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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-02-02 23:22:20 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-02-02 23:22:20 -0300
commit5c545e1fb127a4b11ddc5f1a5ed066b853dd1a1a (patch)
treed4cd913bc79d37d32756a9bffbeedabf93e32579 /arch/powerpc/kernel
parentb4b7ff4b08e691656c9d77c758fc355833128ac0 (diff)
Linux-libre 4.4.1-gnupck-4.4.1-gnu
Diffstat (limited to 'arch/powerpc/kernel')
-rw-r--r--arch/powerpc/kernel/module_64.c27
-rw-r--r--arch/powerpc/kernel/process.c18
2 files changed, 45 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c
index 683845145..59663af93 100644
--- a/arch/powerpc/kernel/module_64.c
+++ b/arch/powerpc/kernel/module_64.c
@@ -635,6 +635,33 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,
*/
break;
+ case R_PPC64_ENTRY:
+ /*
+ * Optimize ELFv2 large code model entry point if
+ * the TOC is within 2GB range of current location.
+ */
+ value = my_r2(sechdrs, me) - (unsigned long)location;
+ if (value + 0x80008000 > 0xffffffff)
+ break;
+ /*
+ * Check for the large code model prolog sequence:
+ * ld r2, ...(r12)
+ * add r2, r2, r12
+ */
+ if ((((uint32_t *)location)[0] & ~0xfffc)
+ != 0xe84c0000)
+ break;
+ if (((uint32_t *)location)[1] != 0x7c426214)
+ break;
+ /*
+ * If found, replace it with:
+ * addis r2, r12, (.TOC.-func)@ha
+ * addi r2, r12, (.TOC.-func)@l
+ */
+ ((uint32_t *)location)[0] = 0x3c4c0000 + PPC_HA(value);
+ ((uint32_t *)location)[1] = 0x38420000 + PPC_LO(value);
+ break;
+
case R_PPC64_REL16_HA:
/* Subtract location pointer */
value -= (unsigned long)location;
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 646bf4d22..ef2ad2d68 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -569,6 +569,24 @@ static void tm_reclaim_thread(struct thread_struct *thr,
if (!MSR_TM_SUSPENDED(mfmsr()))
return;
+ /*
+ * Use the current MSR TM suspended bit to track if we have
+ * checkpointed state outstanding.
+ * On signal delivery, we'd normally reclaim the checkpointed
+ * state to obtain stack pointer (see:get_tm_stackpointer()).
+ * This will then directly return to userspace without going
+ * through __switch_to(). However, if the stack frame is bad,
+ * we need to exit this thread which calls __switch_to() which
+ * will again attempt to reclaim the already saved tm state.
+ * Hence we need to check that we've not already reclaimed
+ * this state.
+ * We do this using the current MSR, rather tracking it in
+ * some specific thread_struct bit, as it has the additional
+ * benifit of checking for a potential TM bad thing exception.
+ */
+ if (!MSR_TM_SUSPENDED(mfmsr()))
+ return;
+
tm_reclaim(thr, thr->regs->msr, cause);
/* Having done the reclaim, we now have the checkpointed