work around broken kernel struct ipc_perm on some big endian archs

the mode member of struct ipc_perm is specified by POSIX to have type
mode_t, which is uniformly defined as unsigned int. however, Linux
defines it with type __kernel_mode_t, and defines __kernel_mode_t as
unsigned short on some archs. since there is a subsequent padding
field, treating it as a 32-bit unsigned int works on little endian
archs, but the order is backwards on big endian archs with the
erroneous definition.

since multiple archs are affected, remedy the situation with fixup
code in the affected functions (shmctl, semctl, and msgctl) rather
than repeating the same shims in syscall_arch.h for every affected
arch.

diff --git a/arch/arm/syscall_arch.h b/arch/arm/syscall_arch.h
index 4db7d152f23bef7eff3044faecc2b3a69825b710..53fb155c0dcb7e94d3878f3a0634890003552bda 100644 (file)
--- a/arch/arm/syscall_arch.h
+++ b/arch/arm/syscall_arch.h
@@ -103,3 +103,5 @@ static inline long __syscall6(long n, long a, long b, long c, long d, long e, lo
 #define VDSO_CGT_VER "LINUX_2.6"
 
 #define SYSCALL_FADVISE_6_ARG
+
+#define SYSCALL_IPC_BROKEN_MODE

diff --git a/arch/m68k/syscall_arch.h b/arch/m68k/syscall_arch.h
index 53a4256f3fe967399e8a3db507f8afedf154df33..af79c3069061c83581d5f2fb51c39ec48bfa83e4 100644 (file)
--- a/arch/m68k/syscall_arch.h
+++ b/arch/m68k/syscall_arch.h
@@ -88,3 +88,4 @@ static inline long __syscall6(long n, long a, long b, long c, long d, long e, lo
 }
 
 #define SYSCALL_USE_SOCKETCALL
+#define SYSCALL_IPC_BROKEN_MODE

diff --git a/arch/microblaze/syscall_arch.h b/arch/microblaze/syscall_arch.h
index 8e2de7eacc2a8f123c6c13a256b74841baa68b4d..6cf631ad5d317070671c114b8c3080ae021ba6f4 100644 (file)
--- a/arch/microblaze/syscall_arch.h
+++ b/arch/microblaze/syscall_arch.h
@@ -102,3 +102,5 @@ static inline long __syscall6(long n, long a, long b, long c, long d, long e, lo
 #define SYSCALL_NO_INLINE
 
 #endif
+
+#define SYSCALL_IPC_BROKEN_MODE

diff --git a/arch/sh/syscall_arch.h b/arch/sh/syscall_arch.h
index 84758fe0a0bf946d4a57c020345c3df04d7a09c6..48f61d94a2f5d34d92f52e1cfc815fc098b6b6f9 100644 (file)
--- a/arch/sh/syscall_arch.h
+++ b/arch/sh/syscall_arch.h
@@ -86,3 +86,5 @@ static inline long __syscall6(long n, long a, long b, long c, long d, long e, lo
        register long r1 __asm__("r1") = f;
        __asm_syscall(22, "r"(r3), "r"(r4), "r"(r5), "r"(r6), "r"(r7), "0"(r0), "r"(r1));
 }
+
+#define SYSCALL_IPC_BROKEN_MODE

diff --git a/src/ipc/msgctl.c b/src/ipc/msgctl.c
index 4372c71939cad44717423282cc6382842ffed1bd..ea9b23377e47dad684ae1e7cc72df2cab81faf4c 100644 (file)
--- a/src/ipc/msgctl.c
+++ b/src/ipc/msgctl.c
@@ -1,12 +1,34 @@
 #include <sys/msg.h>
+#include <endian.h>
 #include "syscall.h"
 #include "ipc.h"
 
+#if __BYTE_ORDER != __BIG_ENDIAN
+#undef SYSCALL_IPC_BROKEN_MODE
+#endif
+
 int msgctl(int q, int cmd, struct msqid_ds *buf)
 {
+#ifdef SYSCALL_IPC_BROKEN_MODE
+       struct msqid_ds tmp;
+       if (cmd == IPC_SET) {
+               tmp = *buf;
+               tmp.msg_perm.mode *= 0x10000U;
+               buf = &tmp;
+       }
+#endif
 #ifdef SYS_msgctl
-       return syscall(SYS_msgctl, q, cmd | IPC_64, buf);
+       int r = __syscall(SYS_msgctl, q, cmd | IPC_64, buf);
 #else
-       return syscall(SYS_ipc, IPCOP_msgctl, q, cmd | IPC_64, 0, buf, 0);
+       int r = __syscall(SYS_ipc, IPCOP_msgctl, q, cmd | IPC_64, 0, buf, 0);
+#endif
+#ifdef SYSCALL_IPC_BROKEN_MODE
+       if (r >= 0) switch (cmd) {
+       case IPC_STAT:
+       case MSG_STAT:
+       case MSG_STAT_ANY:
+               buf->msg_perm.mode >>= 16;
+       }
 #endif
+       return __syscall_ret(r);
 }

diff --git a/src/ipc/semctl.c b/src/ipc/semctl.c
index 673a9a8c996b2bd18657b1dff7f6934ec34b2d69..941e28136adb5f25b3ad289e3fd541b057e0a3ad 100644 (file)
--- a/src/ipc/semctl.c
+++ b/src/ipc/semctl.c
@@ -1,8 +1,13 @@
 #include <sys/sem.h>
 #include <stdarg.h>
+#include <endian.h>
 #include "syscall.h"
 #include "ipc.h"
 
+#if __BYTE_ORDER != __BIG_ENDIAN
+#undef SYSCALL_IPC_BROKEN_MODE
+#endif
+
 union semun {
        int val;
        struct semid_ds *buf;
@@ -20,9 +25,26 @@ int semctl(int id, int num, int cmd, ...)
                arg = va_arg(ap, union semun);
                va_end(ap);
        }
+#ifdef SYSCALL_IPC_BROKEN_MODE
+       struct semid_ds tmp;
+       if (cmd == IPC_SET) {
+               tmp = *arg.buf;
+               tmp.sem_perm.mode *= 0x10000U;
+               arg.buf = &tmp;
+       }
+#endif
 #ifdef SYS_semctl
-       return syscall(SYS_semctl, id, num, cmd | IPC_64, arg.buf);
+       int r = __syscall(SYS_semctl, id, num, cmd | IPC_64, arg.buf);
 #else
-       return syscall(SYS_ipc, IPCOP_semctl, id, num, cmd | IPC_64, &arg.buf);
+       int r = __syscall(SYS_ipc, IPCOP_semctl, id, num, cmd | IPC_64, &arg.buf);
+#endif
+#ifdef SYSCALL_IPC_BROKEN_MODE
+       if (r >= 0) switch (cmd) {
+       case IPC_STAT:
+       case SEM_STAT:
+       case SEM_STAT_ANY:
+               arg.buf->sem_perm.mode >>= 16;
+       }
 #endif
+       return __syscall_ret(r);
 }

diff --git a/src/ipc/shmctl.c b/src/ipc/shmctl.c
index e2879f20aa8009e15f4b0851a9bf749f4e3dd4ad..c951a58156c92446510e2a98e64ea7a558e2eb83 100644 (file)
--- a/src/ipc/shmctl.c
+++ b/src/ipc/shmctl.c
@@ -1,12 +1,34 @@
 #include <sys/shm.h>
+#include <endian.h>
 #include "syscall.h"
 #include "ipc.h"
 
+#if __BYTE_ORDER != __BIG_ENDIAN
+#undef SYSCALL_IPC_BROKEN_MODE
+#endif
+
 int shmctl(int id, int cmd, struct shmid_ds *buf)
 {
+#ifdef SYSCALL_IPC_BROKEN_MODE
+       struct shmid_ds tmp;
+       if (cmd == IPC_SET) {
+               tmp = *buf;
+               tmp.shm_perm.mode *= 0x10000U;
+               buf = &tmp;
+       }
+#endif
 #ifdef SYS_shmctl
-       return syscall(SYS_shmctl, id, cmd | IPC_64, buf);
+       int r = __syscall(SYS_shmctl, id, cmd | IPC_64, buf);
 #else
-       return syscall(SYS_ipc, IPCOP_shmctl, id, cmd | IPC_64, 0, buf, 0);
+       int r = __syscall(SYS_ipc, IPCOP_shmctl, id, cmd | IPC_64, 0, buf, 0);
+#endif
+#ifdef SYSCALL_IPC_BROKEN_MODE
+       if (r >= 0) switch (cmd) {
+       case IPC_STAT:
+       case SHM_STAT:
+       case SHM_STAT_ANY:
+               buf->shm_perm.mode >>= 16;
+       }
 #endif
+       return __syscall_ret(r);
 }