bbc2becd8bf61912dbedeb8b371f3 /arch/powerpc | |
| parent | e45fbae51553a57cb591abf24398ed79ecbf8923 (diff) | |
powerpc/le: Big endian arguments for ppc_rtas()
The ppc_rtas() syscall allows userspace to interact directly with RTAS.
For the moment, it assumes every thing is big endian and returns either
EINVAL or EFAULT when called in a little endian environment.
As suggested by Benjamin, to avoid bugs when userspace wants to pass
a non 32 bit value to RTAS, it is far better to stick with a simple
rationale: ppc_rtas() should be called with a big endian rtas_args
structure.
With this patch, it is now up to userspace to forge big endian arguments,
as expected by RTAS.
Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc')
| -rw-r--r-- | arch/powerpc/kernel/rtas.c | 22 |
1 files changed, 13 insertions, 9 deletions
diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c index 4cf674d7d5ae..f386296ff378 100644 --- a/arch/powerpc/kernel/rtas.c +++ b/arch/powerpc/kernel/rtas.c @@ -1013,12 +1013,13 @@ struct pseries_errorlog *get_pseries_errorlog(struct rtas_error_log *log, return NULL; } +/* We assume to be passed big endian arguments */ asmlinkage int ppc_rtas(struct rtas_args __user *uargs) { struct rtas_args args; unsigned long flags; char *buff_copy, *errbuf = NULL; - int nargs; + int nargs, nret, token; int rc; if (!capable(CAP_SYS_ADMIN)) @@ -1027,10 +1028,13 @@ asmlinkage int ppc_rtas(struct rtas_args __user *uargs) if (copy_from_user(&args, uargs, 3 * sizeof(u32)) != 0) return -EFAULT; - nargs = args.nargs; + nargs = be32_to_cpu(args.nargs); + nret = be32_to_cpu(args.nret); + token = be32_to_cpu(args.token); + if (nargs > ARRAY_SIZE(args.args) - || args.nret > ARRAY_SIZE(args.args) - || nargs + args.nret > ARRAY_SIZE(args.args)) + || nret > ARRAY_SIZE(args.args) + || nargs + nret > ARRAY_SIZE(args.args)) return -EINVAL; /* Copy in args. */ @@ -1038,14 +1042,14 @@ asmlinkage int ppc_rtas(struct rtas_args __user *uargs) nargs * sizeof(rtas_arg_t)) != 0) return -EFAULT; - if (args.token == RTAS_UNKNOWN_SERVICE) + if (token == RTAS_UNKNOWN_SERVICE) return -EINVAL; args.rets = &args.args[nargs]; - memset(args.rets, 0, args.nret * sizeof(rtas_arg_t)); + memset(args.rets, 0, nret * sizeof(rtas_arg_t)); /* Need to handle ibm,suspend_me call specially */ - if (args.token == ibm_suspend_me_token) { + if (token == ibm_suspend_me_token) { rc = rtas_ibm_suspend_me(&args); if (rc) return rc; @@ -1062,7 +1066,7 @@ asmlinkage int ppc_rtas(struct rtas_args __user *uargs) /* A -1 return code indicates that the last command couldn't be completed due to a hardware error. */ - if (args.rets[0] == -1) + if (be32_to_cpu(args.rets[0]) == -1) errbuf = __fetch_rtas_last_error(buff_copy); unlock_rtas(flags); @@ -1077,7 +1081,7 @@ asmlinkage int ppc_rtas(struct rtas_args __user *uargs) /* Copy out args. */ if (copy_to_user(uargs->args + nargs, args.args + nargs, - args.nret * sizeof(rtas_arg_t)) != 0) + nret * sizeof(rtas_arg_t)) != 0) return -EFAULT; return 0; |