| Message ID | 20210804002148.96Sth%akpm@linux-foundation.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | + lib-use-pfn_phys-in-devmem_is_allowed.patch added to -mm tree | expand |
--- a/lib/devmem_is_allowed.c~lib-use-pfn_phys-in-devmem_is_allowed +++ a/lib/devmem_is_allowed.c @@ -19,7 +19,7 @@ */ int devmem_is_allowed(unsigned long pfn) { - if (iomem_is_exclusive(pfn << PAGE_SHIFT)) + if (iomem_is_exclusive(PFN_PHYS(pfn))) return 0; if (!page_is_ram(pfn)) return 1;
The patch titled Subject: lib: use PFN_PHYS() in devmem_is_allowed() has been added to the -mm tree. Its filename is lib-use-pfn_phys-in-devmem_is_allowed.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/lib-use-pfn_phys-in-devmem_is_allowed.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/lib-use-pfn_phys-in-devmem_is_allowed.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Liang Wang <wangliang101@huawei.com> Subject: lib: use PFN_PHYS() in devmem_is_allowed() The physical address may exceed 32 bits on 32-bit systems with more than 32 bits of physcial address,use PFN_PHYS() in devmem_is_allowed(), or the physical address may overflow and be truncated. We found this bug when mapping a high addresses through devmem tool, when CONFIG_STRICT_DEVMEM is enabled on the ARM with ARM_LPAE and devmem is used to map a high address that is not in the iomem address range, an unexpected error indicating no permission is returned. This bug was initially introduced from v2.6.37, and the function was moved to lib when v5.11. Link: https://lkml.kernel.org/r/20210731025057.78825-1-wangliang101@huawei.com Fixes: 087aaffcdf9c ("ARM: implement CONFIG_STRICT_DEVMEM by disabling access to RAM via /dev/mem") Fixes: 527701eda5f1 ("lib: Add a generic version of devmem_is_allowed()") Signed-off-by: Liang Wang <wangliang101@huawei.com> Cc: Palmer Dabbelt <palmerdabbelt@google.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Liang Wang <wangliang101@huawei.com> Cc: Xiaoming Ni <nixiaoming@huawei.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: <stable@vger.kernel.org> [2.6.37+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> --- lib/devmem_is_allowed.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)