X-Git-Url: https://git.kernel.dk/?a=blobdiff_plain;f=arch%2Fum%2Fsys-i386%2Fbugs.c;h=a74442d1376213bc5ad41bf3eb11772a743cdeaa;hb=70ec75c5b8e0bda7a16fb387f91e08545f379a0e;hp=0393e44813e775e1adf6e4274789caabb3d09493;hpb=5c34202b8bf942da411b6599668a76b07449bbfd;p=linux-2.6-block.git diff --git a/arch/um/sys-i386/bugs.c b/arch/um/sys-i386/bugs.c index 0393e44813e7..a74442d13762 100644 --- a/arch/um/sys-i386/bugs.c +++ b/arch/um/sys-i386/bugs.c @@ -1,193 +1,76 @@ /* - * Copyright (C) 2002 Jeff Dike (jdike@karaya.com) + * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) * Licensed under the GPL */ -#include -#include -#include -#include -#include +#include +#include "kern_constants.h" #include "kern_util.h" +#include "longjmp.h" +#include "task.h" #include "user.h" #include "sysdep/ptrace.h" -#include "task.h" -#include "os.h" - -#define MAXTOKEN 64 /* Set during early boot */ int host_has_cmov = 1; -int host_has_xmm = 0; +static jmp_buf cmov_test_return; -static char token(int fd, char *buf, int len, char stop) +static void cmov_sigill_test_handler(int sig) { - int n; - char *ptr, *end, c; - - ptr = buf; - end = &buf[len]; - do { - n = os_read_file(fd, ptr, sizeof(*ptr)); - c = *ptr++; - if(n != sizeof(*ptr)){ - if(n == 0) - return 0; - printk("Reading /proc/cpuinfo failed, err = %d\n", -n); - if(n < 0) - return n; - else return -EIO; - } - } while((c != '\n') && (c != stop) && (ptr < end)); - - if(ptr == end){ - printk("Failed to find '%c' in /proc/cpuinfo\n", stop); - return -1; - } - *(ptr - 1) = '\0'; - return c; + host_has_cmov = 0; + longjmp(cmov_test_return, 1); } -static int find_cpuinfo_line(int fd, char *key, char *scratch, int len) -{ - int n; - char c; - - scratch[len - 1] = '\0'; - while(1){ - c = token(fd, scratch, len - 1, ':'); - if(c <= 0) - return 0; - else if(c != ':'){ - printk("Failed to find ':' in /proc/cpuinfo\n"); - return 0; - } - - if(!strncmp(scratch, key, strlen(key))) - return 1; - - do { - n = os_read_file(fd, &c, sizeof(c)); - if(n != sizeof(c)){ - printk("Failed to find newline in " - "/proc/cpuinfo, err = %d\n", -n); - return 0; - } - } while(c != '\n'); - } - return 0; -} - -static int check_cpu_flag(char *feature, int *have_it) -{ - char buf[MAXTOKEN], c; - int fd, len = ARRAY_SIZE(buf); - - printk("Checking for host processor %s support...", feature); - fd = os_open_file("/proc/cpuinfo", of_read(OPENFLAGS()), 0); - if(fd < 0){ - printk("Couldn't open /proc/cpuinfo, err = %d\n", -fd); - return 0; - } - - *have_it = 0; - if(!find_cpuinfo_line(fd, "flags", buf, ARRAY_SIZE(buf))) - goto out; - - c = token(fd, buf, len - 1, ' '); - if(c < 0) - goto out; - else if(c != ' '){ - printk("Failed to find ' ' in /proc/cpuinfo\n"); - goto out; - } - - while(1){ - c = token(fd, buf, len - 1, ' '); - if(c < 0) - goto out; - else if(c == '\n') break; - - if(!strcmp(buf, feature)){ - *have_it = 1; - goto out; - } - } - out: - if(*have_it == 0) - printk("No\n"); - else if(*have_it == 1) - printk("Yes\n"); - os_close_file(fd); - return 1; -} - -#if 0 /* This doesn't work in tt mode, plus it's causing compilation problems - * for some people. - */ -static void disable_lcall(void) +void arch_check_bugs(void) { - struct modify_ldt_ldt_s ldt; - int err; + struct sigaction old, new; - bzero(&ldt, sizeof(ldt)); - ldt.entry_number = 7; - ldt.base_addr = 0; - ldt.limit = 0; - err = modify_ldt(1, &ldt, sizeof(ldt)); - if(err) - printk("Failed to disable lcall7 - errno = %d\n", errno); -} -#endif + printk(UM_KERN_INFO "Checking for host processor cmov support..."); + new.sa_handler = cmov_sigill_test_handler; -void arch_init_thread(void) -{ -#if 0 - disable_lcall(); -#endif -} + /* Make sure that SIGILL is enabled after the handler longjmps back */ + new.sa_flags = SA_NODEFER; + sigemptyset(&new.sa_mask); + sigaction(SIGILL, &new, &old); -void arch_check_bugs(void) -{ - int have_it; + if (setjmp(cmov_test_return) == 0) { + unsigned long foo = 0; + __asm__ __volatile__("cmovz %0, %1" : "=r" (foo) : "0" (foo)); + printk(UM_KERN_CONT "Yes\n"); + } else + printk(UM_KERN_CONT "No\n"); - if(os_access("/proc/cpuinfo", OS_ACC_R_OK) < 0){ - printk("/proc/cpuinfo not available - skipping CPU capability " - "checks\n"); - return; - } - if(check_cpu_flag("cmov", &have_it)) - host_has_cmov = have_it; - if(check_cpu_flag("xmm", &have_it)) - host_has_xmm = have_it; + sigaction(SIGILL, &old, &new); } -int arch_handle_signal(int sig, union uml_pt_regs *regs) +void arch_examine_signal(int sig, struct uml_pt_regs *regs) { unsigned char tmp[2]; - /* This is testing for a cmov (0x0f 0x4x) instruction causing a + /* + * This is testing for a cmov (0x0f 0x4x) instruction causing a * SIGILL in init. */ - if((sig != SIGILL) || (TASK_PID(get_current()) != 1)) - return 0; + if ((sig != SIGILL) || (TASK_PID(get_current()) != 1)) + return; - if (copy_from_user_proc(tmp, (void *) UPT_IP(regs), 2)) - panic("SIGILL in init, could not read instructions!\n"); - if((tmp[0] != 0x0f) || ((tmp[1] & 0xf0) != 0x40)) - return 0; + if (copy_from_user_proc(tmp, (void *) UPT_IP(regs), 2)) { + printk(UM_KERN_ERR "SIGILL in init, could not read " + "instructions!\n"); + return; + } + + if ((tmp[0] != 0x0f) || ((tmp[1] & 0xf0) != 0x40)) + return; - if(host_has_cmov == 0) - panic("SIGILL caused by cmov, which this processor doesn't " - "implement, boot a filesystem compiled for older " - "processors"); - else if(host_has_cmov == 1) - panic("SIGILL caused by cmov, which this processor claims to " - "implement"); - else if(host_has_cmov == -1) - panic("SIGILL caused by cmov, couldn't tell if this processor " - "implements it, boot a filesystem compiled for older " - "processors"); - else panic("Bad value for host_has_cmov (%d)", host_has_cmov); - return 0; + if (host_has_cmov == 0) + printk(UM_KERN_ERR "SIGILL caused by cmov, which this " + "processor doesn't implement. Boot a filesystem " + "compiled for older processors"); + else if (host_has_cmov == 1) + printk(UM_KERN_ERR "SIGILL caused by cmov, which this " + "processor claims to implement"); + else + printk(UM_KERN_ERR "Bad value for host_has_cmov (%d)", + host_has_cmov); }