From 279b2b827810d149b5b8453900cdea57874ae234 Mon Sep 17 00:00:00 2001 From: jhb Date: Wed, 4 Feb 2004 21:52:57 +0000 Subject: Locking for the per-process resource limits structure. - struct plimit includes a mutex to protect a reference count. The plimit structure is treated similarly to struct ucred in that is is always copy on write, so having a reference to a structure is sufficient to read from it without needing a further lock. - The proc lock protects the p_limit pointer and must be held while reading limits from a process to keep the limit structure from changing out from under you while reading from it. - Various global limits that are ints are not protected by a lock since int writes are atomic on all the archs we support and thus a lock wouldn't buy us anything. - All accesses to individual resource limits from a process are abstracted behind a simple lim_rlimit(), lim_max(), and lim_cur() API that return either an rlimit, or the current or max individual limit of the specified resource from a process. - dosetrlimit() was renamed to kern_setrlimit() to match existing style of other similar syscall helper functions. - The alpha OSF/1 compat layer no longer calls getrlimit() and setrlimit() (it didn't used the stackgap when it should have) but uses lim_rlimit() and kern_setrlimit() instead. - The svr4 compat no longer uses the stackgap for resource limits calls, but uses lim_rlimit() and kern_setrlimit() instead. - The ibcs2 compat no longer uses the stackgap for resource limits. It also no longer uses the stackgap for accessing sysctl's for the ibcs2_sysconf() syscall but uses kernel_sysctl() instead. As a result, ibcs2_sysconf() no longer needs Giant. - The p_rlimit macro no longer exists. Submitted by: mtm (mostly, I only did a few cleanups and catchups) Tested on: i386 Compiled on: alpha, amd64 --- sys/kern/imgact_aout.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'sys/kern/imgact_aout.c') diff --git a/sys/kern/imgact_aout.c b/sys/kern/imgact_aout.c index 4cb7b63..6bad705 100644 --- a/sys/kern/imgact_aout.c +++ b/sys/kern/imgact_aout.c @@ -177,14 +177,16 @@ exec_aout_imgact(imgp) /* * text/data/bss must not exceed limits */ - mtx_assert(&Giant, MA_OWNED); + PROC_LOCK(imgp->proc); if (/* text can't exceed maximum text size */ a_out->a_text > maxtsiz || /* data + bss can't exceed rlimit */ - a_out->a_data + bss_size > - imgp->proc->p_rlimit[RLIMIT_DATA].rlim_cur) + a_out->a_data + bss_size > lim_cur(imgp->proc, RLIMIT_DATA)) { + PROC_UNLOCK(imgp->proc); return (ENOMEM); + } + PROC_UNLOCK(imgp->proc); /* copy in arguments and/or environment from old process */ error = exec_extract_strings(imgp); -- cgit v1.1