* [PATCH v7 1/5] x86/KASLR: Add kaslr_mem=nn[KMG]@ss[KMG]
2018-01-17 10:53 [PATCH v7 0/5] x86/KASLR: Add parameter kaslr_mem=nn[KMG]@ss[KMG] Chao Fan
@ 2018-01-17 10:53 ` Chao Fan
2018-01-19 2:34 ` Baoquan He
2018-01-17 10:53 ` [PATCH v7 2/5] x86/KASLR: Handle the memory regions specified in kaslr_mem Chao Fan
` (4 subsequent siblings)
5 siblings, 1 reply; 27+ messages in thread
From: Chao Fan @ 2018-01-17 10:53 UTC (permalink / raw)
To: linux-kernel, x86, hpa, tglx, mingo, bhe, keescook, yasu.isimatu
Cc: indou.takao, lcapitulino, Chao Fan
Introduce a new kernel parameter kaslr_mem=nn[KMG]@ss[KMG] which is used
by KASLR only during kernel decompression stage.
Users can use it to specify memory regions where kernel can be randomized
into. E.g if movable_node specified in kernel cmdline, kernel could be
extracted into those movable regions, this will make memory hotplug fail.
With the help of 'kaslr_mem=', limit kernel in those immovable regions
specified.
Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com>
---
arch/x86/boot/compressed/kaslr.c | 73 ++++++++++++++++++++++++++++++++++++++--
1 file changed, 70 insertions(+), 3 deletions(-)
diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c
index 8199a6187251..b21741135673 100644
--- a/arch/x86/boot/compressed/kaslr.c
+++ b/arch/x86/boot/compressed/kaslr.c
@@ -108,6 +108,15 @@ enum mem_avoid_index {
static struct mem_vector mem_avoid[MEM_AVOID_MAX];
+/* Only support at most 4 usable memory regions specified for kaslr */
+#define MAX_KASLR_MEM_USABLE 4
+
+/* Store the usable memory regions for kaslr */
+static struct mem_vector mem_usable[MAX_KASLR_MEM_USABLE];
+
+/* The amount of usable regions for kaslr user specify, not more than 4 */
+static int num_usable_region;
+
static bool mem_overlaps(struct mem_vector *one, struct mem_vector *two)
{
/* Item one is entirely before item two. */
@@ -206,7 +215,62 @@ static void mem_avoid_memmap(char *str)
memmap_too_large = true;
}
-static int handle_mem_memmap(void)
+static int parse_kaslr_mem(char *p,
+ unsigned long long *start,
+ unsigned long long *size)
+{
+ char *oldp;
+
+ if (!p)
+ return -EINVAL;
+
+ oldp = p;
+ *size = memparse(p, &p);
+ if (p == oldp)
+ return -EINVAL;
+
+ switch (*p) {
+ case '@':
+ *start = memparse(p + 1, &p);
+ return 0;
+ default:
+ /*
+ * If w/o offset, only size specified, kaslr_mem=nn[KMG]
+ * has the same behaviour as kaslr_mem=nn[KMG]@0. It means
+ * the region starts from 0.
+ */
+ *start = 0;
+ return 0;
+ }
+
+ return -EINVAL;
+}
+
+static void parse_kaslr_mem_regions(char *str)
+{
+ static int i;
+
+ while (str && (i < MAX_KASLR_MEM_USABLE)) {
+ int rc;
+ unsigned long long start, size;
+ char *k = strchr(str, ',');
+
+ if (k)
+ *k++ = 0;
+
+ rc = parse_kaslr_mem(str, &start, &size);
+ if (rc < 0)
+ break;
+ str = k;
+
+ mem_usable[i].start = start;
+ mem_usable[i].size = size;
+ i++;
+ }
+ num_usable_region = i;
+}
+
+static int handle_mem_filter(void)
{
char *args = (char *)get_cmd_line_ptr();
size_t len = strlen((char *)args);
@@ -214,7 +278,8 @@ static int handle_mem_memmap(void)
char *param, *val;
u64 mem_size;
- if (!strstr(args, "memmap=") && !strstr(args, "mem="))
+ if (!strstr(args, "memmap=") && !strstr(args, "mem=") &&
+ !strstr(args, "kaslr_mem="))
return 0;
tmp_cmdline = malloc(len + 1);
@@ -239,6 +304,8 @@ static int handle_mem_memmap(void)
if (!strcmp(param, "memmap")) {
mem_avoid_memmap(val);
+ } else if (!strcmp(param, "kaslr_mem")) {
+ parse_kaslr_mem_regions(val);
} else if (!strcmp(param, "mem")) {
char *p = val;
@@ -378,7 +445,7 @@ static void mem_avoid_init(unsigned long input, unsigned long input_size,
/* We don't need to set a mapping for setup_data. */
/* Mark the memmap regions we need to avoid */
- handle_mem_memmap();
+ handle_mem_filter();
#ifdef CONFIG_X86_VERBOSE_BOOTUP
/* Make sure video RAM can be used. */
--
2.14.3
^ permalink raw reply related [flat|nested] 27+ messages in thread
* Re: [PATCH v7 1/5] x86/KASLR: Add kaslr_mem=nn[KMG]@ss[KMG]
2018-01-17 10:53 ` [PATCH v7 1/5] x86/KASLR: Add kaslr_mem=nn[KMG]@ss[KMG] Chao Fan
@ 2018-01-19 2:34 ` Baoquan He
0 siblings, 0 replies; 27+ messages in thread
From: Baoquan He @ 2018-01-19 2:34 UTC (permalink / raw)
To: Chao Fan
Cc: linux-kernel, x86, hpa, tglx, mingo, keescook, yasu.isimatu,
indou.takao, lcapitulino
On 01/17/18 at 06:53pm, Chao Fan wrote:
> Introduce a new kernel parameter kaslr_mem=nn[KMG]@ss[KMG] which is used
> by KASLR only during kernel decompression stage.
>
> Users can use it to specify memory regions where kernel can be randomized
> into. E.g if movable_node specified in kernel cmdline, kernel could be
~ remove 'into'
> extracted into those movable regions, this will make memory hotplug fail.
> With the help of 'kaslr_mem=', limit kernel in those immovable regions
> specified.
>
> Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com>
> ---
> arch/x86/boot/compressed/kaslr.c | 73 ++++++++++++++++++++++++++++++++++++++--
> 1 file changed, 70 insertions(+), 3 deletions(-)
>
> diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c
> index 8199a6187251..b21741135673 100644
> --- a/arch/x86/boot/compressed/kaslr.c
> +++ b/arch/x86/boot/compressed/kaslr.c
> @@ -108,6 +108,15 @@ enum mem_avoid_index {
>
> static struct mem_vector mem_avoid[MEM_AVOID_MAX];
>
> +/* Only support at most 4 usable memory regions specified for kaslr */
> +#define MAX_KASLR_MEM_USABLE 4
> +
> +/* Store the usable memory regions for kaslr */
> +static struct mem_vector mem_usable[MAX_KASLR_MEM_USABLE];
The name xx_usable sounds not so good, while I don't know what
is better. Otherwise this patch looks good to me.
Ack it.
Acked-by: Baoquan He <bhe@redhat.com>
> +
> +/* The amount of usable regions for kaslr user specify, not more than 4 */
> +static int num_usable_region;
> +
> static bool mem_overlaps(struct mem_vector *one, struct mem_vector *two)
> {
> /* Item one is entirely before item two. */
> @@ -206,7 +215,62 @@ static void mem_avoid_memmap(char *str)
> memmap_too_large = true;
> }
>
> -static int handle_mem_memmap(void)
> +static int parse_kaslr_mem(char *p,
> + unsigned long long *start,
> + unsigned long long *size)
> +{
> + char *oldp;
> +
> + if (!p)
> + return -EINVAL;
> +
> + oldp = p;
> + *size = memparse(p, &p);
> + if (p == oldp)
> + return -EINVAL;
> +
> + switch (*p) {
> + case '@':
> + *start = memparse(p + 1, &p);
> + return 0;
> + default:
> + /*
> + * If w/o offset, only size specified, kaslr_mem=nn[KMG]
> + * has the same behaviour as kaslr_mem=nn[KMG]@0. It means
> + * the region starts from 0.
> + */
> + *start = 0;
> + return 0;
> + }
> +
> + return -EINVAL;
> +}
> +
> +static void parse_kaslr_mem_regions(char *str)
> +{
> + static int i;
> +
> + while (str && (i < MAX_KASLR_MEM_USABLE)) {
> + int rc;
> + unsigned long long start, size;
> + char *k = strchr(str, ',');
> +
> + if (k)
> + *k++ = 0;
> +
> + rc = parse_kaslr_mem(str, &start, &size);
> + if (rc < 0)
> + break;
> + str = k;
> +
> + mem_usable[i].start = start;
> + mem_usable[i].size = size;
> + i++;
> + }
> + num_usable_region = i;
> +}
> +
> +static int handle_mem_filter(void)
> {
> char *args = (char *)get_cmd_line_ptr();
> size_t len = strlen((char *)args);
> @@ -214,7 +278,8 @@ static int handle_mem_memmap(void)
> char *param, *val;
> u64 mem_size;
>
> - if (!strstr(args, "memmap=") && !strstr(args, "mem="))
> + if (!strstr(args, "memmap=") && !strstr(args, "mem=") &&
> + !strstr(args, "kaslr_mem="))
> return 0;
>
> tmp_cmdline = malloc(len + 1);
> @@ -239,6 +304,8 @@ static int handle_mem_memmap(void)
>
> if (!strcmp(param, "memmap")) {
> mem_avoid_memmap(val);
> + } else if (!strcmp(param, "kaslr_mem")) {
> + parse_kaslr_mem_regions(val);
> } else if (!strcmp(param, "mem")) {
> char *p = val;
>
> @@ -378,7 +445,7 @@ static void mem_avoid_init(unsigned long input, unsigned long input_size,
> /* We don't need to set a mapping for setup_data. */
>
> /* Mark the memmap regions we need to avoid */
> - handle_mem_memmap();
> + handle_mem_filter();
>
> #ifdef CONFIG_X86_VERBOSE_BOOTUP
> /* Make sure video RAM can be used. */
> --
> 2.14.3
>
>
>
^ permalink raw reply [flat|nested] 27+ messages in thread
* [PATCH v7 2/5] x86/KASLR: Handle the memory regions specified in kaslr_mem
2018-01-17 10:53 [PATCH v7 0/5] x86/KASLR: Add parameter kaslr_mem=nn[KMG]@ss[KMG] Chao Fan
2018-01-17 10:53 ` [PATCH v7 1/5] x86/KASLR: Add kaslr_mem=nn[KMG]@ss[KMG] Chao Fan
@ 2018-01-17 10:53 ` Chao Fan
2018-01-19 2:39 ` Baoquan He
2018-01-17 10:53 ` [PATCH v7 3/5] x86/KASLR: Give a warning if movable_node specified without kaslr_mem= Chao Fan
` (3 subsequent siblings)
5 siblings, 1 reply; 27+ messages in thread
From: Chao Fan @ 2018-01-17 10:53 UTC (permalink / raw)
To: linux-kernel, x86, hpa, tglx, mingo, bhe, keescook, yasu.isimatu
Cc: indou.takao, lcapitulino, Chao Fan
If no 'kaslr_mem=' specified, just handle the e820/efi entries directly
as before. Otherwise, limit kernel to memory regions specified in
'kaslr_mem=' commandline.
Rename process_mem_region to slots_count to match
slots_fetch_random, and name new function as process_mem_region.
Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com>
---
arch/x86/boot/compressed/kaslr.c | 64 +++++++++++++++++++++++++++++++++-------
1 file changed, 53 insertions(+), 11 deletions(-)
diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c
index b21741135673..b200a7ceafc1 100644
--- a/arch/x86/boot/compressed/kaslr.c
+++ b/arch/x86/boot/compressed/kaslr.c
@@ -548,9 +548,9 @@ static unsigned long slots_fetch_random(void)
return 0;
}
-static void process_mem_region(struct mem_vector *entry,
- unsigned long minimum,
- unsigned long image_size)
+static void slots_count(struct mem_vector *entry,
+ unsigned long minimum,
+ unsigned long image_size)
{
struct mem_vector region, overlap;
struct slot_area slot_area;
@@ -627,6 +627,52 @@ static void process_mem_region(struct mem_vector *entry,
}
}
+static bool process_mem_region(struct mem_vector region,
+ unsigned long long minimum,
+ unsigned long long image_size)
+{
+ /*
+ * If kaslr_mem= specified, walk all the regions, and
+ * filter the intersection to slots_count.
+ */
+ if (num_usable_region > 0) {
+ int i;
+
+ for (i = 0; i < num_usable_region; i++) {
+ struct mem_vector entry;
+ unsigned long long start, end, entry_end, region_end;
+
+ start = mem_usable[i].start;
+ end = start + mem_usable[i].size;
+ region_end = region.start + region.size;
+
+ entry.start = clamp(region.start, start, end);
+ entry_end = clamp(region_end, start, end);
+
+ if (entry.start < entry_end) {
+ entry.size = entry_end - entry.start;
+ slots_count(&entry, minimum, image_size);
+ }
+
+ if (slot_area_index == MAX_SLOT_AREA) {
+ debug_putstr("Aborted e820/efi memmap scan (slot_areas full)!\n");
+ return 1;
+ }
+ }
+ return 0;
+ }
+
+ /*
+ * If no kaslr_mem stored, use region directly
+ */
+ slots_count(®ion, minimum, image_size);
+ if (slot_area_index == MAX_SLOT_AREA) {
+ debug_putstr("Aborted e820/efi memmap scan (slot_areas full)!\n");
+ return 1;
+ }
+ return 0;
+}
+
#ifdef CONFIG_EFI
/*
* Returns true if mirror region found (and must have been processed
@@ -692,11 +738,9 @@ process_efi_entries(unsigned long minimum, unsigned long image_size)
region.start = md->phys_addr;
region.size = md->num_pages << EFI_PAGE_SHIFT;
- process_mem_region(®ion, minimum, image_size);
- if (slot_area_index == MAX_SLOT_AREA) {
- debug_putstr("Aborted EFI scan (slot_areas full)!\n");
+
+ if (process_mem_region(region, minimum, image_size))
break;
- }
}
return true;
}
@@ -723,11 +767,9 @@ static void process_e820_entries(unsigned long minimum,
continue;
region.start = entry->addr;
region.size = entry->size;
- process_mem_region(®ion, minimum, image_size);
- if (slot_area_index == MAX_SLOT_AREA) {
- debug_putstr("Aborted e820 scan (slot_areas full)!\n");
+
+ if (process_mem_region(region, minimum, image_size))
break;
- }
}
}
--
2.14.3
^ permalink raw reply related [flat|nested] 27+ messages in thread
* Re: [PATCH v7 2/5] x86/KASLR: Handle the memory regions specified in kaslr_mem
2018-01-17 10:53 ` [PATCH v7 2/5] x86/KASLR: Handle the memory regions specified in kaslr_mem Chao Fan
@ 2018-01-19 2:39 ` Baoquan He
0 siblings, 0 replies; 27+ messages in thread
From: Baoquan He @ 2018-01-19 2:39 UTC (permalink / raw)
To: Chao Fan
Cc: linux-kernel, x86, hpa, tglx, mingo, keescook, yasu.isimatu,
indou.takao, lcapitulino
On 01/17/18 at 06:53pm, Chao Fan wrote:
> If no 'kaslr_mem=' specified, just handle the e820/efi entries directly
> as before. Otherwise, limit kernel to memory regions specified in
> 'kaslr_mem=' commandline.
>
> Rename process_mem_region to slots_count to match
> slots_fetch_random, and name new function as process_mem_region.
>
> Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com>
> ---
> arch/x86/boot/compressed/kaslr.c | 64 +++++++++++++++++++++++++++++++++-------
> 1 file changed, 53 insertions(+), 11 deletions(-)
>
> diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c
> index b21741135673..b200a7ceafc1 100644
> --- a/arch/x86/boot/compressed/kaslr.c
> +++ b/arch/x86/boot/compressed/kaslr.c
> @@ -548,9 +548,9 @@ static unsigned long slots_fetch_random(void)
> return 0;
> }
Looks good, ack.
Acked-by: Baoquan He <bhe@redhat.com>
>
> -static void process_mem_region(struct mem_vector *entry,
> - unsigned long minimum,
> - unsigned long image_size)
> +static void slots_count(struct mem_vector *entry,
> + unsigned long minimum,
> + unsigned long image_size)
> {
> struct mem_vector region, overlap;
> struct slot_area slot_area;
> @@ -627,6 +627,52 @@ static void process_mem_region(struct mem_vector *entry,
> }
> }
>
> +static bool process_mem_region(struct mem_vector region,
> + unsigned long long minimum,
> + unsigned long long image_size)
> +{
> + /*
> + * If kaslr_mem= specified, walk all the regions, and
> + * filter the intersection to slots_count.
> + */
> + if (num_usable_region > 0) {
> + int i;
> +
> + for (i = 0; i < num_usable_region; i++) {
> + struct mem_vector entry;
> + unsigned long long start, end, entry_end, region_end;
> +
> + start = mem_usable[i].start;
> + end = start + mem_usable[i].size;
> + region_end = region.start + region.size;
> +
> + entry.start = clamp(region.start, start, end);
> + entry_end = clamp(region_end, start, end);
> +
> + if (entry.start < entry_end) {
> + entry.size = entry_end - entry.start;
> + slots_count(&entry, minimum, image_size);
> + }
> +
> + if (slot_area_index == MAX_SLOT_AREA) {
> + debug_putstr("Aborted e820/efi memmap scan (slot_areas full)!\n");
> + return 1;
> + }
> + }
> + return 0;
> + }
> +
> + /*
> + * If no kaslr_mem stored, use region directly
> + */
> + slots_count(®ion, minimum, image_size);
> + if (slot_area_index == MAX_SLOT_AREA) {
> + debug_putstr("Aborted e820/efi memmap scan (slot_areas full)!\n");
> + return 1;
> + }
> + return 0;
> +}
> +
> #ifdef CONFIG_EFI
> /*
> * Returns true if mirror region found (and must have been processed
> @@ -692,11 +738,9 @@ process_efi_entries(unsigned long minimum, unsigned long image_size)
>
> region.start = md->phys_addr;
> region.size = md->num_pages << EFI_PAGE_SHIFT;
> - process_mem_region(®ion, minimum, image_size);
> - if (slot_area_index == MAX_SLOT_AREA) {
> - debug_putstr("Aborted EFI scan (slot_areas full)!\n");
> +
> + if (process_mem_region(region, minimum, image_size))
> break;
> - }
> }
> return true;
> }
> @@ -723,11 +767,9 @@ static void process_e820_entries(unsigned long minimum,
> continue;
> region.start = entry->addr;
> region.size = entry->size;
> - process_mem_region(®ion, minimum, image_size);
> - if (slot_area_index == MAX_SLOT_AREA) {
> - debug_putstr("Aborted e820 scan (slot_areas full)!\n");
> +
> + if (process_mem_region(region, minimum, image_size))
> break;
> - }
> }
> }
>
> --
> 2.14.3
>
>
>
^ permalink raw reply [flat|nested] 27+ messages in thread
* [PATCH v7 3/5] x86/KASLR: Give a warning if movable_node specified without kaslr_mem=
2018-01-17 10:53 [PATCH v7 0/5] x86/KASLR: Add parameter kaslr_mem=nn[KMG]@ss[KMG] Chao Fan
2018-01-17 10:53 ` [PATCH v7 1/5] x86/KASLR: Add kaslr_mem=nn[KMG]@ss[KMG] Chao Fan
2018-01-17 10:53 ` [PATCH v7 2/5] x86/KASLR: Handle the memory regions specified in kaslr_mem Chao Fan
@ 2018-01-17 10:53 ` Chao Fan
2018-01-17 14:02 ` Baoquan He
` (2 more replies)
2018-01-17 10:53 ` [PATCH v7 4/5] x86/KASLR: Skip memory mirror handling if movable_node specified Chao Fan
` (2 subsequent siblings)
5 siblings, 3 replies; 27+ messages in thread
From: Chao Fan @ 2018-01-17 10:53 UTC (permalink / raw)
To: linux-kernel, x86, hpa, tglx, mingo, bhe, keescook, yasu.isimatu
Cc: indou.takao, lcapitulino, Chao Fan
Since only 'movable_node' specified without 'kaslr_mem=' may break
memory hotplug, so reconmmend users using 'kaslr_mem=' when
'movable_node' specified..
Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com>
---
arch/x86/boot/compressed/kaslr.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c
index b200a7ceafc1..dca846b522fc 100644
--- a/arch/x86/boot/compressed/kaslr.c
+++ b/arch/x86/boot/compressed/kaslr.c
@@ -282,6 +282,16 @@ static int handle_mem_filter(void)
!strstr(args, "kaslr_mem="))
return 0;
+#ifdef CONFIG_MEMORY_HOTPLUG
+ /*
+ * Check if "kaslr_mem=" specified when "movable_node" found. If not,
+ * just give warrning. Otherwise memory hotplug could be
+ * affected if kernel put on movable memory regions.
+ */
+ if (strstr(args, "movable_node") && !strstr(args, "kaslr_mem="))
+ warn("kaslr_mem= should specified when using movable_node.\n");
+#endif
+
tmp_cmdline = malloc(len + 1);
if (!tmp_cmdline)
error("Failed to allocate space for tmp_cmdline");
--
2.14.3
^ permalink raw reply related [flat|nested] 27+ messages in thread
* Re: [PATCH v7 3/5] x86/KASLR: Give a warning if movable_node specified without kaslr_mem=
2018-01-17 10:53 ` [PATCH v7 3/5] x86/KASLR: Give a warning if movable_node specified without kaslr_mem= Chao Fan
@ 2018-01-17 14:02 ` Baoquan He
2018-01-18 1:20 ` Chao Fan
2018-01-17 14:04 ` Baoquan He
2018-01-19 3:31 ` [PATCH v8 " Chao Fan
2 siblings, 1 reply; 27+ messages in thread
From: Baoquan He @ 2018-01-17 14:02 UTC (permalink / raw)
To: Chao Fan
Cc: linux-kernel, x86, hpa, tglx, mingo, keescook, yasu.isimatu,
indou.takao, lcapitulino
On 01/17/18 at 06:53pm, Chao Fan wrote:
> Since only 'movable_node' specified without 'kaslr_mem=' may break
> memory hotplug, so reconmmend users using 'kaslr_mem=' when
> 'movable_node' specified..
>
> Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com>
> ---
> arch/x86/boot/compressed/kaslr.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c
> index b200a7ceafc1..dca846b522fc 100644
> --- a/arch/x86/boot/compressed/kaslr.c
> +++ b/arch/x86/boot/compressed/kaslr.c
> @@ -282,6 +282,16 @@ static int handle_mem_filter(void)
> !strstr(args, "kaslr_mem="))
> return 0;
>
> +#ifdef CONFIG_MEMORY_HOTPLUG
> + /*
> + * Check if "kaslr_mem=" specified when "movable_node" found. If not,
> + * just give warrning. Otherwise memory hotplug could be
> + * affected if kernel put on movable memory regions.
> + */
> + if (strstr(args, "movable_node") && !strstr(args, "kaslr_mem="))
> + warn("kaslr_mem= should specified when using movable_node.\n");
'kaslr_mem=' ^be
> +#endif
> +
> tmp_cmdline = malloc(len + 1);
> if (!tmp_cmdline)
> error("Failed to allocate space for tmp_cmdline");
> --
> 2.14.3
>
>
>
^ permalink raw reply [flat|nested] 27+ messages in thread
* Re: [PATCH v7 3/5] x86/KASLR: Give a warning if movable_node specified without kaslr_mem=
2018-01-17 14:02 ` Baoquan He
@ 2018-01-18 1:20 ` Chao Fan
0 siblings, 0 replies; 27+ messages in thread
From: Chao Fan @ 2018-01-18 1:20 UTC (permalink / raw)
To: Baoquan He
Cc: linux-kernel, x86, hpa, tglx, mingo, keescook, yasu.isimatu,
indou.takao, lcapitulino
On Wed, Jan 17, 2018 at 10:02:48PM +0800, Baoquan He wrote:
>On 01/17/18 at 06:53pm, Chao Fan wrote:
>> Since only 'movable_node' specified without 'kaslr_mem=' may break
>> memory hotplug, so reconmmend users using 'kaslr_mem=' when
>> 'movable_node' specified..
>>
>> Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com>
>> ---
>> arch/x86/boot/compressed/kaslr.c | 10 ++++++++++
>> 1 file changed, 10 insertions(+)
>>
>> diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c
>> index b200a7ceafc1..dca846b522fc 100644
>> --- a/arch/x86/boot/compressed/kaslr.c
>> +++ b/arch/x86/boot/compressed/kaslr.c
>> @@ -282,6 +282,16 @@ static int handle_mem_filter(void)
>> !strstr(args, "kaslr_mem="))
>> return 0;
>>
>> +#ifdef CONFIG_MEMORY_HOTPLUG
>> + /*
>> + * Check if "kaslr_mem=" specified when "movable_node" found. If not,
>> + * just give warrning. Otherwise memory hotplug could be
>> + * affected if kernel put on movable memory regions.
>> + */
>> + if (strstr(args, "movable_node") && !strstr(args, "kaslr_mem="))
>> + warn("kaslr_mem= should specified when using movable_node.\n");
> 'kaslr_mem=' ^be
You have given me a large help for my poor English.
Thanks,
Chao Fan
>> +#endif
>> +
>> tmp_cmdline = malloc(len + 1);
>> if (!tmp_cmdline)
>> error("Failed to allocate space for tmp_cmdline");
>> --
>> 2.14.3
>>
>>
>>
>
>
^ permalink raw reply [flat|nested] 27+ messages in thread
* Re: [PATCH v7 3/5] x86/KASLR: Give a warning if movable_node specified without kaslr_mem=
2018-01-17 10:53 ` [PATCH v7 3/5] x86/KASLR: Give a warning if movable_node specified without kaslr_mem= Chao Fan
2018-01-17 14:02 ` Baoquan He
@ 2018-01-17 14:04 ` Baoquan He
2018-01-19 3:31 ` [PATCH v8 " Chao Fan
2 siblings, 0 replies; 27+ messages in thread
From: Baoquan He @ 2018-01-17 14:04 UTC (permalink / raw)
To: Chao Fan
Cc: linux-kernel, x86, hpa, tglx, mingo, keescook, yasu.isimatu,
indou.takao, lcapitulino
On 01/17/18 at 06:53pm, Chao Fan wrote:
> Since only 'movable_node' specified without 'kaslr_mem=' may break
> memory hotplug, so reconmmend users using 'kaslr_mem=' when
> 'movable_node' specified..
>
> Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com>
> ---
> arch/x86/boot/compressed/kaslr.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c
> index b200a7ceafc1..dca846b522fc 100644
> --- a/arch/x86/boot/compressed/kaslr.c
> +++ b/arch/x86/boot/compressed/kaslr.c
> @@ -282,6 +282,16 @@ static int handle_mem_filter(void)
> !strstr(args, "kaslr_mem="))
> return 0;
>
> +#ifdef CONFIG_MEMORY_HOTPLUG
> + /*
> + * Check if "kaslr_mem=" specified when "movable_node" found. If not,
> + * just give warrning. Otherwise memory hotplug could be
> + * affected if kernel put on movable memory regions.
^is put
> + */
> + if (strstr(args, "movable_node") && !strstr(args, "kaslr_mem="))
> + warn("kaslr_mem= should specified when using movable_node.\n");
> +#endif
> +
> tmp_cmdline = malloc(len + 1);
> if (!tmp_cmdline)
> error("Failed to allocate space for tmp_cmdline");
> --
> 2.14.3
>
>
>
^ permalink raw reply [flat|nested] 27+ messages in thread
* [PATCH v8 3/5] x86/KASLR: Give a warning if movable_node specified without kaslr_mem=
2018-01-17 10:53 ` [PATCH v7 3/5] x86/KASLR: Give a warning if movable_node specified without kaslr_mem= Chao Fan
2018-01-17 14:02 ` Baoquan He
2018-01-17 14:04 ` Baoquan He
@ 2018-01-19 3:31 ` Chao Fan
2018-01-19 3:48 ` Baoquan He
2 siblings, 1 reply; 27+ messages in thread
From: Chao Fan @ 2018-01-19 3:31 UTC (permalink / raw)
To: linux-kernel, x86, hpa, tglx, mingo, bhe, keescook, yasu.isimatu
Cc: indou.takao, lcapitulino, Chao Fan
Since only 'movable_node' specified without 'kaslr_mem=' may break
memory hotplug, so reconmmend users using 'kaslr_mem=' when
'movable_node' specified.
Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com>
---
arch/x86/boot/compressed/kaslr.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c
index b200a7ceafc1..8703cc764306 100644
--- a/arch/x86/boot/compressed/kaslr.c
+++ b/arch/x86/boot/compressed/kaslr.c
@@ -282,6 +282,16 @@ static int handle_mem_filter(void)
!strstr(args, "kaslr_mem="))
return 0;
+#ifdef CONFIG_MEMORY_HOTPLUG
+ /*
+ * Check if 'kaslr_mem=' specified when 'movable_node' found. If not,
+ * just give warrning. Otherwise memory hotplug could be
+ * affected if kernel is put on movable memory regions.
+ */
+ if (strstr(args, "movable_node") && !strstr(args, "kaslr_mem="))
+ warn("'kaslr_mem=' should be specified when using 'movable_node'.\n");
+#endif
+
tmp_cmdline = malloc(len + 1);
if (!tmp_cmdline)
error("Failed to allocate space for tmp_cmdline");
--
2.14.3
^ permalink raw reply related [flat|nested] 27+ messages in thread
* Re: [PATCH v8 3/5] x86/KASLR: Give a warning if movable_node specified without kaslr_mem=
2018-01-19 3:31 ` [PATCH v8 " Chao Fan
@ 2018-01-19 3:48 ` Baoquan He
0 siblings, 0 replies; 27+ messages in thread
From: Baoquan He @ 2018-01-19 3:48 UTC (permalink / raw)
To: Chao Fan
Cc: linux-kernel, x86, hpa, tglx, mingo, keescook, yasu.isimatu,
indou.takao, lcapitulino
On 01/19/18 at 11:31am, Chao Fan wrote:
> Since only 'movable_node' specified without 'kaslr_mem=' may break
> memory hotplug, so reconmmend users using 'kaslr_mem=' when
> 'movable_node' specified.
>
> Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com>
> ---
> arch/x86/boot/compressed/kaslr.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c
> index b200a7ceafc1..8703cc764306 100644
> --- a/arch/x86/boot/compressed/kaslr.c
> +++ b/arch/x86/boot/compressed/kaslr.c
> @@ -282,6 +282,16 @@ static int handle_mem_filter(void)
> !strstr(args, "kaslr_mem="))
> return 0;
Looks good to me.
Acked-by: Baoquan He <bhe@redhat.com>
>
> +#ifdef CONFIG_MEMORY_HOTPLUG
> + /*
> + * Check if 'kaslr_mem=' specified when 'movable_node' found. If not,
> + * just give warrning. Otherwise memory hotplug could be
> + * affected if kernel is put on movable memory regions.
> + */
> + if (strstr(args, "movable_node") && !strstr(args, "kaslr_mem="))
> + warn("'kaslr_mem=' should be specified when using 'movable_node'.\n");
> +#endif
> +
> tmp_cmdline = malloc(len + 1);
> if (!tmp_cmdline)
> error("Failed to allocate space for tmp_cmdline");
> --
> 2.14.3
>
>
>
^ permalink raw reply [flat|nested] 27+ messages in thread
* [PATCH v7 4/5] x86/KASLR: Skip memory mirror handling if movable_node specified
2018-01-17 10:53 [PATCH v7 0/5] x86/KASLR: Add parameter kaslr_mem=nn[KMG]@ss[KMG] Chao Fan
` (2 preceding siblings ...)
2018-01-17 10:53 ` [PATCH v7 3/5] x86/KASLR: Give a warning if movable_node specified without kaslr_mem= Chao Fan
@ 2018-01-17 10:53 ` Chao Fan
2018-01-17 14:03 ` Baoquan He
2018-01-19 3:33 ` [PATCH v8 " Chao Fan
2018-01-17 10:53 ` [PATCH v7 5/5] document: add document for kaslr_mem Chao Fan
2018-01-17 17:32 ` [PATCH v7 0/5] x86/KASLR: Add parameter kaslr_mem=nn[KMG]@ss[KMG] Luiz Capitulino
5 siblings, 2 replies; 27+ messages in thread
From: Chao Fan @ 2018-01-17 10:53 UTC (permalink / raw)
To: linux-kernel, x86, hpa, tglx, mingo, bhe, keescook, yasu.isimatu
Cc: indou.takao, lcapitulino, Chao Fan
In kernel code, if movable_node specified, it will skip the mirror
feature. So we should also skip mirror feature in KASLR.
Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com>
---
arch/x86/boot/compressed/kaslr.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c
index dca846b522fc..84b9db26d026 100644
--- a/arch/x86/boot/compressed/kaslr.c
+++ b/arch/x86/boot/compressed/kaslr.c
@@ -692,6 +692,7 @@ static bool
process_efi_entries(unsigned long minimum, unsigned long image_size)
{
struct efi_info *e = &boot_params->efi_info;
+ char *args = (char *)get_cmd_line_ptr();
bool efi_mirror_found = false;
struct mem_vector region;
efi_memory_desc_t *md;
@@ -725,6 +726,12 @@ process_efi_entries(unsigned long minimum, unsigned long image_size)
}
}
+#ifdef CONFIG_MEMORY_HOTPLUG
+ /* Skip memory mirror if movabale_node or immovable_mem specified */
+ if (strstr(args, "movable_node"))
+ efi_mirror_found = false;
+#endif
+
for (i = 0; i < nr_desc; i++) {
md = efi_early_memdesc_ptr(pmap, e->efi_memdesc_size, i);
--
2.14.3
^ permalink raw reply related [flat|nested] 27+ messages in thread
* Re: [PATCH v7 4/5] x86/KASLR: Skip memory mirror handling if movable_node specified
2018-01-17 10:53 ` [PATCH v7 4/5] x86/KASLR: Skip memory mirror handling if movable_node specified Chao Fan
@ 2018-01-17 14:03 ` Baoquan He
2018-01-18 1:13 ` Chao Fan
2018-01-19 3:33 ` [PATCH v8 " Chao Fan
1 sibling, 1 reply; 27+ messages in thread
From: Baoquan He @ 2018-01-17 14:03 UTC (permalink / raw)
To: Chao Fan
Cc: linux-kernel, x86, hpa, tglx, mingo, keescook, yasu.isimatu,
indou.takao, lcapitulino
On 01/17/18 at 06:53pm, Chao Fan wrote:
> In kernel code, if movable_node specified, it will skip the mirror
> feature. So we should also skip mirror feature in KASLR.
>
> Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com>
> ---
> arch/x86/boot/compressed/kaslr.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c
> index dca846b522fc..84b9db26d026 100644
> --- a/arch/x86/boot/compressed/kaslr.c
> +++ b/arch/x86/boot/compressed/kaslr.c
> @@ -692,6 +692,7 @@ static bool
> process_efi_entries(unsigned long minimum, unsigned long image_size)
> {
> struct efi_info *e = &boot_params->efi_info;
> + char *args = (char *)get_cmd_line_ptr();
> bool efi_mirror_found = false;
> struct mem_vector region;
> efi_memory_desc_t *md;
> @@ -725,6 +726,12 @@ process_efi_entries(unsigned long minimum, unsigned long image_size)
> }
> }
>
> +#ifdef CONFIG_MEMORY_HOTPLUG
> + /* Skip memory mirror if movabale_node or immovable_mem specified */
~~~~~~~~~~~~~
^^ need be removed?
> + if (strstr(args, "movable_node"))
> + efi_mirror_found = false;
> +#endif
> +
> for (i = 0; i < nr_desc; i++) {
> md = efi_early_memdesc_ptr(pmap, e->efi_memdesc_size, i);
>
> --
> 2.14.3
>
>
>
^ permalink raw reply [flat|nested] 27+ messages in thread
* Re: [PATCH v7 4/5] x86/KASLR: Skip memory mirror handling if movable_node specified
2018-01-17 14:03 ` Baoquan He
@ 2018-01-18 1:13 ` Chao Fan
0 siblings, 0 replies; 27+ messages in thread
From: Chao Fan @ 2018-01-18 1:13 UTC (permalink / raw)
To: Baoquan He
Cc: linux-kernel, x86, hpa, tglx, mingo, keescook, yasu.isimatu,
indou.takao, lcapitulino
On Wed, Jan 17, 2018 at 10:03:54PM +0800, Baoquan He wrote:
>On 01/17/18 at 06:53pm, Chao Fan wrote:
>> In kernel code, if movable_node specified, it will skip the mirror
>> feature. So we should also skip mirror feature in KASLR.
>>
>> Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com>
>> ---
>> arch/x86/boot/compressed/kaslr.c | 7 +++++++
>> 1 file changed, 7 insertions(+)
>>
>> diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c
>> index dca846b522fc..84b9db26d026 100644
>> --- a/arch/x86/boot/compressed/kaslr.c
>> +++ b/arch/x86/boot/compressed/kaslr.c
>> @@ -692,6 +692,7 @@ static bool
>> process_efi_entries(unsigned long minimum, unsigned long image_size)
>> {
>> struct efi_info *e = &boot_params->efi_info;
>> + char *args = (char *)get_cmd_line_ptr();
>> bool efi_mirror_found = false;
>> struct mem_vector region;
>> efi_memory_desc_t *md;
>> @@ -725,6 +726,12 @@ process_efi_entries(unsigned long minimum, unsigned long image_size)
>> }
>> }
>>
>> +#ifdef CONFIG_MEMORY_HOTPLUG
>> + /* Skip memory mirror if movabale_node or immovable_mem specified */
> ~~~~~~~~~~~~~
> ^^ need be removed?
Yes, sorry for the mistake, I change the old versions and miss some
points. Will change that.
Thanks,
Chao Fan
>> + if (strstr(args, "movable_node"))
>> + efi_mirror_found = false;
>> +#endif
>> +
>> for (i = 0; i < nr_desc; i++) {
>> md = efi_early_memdesc_ptr(pmap, e->efi_memdesc_size, i);
>>
>> --
>> 2.14.3
>>
>>
>>
>
>
^ permalink raw reply [flat|nested] 27+ messages in thread
* [PATCH v8 4/5] x86/KASLR: Skip memory mirror handling if movable_node specified
2018-01-17 10:53 ` [PATCH v7 4/5] x86/KASLR: Skip memory mirror handling if movable_node specified Chao Fan
2018-01-17 14:03 ` Baoquan He
@ 2018-01-19 3:33 ` Chao Fan
2018-01-19 3:47 ` Baoquan He
1 sibling, 1 reply; 27+ messages in thread
From: Chao Fan @ 2018-01-19 3:33 UTC (permalink / raw)
To: linux-kernel, x86, hpa, tglx, mingo, bhe, keescook, yasu.isimatu
Cc: indou.takao, lcapitulino, Chao Fan
In kernel code, if movable_node specified, it will skip the mirror
feature. So we should also skip mirror feature in KASLR.
Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com>
---
arch/x86/boot/compressed/kaslr.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c
index 8703cc764306..e4b487f0b7af 100644
--- a/arch/x86/boot/compressed/kaslr.c
+++ b/arch/x86/boot/compressed/kaslr.c
@@ -692,6 +692,7 @@ static bool
process_efi_entries(unsigned long minimum, unsigned long image_size)
{
struct efi_info *e = &boot_params->efi_info;
+ char *args = (char *)get_cmd_line_ptr();
bool efi_mirror_found = false;
struct mem_vector region;
efi_memory_desc_t *md;
@@ -725,6 +726,12 @@ process_efi_entries(unsigned long minimum, unsigned long image_size)
}
}
+#ifdef CONFIG_MEMORY_HOTPLUG
+ /* Skip memory mirror if 'movabale_node' specified */
+ if (strstr(args, "movable_node"))
+ efi_mirror_found = false;
+#endif
+
for (i = 0; i < nr_desc; i++) {
md = efi_early_memdesc_ptr(pmap, e->efi_memdesc_size, i);
--
2.14.3
^ permalink raw reply related [flat|nested] 27+ messages in thread
* Re: [PATCH v8 4/5] x86/KASLR: Skip memory mirror handling if movable_node specified
2018-01-19 3:33 ` [PATCH v8 " Chao Fan
@ 2018-01-19 3:47 ` Baoquan He
0 siblings, 0 replies; 27+ messages in thread
From: Baoquan He @ 2018-01-19 3:47 UTC (permalink / raw)
To: Chao Fan
Cc: linux-kernel, x86, hpa, tglx, mingo, keescook, yasu.isimatu,
indou.takao, lcapitulino
On 01/19/18 at 11:33am, Chao Fan wrote:
> In kernel code, if movable_node specified, it will skip the mirror
> feature. So we should also skip mirror feature in KASLR.
>
> Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com>
> ---
> arch/x86/boot/compressed/kaslr.c | 7 +++++++
> 1 file changed, 7 insertions(+)
Ack.
Acked-by: Baoquan He <bhe@redhat.com>
>
> diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c
> index 8703cc764306..e4b487f0b7af 100644
> --- a/arch/x86/boot/compressed/kaslr.c
> +++ b/arch/x86/boot/compressed/kaslr.c
> @@ -692,6 +692,7 @@ static bool
> process_efi_entries(unsigned long minimum, unsigned long image_size)
> {
> struct efi_info *e = &boot_params->efi_info;
> + char *args = (char *)get_cmd_line_ptr();
> bool efi_mirror_found = false;
> struct mem_vector region;
> efi_memory_desc_t *md;
> @@ -725,6 +726,12 @@ process_efi_entries(unsigned long minimum, unsigned long image_size)
> }
> }
>
> +#ifdef CONFIG_MEMORY_HOTPLUG
> + /* Skip memory mirror if 'movabale_node' specified */
> + if (strstr(args, "movable_node"))
> + efi_mirror_found = false;
> +#endif
> +
> for (i = 0; i < nr_desc; i++) {
> md = efi_early_memdesc_ptr(pmap, e->efi_memdesc_size, i);
>
> --
> 2.14.3
>
>
>
^ permalink raw reply [flat|nested] 27+ messages in thread
* [PATCH v7 5/5] document: add document for kaslr_mem
2018-01-17 10:53 [PATCH v7 0/5] x86/KASLR: Add parameter kaslr_mem=nn[KMG]@ss[KMG] Chao Fan
` (3 preceding siblings ...)
2018-01-17 10:53 ` [PATCH v7 4/5] x86/KASLR: Skip memory mirror handling if movable_node specified Chao Fan
@ 2018-01-17 10:53 ` Chao Fan
2018-01-19 3:00 ` Baoquan He
` (2 more replies)
2018-01-17 17:32 ` [PATCH v7 0/5] x86/KASLR: Add parameter kaslr_mem=nn[KMG]@ss[KMG] Luiz Capitulino
5 siblings, 3 replies; 27+ messages in thread
From: Chao Fan @ 2018-01-17 10:53 UTC (permalink / raw)
To: linux-kernel, x86, hpa, tglx, mingo, bhe, keescook, yasu.isimatu
Cc: indou.takao, lcapitulino, Chao Fan
Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com>
---
Documentation/admin-guide/kernel-parameters.txt | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index e2de7c006a74..f6d5adde1a73 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -2350,6 +2350,16 @@
allocations which rules out almost all kernel
allocations. Use with caution!
+ kaslr_mem=nn[KMG][@ss[KMG]]
+ [KNL] Force usage of a specific region of memory.
+ Make some features, like memory hotplug and 1G huge
+ page work well with KASLR. Region of usable memory is
+ from ss to ss+nn. If ss is omitted, it defaults to 0.
+ Multiple regions can be specified, comma delimited.
+ Notice: we support 4 regions at most now.
+ Example:
+ kaslr_mem=1G,500M@2G,1G@4G
+
MTD_Partition= [MTD]
Format: <name>,<region-number>,<size>,<offset>
--
2.14.3
^ permalink raw reply related [flat|nested] 27+ messages in thread
* Re: [PATCH v7 5/5] document: add document for kaslr_mem
2018-01-17 10:53 ` [PATCH v7 5/5] document: add document for kaslr_mem Chao Fan
@ 2018-01-19 3:00 ` Baoquan He
2018-01-19 3:36 ` [PATCH v8 " Chao Fan
2018-01-19 5:23 ` [RESEND PATCH " Chao Fan
2 siblings, 0 replies; 27+ messages in thread
From: Baoquan He @ 2018-01-19 3:00 UTC (permalink / raw)
To: Chao Fan
Cc: linux-kernel, x86, hpa, tglx, mingo, keescook, yasu.isimatu,
indou.takao, lcapitulino
On 01/17/18 at 06:53pm, Chao Fan wrote:
> Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com>
> ---
> Documentation/admin-guide/kernel-parameters.txt | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index e2de7c006a74..f6d5adde1a73 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -2350,6 +2350,16 @@
> allocations which rules out almost all kernel
> allocations. Use with caution!
>
> + kaslr_mem=nn[KMG][@ss[KMG]]
> + [KNL] Force usage of a specific region of memory.
[KNL] Force usage of a specific region of memory
for KASLR during kernel decompression stage.
Region of memory to be used is from ss to ss+nn.
If ss is omitted, it is equivalent to kaslr_mem=nn[KMG]@0.
Multiple regions can be specified, comma delimited.
Notice: only support 4 regions at most now.
Example:
kaslr_mem=1G,500M@2G,1G@4G
Try to rewrite the doc, just for reference.
> + Make some features, like memory hotplug and 1G huge
> + page work well with KASLR. Region of usable memory is
> + from ss to ss+nn. If ss is omitted, it defaults to 0.
> + Multiple regions can be specified, comma delimited.
> + Notice: we support 4 regions at most now.
> + Example:
> + kaslr_mem=1G,500M@2G,1G@4G
> +
> MTD_Partition= [MTD]
> Format: <name>,<region-number>,<size>,<offset>
>
> --
> 2.14.3
>
>
>
^ permalink raw reply [flat|nested] 27+ messages in thread
* [PATCH v8 5/5] document: add document for kaslr_mem
2018-01-17 10:53 ` [PATCH v7 5/5] document: add document for kaslr_mem Chao Fan
2018-01-19 3:00 ` Baoquan He
@ 2018-01-19 3:36 ` Chao Fan
2018-01-19 3:53 ` Baoquan He
2018-01-19 5:23 ` [RESEND PATCH " Chao Fan
2 siblings, 1 reply; 27+ messages in thread
From: Chao Fan @ 2018-01-19 3:36 UTC (permalink / raw)
To: linux-kernel, x86, hpa, tglx, mingo, bhe, keescook, yasu.isimatu
Cc: indou.takao, lcapitulino, Chao Fan
Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com>
---
Documentation/admin-guide/kernel-parameters.txt | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index e2de7c006a74..28a879f62560 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -2350,6 +2350,16 @@
allocations which rules out almost all kernel
allocations. Use with caution!
+ kaslr_mem=nn[KMG][@ss[KMG]]
+ [KNL] Force usage of a specific region of memory
+ for KASLR during kernel decompression stage.
+ Region of usable memory is from ss to ss+nn. If ss
+ is omitted, it is qeuivalent to kaslr_mem=nn[KMG]@0.
+ Multiple regions can be specified, comma delimited.
+ Notice: we support 4 regions at most now.
+ Example:
+ kaslr_mem=1G,500M@2G,1G@4G
+
MTD_Partition= [MTD]
Format: <name>,<region-number>,<size>,<offset>
--
2.14.3
^ permalink raw reply related [flat|nested] 27+ messages in thread
* Re: [PATCH v8 5/5] document: add document for kaslr_mem
2018-01-19 3:36 ` [PATCH v8 " Chao Fan
@ 2018-01-19 3:53 ` Baoquan He
2018-01-19 5:27 ` Chao Fan
0 siblings, 1 reply; 27+ messages in thread
From: Baoquan He @ 2018-01-19 3:53 UTC (permalink / raw)
To: Chao Fan
Cc: linux-kernel, x86, hpa, tglx, mingo, keescook, yasu.isimatu,
indou.takao, lcapitulino
On 01/19/18 at 11:36am, Chao Fan wrote:
> Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com>
> ---
> Documentation/admin-guide/kernel-parameters.txt | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index e2de7c006a74..28a879f62560 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -2350,6 +2350,16 @@
> allocations which rules out almost all kernel
> allocations. Use with caution!
>
> + kaslr_mem=nn[KMG][@ss[KMG]]
> + [KNL] Force usage of a specific region of memory
> + for KASLR during kernel decompression stage.
> + Region of usable memory is from ss to ss+nn. If ss
> + is omitted, it is qeuivalent to kaslr_mem=nn[KMG]@0.
> + Multiple regions can be specified, comma delimited.
> + Notice: we support 4 regions at most now.
Better not use 'we' here. You can refer to kernel-parameter.txt.
> + Example:
> + kaslr_mem=1G,500M@2G,1G@4G
> +
> MTD_Partition= [MTD]
> Format: <name>,<region-number>,<size>,<offset>
>
> --
> 2.14.3
>
>
>
^ permalink raw reply [flat|nested] 27+ messages in thread
* Re: [PATCH v8 5/5] document: add document for kaslr_mem
2018-01-19 3:53 ` Baoquan He
@ 2018-01-19 5:27 ` Chao Fan
0 siblings, 0 replies; 27+ messages in thread
From: Chao Fan @ 2018-01-19 5:27 UTC (permalink / raw)
To: Baoquan He
Cc: linux-kernel, x86, hpa, tglx, mingo, keescook, yasu.isimatu,
indou.takao, lcapitulino
On Fri, Jan 19, 2018 at 11:53:31AM +0800, Baoquan He wrote:
>On 01/19/18 at 11:36am, Chao Fan wrote:
>> Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com>
>> ---
>> Documentation/admin-guide/kernel-parameters.txt | 10 ++++++++++
>> 1 file changed, 10 insertions(+)
>>
>> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
>> index e2de7c006a74..28a879f62560 100644
>> --- a/Documentation/admin-guide/kernel-parameters.txt
>> +++ b/Documentation/admin-guide/kernel-parameters.txt
>> @@ -2350,6 +2350,16 @@
>> allocations which rules out almost all kernel
>> allocations. Use with caution!
>>
>> + kaslr_mem=nn[KMG][@ss[KMG]]
>> + [KNL] Force usage of a specific region of memory
>> + for KASLR during kernel decompression stage.
>> + Region of usable memory is from ss to ss+nn. If ss
>> + is omitted, it is qeuivalent to kaslr_mem=nn[KMG]@0.
>> + Multiple regions can be specified, comma delimited.
>> + Notice: we support 4 regions at most now.
>
>Better not use 'we' here. You can refer to kernel-parameter.txt.
You are right, so I resend this part, and add several Cc.
Thanks,
Chao Fan
>
>> + Example:
>> + kaslr_mem=1G,500M@2G,1G@4G
>> +
>> MTD_Partition= [MTD]
>> Format: <name>,<region-number>,<size>,<offset>
>>
>> --
>> 2.14.3
>>
>>
>>
>
>
^ permalink raw reply [flat|nested] 27+ messages in thread
* [RESEND PATCH v8 5/5] document: add document for kaslr_mem
2018-01-17 10:53 ` [PATCH v7 5/5] document: add document for kaslr_mem Chao Fan
2018-01-19 3:00 ` Baoquan He
2018-01-19 3:36 ` [PATCH v8 " Chao Fan
@ 2018-01-19 5:23 ` Chao Fan
2018-01-19 18:20 ` Randy Dunlap
2 siblings, 1 reply; 27+ messages in thread
From: Chao Fan @ 2018-01-19 5:23 UTC (permalink / raw)
To: linux-kernel, x86, hpa, tglx, mingo, bhe, keescook, yasu.isimatu
Cc: indou.takao, lcapitulino, Chao Fan, linux-doc, Jonathan Corbet,
Randy Dunlap
Cc: linux-doc@vger.kernel.org
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com>
---
Documentation/admin-guide/kernel-parameters.txt | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index e2de7c006a74..2e3d5fb13f7f 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -2350,6 +2350,16 @@
allocations which rules out almost all kernel
allocations. Use with caution!
+ kaslr_mem=nn[KMG][@ss[KMG]]
+ [KNL] Force usage of a specific region of memory
+ for KASLR during kernel decompression stage.
+ Region of usable memory is from ss to ss+nn. If ss
+ is omitted, it is qeuivalent to kaslr_mem=nn[KMG]@0.
+ Multiple regions can be specified, comma delimited.
+ Notice: only support 4 regions at most now.
+ Example:
+ kaslr_mem=1G,500M@2G,1G@4G
+
MTD_Partition= [MTD]
Format: <name>,<region-number>,<size>,<offset>
--
2.14.3
^ permalink raw reply related [flat|nested] 27+ messages in thread
* Re: [RESEND PATCH v8 5/5] document: add document for kaslr_mem
2018-01-19 5:23 ` [RESEND PATCH " Chao Fan
@ 2018-01-19 18:20 ` Randy Dunlap
0 siblings, 0 replies; 27+ messages in thread
From: Randy Dunlap @ 2018-01-19 18:20 UTC (permalink / raw)
To: Chao Fan, linux-kernel, x86, hpa, tglx, mingo, bhe, keescook,
yasu.isimatu
Cc: indou.takao, lcapitulino, linux-doc, Jonathan Corbet
On 01/18/2018 09:23 PM, Chao Fan wrote:
> Cc: linux-doc@vger.kernel.org
> Cc: Jonathan Corbet <corbet@lwn.net>
> Cc: Randy Dunlap <rdunlap@infradead.org>
> Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com>
> ---
> Documentation/admin-guide/kernel-parameters.txt | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index e2de7c006a74..2e3d5fb13f7f 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -2350,6 +2350,16 @@
> allocations which rules out almost all kernel
> allocations. Use with caution!
>
> + kaslr_mem=nn[KMG][@ss[KMG]]
> + [KNL] Force usage of a specific region of memory
> + for KASLR during kernel decompression stage.
> + Region of usable memory is from ss to ss+nn. If ss
> + is omitted, it is qeuivalent to kaslr_mem=nn[KMG]@0.
equivalent
> + Multiple regions can be specified, comma delimited.
> + Notice: only support 4 regions at most now.
> + Example:
> + kaslr_mem=1G,500M@2G,1G@4G
> +
> MTD_Partition= [MTD]
> Format: <name>,<region-number>,<size>,<offset>
>
>
--
~Randy
^ permalink raw reply [flat|nested] 27+ messages in thread
* Re: [PATCH v7 0/5] x86/KASLR: Add parameter kaslr_mem=nn[KMG]@ss[KMG]
2018-01-17 10:53 [PATCH v7 0/5] x86/KASLR: Add parameter kaslr_mem=nn[KMG]@ss[KMG] Chao Fan
` (4 preceding siblings ...)
2018-01-17 10:53 ` [PATCH v7 5/5] document: add document for kaslr_mem Chao Fan
@ 2018-01-17 17:32 ` Luiz Capitulino
2018-01-18 1:11 ` Chao Fan
5 siblings, 1 reply; 27+ messages in thread
From: Luiz Capitulino @ 2018-01-17 17:32 UTC (permalink / raw)
To: Chao Fan
Cc: linux-kernel, x86, hpa, tglx, mingo, bhe, keescook, yasu.isimatu,
indou.takao
On Wed, 17 Jan 2018 18:53:46 +0800
Chao Fan <fanc.fnst@cn.fujitsu.com> wrote:
> ***Background:
> People reported that kaslr may randomly chooses some positions
> which are located in movable memory regions. This will break memory
> hotplug feature.
>
> And also on kvm guest with 4GB meory, the good unfragmented 1GB could
> be occupied by randomized kernel. It will cause hugetlb failing to
> allocate 1GB page. While kernel with 'nokaslr' has not such issue.
> This causes regression. Please see the discussion mail:
> https://lkml.org/lkml/2018/1/4/236
>
> ***Solutions:
> Introduce a new kernel parameter 'kaslr_mem=nn@ss' to let users to
> specify the memory regions where kernel can be allowed to randomize
> safely.
I've tested this series with a 4GB KVM guest. With kaslr_mem=1G, I
got one 1GB page allocated 100% of the time in 85 boots. Without
kaslr_mem=, I got 3 failures in only 10 boots (that is, in 3 boots
I had no 1GB page allocated).
So, this series solves the 1GB page problem for me.
>
> E.g if 'movable_node' is spedified, we can use 'kaslr_mem=nn@ss' to
> tell KASLR where we can put kernel safely. Then KASLR code can avoid
> those movable regions and only choose those immovable regions
> specified.
>
> For hugetlb case, users can always add 'kaslr_mem=1G' in kernel
> cmdline since the 0~1G is always fragmented region because of BIOS
> reserved area. Surely users can specify regions more precisely if
> they know system memory very well.
>
> *** Issues need be discussed
> There are several issues I am not quite sure, please help review and
> give suggestions:
>
> 1) Since there's already mem_avoid[] which stores the memory regions
> KASLR need avoid. For the regions KASLR can safely use, I name it as
> mem_usable[], not sure if it's appropriate. Or kaslr_mem[] directly?
>
> 2) In v6, I made 'kaslr_mem=' as a kernel parameter which users can use
> to specify memory regions where kenrel can be extracted safely by
> 'kaslr_mem=nn@ss', or regions where we need avoid to extract kernel by
> 'kaslr_mem=nn!ss'. While later I rethink about it, seems
> 'kaslr_mem=nn@ss' can satisfy the current requirement, there's no need
> to introduce the 'kaslr_mem=nn!ss'. So I just take that
> 'kaslr_mem=nn!ss' handling patch off, may add it later if anyone think
> it's necessary. Any suggestions?
> https://www.spinics.net/lists/kernel/msg2698457.html
>
> ***Test results:
> - I did some tests for the memory hotplug issues. I specify the memory
> region in one node, then I found every time the kernel will be
> extracted to the memory of this node.
> - Luiz said he will do some tests for the 1G huge page issue.
>
> ***History
> v6->v7:
> - Drop the unnecessary avoid part for now.
> - Add document for the new parameter.
>
> v5->v6:
> - Add the last patch to save the avoid memory regions.
>
> v4->v5:
> - Change the problem reported by LKP
> Follow Dou's suggestion:
> - Also return if match "movable_node" when parsing kernel commandline
> in handle_mem_filter without define CONFIG_MEMORY_HOTPLUG
>
> v3->v4:
> Follow Kees's suggestion:
> - Put the functions variables of immovable_mem to #ifdef
> CONFIG_MEMORY_HOTPLUG and change some code place
> - Change the name of "process_mem_region" to "slots_count"
> - Reanme the new function "process_immovable_mem" to "process_mem_region"
> Follow Baoquan's suggestion:
> - Fail KASLR if "movable_node" specified without "immovable_mem"
> - Ajust the code place of handling mem_region directely if no
> immovable_mem specified
> Follow Randy's suggestion:
> - Change the mistake and add detailed description for the document.
>
> v2->v3:
> Follow Baoquan He's suggestion:
> - Change names of several functions.
> - Add a new parameter "immovable_mem" instead of extending mvoable_node
> - Use the clamp to calculate the memory intersecting, which makes
> logical more clear.
> - Disable memory mirror if movable_node specified
>
> v1->v2:
> Follow Dou Liyang's suggestion:
> - Add the parse for movable_node=nn[KMG] without @ss[KMG]
> - Fix the bug for more than one "movable_node=" specified
> - Drop useless variables and use mem_vector region directely
> - Add more comments.
>
> Chao Fan (5):
> x86/KASLR: Add kaslr_mem=nn[KMG]@ss[KMG]
> x86/KASLR: Handle the memory regions specified in kaslr_mem
> x86/KASLR: Give a warning if movable_node specified without kaslr_mem=
> x86/KASLR: Skip memory mirror handling if movable_node specified
> document: add document for kaslr_mem
>
> Documentation/admin-guide/kernel-parameters.txt | 10 ++
> arch/x86/boot/compressed/kaslr.c | 154 +++++++++++++++++++++---
> 2 files changed, 150 insertions(+), 14 deletions(-)
>
^ permalink raw reply [flat|nested] 27+ messages in thread
* Re: [PATCH v7 0/5] x86/KASLR: Add parameter kaslr_mem=nn[KMG]@ss[KMG]
2018-01-17 17:32 ` [PATCH v7 0/5] x86/KASLR: Add parameter kaslr_mem=nn[KMG]@ss[KMG] Luiz Capitulino
@ 2018-01-18 1:11 ` Chao Fan
2018-01-18 13:39 ` Luiz Capitulino
0 siblings, 1 reply; 27+ messages in thread
From: Chao Fan @ 2018-01-18 1:11 UTC (permalink / raw)
To: Luiz Capitulino
Cc: linux-kernel, x86, hpa, tglx, mingo, bhe, keescook, yasu.isimatu,
indou.takao
On Wed, Jan 17, 2018 at 12:32:35PM -0500, Luiz Capitulino wrote:
>On Wed, 17 Jan 2018 18:53:46 +0800
>Chao Fan <fanc.fnst@cn.fujitsu.com> wrote:
>
>> ***Background:
>> People reported that kaslr may randomly chooses some positions
>> which are located in movable memory regions. This will break memory
>> hotplug feature.
>>
>> And also on kvm guest with 4GB meory, the good unfragmented 1GB could
>> be occupied by randomized kernel. It will cause hugetlb failing to
>> allocate 1GB page. While kernel with 'nokaslr' has not such issue.
>> This causes regression. Please see the discussion mail:
>> https://lkml.org/lkml/2018/1/4/236
>>
>> ***Solutions:
>> Introduce a new kernel parameter 'kaslr_mem=nn@ss' to let users to
>> specify the memory regions where kernel can be allowed to randomize
>> safely.
>
>I've tested this series with a 4GB KVM guest. With kaslr_mem=1G, I
>got one 1GB page allocated 100% of the time in 85 boots. Without
>kaslr_mem=, I got 3 failures in only 10 boots (that is, in 3 boots
>I had no 1GB page allocated).
>
>So, this series solves the 1GB page problem for me.
>
Thanks for Luiz's test.
Thanks,
Chao Fan
>>
>> E.g if 'movable_node' is spedified, we can use 'kaslr_mem=nn@ss' to
>> tell KASLR where we can put kernel safely. Then KASLR code can avoid
>> those movable regions and only choose those immovable regions
>> specified.
>>
>> For hugetlb case, users can always add 'kaslr_mem=1G' in kernel
>> cmdline since the 0~1G is always fragmented region because of BIOS
>> reserved area. Surely users can specify regions more precisely if
>> they know system memory very well.
>>
>> *** Issues need be discussed
>> There are several issues I am not quite sure, please help review and
>> give suggestions:
>>
>> 1) Since there's already mem_avoid[] which stores the memory regions
>> KASLR need avoid. For the regions KASLR can safely use, I name it as
>> mem_usable[], not sure if it's appropriate. Or kaslr_mem[] directly?
>>
>> 2) In v6, I made 'kaslr_mem=' as a kernel parameter which users can use
>> to specify memory regions where kenrel can be extracted safely by
>> 'kaslr_mem=nn@ss', or regions where we need avoid to extract kernel by
>> 'kaslr_mem=nn!ss'. While later I rethink about it, seems
>> 'kaslr_mem=nn@ss' can satisfy the current requirement, there's no need
>> to introduce the 'kaslr_mem=nn!ss'. So I just take that
>> 'kaslr_mem=nn!ss' handling patch off, may add it later if anyone think
>> it's necessary. Any suggestions?
>> https://www.spinics.net/lists/kernel/msg2698457.html
>>
>> ***Test results:
>> - I did some tests for the memory hotplug issues. I specify the memory
>> region in one node, then I found every time the kernel will be
>> extracted to the memory of this node.
>> - Luiz said he will do some tests for the 1G huge page issue.
>>
>> ***History
>> v6->v7:
>> - Drop the unnecessary avoid part for now.
>> - Add document for the new parameter.
>>
>> v5->v6:
>> - Add the last patch to save the avoid memory regions.
>>
>> v4->v5:
>> - Change the problem reported by LKP
>> Follow Dou's suggestion:
>> - Also return if match "movable_node" when parsing kernel commandline
>> in handle_mem_filter without define CONFIG_MEMORY_HOTPLUG
>>
>> v3->v4:
>> Follow Kees's suggestion:
>> - Put the functions variables of immovable_mem to #ifdef
>> CONFIG_MEMORY_HOTPLUG and change some code place
>> - Change the name of "process_mem_region" to "slots_count"
>> - Reanme the new function "process_immovable_mem" to "process_mem_region"
>> Follow Baoquan's suggestion:
>> - Fail KASLR if "movable_node" specified without "immovable_mem"
>> - Ajust the code place of handling mem_region directely if no
>> immovable_mem specified
>> Follow Randy's suggestion:
>> - Change the mistake and add detailed description for the document.
>>
>> v2->v3:
>> Follow Baoquan He's suggestion:
>> - Change names of several functions.
>> - Add a new parameter "immovable_mem" instead of extending mvoable_node
>> - Use the clamp to calculate the memory intersecting, which makes
>> logical more clear.
>> - Disable memory mirror if movable_node specified
>>
>> v1->v2:
>> Follow Dou Liyang's suggestion:
>> - Add the parse for movable_node=nn[KMG] without @ss[KMG]
>> - Fix the bug for more than one "movable_node=" specified
>> - Drop useless variables and use mem_vector region directely
>> - Add more comments.
>>
>> Chao Fan (5):
>> x86/KASLR: Add kaslr_mem=nn[KMG]@ss[KMG]
>> x86/KASLR: Handle the memory regions specified in kaslr_mem
>> x86/KASLR: Give a warning if movable_node specified without kaslr_mem=
>> x86/KASLR: Skip memory mirror handling if movable_node specified
>> document: add document for kaslr_mem
>>
>> Documentation/admin-guide/kernel-parameters.txt | 10 ++
>> arch/x86/boot/compressed/kaslr.c | 154 +++++++++++++++++++++---
>> 2 files changed, 150 insertions(+), 14 deletions(-)
>>
>
>
>
^ permalink raw reply [flat|nested] 27+ messages in thread
* Re: [PATCH v7 0/5] x86/KASLR: Add parameter kaslr_mem=nn[KMG]@ss[KMG]
2018-01-18 1:11 ` Chao Fan
@ 2018-01-18 13:39 ` Luiz Capitulino
0 siblings, 0 replies; 27+ messages in thread
From: Luiz Capitulino @ 2018-01-18 13:39 UTC (permalink / raw)
To: Chao Fan
Cc: linux-kernel, x86, hpa, tglx, mingo, bhe, keescook, yasu.isimatu,
indou.takao
On Thu, 18 Jan 2018 09:11:14 +0800
Chao Fan <fanc.fnst@cn.fujitsu.com> wrote:
> On Wed, Jan 17, 2018 at 12:32:35PM -0500, Luiz Capitulino wrote:
> >On Wed, 17 Jan 2018 18:53:46 +0800
> >Chao Fan <fanc.fnst@cn.fujitsu.com> wrote:
> >
> >> ***Background:
> >> People reported that kaslr may randomly chooses some positions
> >> which are located in movable memory regions. This will break memory
> >> hotplug feature.
> >>
> >> And also on kvm guest with 4GB meory, the good unfragmented 1GB could
> >> be occupied by randomized kernel. It will cause hugetlb failing to
> >> allocate 1GB page. While kernel with 'nokaslr' has not such issue.
> >> This causes regression. Please see the discussion mail:
> >> https://lkml.org/lkml/2018/1/4/236
> >>
> >> ***Solutions:
> >> Introduce a new kernel parameter 'kaslr_mem=nn@ss' to let users to
> >> specify the memory regions where kernel can be allowed to randomize
> >> safely.
> >
> >I've tested this series with a 4GB KVM guest. With kaslr_mem=1G, I
> >got one 1GB page allocated 100% of the time in 85 boots. Without
> >kaslr_mem=, I got 3 failures in only 10 boots (that is, in 3 boots
> >I had no 1GB page allocated).
> >
> >So, this series solves the 1GB page problem for me.
> >
>
>
> Thanks for Luiz's test.
Btw, my test tested a simple single case, but I think you can add:
Tested-by: Luiz Capitulino <lcapitulino@redhat.com>
>
> Thanks,
> Chao Fan
>
> >>
> >> E.g if 'movable_node' is spedified, we can use 'kaslr_mem=nn@ss' to
> >> tell KASLR where we can put kernel safely. Then KASLR code can avoid
> >> those movable regions and only choose those immovable regions
> >> specified.
> >>
> >> For hugetlb case, users can always add 'kaslr_mem=1G' in kernel
> >> cmdline since the 0~1G is always fragmented region because of BIOS
> >> reserved area. Surely users can specify regions more precisely if
> >> they know system memory very well.
> >>
> >> *** Issues need be discussed
> >> There are several issues I am not quite sure, please help review and
> >> give suggestions:
> >>
> >> 1) Since there's already mem_avoid[] which stores the memory regions
> >> KASLR need avoid. For the regions KASLR can safely use, I name it as
> >> mem_usable[], not sure if it's appropriate. Or kaslr_mem[] directly?
> >>
> >> 2) In v6, I made 'kaslr_mem=' as a kernel parameter which users can use
> >> to specify memory regions where kenrel can be extracted safely by
> >> 'kaslr_mem=nn@ss', or regions where we need avoid to extract kernel by
> >> 'kaslr_mem=nn!ss'. While later I rethink about it, seems
> >> 'kaslr_mem=nn@ss' can satisfy the current requirement, there's no need
> >> to introduce the 'kaslr_mem=nn!ss'. So I just take that
> >> 'kaslr_mem=nn!ss' handling patch off, may add it later if anyone think
> >> it's necessary. Any suggestions?
> >> https://www.spinics.net/lists/kernel/msg2698457.html
> >>
> >> ***Test results:
> >> - I did some tests for the memory hotplug issues. I specify the memory
> >> region in one node, then I found every time the kernel will be
> >> extracted to the memory of this node.
> >> - Luiz said he will do some tests for the 1G huge page issue.
> >>
> >> ***History
> >> v6->v7:
> >> - Drop the unnecessary avoid part for now.
> >> - Add document for the new parameter.
> >>
> >> v5->v6:
> >> - Add the last patch to save the avoid memory regions.
> >>
> >> v4->v5:
> >> - Change the problem reported by LKP
> >> Follow Dou's suggestion:
> >> - Also return if match "movable_node" when parsing kernel commandline
> >> in handle_mem_filter without define CONFIG_MEMORY_HOTPLUG
> >>
> >> v3->v4:
> >> Follow Kees's suggestion:
> >> - Put the functions variables of immovable_mem to #ifdef
> >> CONFIG_MEMORY_HOTPLUG and change some code place
> >> - Change the name of "process_mem_region" to "slots_count"
> >> - Reanme the new function "process_immovable_mem" to "process_mem_region"
> >> Follow Baoquan's suggestion:
> >> - Fail KASLR if "movable_node" specified without "immovable_mem"
> >> - Ajust the code place of handling mem_region directely if no
> >> immovable_mem specified
> >> Follow Randy's suggestion:
> >> - Change the mistake and add detailed description for the document.
> >>
> >> v2->v3:
> >> Follow Baoquan He's suggestion:
> >> - Change names of several functions.
> >> - Add a new parameter "immovable_mem" instead of extending mvoable_node
> >> - Use the clamp to calculate the memory intersecting, which makes
> >> logical more clear.
> >> - Disable memory mirror if movable_node specified
> >>
> >> v1->v2:
> >> Follow Dou Liyang's suggestion:
> >> - Add the parse for movable_node=nn[KMG] without @ss[KMG]
> >> - Fix the bug for more than one "movable_node=" specified
> >> - Drop useless variables and use mem_vector region directely
> >> - Add more comments.
> >>
> >> Chao Fan (5):
> >> x86/KASLR: Add kaslr_mem=nn[KMG]@ss[KMG]
> >> x86/KASLR: Handle the memory regions specified in kaslr_mem
> >> x86/KASLR: Give a warning if movable_node specified without kaslr_mem=
> >> x86/KASLR: Skip memory mirror handling if movable_node specified
> >> document: add document for kaslr_mem
> >>
> >> Documentation/admin-guide/kernel-parameters.txt | 10 ++
> >> arch/x86/boot/compressed/kaslr.c | 154 +++++++++++++++++++++---
> >> 2 files changed, 150 insertions(+), 14 deletions(-)
> >>
> >
> >
> >
>
>
^ permalink raw reply [flat|nested] 27+ messages in thread