--- /dev/null
+From 1021cb268b3025573c4811f1dee4a11260c4507b Mon Sep 17 00:00:00 2001
+From: Anton Blanchard <anton@samba.org>
+Date: Mon, 3 Sep 2012 16:49:47 +0000
+Subject: powerpc: Fix DSCR inheritance in copy_thread()
+
+From: Anton Blanchard <anton@samba.org>
+
+commit 1021cb268b3025573c4811f1dee4a11260c4507b upstream.
+
+If the default DSCR is non zero we set thread.dscr_inherit in
+copy_thread() meaning the new thread and all its children will ignore
+future updates to the default DSCR. This is not intended and is
+a change in behaviour that a number of our users have hit.
+
+We just need to inherit thread.dscr and thread.dscr_inherit from
+the parent which ends up being much simpler.
+
+This was found with the following test case:
+
+http://ozlabs.org/~anton/junkcode/dscr_default_test.c
+
+Signed-off-by: Anton Blanchard <anton@samba.org>
+Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ arch/powerpc/kernel/process.c | 12 ++----------
+ 1 file changed, 2 insertions(+), 10 deletions(-)
+
+--- a/arch/powerpc/kernel/process.c
++++ b/arch/powerpc/kernel/process.c
+@@ -794,16 +794,8 @@ int copy_thread(unsigned long clone_flag
+ #endif /* CONFIG_PPC_STD_MMU_64 */
+ #ifdef CONFIG_PPC64
+ if (cpu_has_feature(CPU_FTR_DSCR)) {
+- if (current->thread.dscr_inherit) {
+- p->thread.dscr_inherit = 1;
+- p->thread.dscr = current->thread.dscr;
+- } else if (0 != dscr_default) {
+- p->thread.dscr_inherit = 1;
+- p->thread.dscr = dscr_default;
+- } else {
+- p->thread.dscr_inherit = 0;
+- p->thread.dscr = 0;
+- }
++ p->thread.dscr_inherit = current->thread.dscr_inherit;
++ p->thread.dscr = current->thread.dscr;
+ }
+ #endif
+
--- /dev/null
+From 714332858bfd40dcf8f741498336d93875c23aa7 Mon Sep 17 00:00:00 2001
+From: Anton Blanchard <anton@samba.org>
+Date: Mon, 3 Sep 2012 16:51:10 +0000
+Subject: powerpc: Restore correct DSCR in context switch
+
+From: Anton Blanchard <anton@samba.org>
+
+commit 714332858bfd40dcf8f741498336d93875c23aa7 upstream.
+
+During a context switch we always restore the per thread DSCR value.
+If we aren't doing explicit DSCR management
+(ie thread.dscr_inherit == 0) and the default DSCR changed while
+the process has been sleeping we end up with the wrong value.
+
+Check thread.dscr_inherit and select the default DSCR or per thread
+DSCR as required.
+
+This was found with the following test case, when running with
+more threads than CPUs (ie forcing context switching):
+
+http://ozlabs.org/~anton/junkcode/dscr_default_test.c
+
+With the four patches applied I can run a combination of all
+test cases successfully at the same time:
+
+http://ozlabs.org/~anton/junkcode/dscr_default_test.c
+http://ozlabs.org/~anton/junkcode/dscr_explicit_test.c
+http://ozlabs.org/~anton/junkcode/dscr_inherit_test.c
+
+Signed-off-by: Anton Blanchard <anton@samba.org>
+Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ arch/powerpc/kernel/asm-offsets.c | 1 +
+ arch/powerpc/kernel/entry_64.S | 23 +++++++++++++++++------
+ 2 files changed, 18 insertions(+), 6 deletions(-)
+
+--- a/arch/powerpc/kernel/asm-offsets.c
++++ b/arch/powerpc/kernel/asm-offsets.c
+@@ -75,6 +75,7 @@ int main(void)
+ DEFINE(SIGSEGV, SIGSEGV);
+ DEFINE(NMI_MASK, NMI_MASK);
+ DEFINE(THREAD_DSCR, offsetof(struct thread_struct, dscr));
++ DEFINE(THREAD_DSCR_INHERIT, offsetof(struct thread_struct, dscr_inherit));
+ #else
+ DEFINE(THREAD_INFO, offsetof(struct task_struct, stack));
+ #endif /* CONFIG_PPC64 */
+--- a/arch/powerpc/kernel/entry_64.S
++++ b/arch/powerpc/kernel/entry_64.S
+@@ -380,6 +380,12 @@ _GLOBAL(ret_from_fork)
+ li r3,0
+ b syscall_exit
+
++ .section ".toc","aw"
++DSCR_DEFAULT:
++ .tc dscr_default[TC],dscr_default
++
++ .section ".text"
++
+ /*
+ * This routine switches between two different tasks. The process
+ * state of one is saved on its kernel stack. Then the state
+@@ -519,9 +525,6 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_1T_SEG
+ mr r1,r8 /* start using new stack pointer */
+ std r7,PACAKSAVE(r13)
+
+- ld r6,_CCR(r1)
+- mtcrf 0xFF,r6
+-
+ #ifdef CONFIG_ALTIVEC
+ BEGIN_FTR_SECTION
+ ld r0,THREAD_VRSAVE(r4)
+@@ -530,14 +533,22 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
+ #endif /* CONFIG_ALTIVEC */
+ #ifdef CONFIG_PPC64
+ BEGIN_FTR_SECTION
++ lwz r6,THREAD_DSCR_INHERIT(r4)
++ ld r7,DSCR_DEFAULT@toc(2)
+ ld r0,THREAD_DSCR(r4)
+- cmpd r0,r25
+- beq 1f
++ cmpwi r6,0
++ bne 1f
++ ld r0,0(r7)
++1: cmpd r0,r25
++ beq 2f
+ mtspr SPRN_DSCR,r0
+-1:
++2:
+ END_FTR_SECTION_IFSET(CPU_FTR_DSCR)
+ #endif
+
++ ld r6,_CCR(r1)
++ mtcrf 0xFF,r6
++
+ /* r3-r13 are destroyed -- Cort */
+ REST_8GPRS(14, r1)
+ REST_10GPRS(22, r1)
--- /dev/null
+From 80de7c3138ee9fd86a98696fd2cf7ad89b995d0a Mon Sep 17 00:00:00 2001
+From: Dave Jones <davej@redhat.com>
+Date: Thu, 6 Sep 2012 12:01:00 -0400
+Subject: Remove user-triggerable BUG from mpol_to_str
+
+From: Dave Jones <davej@redhat.com>
+
+commit 80de7c3138ee9fd86a98696fd2cf7ad89b995d0a upstream.
+
+Trivially triggerable, found by trinity:
+
+ kernel BUG at mm/mempolicy.c:2546!
+ Process trinity-child2 (pid: 23988, threadinfo ffff88010197e000, task ffff88007821a670)
+ Call Trace:
+ show_numa_map+0xd5/0x450
+ show_pid_numa_map+0x13/0x20
+ traverse+0xf2/0x230
+ seq_read+0x34b/0x3e0
+ vfs_read+0xac/0x180
+ sys_pread64+0xa2/0xc0
+ system_call_fastpath+0x1a/0x1f
+ RIP: mpol_to_str+0x156/0x360
+
+Signed-off-by: Dave Jones <davej@redhat.com>
+Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ mm/mempolicy.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/mm/mempolicy.c
++++ b/mm/mempolicy.c
+@@ -2500,7 +2500,7 @@ int mpol_to_str(char *buffer, int maxlen
+ break;
+
+ default:
+- BUG();
++ return -EINVAL;
+ }
+
+ l = strlen(policy_modes[mode]);
usb-rtl8187-remove-__devinit-from-the-struct-usb_device_id-table.patch
usb-smsusb-remove-__devinit-from-the-struct-usb_device_id-table.patch
usb-cdc-acm-fix-null-pointer-dereference.patch
+powerpc-fix-dscr-inheritance-in-copy_thread.patch
+powerpc-restore-correct-dscr-in-context-switch.patch
+remove-user-triggerable-bug-from-mpol_to_str.patch
projects / thirdparty / kernel / stable-queue.git / commitdiff
