[Xen-changelog] [xen-4.0-testing] Xen: fix various checks of unsigned integers < 0

["Xen patchbot-4.0-testing" <patchbot-4.0-testing@xxxxxxxxxxxxxxxxxxx>]

# HG changeset patch
# User Keir Fraser <keir@xxxxxxx>
# Date 1288374294 -3600
# Node ID 43b3f8ceb991c8410541fa763d2265dc3a539baa
# Parent  179150c0b36614a6a596ca5e872fea80d852a819
Xen: fix various checks of unsigned integers < 0

Some of these could be benignly discarded by the compiler but some are
actual bugs.

Signed-off-by: Tim Deegan <Tim.Deegan@xxxxxxxxxx>
xen-unstable changeset:   22336:49803ac994f4
xen-unstable date:        Fri Oct 29 18:05:50 2010 +0100
---
 xen/arch/x86/mm.c                      |    4 ++--
 xen/arch/x86/physdev.c                 |    2 +-
 xen/arch/x86/platform_hypercall.c      |    1 -
 xen/arch/x86/x86_emulate/x86_emulate.c |    2 +-
 xen/drivers/cpufreq/cpufreq.c          |    3 +--
 5 files changed, 5 insertions(+), 7 deletions(-)

diff -r 179150c0b366 -r 43b3f8ceb991 xen/arch/x86/mm.c
--- a/xen/arch/x86/mm.c Fri Oct 29 10:44:23 2010 +0100
+++ b/xen/arch/x86/mm.c Fri Oct 29 18:44:54 2010 +0100
@@ -4223,7 +4223,7 @@ static int handle_iomem_range(unsigned l
         ent.size = (uint64_t)(s - ctxt->s) << PAGE_SHIFT;
         ent.type = E820_RESERVED;
         buffer = guest_handle_cast(ctxt->map.buffer, e820entry_t);
-        if ( __copy_to_guest_offset(buffer, ctxt->n, &ent, 1) < 0 )
+        if ( __copy_to_guest_offset(buffer, ctxt->n, &ent, 1) )
             return -EFAULT;
         ctxt->n++;
     }
@@ -4439,7 +4439,7 @@ long arch_memory_op(int op, XEN_GUEST_HA
             }
             if ( ctxt.map.nr_entries <= ctxt.n + (e820.nr_map - i) )
                 return -EINVAL;
-            if ( __copy_to_guest_offset(buffer, ctxt.n, e820.map + i, 1) < 0 )
+            if ( __copy_to_guest_offset(buffer, ctxt.n, e820.map + i, 1) )
                 return -EFAULT;
             ctxt.s = PFN_UP(e820.map[i].addr + e820.map[i].size);
         }
diff -r 179150c0b366 -r 43b3f8ceb991 xen/arch/x86/physdev.c
--- a/xen/arch/x86/physdev.c    Fri Oct 29 10:44:23 2010 +0100
+++ b/xen/arch/x86/physdev.c    Fri Oct 29 18:44:54 2010 +0100
@@ -202,7 +202,7 @@ ret_t do_physdev_op(int cmd, XEN_GUEST_H
         if ( copy_from_guest(&eoi, arg, 1) != 0 )
             break;
         ret = -EINVAL;
-        if ( eoi.irq < 0 || eoi.irq >= v->domain->nr_pirqs )
+        if ( eoi.irq >= v->domain->nr_pirqs )
             break;
         if ( v->domain->arch.pirq_eoi_map )
             evtchn_unmask(v->domain->pirq_to_evtchn[eoi.irq]);
diff -r 179150c0b366 -r 43b3f8ceb991 xen/arch/x86/platform_hypercall.c
--- a/xen/arch/x86/platform_hypercall.c Fri Oct 29 10:44:23 2010 +0100
+++ b/xen/arch/x86/platform_hypercall.c Fri Oct 29 18:44:54 2010 +0100
@@ -413,7 +413,6 @@ ret_t do_platform_op(XEN_GUEST_HANDLE(xe
         }
 
         if ( (g_info->xen_cpuid >= NR_CPUS) ||
-             (g_info->xen_cpuid < 0) ||
              !cpu_present(g_info->xen_cpuid) )
         {
             g_info->flags |= XEN_PCPU_FLAGS_INVALID;
diff -r 179150c0b366 -r 43b3f8ceb991 xen/arch/x86/x86_emulate/x86_emulate.c
--- a/xen/arch/x86/x86_emulate/x86_emulate.c    Fri Oct 29 10:44:23 2010 +0100
+++ b/xen/arch/x86/x86_emulate/x86_emulate.c    Fri Oct 29 18:44:54 2010 +0100
@@ -2102,7 +2102,7 @@ x86_emulate(
             _regs.edx = (uint32_t)(((int32_t)_regs.eax < 0) ? -1 : 0);
             break;
         case 8:
-            _regs.edx = (_regs.eax < 0) ? -1 : 0;
+            _regs.edx = ((int64_t)_regs.eax < 0) ? -1 : 0;
             break;
         }
         break;
diff -r 179150c0b366 -r 43b3f8ceb991 xen/drivers/cpufreq/cpufreq.c
--- a/xen/drivers/cpufreq/cpufreq.c     Fri Oct 29 10:44:23 2010 +0100
+++ b/xen/drivers/cpufreq/cpufreq.c     Fri Oct 29 18:44:54 2010 +0100
@@ -115,8 +115,7 @@ int cpufreq_limit_change(unsigned int cp
     if (!cpu_online(cpu) || !data || !processor_pminfo[cpu])
         return -ENODEV;
 
-    if ((perf->platform_limit < 0) || 
-        (perf->platform_limit >= perf->state_count))
+    if (perf->platform_limit >= perf->state_count)
         return -EINVAL;
 
     memcpy(&policy, data, sizeof(struct cpufreq_policy)); 

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