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s390/mm: Get rid of fault type switch statements

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With GMAP_FAULT fault type gone, there are only KERNEL_FAULT and
USER_FAULT fault types left. Therefore there is no need for any fault
type switch statements left.

Rename get_fault_type() into is_kernel_fault() and let it return a
boolean value. Change all switch statements to if statements. This
removes quite a bit of code.

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/r/20241022120601.167009-11-imbrenda@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
This commit is contained in:
Heiko Carstens 2024-10-22 14:06:00 +02:00
parent f76901d160
commit a12d622ad5
1 changed files with 22 additions and 48 deletions
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70
arch/s390/mm/fault.c
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@ -46,11 +46,6 @@
#include <asm/uv.h>
#include "../kernel/entry.h"
enum fault_type {
KERNEL_FAULT,
USER_FAULT,
};
static DEFINE_STATIC_KEY_FALSE(have_store_indication);
static int __init fault_init(void)
@ -64,15 +59,15 @@ early_initcall(fault_init);
/*
* Find out which address space caused the exception.
*/
static enum fault_type get_fault_type(struct pt_regs *regs)
static bool is_kernel_fault(struct pt_regs *regs)
{
union teid teid = { .val = regs->int_parm_long };
if (user_mode(regs))
return USER_FAULT;
return false;
if (teid.as == PSW_BITS_AS_SECONDARY)
return USER_FAULT;
return KERNEL_FAULT;
return false;
return true;
}
static unsigned long get_fault_address(struct pt_regs *regs)
@ -167,17 +162,12 @@ static void dump_fault_info(struct pt_regs *regs)
break;
}
pr_cont("mode while using ");
switch (get_fault_type(regs)) {
case USER_FAULT:
asce = get_lowcore()->user_asce.val;
pr_cont("user ");
break;
case KERNEL_FAULT:
if (is_kernel_fault(regs)) {
asce = get_lowcore()->kernel_asce.val;
pr_cont("kernel ");
break;
default:
unreachable();
} else {
asce = get_lowcore()->user_asce.val;
pr_cont("user ");
}
pr_cont("ASCE.\n");
dump_pagetable(asce, get_fault_address(regs));
@ -212,7 +202,6 @@ static void do_sigsegv(struct pt_regs *regs, int si_code)
static void handle_fault_error_nolock(struct pt_regs *regs, int si_code)
{
enum fault_type fault_type;
unsigned long address;
bool is_write;
@ -223,17 +212,15 @@ static void handle_fault_error_nolock(struct pt_regs *regs, int si_code)
}
if (fixup_exception(regs))
return;
fault_type = get_fault_type(regs);
if (fault_type == KERNEL_FAULT) {
if (is_kernel_fault(regs)) {
address = get_fault_address(regs);
is_write = fault_is_write(regs);
if (kfence_handle_page_fault(address, is_write, regs))
return;
}
if (fault_type == KERNEL_FAULT)
pr_alert("Unable to handle kernel pointer dereference in virtual kernel address space\n");
else
} else {
pr_alert("Unable to handle kernel paging request in virtual user address space\n");
}
dump_fault_info(regs);
die(regs, "Oops");
}
@ -267,7 +254,6 @@ static void do_exception(struct pt_regs *regs, int access)
struct vm_area_struct *vma;
unsigned long address;
struct mm_struct *mm;
enum fault_type type;
unsigned int flags;
vm_fault_t fault;
bool is_write;
@ -282,15 +268,8 @@ static void do_exception(struct pt_regs *regs, int access)
mm = current->mm;
address = get_fault_address(regs);
is_write = fault_is_write(regs);
type = get_fault_type(regs);
switch (type) {
case KERNEL_FAULT:
if (is_kernel_fault(regs) || faulthandler_disabled() || !mm)
return handle_fault_error_nolock(regs, 0);
case USER_FAULT:
if (faulthandler_disabled() || !mm)
return handle_fault_error_nolock(regs, 0);
break;
}
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
flags = FAULT_FLAG_DEFAULT;
if (user_mode(regs))
@ -460,8 +439,15 @@ void do_secure_storage_access(struct pt_regs *regs)
*/
panic("Unexpected PGM 0x3d with TEID bit 61=0");
}
switch (get_fault_type(regs)) {
case USER_FAULT:
if (is_kernel_fault(regs)) {
folio = phys_to_folio(addr);
if (unlikely(!folio_try_get(folio)))
return;
rc = arch_make_folio_accessible(folio);
folio_put(folio);
if (rc)
BUG();
} else {
mm = current->mm;
mmap_read_lock(mm);
vma = find_vma(mm, addr);
@ -470,7 +456,7 @@ void do_secure_storage_access(struct pt_regs *regs)
folio = folio_walk_start(&fw, vma, addr, 0);
if (!folio) {
mmap_read_unlock(mm);
break;
return;
}
/* arch_make_folio_accessible() needs a raised refcount. */
folio_get(folio);
@ -480,18 +466,6 @@ void do_secure_storage_access(struct pt_regs *regs)
if (rc)
send_sig(SIGSEGV, current, 0);
mmap_read_unlock(mm);
break;
case KERNEL_FAULT:
folio = phys_to_folio(addr);
if (unlikely(!folio_try_get(folio)))
break;
rc = arch_make_folio_accessible(folio);
folio_put(folio);
if (rc)
BUG();
break;
default:
unreachable();
}
}
NOKPROBE_SYMBOL(do_secure_storage_access);