From 7e61560628d17ea6b1d8ee370f6d42694cff8758 Mon Sep 17 00:00:00 2001 From: Ulises Mendez Martinez Date: Fri, 4 Sep 2026 15:07:09 +0000 Subject: objtool: Validate disassembler headers in libopcodes probe commit 3f2de814c059 ("objtool: Fix libopcodes linking with static libraries") tested for libopcodes availability by linking a test snippet with a forward declaration of disassemble_init_for_target(). However, testing symbol linkage with an extern declaration only verifies the presence of the library (.so/.a) and bypasses checking for development headers (binutils-dev). On systems where libopcodes is present without development headers installed, the probe succeeds, enabling BUILD_DISAS. Subsequent compilation of objtool then fails: fatal error: 'bfd.h' file not found 113 | #include Additionally, the probe invokes $(HOSTCC) without $(HOSTCFLAGS), ignoring any sysroot or include flags specified for the host compiler. Fix this by including and directly in the test snippet, passing $(HOSTCFLAGS) so host compiler options are respected, and defining PACKAGE="objtool" to satisfy the configuration check in . Fixes: 3f2de814c059 ("objtool: Fix libopcodes linking with static libraries") Fixes: 436326bc525d ("objtool: fix build failure due to missing libopcodes check") Reported-by: Alice Ryhl Assisted-by: Antigravity:Gemini-Next Signed-off-by: Ulises Mendez Martinez Link: https://patch.msgid.link/20260904150710.2997558-1-umendez@google.com Signed-off-by: Josh Poimboeuf --- Documentation/admin-guide/device-mapper/dm-ebs.rst | 51 ++++++++++++++++++++++ 1 file changed, 51 insertions(+) create mode 100644 Documentation/admin-guide/device-mapper/dm-ebs.rst (limited to 'Documentation/admin-guide/device-mapper/dm-ebs.rst') diff --git a/Documentation/admin-guide/device-mapper/dm-ebs.rst b/Documentation/admin-guide/device-mapper/dm-ebs.rst new file mode 100644 index 000000000..c09f66db5 --- /dev/null +++ b/Documentation/admin-guide/device-mapper/dm-ebs.rst @@ -0,0 +1,51 @@ +====== +dm-ebs +====== + + +This target is similar to the linear target except that it emulates +a smaller logical block size on a device with a larger logical block +size. Its main purpose is to provide emulation of 512 byte sectors on +devices that do not provide this emulation (i.e. 4K native disks). + +Supported emulated logical block sizes 512, 1024, 2048 and 4096. + +Underlying block size can be set to > 4K to test buffering larger units. + + +Table parameters +---------------- + [] + +Mandatory parameters: + + : + Full pathname to the underlying block-device, + or a "major:minor" device-number. + : + Starting sector within the device; + has to be a multiple of . + : + Number of sectors defining the logical block size to be emulated; + 1, 2, 4, 8 sectors of 512 bytes supported. + +Optional parameter: + + : + Number of sectors defining the logical block size of . + 2^N supported, e.g. 8 = emulate 8 sectors of 512 bytes = 4KiB. + If not provided, the logical block size of will be used. + + +Examples: + +Emulate 1 sector = 512 bytes logical block size on /dev/sda starting at +offset 1024 sectors with underlying devices block size automatically set: + +ebs /dev/sda 1024 1 + +Emulate 2 sector = 1KiB logical block size on /dev/sda starting at +offset 128 sectors, enforce 2KiB underlying device block size. +This presumes 2KiB logical blocksize on /dev/sda or less to work: + +ebs /dev/sda 128 2 4 -- cgit v1.3.1