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authorJeff Dike <jdike@addtoit.com>2008-05-12 17:01:47 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2008-05-13 11:02:21 -0400
commit53c258787427ea43ebfa76fefa6534cae507e521 (patch)
tree6054ebe6156c629234fcd5523a702b6703e0f017 /arch
parentc714a534d85576af21b06be605ca55cb2fb887ee (diff)
uml: redo host capability detection and disabling
Redo how host capabilities are recorded at startup and disabled on the command line. There are now explicit variables saying what's been disabled by the command line rather than the implicitness of the have_* variable being zero. The capability variables now start at zero and are set to one as their capabilities are found to be present on the host. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: WANG Cong <xiyou.wangcong@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/um/os-Linux/start_up.c81
1 files changed, 41 insertions, 40 deletions
diff --git a/arch/um/os-Linux/start_up.c b/arch/um/os-Linux/start_up.c
index 997d01944f91..b4b36e0f2e89 100644
--- a/arch/um/os-Linux/start_up.c
+++ b/arch/um/os-Linux/start_up.c
@@ -23,6 +23,7 @@
23#include "mem_user.h" 23#include "mem_user.h"
24#include "ptrace_user.h" 24#include "ptrace_user.h"
25#include "registers.h" 25#include "registers.h"
26#include "skas.h"
26#include "skas_ptrace.h" 27#include "skas_ptrace.h"
27 28
28static void ptrace_child(void) 29static void ptrace_child(void)
@@ -140,14 +141,27 @@ static int stop_ptraced_child(int pid, int exitcode, int mustexit)
140} 141}
141 142
142/* Changed only during early boot */ 143/* Changed only during early boot */
143int ptrace_faultinfo = 1; 144int ptrace_faultinfo;
144int ptrace_ldt = 1; 145static int disable_ptrace_faultinfo;
145int proc_mm = 1; 146
146int skas_needs_stub = 0; 147int ptrace_ldt;
148static int disable_ptrace_ldt;
149
150int proc_mm;
151static int disable_proc_mm;
152
153int have_switch_mm;
154static int disable_switch_mm;
155
156int skas_needs_stub;
147 157
148static int __init skas0_cmd_param(char *str, int* add) 158static int __init skas0_cmd_param(char *str, int* add)
149{ 159{
150 ptrace_faultinfo = proc_mm = 0; 160 disable_ptrace_faultinfo = 1;
161 disable_ptrace_ldt = 1;
162 disable_proc_mm = 1;
163 disable_switch_mm = 1;
164
151 return 0; 165 return 0;
152} 166}
153 167
@@ -157,15 +171,12 @@ static int __init mode_skas0_cmd_param(char *str, int* add)
157 __attribute__((alias("skas0_cmd_param"))); 171 __attribute__((alias("skas0_cmd_param")));
158 172
159__uml_setup("skas0", skas0_cmd_param, 173__uml_setup("skas0", skas0_cmd_param,
160 "skas0\n" 174"skas0\n"
161 " Disables SKAS3 usage, so that SKAS0 is used, unless \n" 175" Disables SKAS3 and SKAS4 usage, so that SKAS0 is used\n\n");
162 " you specify mode=tt.\n\n");
163 176
164__uml_setup("mode=skas0", mode_skas0_cmd_param, 177__uml_setup("mode=skas0", mode_skas0_cmd_param,
165 "mode=skas0\n" 178"mode=skas0\n"
166 " Disables SKAS3 usage, so that SKAS0 is used, unless you \n" 179" Disables SKAS3 and SKAS4 usage, so that SKAS0 is used.\n\n");
167 " specify mode=tt. Note that this was recently added - on \n"
168 " older kernels you must use simply \"skas0\".\n\n");
169 180
170/* Changed only during early boot */ 181/* Changed only during early boot */
171static int force_sysemu_disabled = 0; 182static int force_sysemu_disabled = 0;
@@ -360,7 +371,7 @@ void __init os_early_checks(void)
360 371
361static int __init noprocmm_cmd_param(char *str, int* add) 372static int __init noprocmm_cmd_param(char *str, int* add)
362{ 373{
363 proc_mm = 0; 374 disable_proc_mm = 1;
364 return 0; 375 return 0;
365} 376}
366 377
@@ -372,7 +383,7 @@ __uml_setup("noprocmm", noprocmm_cmd_param,
372 383
373static int __init noptracefaultinfo_cmd_param(char *str, int* add) 384static int __init noptracefaultinfo_cmd_param(char *str, int* add)
374{ 385{
375 ptrace_faultinfo = 0; 386 disable_ptrace_faultinfo = 1;
376 return 0; 387 return 0;
377} 388}
378 389
@@ -384,7 +395,7 @@ __uml_setup("noptracefaultinfo", noptracefaultinfo_cmd_param,
384 395
385static int __init noptraceldt_cmd_param(char *str, int* add) 396static int __init noptraceldt_cmd_param(char *str, int* add)
386{ 397{
387 ptrace_ldt = 0; 398 disable_ptrace_ldt = 1;
388 return 0; 399 return 0;
389} 400}
390 401
@@ -404,17 +415,15 @@ static inline void check_skas3_ptrace_faultinfo(void)
404 415
405 n = ptrace(PTRACE_FAULTINFO, pid, 0, &fi); 416 n = ptrace(PTRACE_FAULTINFO, pid, 0, &fi);
406 if (n < 0) { 417 if (n < 0) {
407 ptrace_faultinfo = 0;
408 if (errno == EIO) 418 if (errno == EIO)
409 non_fatal("not found\n"); 419 non_fatal("not found\n");
410 else 420 else
411 perror("not found"); 421 perror("not found");
412 } 422 } else if (disable_ptrace_faultinfo)
423 non_fatal("found but disabled on command line\n");
413 else { 424 else {
414 if (!ptrace_faultinfo) 425 ptrace_faultinfo = 1;
415 non_fatal("found but disabled on command line\n"); 426 non_fatal("found\n");
416 else
417 non_fatal("found\n");
418 } 427 }
419 428
420 stop_ptraced_child(pid, 1, 1); 429 stop_ptraced_child(pid, 1, 1);
@@ -437,38 +446,30 @@ static inline void check_skas3_ptrace_ldt(void)
437 if (n < 0) { 446 if (n < 0) {
438 if (errno == EIO) 447 if (errno == EIO)
439 non_fatal("not found\n"); 448 non_fatal("not found\n");
440 else { 449 else
441 perror("not found"); 450 perror("not found");
442 } 451 } else if (disable_ptrace_ldt)
443 ptrace_ldt = 0; 452 non_fatal("found, but use is disabled\n");
444 }
445 else { 453 else {
446 if (ptrace_ldt) 454 ptrace_ldt = 1;
447 non_fatal("found\n"); 455 non_fatal("found\n");
448 else
449 non_fatal("found, but use is disabled\n");
450 } 456 }
451 457
452 stop_ptraced_child(pid, 1, 1); 458 stop_ptraced_child(pid, 1, 1);
453#else
454 /* PTRACE_LDT might be disabled via cmdline option.
455 * We want to override this, else we might use the stub
456 * without real need
457 */
458 ptrace_ldt = 1;
459#endif 459#endif
460} 460}
461 461
462static inline void check_skas3_proc_mm(void) 462static inline void check_skas3_proc_mm(void)
463{ 463{
464 non_fatal(" - /proc/mm..."); 464 non_fatal(" - /proc/mm...");
465 if (access("/proc/mm", W_OK) < 0) { 465 if (access("/proc/mm", W_OK) < 0)
466 proc_mm = 0;
467 perror("not found"); 466 perror("not found");
468 } 467 else if (disable_proc_mm)
469 else if (!proc_mm)
470 non_fatal("found but disabled on command line\n"); 468 non_fatal("found but disabled on command line\n");
471 else non_fatal("found\n"); 469 else {
470 proc_mm = 1;
471 non_fatal("found\n");
472 }
472} 473}
473 474
474void can_do_skas(void) 475void can_do_skas(void)