drivers: flash: simulator: fix address resolution #79084
+6
−8
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
fgrandel
force-pushed
the
fix/79082-flash-simulator-memfault
branch
from
0bbd325
to
8cee40d
Compare
de-nordic
reviewed
Sep 27, 2024
drivers/flash/flash_simulator.c
Outdated
| FLASH_SIMULATOR_BASE_OFFSET) || | ||
| (offset < FLASH_SIMULATOR_BASE_OFFSET)) { | ||
|
|
||
| if ((offset + len > FLASH_SIMULATOR_FLASH_SIZE) || (offset < 0)) { |
There was a problem hiding this comment.
Since you are fixing this, can we fix the somehow absurd check for correctness of offset after doing calculations with it? I know that it was here before...
Also the more correct approach would be to do:
(offset < 0 || offset >= FLASH_SIMULATOR_FLASH_SIZE || (FLASH_SIMULATOR_FLASH_SIZE - offset) < size)
this should let us avoid all overflows the addition could cause.
There was a problem hiding this comment.
Good catch! Fixed. BTW: The reason, why I'm fixing this is #79130.
zephyrbot
requested review from
57300,
jeremybettis,
nashif,
nordicjm and
tejlmand
The flash simulator assumes that flash is being addressed with absolute addresses by clients. But this is not the case. Given addresses are relative to the flash base address. The existing code only worked because the base address was always zero. Testing with non-zero base addresses caused a mem fault/page fault. (Reproducible e.g. when using the NVS settings subsystem on QEMU x86 with a non-zero base address in the soc-nv-flash node.) Fixes zephyrproject-rtos#79082 Signed-off-by: Florian Grandel <fgrandel@code-for-humans.de>
fgrandel
force-pushed
the
fix/79082-flash-simulator-memfault
branch
from
a6b9282
to
3af7da8
Compare
fgrandel
added
bug
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
The flash simulator assumes that flash is being addressed with absolute addresses by clients. But this is not the case. Given addresses are relative to the flash base address.
The existing code only worked because the base address was always zero. Testing with non-zero base addresses caused a mem fault/page fault.
(Reproducible e.g. when using the NVS settings subsystem on QEMU x86 with a non-zero base address in the soc-nv-flash node.)
Fixes #79082