From: Ben Gras Date: Tue, 20 Jun 2006 09:58:58 +0000 (+0000) Subject: Introduced global sys_call_code to check in called kernel call X-Git-Tag: v3.1.3~317 X-Git-Url: http://zhaoyanbai.com/repos/icons/debian/static/doxygen.log?a=commitdiff_plain;h=bf6fa2acd052f61b041b47737b930bc3bbde084d;p=minix.git Introduced global sys_call_code to check in called kernel call implementation functions. Changed check in system.c to check compile-time-sized bitmap of kernel calls. Added SYS_SAFECOPYFROM and SYS_SAFECOPYTO, both mapping to do_safecopy (that's what sys_call_code is used for). --- diff --git a/kernel/system.c b/kernel/system.c index 5c964ea89..61b226504 100755 --- a/kernel/system.c +++ b/kernel/system.c @@ -17,6 +17,7 @@ * umap_local: map virtual address in LOCAL_SEG to physical * umap_remote: map virtual address in REMOTE_SEG to physical * umap_bios: map virtual address in BIOS_SEG to physical + * umap_grant: map grant number in a process to physical * virtual_copy: copy bytes from one virtual address to another * get_randomness: accumulate randomness in a buffer * clear_endpoint: remove a process' ability to send and receive messages @@ -37,6 +38,7 @@ #include #include #include +#include #if (CHIP == INTEL) #include #include "protect.h" @@ -65,8 +67,8 @@ PUBLIC void sys_task() static message m; register int result; register struct proc *caller_ptr; - unsigned int call_nr; int s; + int call_nr; /* Initialize the system task. */ initialize(); @@ -74,25 +76,29 @@ PUBLIC void sys_task() while (TRUE) { /* Get work. Block and wait until a request message arrives. */ receive(ANY, &m); - call_nr = (unsigned) m.m_type - KERNEL_CALL; + sys_call_code = (unsigned) m.m_type; + call_nr = sys_call_code - KERNEL_CALL; who_e = m.m_source; okendpt(who_e, &who_p); caller_ptr = proc_addr(who_p); /* See if the caller made a valid request and try to handle it. */ - if (! (priv(caller_ptr)->s_call_mask & (1<s_k_call_mask, call_nr)) { #if DEBUG_ENABLE_IPC_WARNINGS - kprintf("SYSTEM: request %d from %d denied.\n", call_nr,m.m_source); + kprintf("SYSTEM: request %d from %d denied.\n", + call_nr,m.m_source); #endif result = ECALLDENIED; /* illegal message type */ - } else if (call_nr >= NR_SYS_CALLS) { /* check call number */ + } /* else */ + if (call_nr >= NR_SYS_CALLS) { /* check call number */ #if DEBUG_ENABLE_IPC_WARNINGS - kprintf("SYSTEM: illegal request %d from %d.\n", call_nr,m.m_source); + kprintf("SYSTEM: illegal request %d from %d.\n", + call_nr,m.m_source); #endif result = EBADREQUEST; /* illegal message type */ } else { - result = (*call_vec[call_nr])(&m); /* handle the system call */ + result = (*call_vec[call_nr])(&m); /* handle the system call */ } /* Send a reply, unless inhibited by a handler function. Use the kernel @@ -170,6 +176,8 @@ PRIVATE void initialize(void) map(SYS_PHYSCOPY, do_physcopy); /* use physical addressing */ map(SYS_VIRVCOPY, do_virvcopy); /* vector with copy requests */ map(SYS_PHYSVCOPY, do_physvcopy); /* vector with copy requests */ + map(SYS_SAFECOPYFROM, do_safecopy); /* copy with pre-granted permission */ + map(SYS_SAFECOPYTO, do_safecopy); /* copy with pre-granted permission */ /* Clock functionality. */ map(SYS_TIMES, do_times); /* get uptime and process times */ @@ -385,6 +393,37 @@ vir_bytes bytes; /* # of bytes to be copied */ #endif } +/*===========================================================================* + * umap_grant * + *===========================================================================*/ +PUBLIC phys_bytes umap_grant(rp, grant, bytes) +struct proc *rp; /* pointer to proc table entry for process */ +cp_grant_id_t grant; /* grant no. */ +vir_bytes bytes; /* size */ +{ + int proc_nr; + vir_bytes offset; + endpoint_t granter; + + /* See if the grant in that process is sensible, and + * find out the virtual address and (optionally) new + * process for that address. + * + * Then convert that process to a slot number. + */ + if(verify_grant(rp->p_endpoint, ANY, grant, bytes, 0, 0, + &offset, &granter) != OK) { + return 0; + } + + if(!isokendpt(granter, &proc_nr)) { + return 0; + } + + /* Do the mapping from virtual to physical. */ + return umap_local(proc_addr(proc_nr), D, offset, bytes); +} + /*===========================================================================* * umap_remote * *===========================================================================*/ @@ -407,6 +446,37 @@ vir_bytes bytes; /* # of bytes to be copied */ return(fm->mem_phys + (phys_bytes) vir_addr); } +/*===========================================================================* + * umap_verify_grant * + *===========================================================================*/ +PUBLIC phys_bytes umap_verify_grant(rp, grantee, grant, offset, bytes, access) +struct proc *rp; /* pointer to proc table entry for process */ +endpoint_t grantee; /* who wants to do this */ +cp_grant_id_t grant; /* grant no. */ +vir_bytes offset; /* offset into grant */ +vir_bytes bytes; /* size */ +int access; /* does grantee want to CPF_READ or _WRITE? */ +{ + int proc_nr; + vir_bytes v_offset; + endpoint_t granter; + + /* See if the grant in that process is sensible, and + * find out the virtual address and (optionally) new + * process for that address. + * + * Then convert that process to a slot number. + */ + if(verify_grant(rp->p_endpoint, grantee, grant, bytes, access, offset, + &v_offset, &granter) != OK + || !isokendpt(granter, &proc_nr)) { + return 0; + } + + /* Do the mapping from virtual to physical. */ + return umap_local(proc_addr(proc_nr), D, v_offset, bytes); +} + /*===========================================================================* * virtual_copy * *===========================================================================*/ @@ -458,6 +528,9 @@ vir_bytes bytes; /* # of bytes to copy */ case PHYS_SEG: phys_addr[i] = vir_addr[i]->offset; break; + case GRANT_SEG: + phys_addr[i] = umap_grant(p, vir_addr[i]->offset, bytes); + break; default: return(EINVAL); }