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Merge branch 'parisc-4.9-3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux

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Pull parisc updates from Helge Deller:
 "The first three patches are trivial and add some required KERN_CONT,
  ignore the new pkey syscalls on parisc and use the LINUX_GATEWAY_ADDR
  define instead of hardcoded values.

  The two patches from Dave Anglin are important.

  The first one avoids trashing the sr2 and sr3 space registers in the
  Light-weight syscall path. Especially the usage of sr3 is critical
  since it may get trashed by the interrupt handler.

  The second patch is even more important and tagged for stable series.
  It protects one critical section in the syscall entry path by
  disabling local interrupts. Without disabling interrupts, the sr7
  space register may not be in sync with the current stack setup and
  thus an incoming hardware interrupt may destroy memory in random
  userspace areas"

* 'parisc-4.9-3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Ignore the pkey system calls for now
  parisc: Use LINUX_GATEWAY_ADDR define instead of hardcoded value
  parisc: Ensure consistent state when switching to kernel stack at syscall entry
  parisc: Avoid trashing sr2 and sr3 in LWS code
  parisc: use KERN_CONT when printing device inventory
This commit is contained in:
Linus Torvalds 2016-11-04 13:01:13 -07:00
commit f7df76e6ac
3 changed files with 40 additions and 36 deletions
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4
arch/parisc/include/uapi/asm/unistd.h
View File

@ -368,7 +368,9 @@
#define __IGNORE_select /* newselect */
#define __IGNORE_fadvise64 /* fadvise64_64 */
#define __IGNORE_pkey_mprotect
#define __IGNORE_pkey_alloc
#define __IGNORE_pkey_free
#define LINUX_GATEWAY_ADDR 0x100

6
arch/parisc/kernel/drivers.c
View File

@ -873,11 +873,11 @@ static void print_parisc_device(struct parisc_device *dev)
if (dev->num_addrs) {
int k;
printk(", additional addresses: ");
pr_cont(", additional addresses: ");
for (k = 0; k < dev->num_addrs; k++)
printk("0x%lx ", dev->addr[k]);
pr_cont("0x%lx ", dev->addr[k]);
}
printk("\n");
pr_cont("\n");
}
/**

66
arch/parisc/kernel/syscall.S
View File

@ -100,14 +100,12 @@ set_thread_pointer:
.endr
/* This address must remain fixed at 0x100 for glibc's syscalls to work */
.align 256
.align LINUX_GATEWAY_ADDR
linux_gateway_entry:
gate .+8, %r0 /* become privileged */
mtsp %r0,%sr4 /* get kernel space into sr4 */
mtsp %r0,%sr5 /* get kernel space into sr5 */
mtsp %r0,%sr6 /* get kernel space into sr6 */
mfsp %sr7,%r1 /* save user sr7 */
mtsp %r1,%sr3 /* and store it in sr3 */
#ifdef CONFIG_64BIT
/* for now we can *always* set the W bit on entry to the syscall
@ -133,6 +131,14 @@ linux_gateway_entry:
depdi 0, 31, 32, %r21
1:
#endif
/* We use a rsm/ssm pair to prevent sr3 from being clobbered
* by external interrupts.
*/
mfsp %sr7,%r1 /* save user sr7 */
rsm PSW_SM_I, %r0 /* disable interrupts */
mtsp %r1,%sr3 /* and store it in sr3 */
mfctl %cr30,%r1
xor %r1,%r30,%r30 /* ye olde xor trick */
xor %r1,%r30,%r1
@ -147,6 +153,7 @@ linux_gateway_entry:
*/
mtsp %r0,%sr7 /* get kernel space into sr7 */
ssm PSW_SM_I, %r0 /* enable interrupts */
STREGM %r1,FRAME_SIZE(%r30) /* save r1 (usp) here for now */
mfctl %cr30,%r1 /* get task ptr in %r1 */
LDREG TI_TASK(%r1),%r1
@ -474,11 +481,6 @@ lws_start:
comiclr,>> __NR_lws_entries, %r20, %r0
b,n lws_exit_nosys
/* WARNING: Trashing sr2 and sr3 */
mfsp %sr7,%r1 /* get userspace into sr3 */
mtsp %r1,%sr3
mtsp %r0,%sr2 /* get kernel space into sr2 */
/* Load table start */
ldil L%lws_table, %r1
ldo R%lws_table(%r1), %r28 /* Scratch use of r28 */
@ -627,9 +629,9 @@ cas_action:
stw %r1, 4(%sr2,%r20)
#endif
/* The load and store could fail */
1: ldw,ma 0(%sr3,%r26), %r28
1: ldw,ma 0(%r26), %r28
sub,<> %r28, %r25, %r0
2: stw,ma %r24, 0(%sr3,%r26)
2: stw,ma %r24, 0(%r26)
/* Free lock */
stw,ma %r20, 0(%sr2,%r20)
#if ENABLE_LWS_DEBUG
@ -706,9 +708,9 @@ lws_compare_and_swap_2:
nop
/* 8bit load */
4: ldb 0(%sr3,%r25), %r25
4: ldb 0(%r25), %r25
b cas2_lock_start
5: ldb 0(%sr3,%r24), %r24
5: ldb 0(%r24), %r24
nop
nop
nop
@ -716,9 +718,9 @@ lws_compare_and_swap_2:
nop
/* 16bit load */
6: ldh 0(%sr3,%r25), %r25
6: ldh 0(%r25), %r25
b cas2_lock_start
7: ldh 0(%sr3,%r24), %r24
7: ldh 0(%r24), %r24
nop
nop
nop
@ -726,9 +728,9 @@ lws_compare_and_swap_2:
nop
/* 32bit load */
8: ldw 0(%sr3,%r25), %r25
8: ldw 0(%r25), %r25
b cas2_lock_start
9: ldw 0(%sr3,%r24), %r24
9: ldw 0(%r24), %r24
nop
nop
nop
@ -737,14 +739,14 @@ lws_compare_and_swap_2:
/* 64bit load */
#ifdef CONFIG_64BIT
10: ldd 0(%sr3,%r25), %r25
11: ldd 0(%sr3,%r24), %r24
10: ldd 0(%r25), %r25
11: ldd 0(%r24), %r24
#else
/* Load new value into r22/r23 - high/low */
10: ldw 0(%sr3,%r25), %r22
11: ldw 4(%sr3,%r25), %r23
10: ldw 0(%r25), %r22
11: ldw 4(%r25), %r23
/* Load new value into fr4 for atomic store later */
12: flddx 0(%sr3,%r24), %fr4
12: flddx 0(%r24), %fr4
#endif
cas2_lock_start:
@ -794,30 +796,30 @@ cas2_action:
ldo 1(%r0),%r28
/* 8bit CAS */
13: ldb,ma 0(%sr3,%r26), %r29
13: ldb,ma 0(%r26), %r29
sub,= %r29, %r25, %r0
b,n cas2_end
14: stb,ma %r24, 0(%sr3,%r26)
14: stb,ma %r24, 0(%r26)
b cas2_end
copy %r0, %r28
nop
nop
/* 16bit CAS */
15: ldh,ma 0(%sr3,%r26), %r29
15: ldh,ma 0(%r26), %r29
sub,= %r29, %r25, %r0
b,n cas2_end
16: sth,ma %r24, 0(%sr3,%r26)
16: sth,ma %r24, 0(%r26)
b cas2_end
copy %r0, %r28
nop
nop
/* 32bit CAS */
17: ldw,ma 0(%sr3,%r26), %r29
17: ldw,ma 0(%r26), %r29
sub,= %r29, %r25, %r0
b,n cas2_end
18: stw,ma %r24, 0(%sr3,%r26)
18: stw,ma %r24, 0(%r26)
b cas2_end
copy %r0, %r28
nop
@ -825,22 +827,22 @@ cas2_action:
/* 64bit CAS */
#ifdef CONFIG_64BIT
19: ldd,ma 0(%sr3,%r26), %r29
19: ldd,ma 0(%r26), %r29
sub,*= %r29, %r25, %r0
b,n cas2_end
20: std,ma %r24, 0(%sr3,%r26)
20: std,ma %r24, 0(%r26)
copy %r0, %r28
#else
/* Compare first word */
19: ldw,ma 0(%sr3,%r26), %r29
19: ldw,ma 0(%r26), %r29
sub,= %r29, %r22, %r0
b,n cas2_end
/* Compare second word */
20: ldw,ma 4(%sr3,%r26), %r29
20: ldw,ma 4(%r26), %r29
sub,= %r29, %r23, %r0
b,n cas2_end
/* Perform the store */
21: fstdx %fr4, 0(%sr3,%r26)
21: fstdx %fr4, 0(%r26)
copy %r0, %r28
#endif