From ee8e76141b4dd00f8e97fda274876a17f9a46bbe Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Mon, 11 Jul 2016 16:48:11 +0100 Subject: [PATCH] linux-user: Use correct target SHMLBA in shmat() The shmat() handling needs to do target-specific handling of the attach address for shmat(): * if the SHM_RND flag is passed, the address is rounded down to a SHMLBA boundary * if SHM_RND is not passed, then the call is failed EINVAL if the address is not a multiple of SHMLBA Since SHMLBA is target-specific, we need to do this checking and rounding in QEMU and can't leave it up to the host syscall. Allow targets to define TARGET_FORCE_SHMLBA and provide a target_shmlba() function if appropriate, and update do_shmat() to honour them. Signed-off-by: Peter Maydell Signed-off-by: Riku Voipio --- linux-user/arm/target_syscall.h | 7 +++++ linux-user/mips/target_syscall.h | 7 +++++ linux-user/mips64/target_syscall.h | 7 +++++ linux-user/sh4/target_syscall.h | 7 +++++ linux-user/sparc/target_syscall.h | 16 +++++++++++ linux-user/syscall.c | 45 ++++++++++++++++++++++++++---- 6 files changed, 83 insertions(+), 6 deletions(-) diff --git a/linux-user/arm/target_syscall.h b/linux-user/arm/target_syscall.h index cd021ff598..0879b4d4a8 100644 --- a/linux-user/arm/target_syscall.h +++ b/linux-user/arm/target_syscall.h @@ -33,4 +33,11 @@ struct target_pt_regs { #define TARGET_MLOCKALL_MCL_CURRENT 1 #define TARGET_MLOCKALL_MCL_FUTURE 2 +#define TARGET_FORCE_SHMLBA + +static inline abi_ulong target_shmlba(CPUARMState *env) +{ + return 4 * 4096; +} + #endif /* ARM_TARGET_SYSCALL_H */ diff --git a/linux-user/mips/target_syscall.h b/linux-user/mips/target_syscall.h index 2b4f390729..6c666dcb73 100644 --- a/linux-user/mips/target_syscall.h +++ b/linux-user/mips/target_syscall.h @@ -230,4 +230,11 @@ struct target_pt_regs { #define TARGET_MLOCKALL_MCL_CURRENT 1 #define TARGET_MLOCKALL_MCL_FUTURE 2 +#define TARGET_FORCE_SHMLBA + +static inline abi_ulong target_shmlba(CPUMIPSState *env) +{ + return 0x40000; +} + #endif /* MIPS_TARGET_SYSCALL_H */ diff --git a/linux-user/mips64/target_syscall.h b/linux-user/mips64/target_syscall.h index 8da9c1f9cc..a9c17f7edf 100644 --- a/linux-user/mips64/target_syscall.h +++ b/linux-user/mips64/target_syscall.h @@ -227,4 +227,11 @@ struct target_pt_regs { #define TARGET_MLOCKALL_MCL_CURRENT 1 #define TARGET_MLOCKALL_MCL_FUTURE 2 +#define TARGET_FORCE_SHMLBA + +static inline abi_ulong target_shmlba(CPUMIPSState *env) +{ + return 0x40000; +} + #endif /* MIPS64_TARGET_SYSCALL_H */ diff --git a/linux-user/sh4/target_syscall.h b/linux-user/sh4/target_syscall.h index 78d5557124..2b5f75be13 100644 --- a/linux-user/sh4/target_syscall.h +++ b/linux-user/sh4/target_syscall.h @@ -19,4 +19,11 @@ struct target_pt_regs { #define TARGET_MLOCKALL_MCL_CURRENT 1 #define TARGET_MLOCKALL_MCL_FUTURE 2 +#define TARGET_FORCE_SHMLBA + +static inline abi_ulong target_shmlba(CPUSH4State *env) +{ + return 0x4000; +} + #endif /* SH4_TARGET_SYSCALL_H */ diff --git a/linux-user/sparc/target_syscall.h b/linux-user/sparc/target_syscall.h index 326f674b4e..f97aa6b075 100644 --- a/linux-user/sparc/target_syscall.h +++ b/linux-user/sparc/target_syscall.h @@ -22,4 +22,20 @@ struct target_pt_regs { #define TARGET_MLOCKALL_MCL_CURRENT 0x2000 #define TARGET_MLOCKALL_MCL_FUTURE 0x4000 +/* For SPARC SHMLBA is determined at runtime in the kernel, and + * libc has to runtime-detect it using the hwcaps (see glibc + * sysdeps/unix/sysv/linux/sparc/getshmlba; we follow the same + * logic here, though we know we're not the sparc v9 64-bit case). + */ +#define TARGET_FORCE_SHMLBA + +static inline abi_ulong target_shmlba(CPUSPARCState *env) +{ + if (!(env->def->features & CPU_FEATURE_FLUSH)) { + return 64 * 1024; + } else { + return 256 * 1024; + } +} + #endif /* SPARC_TARGET_SYSCALL_H */ diff --git a/linux-user/syscall.c b/linux-user/syscall.c index e28690713a..85699f9f31 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -4575,12 +4575,34 @@ static inline abi_long do_shmctl(int shmid, int cmd, abi_long buf) return ret; } -static inline abi_ulong do_shmat(int shmid, abi_ulong shmaddr, int shmflg) +#ifndef TARGET_FORCE_SHMLBA +/* For most architectures, SHMLBA is the same as the page size; + * some architectures have larger values, in which case they should + * define TARGET_FORCE_SHMLBA and provide a target_shmlba() function. + * This corresponds to the kernel arch code defining __ARCH_FORCE_SHMLBA + * and defining its own value for SHMLBA. + * + * The kernel also permits SHMLBA to be set by the architecture to a + * value larger than the page size without setting __ARCH_FORCE_SHMLBA; + * this means that addresses are rounded to the large size if + * SHM_RND is set but addresses not aligned to that size are not rejected + * as long as they are at least page-aligned. Since the only architecture + * which uses this is ia64 this code doesn't provide for that oddity. + */ +static inline abi_ulong target_shmlba(CPUArchState *cpu_env) +{ + return TARGET_PAGE_SIZE; +} +#endif + +static inline abi_ulong do_shmat(CPUArchState *cpu_env, + int shmid, abi_ulong shmaddr, int shmflg) { abi_long raddr; void *host_raddr; struct shmid_ds shm_info; int i,ret; + abi_ulong shmlba; /* find out the length of the shared memory segment */ ret = get_errno(shmctl(shmid, IPC_STAT, &shm_info)); @@ -4589,6 +4611,16 @@ static inline abi_ulong do_shmat(int shmid, abi_ulong shmaddr, int shmflg) return ret; } + shmlba = target_shmlba(cpu_env); + + if (shmaddr & (shmlba - 1)) { + if (shmflg & SHM_RND) { + shmaddr &= ~(shmlba - 1); + } else { + return -TARGET_EINVAL; + } + } + mmap_lock(); if (shmaddr) @@ -4647,7 +4679,8 @@ static inline abi_long do_shmdt(abi_ulong shmaddr) #ifdef TARGET_NR_ipc /* ??? This only works with linear mappings. */ /* do_ipc() must return target values and target errnos. */ -static abi_long do_ipc(unsigned int call, abi_long first, +static abi_long do_ipc(CPUArchState *cpu_env, + unsigned int call, abi_long first, abi_long second, abi_long third, abi_long ptr, abi_long fifth) { @@ -4716,7 +4749,7 @@ static abi_long do_ipc(unsigned int call, abi_long first, default: { abi_ulong raddr; - raddr = do_shmat(first, ptr, second); + raddr = do_shmat(cpu_env, first, ptr, second); if (is_error(raddr)) return get_errno(raddr); if (put_user_ual(raddr, third)) @@ -9304,8 +9337,8 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1, break; #ifdef TARGET_NR_ipc case TARGET_NR_ipc: - ret = do_ipc(arg1, arg2, arg3, arg4, arg5, arg6); - break; + ret = do_ipc(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6); + break; #endif #ifdef TARGET_NR_semget case TARGET_NR_semget: @@ -9354,7 +9387,7 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1, #endif #ifdef TARGET_NR_shmat case TARGET_NR_shmat: - ret = do_shmat(arg1, arg2, arg3); + ret = do_shmat(cpu_env, arg1, arg2, arg3); break; #endif #ifdef TARGET_NR_shmdt