From 2df7a7d1cd07626dd235ca102830ebfc6c01a09e Mon Sep 17 00:00:00 2001 From: Sergei Trofimovich Date: Thu, 25 Aug 2011 15:59:02 -0700 Subject: [PATCH] alpha: unbreak osf_setsysinfo(SSI_NVPAIRS, [SSIN_UACPROC, UAC_SIGBUS]) The bug was accidentally found by the following program: #include #include #include static int setsysinfo(unsigned long op, void *buffer, unsigned long size, int *start, void *arg, unsigned long flag) { return syscall(__NR_osf_setsysinfo, op, buffer, size, start, arg, flag); } int main(int argc, char **argv) { short x[10]; unsigned int buf[2] = { SSIN_UACPROC, UAC_SIGBUS, }; setsysinfo(SSI_NVPAIRS, buf, 1, 0, 0, 0); int *y = (int*) (x+1); *y = 0; return 0; } The program shoud fail on SIGBUS, but didn't. The patch is a second part of userspace flag fix (commit 745dd2405e28 "Alpha: Rearrange thread info flags fixing two regressions"). Deleted outdated out-of-sync 'UAC_SHIFT' (the cause of bug) in favour of 'ALPHA_UAC_SHIFT'. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Sergei Trofimovich Acked-by: Michael Cree Cc: Richard Henderson Cc: Ivan Kokshaysky Cc: Matt Turner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/alpha/include/asm/sysinfo.h | 9 --------- arch/alpha/include/asm/thread_info.h | 8 ++++---- arch/alpha/kernel/osf_sys.c | 12 +++++++----- 3 files changed, 11 insertions(+), 18 deletions(-) diff --git a/arch/alpha/include/asm/sysinfo.h b/arch/alpha/include/asm/sysinfo.h index 086aba284df2..e77d77cd07b8 100644 --- a/arch/alpha/include/asm/sysinfo.h +++ b/arch/alpha/include/asm/sysinfo.h @@ -27,13 +27,4 @@ #define UAC_NOFIX 2 #define UAC_SIGBUS 4 - -#ifdef __KERNEL__ - -/* This is the shift that is applied to the UAC bits as stored in the - per-thread flags. See thread_info.h. */ -#define UAC_SHIFT 6 - -#endif - #endif /* __ASM_ALPHA_SYSINFO_H */ diff --git a/arch/alpha/include/asm/thread_info.h b/arch/alpha/include/asm/thread_info.h index 6f32f9c84a2d..ff73db022342 100644 --- a/arch/alpha/include/asm/thread_info.h +++ b/arch/alpha/include/asm/thread_info.h @@ -74,9 +74,9 @@ register struct thread_info *__current_thread_info __asm__("$8"); #define TIF_NEED_RESCHED 3 /* rescheduling necessary */ #define TIF_POLLING_NRFLAG 8 /* poll_idle is polling NEED_RESCHED */ #define TIF_DIE_IF_KERNEL 9 /* dik recursion lock */ -#define TIF_UAC_NOPRINT 10 /* see sysinfo.h */ -#define TIF_UAC_NOFIX 11 -#define TIF_UAC_SIGBUS 12 +#define TIF_UAC_NOPRINT 10 /* ! Preserve sequence of following */ +#define TIF_UAC_NOFIX 11 /* ! flags as they match */ +#define TIF_UAC_SIGBUS 12 /* ! userspace part of 'osf_sysinfo' */ #define TIF_MEMDIE 13 /* is terminating due to OOM killer */ #define TIF_RESTORE_SIGMASK 14 /* restore signal mask in do_signal */ #define TIF_FREEZE 16 /* is freezing for suspend */ @@ -97,7 +97,7 @@ register struct thread_info *__current_thread_info __asm__("$8"); #define _TIF_ALLWORK_MASK (_TIF_WORK_MASK \ | _TIF_SYSCALL_TRACE) -#define ALPHA_UAC_SHIFT 10 +#define ALPHA_UAC_SHIFT TIF_UAC_NOPRINT #define ALPHA_UAC_MASK (1 << TIF_UAC_NOPRINT | 1 << TIF_UAC_NOFIX | \ 1 << TIF_UAC_SIGBUS) diff --git a/arch/alpha/kernel/osf_sys.c b/arch/alpha/kernel/osf_sys.c index 326f0a2d56e5..01e8715e26d9 100644 --- a/arch/alpha/kernel/osf_sys.c +++ b/arch/alpha/kernel/osf_sys.c @@ -42,6 +42,7 @@ #include #include #include +#include #include #include @@ -633,9 +634,10 @@ SYSCALL_DEFINE5(osf_getsysinfo, unsigned long, op, void __user *, buffer, case GSI_UACPROC: if (nbytes < sizeof(unsigned int)) return -EINVAL; - w = (current_thread_info()->flags >> UAC_SHIFT) & UAC_BITMASK; - if (put_user(w, (unsigned int __user *)buffer)) - return -EFAULT; + w = (current_thread_info()->flags >> ALPHA_UAC_SHIFT) & + UAC_BITMASK; + if (put_user(w, (unsigned int __user *)buffer)) + return -EFAULT; return 1; case GSI_PROC_TYPE: @@ -756,8 +758,8 @@ SYSCALL_DEFINE5(osf_setsysinfo, unsigned long, op, void __user *, buffer, case SSIN_UACPROC: again: old = current_thread_info()->flags; - new = old & ~(UAC_BITMASK << UAC_SHIFT); - new = new | (w & UAC_BITMASK) << UAC_SHIFT; + new = old & ~(UAC_BITMASK << ALPHA_UAC_SHIFT); + new = new | (w & UAC_BITMASK) << ALPHA_UAC_SHIFT; if (cmpxchg(¤t_thread_info()->flags, old, new) != old) goto again;