fs/vfs: allow NULL iov_base in KERNEL build with zero-based text#18830
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ldube wants to merge 1 commit intoapache:masterfrom
Open
fs/vfs: allow NULL iov_base in KERNEL build with zero-based text#18830ldube wants to merge 1 commit intoapache:masterfrom
ldube wants to merge 1 commit intoapache:masterfrom
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This commit fixes a regression introduced by 89df084. That commit added a check to ensure iov_base is not NULL, assuming NULL always represents an inaccessible address. However, in CONFIG_BUILD_KERNEL mode where CONFIG_ARCH_TEXT_VBASE is set to 0, address zero is a valid virtual address for the user-space text segment. The previous check caused libelf to fail with -EFAULT when attempting to load ELF program headers into the base of the user address space. This patch wraps the safety check in a conditional to ensure it is only executed when address zero is not considered a valid executable base. Signed-off-by: Lwazi Dube <lwazeh@gmail.com>
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Summary
This commit fixes a regression introduced by
89df084. That commit added a check to ensure iov_base is not NULL, assuming NULL always represents an inaccessible address.
However, in CONFIG_BUILD_KERNEL mode where CONFIG_ARCH_TEXT_VBASE is set to 0, address zero is a valid virtual address for the user-space text segment. The previous check caused libelf to fail with -EFAULT when attempting to load ELF program headers into the base of the user address space.
This patch wraps the safety check in a conditional to ensure it is only executed when address zero is not considered a valid executable base.
Impact
Make kernel builds work on armv7a again
Testing
Successfully reached the NuttShell prompt
NuttShell (NSH) NuttX-12.13.0
knsh> /bin/hello
Hello, World!!
knsh>
Without this change this change the machine does not run NuttShell.
[ 0.000000] libelf_loadfile: Loading sections - text: 0.b530 data: 0x80101000.7a8
[ 0.000000] libelf_read: ERROR: Read from offset 56 failed: 14
[ 0.010000] libelf_loadfile: ERROR: Failed to read section 1: -14
[ 0.020000] libelf_load_with_addrenv: ERROR: libelf_loadfile failed: -14
[ 0.020000] elf_loadbinary: Failed to load ELF program binary: -14
[ 0.030000] exec_internal: ERROR: Failed to load program '/bin/init': -14