From 0cd2be231481d68d244662bde25ad9cadbd7221d Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Wed, 20 Jun 2018 00:07:09 -0400 Subject: 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. --- src/ipc/shmctl.c | 26 ++++++++++++++++++++++++-- 1 file changed, 24 insertions(+), 2 deletions(-) (limited to 'src/ipc/shmctl.c') diff --git a/src/ipc/shmctl.c b/src/ipc/shmctl.c index e2879f20..c951a581 100644 --- a/src/ipc/shmctl.c +++ b/src/ipc/shmctl.c @@ -1,12 +1,34 @@ #include +#include #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); } -- cgit v1.2.1