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[S390] Improve address space mode selection.

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Introduce user_mode to replace the two variables switch_amode and
s390_noexec. There are three valid combinations of the old values:
  1) switch_amode == 0 && s390_noexec == 0
  2) switch_amode == 1 && s390_noexec == 0
  3) switch_amode == 1 && s390_noexec == 1
They get replaced by
  1) user_mode == HOME_SPACE_MODE
  2) user_mode == PRIMARY_SPACE_MODE
  3) user_mode == SECONDARY_SPACE_MODE
The new kernel parameter user_mode=[primary,secondary,home] lets
you choose the address space mode the user space processes should
use. In addition the CONFIG_S390_SWITCH_AMODE config option
is removed.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Martin Schwidefsky
2009-12-07 12:51:43 +01:00
committed by Martin Schwidefsky
parent 61365e132e
commit b11b533427
11 changed files with 37 additions and 57 deletions
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36
arch/s390/kernel/setup.c
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@@ -305,9 +305,8 @@ static int __init early_parse_mem(char *p)
}
early_param("mem", early_parse_mem);
#ifdef CONFIG_S390_SWITCH_AMODE
unsigned int switch_amode = 0;
EXPORT_SYMBOL_GPL(switch_amode);
unsigned int user_mode = HOME_SPACE_MODE;
EXPORT_SYMBOL_GPL(user_mode);
static int set_amode_and_uaccess(unsigned long user_amode,
unsigned long user32_amode)
@@ -340,23 +339,29 @@ static int set_amode_and_uaccess(unsigned long user_amode,
*/
static int __init early_parse_switch_amode(char *p)
{
switch_amode = 1;
if (user_mode != SECONDARY_SPACE_MODE)
user_mode = PRIMARY_SPACE_MODE;
return 0;
}
early_param("switch_amode", early_parse_switch_amode);
#else /* CONFIG_S390_SWITCH_AMODE */
static inline int set_amode_and_uaccess(unsigned long user_amode,
unsigned long user32_amode)
static int __init early_parse_user_mode(char *p)
{
if (p && strcmp(p, "primary") == 0)
user_mode = PRIMARY_SPACE_MODE;
#ifdef CONFIG_S390_EXEC_PROTECT
else if (p && strcmp(p, "secondary") == 0)
user_mode = SECONDARY_SPACE_MODE;
#endif
else if (!p || strcmp(p, "home") == 0)
user_mode = HOME_SPACE_MODE;
else
return 1;
return 0;
}
#endif /* CONFIG_S390_SWITCH_AMODE */
early_param("user_mode", early_parse_user_mode);
#ifdef CONFIG_S390_EXEC_PROTECT
unsigned int s390_noexec = 0;
EXPORT_SYMBOL_GPL(s390_noexec);
/*
* Enable execute protection?
*/
@@ -364,8 +369,7 @@ static int __init early_parse_noexec(char *p)
{
if (!strncmp(p, "off", 3))
return 0;
switch_amode = 1;
s390_noexec = 1;
user_mode = SECONDARY_SPACE_MODE;
return 0;
}
early_param("noexec", early_parse_noexec);
@@ -373,7 +377,7 @@ early_param("noexec", early_parse_noexec);
static void setup_addressing_mode(void)
{
if (s390_noexec) {
if (user_mode == SECONDARY_SPACE_MODE) {
if (set_amode_and_uaccess(PSW_ASC_SECONDARY,
PSW32_ASC_SECONDARY))
pr_info("Execute protection active, "
@@ -381,7 +385,7 @@ static void setup_addressing_mode(void)
else
pr_info("Execute protection active, "
"mvcos not available\n");
} else if (switch_amode) {
} else if (user_mode == PRIMARY_SPACE_MODE) {
if (set_amode_and_uaccess(PSW_ASC_PRIMARY, PSW32_ASC_PRIMARY))
pr_info("Address spaces switched, "
"mvcos available\n");
@@ -411,7 +415,7 @@ setup_lowcore(void)
lc->restart_psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY;
lc->restart_psw.addr =
PSW_ADDR_AMODE | (unsigned long) restart_int_handler;
if (switch_amode)
if (user_mode != HOME_SPACE_MODE)
lc->restart_psw.mask |= PSW_ASC_HOME;
lc->external_new_psw.mask = psw_kernel_bits;
lc->external_new_psw.addr =