kernel/linux.git/fs/proc/kcore.c, branch v6.12.80

fs/proc/kcore.c: Clear ret value in read_kcore_iter after successful iov_iter_zero

2024-12-09T09:41:07+00:00

commit 088f294609d8f8816dc316681aef2eb61982e0da upstream. If iov_iter_zero succeeds after failed copy_from_kernel_nofault, we need to reset the ret value to zero otherwise it will be returned as final return value of read_kcore_iter. This fixes objdump -d dump over /proc/kcore for me. Cc: stable@vger.kernel.org Cc: Alexander Gordeev Fixes: 3d5854d75e31 ("fs/proc/kcore.c: allow translation of physical memory addresses") Signed-off-by: Jiri Olsa Link: https://lore.kernel.org/r/20241121231118.3212000-1-jolsa@kernel.org Acked-by: Alexander Gordeev Signed-off-by: Christian Brauner Signed-off-by: Greg Kroah-Hartman

fs/proc/kcore.c: fix coccinelle reported ERROR instances

2024-12-05T13:02:10+00:00

[ Upstream commit 82e33f249f1126cf3c5f39a31b850d485ac33bc3 ] Coccinelle complains about the nested reuse of the pointer `iter' with different pointer type: ./fs/proc/kcore.c:515:26-30: ERROR: invalid reference to the index variable of the iterator on line 499 ./fs/proc/kcore.c:534:23-27: ERROR: invalid reference to the index variable of the iterator on line 499 ./fs/proc/kcore.c:550:40-44: ERROR: invalid reference to the index variable of the iterator on line 499 ./fs/proc/kcore.c:568:27-31: ERROR: invalid reference to the index variable of the iterator on line 499 ./fs/proc/kcore.c:581:28-32: ERROR: invalid reference to the index variable of the iterator on line 499 ./fs/proc/kcore.c:599:27-31: ERROR: invalid reference to the index variable of the iterator on line 499 ./fs/proc/kcore.c:607:38-42: ERROR: invalid reference to the index variable of the iterator on line 499 ./fs/proc/kcore.c:614:26-30: ERROR: invalid reference to the index variable of the iterator on line 499 Replacing `struct kcore_list *iter' with `struct kcore_list *tmp' doesn't change the scope and the functionality is the same and coccinelle seems happy. NOTE: There was an issue with using `struct kcore_list *pos' as the nested iterator. The build did not work! [akpm@linux-foundation.org: s/tmp/pos/] Link: https://lkml.kernel.org/r/20241029054651.86356-2-mtodorovac69@gmail.com Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1] Link: https://lkml.kernel.org/r/20220331223700.902556-1-jakobkoschel@gmail.com Fixes: 04d168c6d42d ("fs/proc/kcore.c: remove check of list iterator against head past the loop body") Signed-off-by: Jakob Koschel Signed-off-by: Mirsad Todorovac Cc: Mike Rapoport Cc: David Hildenbrand Cc: Oscar Salvador Cc: "Brian Johannesmeyer" Cc: Cristiano Giuffrida Cc: "Bos, H.J." Cc: Alexey Dobriyan Cc: Andrew Morton Cc: Yang Li Cc: Baoquan He Cc: Hari Bathini Cc: Yan Zhen Cc: Alexander Gordeev Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin

fs/proc/kcore.c: allow translation of physical memory addresses

2024-10-09T19:47:19+00:00

When /proc/kcore is read an attempt to read the first two pages results in HW-specific page swap on s390 and another (so called prefix) pages are accessed instead. That leads to a wrong read. Allow architecture-specific translation of memory addresses using kc_xlate_dev_mem_ptr() and kc_unxlate_dev_mem_ptr() callbacks similarily to /dev/mem xlate_dev_mem_ptr() and unxlate_dev_mem_ptr() callbacks. That way an architecture can deal with specific physical memory ranges. Re-use the existing /dev/mem callback implementation on s390, which handles the described prefix pages swapping correctly. For other architectures the default callback is basically NOP. It is expected the condition (vaddr == __va(__pa(vaddr))) always holds true for KCORE_RAM memory type. Link: https://lkml.kernel.org/r/20240930122119.1651546-1-agordeev@linux.ibm.com Signed-off-by: Alexander Gordeev Suggested-by: Heiko Carstens Cc: Vasily Gorbik Cc: Signed-off-by: Andrew Morton

proc: Fix typo in the comment

2024-09-09T07:51:16+00:00

The deference here confuses me. Maybe here want to say that because show_fd_locks() does not dereference the files pointer, using the stale value of the files pointer is safe. Correctly spelled comments make it easier for the reader to understand the code. replace 'deferences' with 'dereferences' in the comment & replace 'inialized' with 'initialized' in the comment. Signed-off-by: Yan Zhen Link: https://lore.kernel.org/r/20240909063353.2246419-1-yanzhen@vivo.com Signed-off-by: Christian Brauner

crash: split vmcoreinfo exporting code out from crash_core.c

2024-02-24T01:48:22+00:00

Now move the relevant codes into separate files: kernel/crash_reserve.c, include/linux/crash_reserve.h. And add config item CRASH_RESERVE to control its enabling. And also update the old ifdeffery of CONFIG_CRASH_CORE, including of and config item dependency on CRASH_CORE accordingly. And also do renaming as follows: - arch/xxx/kernel/{crash_core.c => vmcore_info.c} because they are only related to vmcoreinfo exporting on x86, arm64, riscv. And also Remove config item CRASH_CORE, and rely on CONFIG_KEXEC_CORE to decide if build in crash_core.c. [yang.lee@linux.alibaba.com: remove duplicated include in vmcore_info.c] Link: https://lkml.kernel.org/r/20240126005744.16561-1-yang.lee@linux.alibaba.com Link: https://lkml.kernel.org/r/20240124051254.67105-3-bhe@redhat.com Signed-off-by: Baoquan He Signed-off-by: Yang Li Acked-by: Hari Bathini Cc: Al Viro Cc: Eric W. Biederman Cc: Pingfan Liu Cc: Klara Modin Cc: Michael Kelley Cc: Nathan Chancellor Cc: Stephen Rothwell Cc: Yang Li Signed-off-by: Andrew Morton

proc/kcore: do not try to access unaccepted memory

2023-10-04T17:32:22+00:00

Support for unaccepted memory was added recently, refer commit dcdfdd40fa82 ("mm: Add support for unaccepted memory"), whereby a virtual machine may need to accept memory before it can be used. Do not try to access unaccepted memory because it can cause the guest to fail. For /proc/kcore, which is read-only and does not support mmap, this means a read of unaccepted memory will return zeros. Link: https://lkml.kernel.org/r/20230911112114.91323-3-adrian.hunter@intel.com Signed-off-by: Adrian Hunter Reviewed-by: David Hildenbrand Cc: Ard Biesheuvel Cc: Baoquan He Cc: Borislav Petkov (AMD) Cc: Dave Hansen Cc: Dave Young Cc: Kirill A. Shutemov Cc: Lorenzo Stoakes Cc: Mike Rapoport Cc: Tom Lendacky Cc: Vivek Goyal Cc: Vlastimil Babka Signed-off-by: Andrew Morton

fs/proc/kcore: reinstate bounce buffer for KCORE_TEXT regions

2023-08-04T20:03:42+00:00

Some architectures do not populate the entire range categorised by KCORE_TEXT, so we must ensure that the kernel address we read from is valid. Unfortunately there is no solution currently available to do so with a purely iterator solution so reinstate the bounce buffer in this instance so we can use copy_from_kernel_nofault() in order to avoid page faults when regions are unmapped. This change partly reverts commit 2e1c0170771e ("fs/proc/kcore: avoid bounce buffer for ktext data"), reinstating the bounce buffer, but adapts the code to continue to use an iterator. [lstoakes@gmail.com: correct comment to be strictly correct about reasoning] Link: https://lkml.kernel.org/r/525a3f14-74fa-4c22-9fca-9dab4de8a0c3@lucifer.local Link: https://lkml.kernel.org/r/20230731215021.70911-1-lstoakes@gmail.com Fixes: 2e1c0170771e ("fs/proc/kcore: avoid bounce buffer for ktext data") Signed-off-by: Lorenzo Stoakes Reported-by: Jiri Olsa Closes: https://lore.kernel.org/all/ZHc2fm+9daF6cgCE@krava Tested-by: Jiri Olsa Tested-by: Will Deacon Cc: Alexander Viro Cc: Ard Biesheuvel Cc: Baoquan He Cc: Catalin Marinas Cc: David Hildenbrand Cc: Jens Axboe Cc: Kefeng Wang Cc: Liu Shixin Cc: Matthew Wilcox Cc: Mike Galbraith Cc: Thorsten Leemhuis Cc: Uladzislau Rezki (Sony) Cc: Signed-off-by: Andrew Morton

Merge tag 'asm-generic-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic

2023-07-06T17:06:04+00:00

Pull asm-generic updates from Arnd Bergmann: "These are cleanups for architecture specific header files: - the comments in include/linux/syscalls.h have gone out of sync and are really pointless, so these get removed - The asm/bitsperlong.h header no longer needs to be architecture specific on modern compilers, so use a generic version for newer architectures that use new enough userspace compilers - A cleanup for virt_to_pfn/virt_to_bus to have proper type checking, forcing the use of pointers" * tag 'asm-generic-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: syscalls: Remove file path comments from headers tools arch: Remove uapi bitsperlong.h of hexagon and microblaze asm-generic: Unify uapi bitsperlong.h for arm64, riscv and loongarch m68k/mm: Make pfn accessors static inlines arm64: memory: Make virt_to_pfn() a static inline ARM: mm: Make virt_to_pfn() a static inline asm-generic/page.h: Make pfn accessors static inlines xen/netback: Pass (void *) to virt_to_page() netfs: Pass a pointer to virt_to_page() cifs: Pass a pointer to virt_to_page() in cifsglob cifs: Pass a pointer to virt_to_page() riscv: mm: init: Pass a pointer to virt_to_page() ARC: init: Pass a pointer to virt_to_pfn() in init m68k: Pass a pointer to virt_to_pfn() virt_to_page() fs/proc/kcore.c: Pass a pointer to virt_addr_valid()

procfs: replace all non-returning strlcpy with strscpy

2023-06-10T00:44:13+00:00

strlcpy() reads the entire source buffer first. This read may exceed the destination size limit. This is both inefficient and can lead to linear read overflows if a source string is not NUL-terminated [1]. In an effort to remove strlcpy() completely [2], replace strlcpy() here with strscpy(). No return values were used, so direct replacement is safe. [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy [2] https://github.com/KSPP/linux/issues/89 Link: https://lkml.kernel.org/r/20230510212457.3491385-1-azeemshaikh38@gmail.com Signed-off-by: Azeem Shaikh Reviewed-by: Kees Cook Reviewed-by: Alexey Dobriyan Cc: Baoquan He Cc: David Hildenbrand Cc: Kefeng Wang Cc: Liu Shixin Cc: Lorenzo Stoakes Signed-off-by: Andrew Morton

fs/proc/kcore.c: Pass a pointer to virt_addr_valid()

2023-05-29T09:27:07+00:00

The virt_addr_valid() should be passed a pointer, the current code passing a long unsigned int is just exploiting the unintentional polymorphism of these calls being implemented as preprocessor macros. Signed-off-by: Linus Walleij