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of: reserved_mem: disable kmemleak scan on removed memory blocks

PATCH In review Prateek Patel 3 participants 6 messages Nov 9, 2018 – Mar 4, 2019

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Prateek Patel

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#0 lore raw

PATCH 1/1 of: reserved_mem: disable kmemleak scan on removed memory blocks

From: Sri Krishna chowdary <[email protected]>

Memory reserved with "nomap" DT property in of_reserved_mem.c removes the memory block. The removed memory blocks don't have VA to PA mapping created in kernel page table. Kmemleak scan on removed memory blocks is causing page faults and leading to kernel panic. So, Disable kmemleak scan on the removed memory blocks.

Following is the observed crash log:

[  154.846370] Unable to handle kernel paging request at virtual address ffffffc070a00000
<1>[  154.846576] Mem abort info:
<1>[  154.846635]   Exception class = DABT (current EL), IL = 32 bits
<1>[  154.846737]   SET = 0, FnV = 0
<1>[  154.846796]   EA = 0, S1PTW = 0
<1>[  154.846859] Data abort info:
<1>[  154.846913]   ISV = 0, ISS = 0x00000006
<1>[  154.846983]   CM = 0, WnR = 0
<1>[  154.847053] swapper pgtable: 4k pages, 39-bit VAs, pgd = ffffff8009df7000
<1>[  154.847228] [ffffffc070a00000] *pgd=000000087fff5803, *pud=000000087fff5803, *pmd=0000000000000000
<0>[  154.847408] Internal error: Oops: 96000006 [#1] PREEMPT SMP
<4>[  154.847511] Modules linked in: nvs_led_test nvs_bmi160 nvs_cm3218 nvs_bh1730fvc nvi_bmpX80 nvi_ak89xx nvi_mpu cdc_acm uas lr388k7_ts imx268 imx318 imx204 imx274 imx185 lc898212 ov23850 ov10823 ov9281 ov5693 tc358840 pca9570 nvs snd_soc_tegra_machine_driver_mobile lp855x_bl spidev input_cfboost pwm_tegra tegra_cryptodev tegra_se_nvhost tegra_se_elp tegra_se ghash_ce sha2_ce sha1_ce aes_ce_ccm cryptd nvgpu cpufreq_userspace snd_soc_tegra186_alt_dspk snd_soc_tegra186_alt_asrc snd_soc_tegra186_alt_arad snd_soc_tegra210_alt_ope snd_soc_tegra210_alt_mvc snd_soc_tegra210_alt_dmic snd_soc_tegra210_alt_amx snd_soc_tegra210_alt_adx snd_soc_tegra210_alt_afc snd_soc_tegra210_alt_mixer snd_soc_tegra210_alt_i2s snd_soc_tegra210_alt_sfc snd_soc_tegra210_alt_adsp snd_soc_tegra210_alt_admaif snd_soc_tegra210_alt_xbar
<4>[  154.882606]  snd_soc_tegra_alt_utils snd_hda_tegra
<4>[  154.888133] CPU: 2 PID: 8079 Comm: sh Not tainted 4.14.53-tegra-05132-g9c33465 #2
<4>[  154.895983] Hardware name: e3360_1099 (DT)
<4>[  154.900447] task: ffffffc7d62dda00 task.stack: ffffff800e2b0000
<4>[  154.906502] PC is at scan_block+0x7c/0x148
<4>[  154.911234] LR is at scan_block+0x78/0x148
<4>[  154.915689] pc : [<ffffff8008271724>] lr : [<ffffff8008271720>] pstate: 804000c9
<4>[  154.923290] sp : ffffff800e2b3b80
<4>[  154.927228] x29: ffffff800e2b3b80 x28: ffffffc7d62dda00
<4>[  154.932999] x27: ffffff8009aaa000 x26: ffffffc070c00000
<4>[  154.938769] x25: 00000000000000c0 x24: ffffff8009d90608
<4>[  154.944287] x23: ffffffc7dc6c6000 x22: ffffff8009d90000
<4>[  154.950320] x21: ffffff8009aeb320 x20: ffffffc070a00ff9
<4>[  154.955919] x19: ffffffc070a00000 x18: 00000000bec4c3f2
<4>[  154.961438] x17: 0000002224777924 x16: ffffff80080bb0e0
<4>[  154.967124] x15: 0000000000000000 x14: 0000000000000f75
<4>[  154.973069] x13: 000fffffffffffff x12: ffffffbf1e9f4240
<4>[  154.978670] x11: 0000000000000040 x10: 0000000000000ad0
<4>[  154.984107] x9 : ffffff800e2b3ab0 x8 : ffffffc7d62de530
<4>[  154.989958] x7 : 0000000780000000 x6 : 0000000000000018
<4>[  154.995645] x5 : 0000000000000000 x4 : 0000000000000000
<4>[  155.001245] x3 : ffffff8009aaa000 x2 : 00000047f6712000
<4>[  155.006846] x1 : ffffffc7d1ae6900 x0 : 0000000000000000
Signed-off-by Sri Krishna chowdary <[email protected]>
Signed-off-by Prateek <[email protected]>
---
 drivers/of/of_reserved_mem.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
drivers/of/of_reserved_mem.c +4 -1
index 1977ee0..ac8f377 100644
@@ -21,6 +21,7 @@
 #include <linux/sort.h>
 #include <linux/slab.h>
 #include <linux/memblock.h>
+#include <linux/kmemleak.h>
 
 #define MAX_RESERVED_REGIONS	32
 static struct reserved_mem reserved_mem[MAX_RESERVED_REGIONS];

@@ -50,8 +51,10 @@ int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
 	}
 
 	*res_base = base;
-	if (nomap)
+	if (nomap) {
+		kmemleak_no_scan(__va(base));
 		return memblock_remove(base, size);
+	}
 	return 0;
 }
Signature · 1 line
2.1.4
#1 lore raw
Quoted 66 lines · Prateek Patel

From: Sri Krishna chowdary <[email protected]>

Memory reserved with "nomap" DT property in of_reserved_mem.c removes the memory block. The removed memory blocks don't have VA to PA mapping created in kernel page table. Kmemleak scan on removed memory blocks is causing page faults and leading to kernel panic. So, Disable kmemleak scan on the removed memory blocks.

Following is the observed crash log:

[  154.846370] Unable to handle kernel paging request at virtual address ffffffc070a00000
<1>[  154.846576] Mem abort info:
<1>[  154.846635]   Exception class = DABT (current EL), IL = 32 bits
<1>[  154.846737]   SET = 0, FnV = 0
<1>[  154.846796]   EA = 0, S1PTW = 0
<1>[  154.846859] Data abort info:
<1>[  154.846913]   ISV = 0, ISS = 0x00000006
<1>[  154.846983]   CM = 0, WnR = 0
<1>[  154.847053] swapper pgtable: 4k pages, 39-bit VAs, pgd = ffffff8009df7000
<1>[  154.847228] [ffffffc070a00000] *pgd=000000087fff5803, *pud=000000087fff5803, *pmd=0000000000000000
<0>[  154.847408] Internal error: Oops: 96000006 [#1] PREEMPT SMP
<4>[  154.847511] Modules linked in: nvs_led_test nvs_bmi160 nvs_cm3218 nvs_bh1730fvc nvi_bmpX80 nvi_ak89xx nvi_mpu cdc_acm uas lr388k7_ts imx268 imx318 imx204 imx274 imx185 lc898212 ov23850 ov10823 ov9281 ov5693 tc358840 pca9570 nvs snd_soc_tegra_machine_driver_mobile lp855x_bl spidev input_cfboost pwm_tegra tegra_cryptodev tegra_se_nvhost tegra_se_elp tegra_se ghash_ce sha2_ce sha1_ce aes_ce_ccm cryptd nvgpu cpufreq_userspace snd_soc_tegra186_alt_dspk snd_soc_tegra186_alt_asrc snd_soc_tegra186_alt_arad snd_soc_tegra210_alt_ope snd_soc_tegra210_alt_mvc snd_soc_tegra210_alt_dmic snd_soc_tegra210_alt_amx snd_soc_tegra210_alt_adx snd_soc_tegra210_alt_afc snd_soc_tegra210_alt_mixer snd_soc_tegra210_alt_i2s snd_soc_tegra210_alt_sfc snd_soc_tegra210_alt_adsp snd_soc_tegra210_alt_admaif snd_soc_tegra210_alt_xbar
<4>[  154.882606]  snd_soc_tegra_alt_utils snd_hda_tegra
<4>[  154.888133] CPU: 2 PID: 8079 Comm: sh Not tainted 4.14.53-tegra-05132-g9c33465 #2
<4>[  154.895983] Hardware name: e3360_1099 (DT)
<4>[  154.900447] task: ffffffc7d62dda00 task.stack: ffffff800e2b0000
<4>[  154.906502] PC is at scan_block+0x7c/0x148
<4>[  154.911234] LR is at scan_block+0x78/0x148
<4>[  154.915689] pc : [<ffffff8008271724>] lr : [<ffffff8008271720>] pstate: 804000c9
<4>[  154.923290] sp : ffffff800e2b3b80
<4>[  154.927228] x29: ffffff800e2b3b80 x28: ffffffc7d62dda00
<4>[  154.932999] x27: ffffff8009aaa000 x26: ffffffc070c00000
<4>[  154.938769] x25: 00000000000000c0 x24: ffffff8009d90608
<4>[  154.944287] x23: ffffffc7dc6c6000 x22: ffffff8009d90000
<4>[  154.950320] x21: ffffff8009aeb320 x20: ffffffc070a00ff9
<4>[  154.955919] x19: ffffffc070a00000 x18: 00000000bec4c3f2
<4>[  154.961438] x17: 0000002224777924 x16: ffffff80080bb0e0
<4>[  154.967124] x15: 0000000000000000 x14: 0000000000000f75
<4>[  154.973069] x13: 000fffffffffffff x12: ffffffbf1e9f4240
<4>[  154.978670] x11: 0000000000000040 x10: 0000000000000ad0
<4>[  154.984107] x9 : ffffff800e2b3ab0 x8 : ffffffc7d62de530
<4>[  154.989958] x7 : 0000000780000000 x6 : 0000000000000018
<4>[  154.995645] x5 : 0000000000000000 x4 : 0000000000000000
<4>[  155.001245] x3 : ffffff8009aaa000 x2 : 00000047f6712000
<4>[  155.006846] x1 : ffffffc7d1ae6900 x0 : 0000000000000000
Signed-off-by Sri Krishna chowdary <[email protected]>
Signed-off-by Prateek <[email protected]>
---
 drivers/of/of_reserved_mem.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
drivers/of/of_reserved_mem.c +1 -0
index 1977ee0..ac8f377 100644
@@ -21,6 +21,7 @@
 #include <linux/sort.h>
 #include <linux/slab.h>
 #include <linux/memblock.h>
+#include <linux/kmemleak.h>
 
 #define MAX_RESERVED_REGIONS   32
 static struct reserved_mem reserved_mem[MAX_RESERVED_REGIONS];

drivers/of/of_reserved_mem.c int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size, · line 56

Quoted 7 lines
drivers/of/of_reserved_mem.c +2 -1
@@ -50,8 +51,10 @@ int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
        }
 
        *res_base = base;
-       if (nomap)
+       if (nomap) {
+               kmemleak_no_scan(__va(base));
                return memblock_remove(base, size);

I'm curious how I can't find any other similar example in the kernel. Please Cc some kmemleak folks.

Perhaps we should be using memblock_mark_nomap() for nomap areas?

Rob

author
#2 lore raw
Quoted 76 lines · Rob Herring
Quoted 65 lines · Prateek Patel

From: Sri Krishna chowdary <[email protected]>

Memory reserved with "nomap" DT property in of_reserved_mem.c removes the memory block. The removed memory blocks don't have VA to PA mapping created in kernel page table. Kmemleak scan on removed memory blocks is causing page faults and leading to kernel panic. So, Disable kmemleak scan on the removed memory blocks.

Following is the observed crash log:

[  154.846370] Unable to handle kernel paging request at virtual address ffffffc070a00000
<1>[  154.846576] Mem abort info:
<1>[  154.846635]   Exception class = DABT (current EL), IL = 32 bits
<1>[  154.846737]   SET = 0, FnV = 0
<1>[  154.846796]   EA = 0, S1PTW = 0
<1>[  154.846859] Data abort info:
<1>[  154.846913]   ISV = 0, ISS = 0x00000006
<1>[  154.846983]   CM = 0, WnR = 0
<1>[  154.847053] swapper pgtable: 4k pages, 39-bit VAs, pgd = ffffff8009df7000
<1>[  154.847228] [ffffffc070a00000] *pgd=000000087fff5803, *pud=000000087fff5803, *pmd=0000000000000000
<0>[  154.847408] Internal error: Oops: 96000006 [#1] PREEMPT SMP
<4>[  154.847511] Modules linked in: nvs_led_test nvs_bmi160 nvs_cm3218 nvs_bh1730fvc nvi_bmpX80 nvi_ak89xx nvi_mpu cdc_acm uas lr388k7_ts imx268 imx318 imx204 imx274 imx185 lc898212 ov23850 ov10823 ov9281 ov5693 tc358840 pca9570 nvs snd_soc_tegra_machine_driver_mobile lp855x_bl spidev input_cfboost pwm_tegra tegra_cryptodev tegra_se_nvhost tegra_se_elp tegra_se ghash_ce sha2_ce sha1_ce aes_ce_ccm cryptd nvgpu cpufreq_userspace snd_soc_tegra186_alt_dspk snd_soc_tegra186_alt_asrc snd_soc_tegra186_alt_arad snd_soc_tegra210_alt_ope snd_soc_tegra210_alt_mvc snd_soc_tegra210_alt_dmic snd_soc_tegra210_alt_amx snd_soc_tegra210_alt_adx snd_soc_tegra210_alt_afc snd_soc_tegra210_alt_mixer snd_soc_tegra210_alt_i2s snd_soc_tegra210_alt_sfc snd_soc_tegra210_alt_adsp snd_soc_tegra210_alt_admaif snd_soc_tegra210_alt_xbar
<4>[  154.882606]  snd_soc_tegra_alt_utils snd_hda_tegra
<4>[  154.888133] CPU: 2 PID: 8079 Comm: sh Not tainted 4.14.53-tegra-05132-g9c33465 #2
<4>[  154.895983] Hardware name: e3360_1099 (DT)
<4>[  154.900447] task: ffffffc7d62dda00 task.stack: ffffff800e2b0000
<4>[  154.906502] PC is at scan_block+0x7c/0x148
<4>[  154.911234] LR is at scan_block+0x78/0x148
<4>[  154.915689] pc : [<ffffff8008271724>] lr : [<ffffff8008271720>] pstate: 804000c9
<4>[  154.923290] sp : ffffff800e2b3b80
<4>[  154.927228] x29: ffffff800e2b3b80 x28: ffffffc7d62dda00
<4>[  154.932999] x27: ffffff8009aaa000 x26: ffffffc070c00000
<4>[  154.938769] x25: 00000000000000c0 x24: ffffff8009d90608
<4>[  154.944287] x23: ffffffc7dc6c6000 x22: ffffff8009d90000
<4>[  154.950320] x21: ffffff8009aeb320 x20: ffffffc070a00ff9
<4>[  154.955919] x19: ffffffc070a00000 x18: 00000000bec4c3f2
<4>[  154.961438] x17: 0000002224777924 x16: ffffff80080bb0e0
<4>[  154.967124] x15: 0000000000000000 x14: 0000000000000f75
<4>[  154.973069] x13: 000fffffffffffff x12: ffffffbf1e9f4240
<4>[  154.978670] x11: 0000000000000040 x10: 0000000000000ad0
<4>[  154.984107] x9 : ffffff800e2b3ab0 x8 : ffffffc7d62de530
<4>[  154.989958] x7 : 0000000780000000 x6 : 0000000000000018
<4>[  154.995645] x5 : 0000000000000000 x4 : 0000000000000000
<4>[  155.001245] x3 : ffffff8009aaa000 x2 : 00000047f6712000
<4>[  155.006846] x1 : ffffffc7d1ae6900 x0 : 0000000000000000
Signed-off-by Sri Krishna chowdary <[email protected]>
Signed-off-by Prateek <[email protected]>
---
  drivers/of/of_reserved_mem.c | 5 ++++-
  1 file changed, 4 insertions(+), 1 deletion(-)
drivers/of/of_reserved_mem.c +1 -0
index 1977ee0..ac8f377 100644
@@ -21,6 +21,7 @@
  #include <linux/sort.h>
  #include <linux/slab.h>
  #include <linux/memblock.h>
+#include <linux/kmemleak.h>
 
  #define MAX_RESERVED_REGIONS   32
  static struct reserved_mem reserved_mem[MAX_RESERVED_REGIONS];

drivers/of/of_reserved_mem.c int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size, · line 56

Quoted 7 lines
drivers/of/of_reserved_mem.c +2 -1
@@ -50,8 +51,10 @@ int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
         }
 
         *res_base = base;
-       if (nomap)
+       if (nomap) {
+               kmemleak_no_scan(__va(base));
                 return memblock_remove(base, size);

I'm curious how I can't find any other similar example in the kernel. Please Cc some kmemleak folks.

Quoted 3 lines

Perhaps we should be using memblock_mark_nomap() for nomap areas?

Rob

Sorry for this late reply.

Yes, memblock_mark_nomap() can be used here but if I understand correctly, memblock_mark_nomap() is used to indicate marked parts of memory should not be covered by the kernel direct mapping and memblock_remove() here is doing that by removing a given memory from the "memblock.memory" list to prevent the memory from CPU accessing by the linear address. I am not 100% sure what will be the side effects of using memblock_mark_nomap(). Adding folks to help me here on MEMBLOCK_NOMAP and kmemleak.

I checked and verified with following and I didn't find any errors on my local setup:

drivers/of/of_reserved_mem.c +0 -0
index 1977ee0..f77cde0 100644
@@ -50,8 +50,10 @@ int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,

        }

        *res_base = base;
-       if (nomap)
-               return memblock_remove(base, size); +       if (nomap) {
+               kmemleak_no_scan(__va(base)); +               return memblock_mark_nomap(base, size); +       }
        return 0;
 }

Tested-by
#3 lore raw
Quoted 85 lines · Prateek Patel
Quoted 76 lines · Rob Herring
Quoted 65 lines · Prateek Patel

From: Sri Krishna chowdary <[email protected]>

Memory reserved with "nomap" DT property in of_reserved_mem.c removes the memory block. The removed memory blocks don't have VA to PA mapping created in kernel page table. Kmemleak scan on removed memory blocks is causing page faults and leading to kernel panic. So, Disable kmemleak scan on the removed memory blocks.

Following is the observed crash log:

[  154.846370] Unable to handle kernel paging request at virtual address ffffffc070a00000
<1>[  154.846576] Mem abort info:
<1>[  154.846635]   Exception class = DABT (current EL), IL = 32 bits
<1>[  154.846737]   SET = 0, FnV = 0
<1>[  154.846796]   EA = 0, S1PTW = 0
<1>[  154.846859] Data abort info:
<1>[  154.846913]   ISV = 0, ISS = 0x00000006
<1>[  154.846983]   CM = 0, WnR = 0
<1>[  154.847053] swapper pgtable: 4k pages, 39-bit VAs, pgd = ffffff8009df7000
<1>[  154.847228] [ffffffc070a00000] *pgd=000000087fff5803, *pud=000000087fff5803, *pmd=0000000000000000
<0>[  154.847408] Internal error: Oops: 96000006 [#1] PREEMPT SMP
<4>[  154.847511] Modules linked in: nvs_led_test nvs_bmi160 nvs_cm3218 nvs_bh1730fvc nvi_bmpX80 nvi_ak89xx nvi_mpu cdc_acm uas lr388k7_ts imx268 imx318 imx204 imx274 imx185 lc898212 ov23850 ov10823 ov9281 ov5693 tc358840 pca9570 nvs snd_soc_tegra_machine_driver_mobile lp855x_bl spidev input_cfboost pwm_tegra tegra_cryptodev tegra_se_nvhost tegra_se_elp tegra_se ghash_ce sha2_ce sha1_ce aes_ce_ccm cryptd nvgpu cpufreq_userspace snd_soc_tegra186_alt_dspk snd_soc_tegra186_alt_asrc snd_soc_tegra186_alt_arad snd_soc_tegra210_alt_ope snd_soc_tegra210_alt_mvc snd_soc_tegra210_alt_dmic snd_soc_tegra210_alt_amx snd_soc_tegra210_alt_adx snd_soc_tegra210_alt_afc snd_soc_tegra210_alt_mixer snd_soc_tegra210_alt_i2s snd_soc_tegra210_alt_sfc snd_soc_tegra210_alt_adsp snd_soc_tegra210_alt_admaif snd_soc_tegra210_alt_xbar
<4>[  154.882606]  snd_soc_tegra_alt_utils snd_hda_tegra
<4>[  154.888133] CPU: 2 PID: 8079 Comm: sh Not tainted 4.14.53-tegra-05132-g9c33465 #2
<4>[  154.895983] Hardware name: e3360_1099 (DT)
<4>[  154.900447] task: ffffffc7d62dda00 task.stack: ffffff800e2b0000
<4>[  154.906502] PC is at scan_block+0x7c/0x148
<4>[  154.911234] LR is at scan_block+0x78/0x148
<4>[  154.915689] pc : [<ffffff8008271724>] lr : [<ffffff8008271720>] pstate: 804000c9
<4>[  154.923290] sp : ffffff800e2b3b80
<4>[  154.927228] x29: ffffff800e2b3b80 x28: ffffffc7d62dda00
<4>[  154.932999] x27: ffffff8009aaa000 x26: ffffffc070c00000
<4>[  154.938769] x25: 00000000000000c0 x24: ffffff8009d90608
<4>[  154.944287] x23: ffffffc7dc6c6000 x22: ffffff8009d90000
<4>[  154.950320] x21: ffffff8009aeb320 x20: ffffffc070a00ff9
<4>[  154.955919] x19: ffffffc070a00000 x18: 00000000bec4c3f2
<4>[  154.961438] x17: 0000002224777924 x16: ffffff80080bb0e0
<4>[  154.967124] x15: 0000000000000000 x14: 0000000000000f75
<4>[  154.973069] x13: 000fffffffffffff x12: ffffffbf1e9f4240
<4>[  154.978670] x11: 0000000000000040 x10: 0000000000000ad0
<4>[  154.984107] x9 : ffffff800e2b3ab0 x8 : ffffffc7d62de530
<4>[  154.989958] x7 : 0000000780000000 x6 : 0000000000000018
<4>[  154.995645] x5 : 0000000000000000 x4 : 0000000000000000
<4>[  155.001245] x3 : ffffff8009aaa000 x2 : 00000047f6712000
<4>[  155.006846] x1 : ffffffc7d1ae6900 x0 : 0000000000000000
Signed-off-by Sri Krishna chowdary <[email protected]>
Signed-off-by Prateek <[email protected]>
---
  drivers/of/of_reserved_mem.c | 5 ++++-
  1 file changed, 4 insertions(+), 1 deletion(-)
drivers/of/of_reserved_mem.c +1 -0
index 1977ee0..ac8f377 100644
@@ -21,6 +21,7 @@
  #include <linux/sort.h>
  #include <linux/slab.h>
  #include <linux/memblock.h>
+#include <linux/kmemleak.h>
 
  #define MAX_RESERVED_REGIONS   32
  static struct reserved_mem reserved_mem[MAX_RESERVED_REGIONS];

drivers/of/of_reserved_mem.c int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size, · line 56

Quoted 7 lines
drivers/of/of_reserved_mem.c +2 -1
@@ -50,8 +51,10 @@ int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
         }
 
         *res_base = base;
-       if (nomap)
+       if (nomap) {
+               kmemleak_no_scan(__va(base));
                 return memblock_remove(base, size);

I'm curious how I can't find any other similar example in the kernel. Please Cc some kmemleak folks.

Quoted 3 lines

Perhaps we should be using memblock_mark_nomap() for nomap areas?

Rob

Sorry for this late reply.

Quoted 8 lines

Yes, memblock_mark_nomap() can be used here but if I understand correctly, memblock_mark_nomap() is used to indicate marked parts of memory should not be covered by the kernel direct mapping and memblock_remove() here is doing that by removing a given memory from the "memblock.memory" list to prevent the memory from CPU accessing by the linear address. I am not 100% sure what will be the side effects of using memblock_mark_nomap(). Adding folks to help me here on MEMBLOCK_NOMAP and kmemleak.

I have no idea about your question: memblock_mark_nomap seems reasonable though, but I think this is orthogonal to this patch, whose main purpose is to add kmemleak_no_scan?

In any case, I tested both the original patch, and the hunk below on a different platform (with some no-map reserved_memory as well), and they fix the issue.

Tested-by Nicolas Boichat <[email protected]>
Quoted 20 lines

I checked and verified with following and I didn't find any errors on my local setup:

drivers/of/of_reserved_mem.c +4 -2
index 1977ee0..f77cde0 100644
@@ -50,8 +50,10 @@ int __init __weak
 early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
         }
 
         *res_base = base;
-       if (nomap)
-               return memblock_remove(base, size);
+       if (nomap) {
+               kmemleak_no_scan(__va(base));
+               return memblock_mark_nomap(base, size);
+       }
         return 0;
  }
#4 lore raw
Quoted 43 lines · Nicolas Boichat
Quoted 41 lines · Prateek Patel
Quoted 38 lines · Rob Herring
Quoted 37 lines · Prateek Patel

From: Sri Krishna chowdary <[email protected]>

Memory reserved with "nomap" DT property in of_reserved_mem.c removes the memory block. The removed memory blocks don't have VA to PA mapping created in kernel page table. Kmemleak scan on removed memory blocks is causing page faults and leading to kernel panic. So, Disable kmemleak scan on the removed memory blocks.

Following is the observed crash log:

[  154.846370] Unable to handle kernel paging request at virtual address ffffffc070a00000
<1>[  154.846576] Mem abort info:
<1>[  154.846635]   Exception class = DABT (current EL), IL = 32 bits
<1>[  154.846737]   SET = 0, FnV = 0
<1>[  154.846796]   EA = 0, S1PTW = 0
<1>[  154.846859] Data abort info:
<1>[  154.846913]   ISV = 0, ISS = 0x00000006
<1>[  154.846983]   CM = 0, WnR = 0
<1>[  154.847053] swapper pgtable: 4k pages, 39-bit VAs, pgd = ffffff8009df7000
<1>[  154.847228] [ffffffc070a00000] *pgd=000000087fff5803, *pud=000000087fff5803, *pmd=0000000000000000
<0>[  154.847408] Internal error: Oops: 96000006 [#1] PREEMPT SMP
<4>[  154.847511] Modules linked in: nvs_led_test nvs_bmi160 nvs_cm3218 nvs_bh1730fvc nvi_bmpX80 nvi_ak89xx nvi_mpu cdc_acm uas lr388k7_ts imx268 imx318 imx204 imx274 imx185 lc898212 ov23850 ov10823 ov9281 ov5693 tc358840 pca9570 nvs snd_soc_tegra_machine_driver_mobile lp855x_bl spidev input_cfboost pwm_tegra tegra_cryptodev tegra_se_nvhost tegra_se_elp tegra_se ghash_ce sha2_ce sha1_ce aes_ce_ccm cryptd nvgpu cpufreq_userspace snd_soc_tegra186_alt_dspk snd_soc_tegra186_alt_asrc snd_soc_tegra186_alt_arad snd_soc_tegra210_alt_ope snd_soc_tegra210_alt_mvc snd_soc_tegra210_alt_dmic snd_soc_tegra210_alt_amx snd_soc_tegra210_alt_adx snd_soc_tegra210_alt_afc snd_soc_tegra210_alt_mixer snd_soc_tegra210_alt_i2s snd_soc_tegra210_alt_sfc snd_soc_tegra210_alt_adsp snd_soc_tegra210_alt_admaif snd_soc_tegra210_alt_xbar
<4>[  154.882606]  snd_soc_tegra_alt_utils snd_hda_tegra
<4>[  154.888133] CPU: 2 PID: 8079 Comm: sh Not tainted 4.14.53-tegra-05132-g9c33465 #2
<4>[  154.895983] Hardware name: e3360_1099 (DT)
<4>[  154.900447] task: ffffffc7d62dda00 task.stack: ffffff800e2b0000
<4>[  154.906502] PC is at scan_block+0x7c/0x148
<4>[  154.911234] LR is at scan_block+0x78/0x148
<4>[  154.915689] pc : [<ffffff8008271724>] lr : [<ffffff8008271720>] pstate: 804000c9
<4>[  154.923290] sp : ffffff800e2b3b80
<4>[  154.927228] x29: ffffff800e2b3b80 x28: ffffffc7d62dda00
<4>[  154.932999] x27: ffffff8009aaa000 x26: ffffffc070c00000
<4>[  154.938769] x25: 00000000000000c0 x24: ffffff8009d90608
<4>[  154.944287] x23: ffffffc7dc6c6000 x22: ffffff8009d90000
<4>[  154.950320] x21: ffffff8009aeb320 x20: ffffffc070a00ff9
<4>[  154.955919] x19: ffffffc070a00000 x18: 00000000bec4c3f2
<4>[  154.961438] x17: 0000002224777924 x16: ffffff80080bb0e0
Quoted 8 lines
Quoted 8 lines
Quoted 8 lines
Quoted 8 lines
<4>[  154.967124] x15: 0000000000000000 x14: 0000000000000f75
<4>[  154.973069] x13: 000fffffffffffff x12: ffffffbf1e9f4240
<4>[  154.978670] x11: 0000000000000040 x10: 0000000000000ad0
<4>[  154.984107] x9 : ffffff800e2b3ab0 x8 : ffffffc7d62de530
<4>[  154.989958] x7 : 0000000780000000 x6 : 0000000000000018
<4>[  154.995645] x5 : 0000000000000000 x4 : 0000000000000000
<4>[  155.001245] x3 : ffffff8009aaa000 x2 : 00000047f6712000
<4>[  155.006846] x1 : ffffffc7d1ae6900 x0 : 0000000000000000

[snip]

For reference, there is another patch series that fixes the problem, by Mike Rapoport (https://lore.kernel.org/patchwork/patch/1041790/),
already in linux-next (through mmotm):
42c9c0ac24393c of: fix kmemleak crash caused by imbalance in early memory reservation
48ec6d51f7d3f2 of: fix parameters order for call to memblock_find_in_range()

If anyone is interested, I backported these patch to our 4.19 tree here, and they fix the issue:
https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/1496707
https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/1496708

Thanks,

author
#5 lore raw
Quoted 14 lines · Nicolas Boichat
Quoted 13 lines · Nicolas Boichat
Quoted 12 lines · Prateek Patel
Quoted 10 lines · Rob Herring
Quoted 9 lines · Prateek Patel

From: Sri Krishna chowdary <[email protected]>

Memory reserved with "nomap" DT property in of_reserved_mem.c removes the memory block. The removed memory blocks don't have VA to PA mapping created in kernel page table. Kmemleak scan on removed memory blocks is causing page faults and leading to kernel panic. So, Disable kmemleak scan on the removed memory blocks.

Quoted 13 lines
Quoted 5 lines
Quoted 5 lines
Quoted 5 lines
Quoted 5 lines

Following is the observed crash log:

[  154.846370] Unable to handle kernel paging request at virtual address ffffffc070a00000
<1>[  154.846576] Mem abort info:
<1>[  154.846635]   Exception class = DABT (current EL), IL = 32 bits
<1>[  154.846737]   SET = 0, FnV = 0
Quoted 8 lines
Quoted 8 lines
Quoted 8 lines
Quoted 8 lines
<1>[  154.846796]   EA = 0, S1PTW = 0
<1>[  154.846859] Data abort info:
<1>[  154.846913]   ISV = 0, ISS = 0x00000006
<1>[  154.846983]   CM = 0, WnR = 0
<1>[  154.847053] swapper pgtable: 4k pages, 39-bit VAs, pgd = ffffff8009df7000
<1>[  154.847228] [ffffffc070a00000] *pgd=000000087fff5803, *pud=000000087fff5803, *pmd=0000000000000000
<0>[  154.847408] Internal error: Oops: 96000006 [#1] PREEMPT SMP
<4>[  154.847511] Modules linked in: nvs_led_test nvs_bmi160 nvs_cm3218 nvs_bh1730fvc nvi_bmpX80 nvi_ak89xx nvi_mpu cdc_acm uas lr388k7_ts imx268 imx318 imx204 imx274 imx185 lc898212 ov23850 ov10823 ov9281 ov5693 tc358840 pca9570 nvs snd_soc_tegra_machine_driver_mobile lp855x_bl spidev input_cfboost pwm_tegra tegra_cryptodev tegra_se_nvhost tegra_se_elp tegra_se ghash_ce sha2_ce sha1_ce aes_ce_ccm cryptd nvgpu cpufreq_userspace snd_soc_tegra186_alt_dspk snd_soc_tegra186_alt_asrc snd_soc_tegra186_alt_arad snd_soc_tegra210_alt_ope snd_soc_tegra210_alt_mvc snd_soc_tegra210_alt_dmic snd_soc_tegra210_alt_amx snd_soc_tegra210_alt_adx snd_soc_tegra210_alt_afc snd_soc_tegra210_alt_mixer snd_soc_tegra210_alt_i2s snd_soc_tegra210_alt_sfc snd_soc_tegra210_alt_adsp snd_soc_tegra210_alt_admaif sn

d_soc_tegra210_alt_xbar

Quoted 32 lines
Quoted 15 lines
Quoted 15 lines
Quoted 15 lines
Quoted 15 lines
<4>[  154.882606]  snd_soc_tegra_alt_utils snd_hda_tegra
<4>[  154.888133] CPU: 2 PID: 8079 Comm: sh Not tainted 4.14.53-tegra-05132-g9c33465 #2
<4>[  154.895983] Hardware name: e3360_1099 (DT)
<4>[  154.900447] task: ffffffc7d62dda00 task.stack: ffffff800e2b0000
<4>[  154.906502] PC is at scan_block+0x7c/0x148
<4>[  154.911234] LR is at scan_block+0x78/0x148
<4>[  154.915689] pc : [<ffffff8008271724>] lr : [<ffffff8008271720>] pstate: 804000c9
<4>[  154.923290] sp : ffffff800e2b3b80
<4>[  154.927228] x29: ffffff800e2b3b80 x28: ffffffc7d62dda00
<4>[  154.932999] x27: ffffff8009aaa000 x26: ffffffc070c00000
<4>[  154.938769] x25: 00000000000000c0 x24: ffffff8009d90608
<4>[  154.944287] x23: ffffffc7dc6c6000 x22: ffffff8009d90000
<4>[  154.950320] x21: ffffff8009aeb320 x20: ffffffc070a00ff9
<4>[  154.955919] x19: ffffffc070a00000 x18: 00000000bec4c3f2
<4>[  154.961438] x17: 0000002224777924 x16: ffffff80080bb0e0
Quoted 8 lines
Quoted 8 lines
Quoted 8 lines
Quoted 8 lines
<4>[  154.967124] x15: 0000000000000000 x14: 0000000000000f75
<4>[  154.973069] x13: 000fffffffffffff x12: ffffffbf1e9f4240
<4>[  154.978670] x11: 0000000000000040 x10: 0000000000000ad0
<4>[  154.984107] x9 : ffffff800e2b3ab0 x8 : ffffffc7d62de530
<4>[  154.989958] x7 : 0000000780000000 x6 : 0000000000000018
<4>[  154.995645] x5 : 0000000000000000 x4 : 0000000000000000
<4>[  155.001245] x3 : ffffff8009aaa000 x2 : 00000047f6712000
<4>[  155.006846] x1 : ffffffc7d1ae6900 x0 : 0000000000000000

[snip]

For reference, there is another patch series that fixes the problem, by Mike Rapoport (https://lore.kernel.org/patchwork/patch/1041790/),
already in linux-next (through mmotm):
42c9c0ac24393c of: fix kmemleak crash caused by imbalance in early memory reservation
48ec6d51f7d3f2 of: fix parameters order for call to memblock_find_in_range()

Quoted 6 lines

If anyone is interested, I backported these patch to our 4.19 tree here, and they fix the issue:
https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/1496707
https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/1496708

Thanks,

Thanks Nicolas for the reference,

My acked-by is already present in the patch (https://lore.kernel.org/patchwork/patch/1041790/)