[Devel] [PATCH vz8 2/4] ia32: add 32-bit vdso virtualization.
Andrey Ryabinin
aryabinin at virtuozzo.com
Thu Oct 22 18:02:21 MSK 2020
Similarly to the 64-bit vdso, make 32-bit vdso mapping per-ve.
This will allow per container modification of the linux version
xin .note section of vdso and monotonic time.
https://jira.sw.ru/browse/PSBM-121668
Signed-off-by: Andrey Ryabinin <aryabinin at virtuozzo.com>
---
arch/x86/entry/vdso/vma.c | 4 ++--
arch/x86/kernel/process_64.c | 2 +-
include/linux/ve.h | 1 +
kernel/ve/ve.c | 35 +++++++++++++++++++++--------------
4 files changed, 25 insertions(+), 17 deletions(-)
diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c
index c48deffc1473..538c6730f436 100644
--- a/arch/x86/entry/vdso/vma.c
+++ b/arch/x86/entry/vdso/vma.c
@@ -56,7 +56,7 @@ static void vdso_fix_landing(const struct vdso_image *image,
struct vm_area_struct *new_vma)
{
#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
- if (in_ia32_syscall() && image == &vdso_image_32) {
+ if (in_ia32_syscall() && image == get_exec_env()->vdso_32) {
struct pt_regs *regs = current_pt_regs();
unsigned long vdso_land = image->sym_int80_landing_pad;
unsigned long old_land_addr = vdso_land +
@@ -281,7 +281,7 @@ static int load_vdso32(void)
if (vdso32_enabled != 1) /* Other values all mean "disabled" */
return 0;
- return map_vdso(&vdso_image_32, 0);
+ return map_vdso(get_exec_env()->vdso_32, 0);
}
#endif
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index a010d4b9d126..dddd22215141 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -686,7 +686,7 @@ long do_arch_prctl_64(struct task_struct *task, int option, unsigned long arg2)
# endif
# if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
case ARCH_MAP_VDSO_32:
- return prctl_map_vdso(&vdso_image_32, arg2);
+ return prctl_map_vdso(get_exec_env()->vdso_32, arg2);
# endif
case ARCH_MAP_VDSO_64:
return prctl_map_vdso(get_exec_env()->vdso_64, arg2);
diff --git a/include/linux/ve.h b/include/linux/ve.h
index 0e85a4032c3a..5b1962ff4c66 100644
--- a/include/linux/ve.h
+++ b/include/linux/ve.h
@@ -95,6 +95,7 @@ struct ve_struct {
struct cn_private *cn;
#endif
struct vdso_image *vdso_64;
+ struct vdso_image *vdso_32;
};
#define VE_MEMINFO_DEFAULT 1 /* default behaviour */
diff --git a/kernel/ve/ve.c b/kernel/ve/ve.c
index 186deb3f88f4..03b8d126a0ed 100644
--- a/kernel/ve/ve.c
+++ b/kernel/ve/ve.c
@@ -58,6 +58,7 @@ struct ve_struct ve0 = {
.netns_max_nr = INT_MAX,
.meminfo_val = VE_MEMINFO_SYSTEM,
.vdso_64 = (struct vdso_image*)&vdso_image_64,
+ .vdso_32 = (struct vdso_image*)&vdso_image_32,
};
EXPORT_SYMBOL(ve0);
@@ -540,13 +541,12 @@ static __u64 ve_setup_iptables_mask(__u64 init_mask)
}
#endif
-static int copy_vdso(struct ve_struct *ve)
+static int copy_vdso(struct vdso_image **vdso_dst, const struct vdso_image *vdso_src)
{
- const struct vdso_image *vdso_src = &vdso_image_64;
struct vdso_image *vdso;
void *vdso_data;
- if (ve->vdso_64)
+ if (*vdso_dst)
return 0;
vdso = kmemdup(vdso_src, sizeof(*vdso), GFP_KERNEL);
@@ -563,10 +563,22 @@ static int copy_vdso(struct ve_struct *ve)
vdso->data = vdso_data;
- ve->vdso_64 = vdso;
+ *vdso_dst = vdso;
return 0;
}
+static void ve_free_vdso(struct ve_struct *ve)
+{
+ if (ve->vdso_64 && ve->vdso_64 != &vdso_image_64) {
+ kfree(ve->vdso_64->data);
+ kfree(ve->vdso_64);
+ }
+ if (ve->vdso_32 && ve->vdso_32 != &vdso_image_32) {
+ kfree(ve->vdso_32->data);
+ kfree(ve->vdso_32);
+ }
+}
+
static struct cgroup_subsys_state *ve_create(struct cgroup_subsys_state *parent_css)
{
struct ve_struct *ve = &ve0;
@@ -592,7 +604,10 @@ static struct cgroup_subsys_state *ve_create(struct cgroup_subsys_state *parent_
if (err)
goto err_log;
- if (copy_vdso(ve))
+ if (copy_vdso(&ve->vdso_64, &vdso_image_64))
+ goto err_vdso;
+
+ if (copy_vdso(&ve->vdso_32, &vdso_image_32))
goto err_vdso;
ve->features = VE_FEATURES_DEF;
@@ -619,6 +634,7 @@ static struct cgroup_subsys_state *ve_create(struct cgroup_subsys_state *parent_
return &ve->css;
err_vdso:
+ ve_free_vdso(ve);
ve_log_destroy(ve);
err_log:
free_percpu(ve->sched_lat_ve.cur);
@@ -658,15 +674,6 @@ static void ve_offline(struct cgroup_subsys_state *css)
ve->ve_name = NULL;
}
-static void ve_free_vdso(struct ve_struct *ve)
-{
- if (ve->vdso_64 == &vdso_image_64)
- return;
-
- kfree(ve->vdso_64->data);
- kfree(ve->vdso_64);
-}
-
static void ve_destroy(struct cgroup_subsys_state *css)
{
struct ve_struct *ve = css_to_ve(css);
--
2.26.2
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