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virt_to_phys.sh also works with nopat

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Ciro Santilli
2017-07-16 11:30:47 +01:00
parent 058c759ec9
commit 2eca9280e1
4 changed files with 9 additions and 8 deletions
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3
buildroot_config_fragment
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@@ -58,8 +58,11 @@ BR2_PACKAGE_HOST_DTC=y
# #
# - https://superuser.com/questions/71389/what-is-dev-mem/1214662#1214662 # - https://superuser.com/questions/71389/what-is-dev-mem/1214662#1214662
# - https://unix.stackexchange.com/questions/4948/shell-command-to-read-device-registers # - https://unix.stackexchange.com/questions/4948/shell-command-to-read-device-registers
# - man mem
# #
# TODO: why with mmap MAP_PRIVATE (used in my previous custom naive version), # TODO: why with mmap MAP_PRIVATE (used in my previous custom naive version),
# the entire register page is read?; # the entire register page is read?;
# #
# TODO: have a look at: https://github.com/kaiwan/device-memory-readwrite
#
BR2_PACKAGE_DEVMEM2=y BR2_PACKAGE_DEVMEM2=y

6
kernel_module/user/usermem.c
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@@ -4,7 +4,7 @@ Only tested in x86_64.
Provide an allocated userland memory address for us to test out kernel memory APIs, including: Provide an allocated userland memory address for us to test out kernel memory APIs, including:
- /proc/pid/maps - /proc/pid/maps
- /proc/pid/pagemap - /proc/pid/pagemap. See also: https://stackoverflow.com/questions/17021214/decode-proc-pid-pagemap-entry/45126141#45126141
- /dev/mem - /dev/mem
Usage: Usage:
@@ -18,13 +18,13 @@ Outputs address and pid, e.g.:
Now translate the virtual address to physical for the given PID: Now translate the virtual address to physical for the given PID:
/pagemap2.out 110 | grep 0x600000 /pagemap_dump.out 110 | grep 0x600000
where 0x600000 is the page that contains 0x600800. where 0x600000 is the page that contains 0x600800.
This produces a line of type: This produces a line of type:
0x600000 0x7c7b 0 0 0 1 /pagemap_test.out 0x600000 0x7c7b 0 0 0 1 /usermem.out
where 0x7c7b is the PFN. To get the physical address, just add three zeros back: where 0x7c7b is the PFN. To get the physical address, just add three zeros back:

6
kernel_module/virt_to_phys.c
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@@ -1,9 +1,5 @@
/* /*
TODO not working. Tested with both: Also try on QEMU monitor:
/virt_to_phys.sh
and on QEMU monitor:
xp 0x<vaddr> xp 0x<vaddr>

2
rootfs_overlay/virt_to_phys.sh
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@@ -3,8 +3,10 @@ set -ex
insmod /virt_to_phys.ko insmod /virt_to_phys.ko
cd /sys/kernel/debug cd /sys/kernel/debug
cat lkmc_virt_to_phys cat lkmc_virt_to_phys
# *i = 0x12345678
addr=$(grep virt_to_phys lkmc_virt_to_phys | cut -d ' ' -f 2) addr=$(grep virt_to_phys lkmc_virt_to_phys | cut -d ' ' -f 2)
devmem2 "$addr" devmem2 "$addr"
devmem2 "$addr" w 0x9ABCDEF0 devmem2 "$addr" w 0x9ABCDEF0
cat lkmc_virt_to_phys cat lkmc_virt_to_phys
# *i = 0x9ABCDEF0
rmmod virt_to_phys rmmod virt_to_phys