path: root/include
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authorTony Luck <tony.luck@intel.com>2008-05-27 13:23:16 -0700
committerTony Luck <tony.luck@intel.com>2008-05-27 13:24:39 -0700
commit4dcc29e1574d88f4465ba865ed82800032f76418 (patch)
tree5579a225a6782f0f5014cbbe6938847b7f3cd53f /include
parentLinux 2.6.26-rc4 (diff)
[IA64] Workaround for RSE issue
Problem: An application violating the architectural rules regarding operation dependencies and having specific Register Stack Engine (RSE) state at the time of the violation, may result in an illegal operation fault and invalid RSE state. Such faults may initiate a cascade of repeated illegal operation faults within OS interruption handlers. The specific behavior is OS dependent. Implication: An application causing an illegal operation fault with specific RSE state may result in a series of illegal operation faults and an eventual OS stack overflow condition. Workaround: OS interruption handlers that switch to kernel backing store implement a check for invalid RSE state to avoid the series of illegal operation faults. The core of the workaround is the RSE_WORKAROUND code sequence inserted into each invocation of the SAVE_MIN_WITH_COVER and SAVE_MIN_WITH_COVER_R19 macros. This sequence includes hard-coded constants that depend on the number of stacked physical registers being 96. The rest of this patch consists of code to disable this workaround should this not be the case (with the presumption that if a future Itanium processor increases the number of registers, it would also remove the need for this patch). Move the start of the RBS up to a mod32 boundary to avoid some corner cases. The dispatch_illegal_op_fault code outgrew the spot it was squatting in when built with this patch and CONFIG_VIRT_CPU_ACCOUNTING=y Move it out to the end of the ivt. Signed-off-by: Tony Luck <tony.luck@intel.com>
Diffstat (limited to 'include')
3 files changed, 3 insertions, 1 deletions
diff --git a/include/asm-ia64/patch.h b/include/asm-ia64/patch.h
index a71543084fb4..295fe6ab4584 100644
--- a/include/asm-ia64/patch.h
+++ b/include/asm-ia64/patch.h
@@ -21,6 +21,7 @@ extern void ia64_patch_imm60 (u64 insn_addr, u64 val); /* patch "brl" w/ip-rel
extern void ia64_patch_mckinley_e9 (unsigned long start, unsigned long end);
extern void ia64_patch_vtop (unsigned long start, unsigned long end);
extern void ia64_patch_phys_stack_reg(unsigned long val);
+extern void ia64_patch_rse (unsigned long start, unsigned long end);
extern void ia64_patch_gate (void);
#endif /* _ASM_IA64_PATCH_H */
diff --git a/include/asm-ia64/ptrace.h b/include/asm-ia64/ptrace.h
index 4b2a8d40ebc5..15f8dcfe6eee 100644
--- a/include/asm-ia64/ptrace.h
+++ b/include/asm-ia64/ptrace.h
@@ -76,7 +76,7 @@
-#define IA64_RBS_OFFSET ((IA64_TASK_SIZE + IA64_THREAD_INFO_SIZE + 15) & ~15)
+#define IA64_RBS_OFFSET ((IA64_TASK_SIZE + IA64_THREAD_INFO_SIZE + 31) & ~31)
diff --git a/include/asm-ia64/sections.h b/include/asm-ia64/sections.h
index dc42a359894f..7286e4a9fe84 100644
--- a/include/asm-ia64/sections.h
+++ b/include/asm-ia64/sections.h
@@ -10,6 +10,7 @@
extern char __per_cpu_start[], __per_cpu_end[], __phys_per_cpu_start[];
extern char __start___vtop_patchlist[], __end___vtop_patchlist[];
+extern char __start___rse_patchlist[], __end___rse_patchlist[];
extern char __start___mckinley_e9_bundles[], __end___mckinley_e9_bundles[];
extern char __start___phys_stack_reg_patchlist[], __end___phys_stack_reg_patchlist[];
extern char __start_gate_section[];