* [PATCH 1/2] x86/boot: Align e820 and video data in the boot trampoline
@ 2016-08-12 10:35 Andrew Cooper
2016-08-12 10:35 ` [PATCH 2/2] x86/cpufreq: Avoid using processor_pminfo[cpu] when it is NULL Andrew Cooper
2016-08-12 12:08 ` [PATCH 1/2] x86/boot: Align e820 and video data in the boot trampoline Jan Beulich
0 siblings, 2 replies; 4+ messages in thread
From: Andrew Cooper @ 2016-08-12 10:35 UTC (permalink / raw)
To: Xen-devel; +Cc: Andrew Cooper, Jan Beulich
The undefined behaviour sanitiser in Clang 3.8 identifies that these are all
misaigned when used in __start_xen().
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
---
CC: Jan Beulich <JBeulich@suse.com>
---
xen/arch/x86/boot/mem.S | 1 +
xen/arch/x86/boot/video.S | 1 +
2 files changed, 2 insertions(+)
diff --git a/xen/arch/x86/boot/mem.S b/xen/arch/x86/boot/mem.S
index 820aea9..602ab2c 100644
--- a/xen/arch/x86/boot/mem.S
+++ b/xen/arch/x86/boot/mem.S
@@ -67,6 +67,7 @@ get_memory_map:
ret
+ .align 4
GLOBAL(e820map)
.fill E820MAX*20,1,0
GLOBAL(e820nr)
diff --git a/xen/arch/x86/boot/video.S b/xen/arch/x86/boot/video.S
index b238bf3..2aafbeb 100644
--- a/xen/arch/x86/boot/video.S
+++ b/xen/arch/x86/boot/video.S
@@ -994,6 +994,7 @@ force_size: .word 0 # Use this size instead of the one in BIOS vars
vesa_size: .word 0,0,0 # width x depth x height
/* If we don't run at all, assume basic video mode 3 at 80x25. */
+ .align 2
GLOBAL(boot_vid_mode)
.word VIDEO_80x25
GLOBAL(boot_vid_info)
--
2.1.4
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^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH 2/2] x86/cpufreq: Avoid using processor_pminfo[cpu] when it is NULL
2016-08-12 10:35 [PATCH 1/2] x86/boot: Align e820 and video data in the boot trampoline Andrew Cooper
@ 2016-08-12 10:35 ` Andrew Cooper
2016-08-12 12:14 ` Jan Beulich
2016-08-12 12:08 ` [PATCH 1/2] x86/boot: Align e820 and video data in the boot trampoline Jan Beulich
1 sibling, 1 reply; 4+ messages in thread
From: Andrew Cooper @ 2016-08-12 10:35 UTC (permalink / raw)
To: Xen-devel; +Cc: Andrew Cooper, Jan Beulich
The undefined behaviour sanitiser shows that it really is NULL via the
pre_initcall path.
(XEN) ================================================================================
(XEN) UBSAN: Undefined behaviour in cpufreq.c:158:66
(XEN) member access within null pointer of type 'struct processor_pminfo'
(XEN) ----[ Xen-4.8-unstable x86_64 debug=y Not tainted ]----
<snip>
(XEN) [<ffff82d0801c4231>] cpufreq_add_cpu+0x161/0xdc0
(XEN) [<ffff82d0801c6610>] cpufreq.c#cpu_callback+0x20/0x30
(XEN) [<ffff82d0804eefad>] cpufreq.c#cpufreq_presmp_init+0x2d/0x50
(XEN) [<ffff82d0804c5942>] do_presmp_initcalls+0x22/0x30
(XEN) [<ffff82d08051852d>] __start_xen+0x378d/0x42f0
(XEN) [<ffff82d080100073>] __high_start+0x53/0x60
Fix two other occurances of the same buggy logic.
The processor_pminfo[] objects are only allocated as a result of
XENPF_set_processor_pminfo hypercalls, which means that this early cpu
callback will always hit the early NULL check, and is therefore pointless.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
---
CC: Jan Beulich <JBeulich@suse.com>
---
xen/drivers/cpufreq/cpufreq.c | 28 +++++++++++++++++-----------
1 file changed, 17 insertions(+), 11 deletions(-)
diff --git a/xen/drivers/cpufreq/cpufreq.c b/xen/drivers/cpufreq/cpufreq.c
index f19b403..fd82ef5 100644
--- a/xen/drivers/cpufreq/cpufreq.c
+++ b/xen/drivers/cpufreq/cpufreq.c
@@ -126,7 +126,7 @@ int __init cpufreq_register_governor(struct cpufreq_governor *governor)
int cpufreq_limit_change(unsigned int cpu)
{
- struct processor_performance *perf = &processor_pminfo[cpu]->perf;
+ struct processor_performance *perf;
struct cpufreq_policy *data;
struct cpufreq_policy policy;
@@ -134,6 +134,8 @@ int cpufreq_limit_change(unsigned int cpu)
!processor_pminfo[cpu])
return -ENODEV;
+ perf = &processor_pminfo[cpu]->perf;
+
if (perf->platform_limit >= perf->state_count)
return -EINVAL;
@@ -155,12 +157,15 @@ int cpufreq_add_cpu(unsigned int cpu)
struct cpufreq_dom *cpufreq_dom = NULL;
struct cpufreq_policy new_policy;
struct cpufreq_policy *policy;
- struct processor_performance *perf = &processor_pminfo[cpu]->perf;
+ struct processor_performance *perf;
/* to protect the case when Px was not controlled by xen */
- if (!processor_pminfo[cpu] ||
- !(perf->init & XEN_PX_INIT) ||
- !cpu_online(cpu))
+ if ( !processor_pminfo[cpu] || !cpu_online(cpu) )
+ return -EINVAL;
+
+ perf = &processor_pminfo[cpu]->perf;
+
+ if ( !(perf->init & XEN_PX_INIT) )
return -EINVAL;
if (!cpufreq_driver)
@@ -310,12 +315,15 @@ int cpufreq_del_cpu(unsigned int cpu)
struct list_head *pos;
struct cpufreq_dom *cpufreq_dom = NULL;
struct cpufreq_policy *policy;
- struct processor_performance *perf = &processor_pminfo[cpu]->perf;
+ struct processor_performance *perf;
/* to protect the case when Px was not controlled by xen */
- if (!processor_pminfo[cpu] ||
- !(perf->init & XEN_PX_INIT) ||
- !cpu_online(cpu))
+ if ( !processor_pminfo[cpu] || !cpu_online(cpu) )
+ return -EINVAL;
+
+ perf = &processor_pminfo[cpu]->perf;
+
+ if ( !(perf->init & XEN_PX_INIT) )
return -EINVAL;
if (!per_cpu(cpufreq_cpu_policy, cpu))
@@ -637,8 +645,6 @@ static struct notifier_block cpu_nfb = {
static int __init cpufreq_presmp_init(void)
{
- void *cpu = (void *)(long)smp_processor_id();
- cpu_callback(&cpu_nfb, CPU_ONLINE, cpu);
register_cpu_notifier(&cpu_nfb);
return 0;
}
--
2.1.4
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^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH 2/2] x86/cpufreq: Avoid using processor_pminfo[cpu] when it is NULL
2016-08-12 10:35 ` [PATCH 2/2] x86/cpufreq: Avoid using processor_pminfo[cpu] when it is NULL Andrew Cooper
@ 2016-08-12 12:14 ` Jan Beulich
0 siblings, 0 replies; 4+ messages in thread
From: Jan Beulich @ 2016-08-12 12:14 UTC (permalink / raw)
To: Andrew Cooper; +Cc: Xen-devel
>>> On 12.08.16 at 12:35, <andrew.cooper3@citrix.com> wrote:
> The undefined behaviour sanitiser shows that it really is NULL via the
> pre_initcall path.
>
> (XEN)
> ================================================================================
> (XEN) UBSAN: Undefined behaviour in cpufreq.c:158:66
> (XEN) member access within null pointer of type 'struct processor_pminfo'
> (XEN) ----[ Xen-4.8-unstable x86_64 debug=y Not tainted ]----
> <snip>
> (XEN) [<ffff82d0801c4231>] cpufreq_add_cpu+0x161/0xdc0
> (XEN) [<ffff82d0801c6610>] cpufreq.c#cpu_callback+0x20/0x30
> (XEN) [<ffff82d0804eefad>] cpufreq.c#cpufreq_presmp_init+0x2d/0x50
> (XEN) [<ffff82d0804c5942>] do_presmp_initcalls+0x22/0x30
> (XEN) [<ffff82d08051852d>] __start_xen+0x378d/0x42f0
> (XEN) [<ffff82d080100073>] __high_start+0x53/0x60
>
> Fix two other occurances of the same buggy logic.
>
> The processor_pminfo[] objects are only allocated as a result of
> XENPF_set_processor_pminfo hypercalls, which means that this early cpu
> callback will always hit the early NULL check, and is therefore pointless.
>
> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
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^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH 1/2] x86/boot: Align e820 and video data in the boot trampoline
2016-08-12 10:35 [PATCH 1/2] x86/boot: Align e820 and video data in the boot trampoline Andrew Cooper
2016-08-12 10:35 ` [PATCH 2/2] x86/cpufreq: Avoid using processor_pminfo[cpu] when it is NULL Andrew Cooper
@ 2016-08-12 12:08 ` Jan Beulich
1 sibling, 0 replies; 4+ messages in thread
From: Jan Beulich @ 2016-08-12 12:08 UTC (permalink / raw)
To: Andrew Cooper; +Cc: Xen-devel
>>> On 12.08.16 at 12:35, <andrew.cooper3@citrix.com> wrote:
> The undefined behaviour sanitiser in Clang 3.8 identifies that these are all
> misaigned when used in __start_xen().
>
> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
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^ permalink raw reply [flat|nested] 4+ messages in thread
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