user/sven/linux.git/scripts/mod, branch v4.4.283

modpost: skip ELF local symbols during section mismatch check

2019-12-21T09:34:42Z

[ Upstream commit a4d26f1a0958bb1c2b60c6f1e67c6f5d43e2647b ] During development of a serial console driver with a gcc 8.2.0 toolchain for RISC-V, the following modpost warning appeared: ---- WARNING: vmlinux.o(.data+0x19b10): Section mismatch in reference from the variable .LANCHOR1 to the function .init.text:sifive_serial_console_setup() The variable .LANCHOR1 references the function __init sifive_serial_console_setup() If the reference is valid then annotate the variable with __init* or __refdata (see linux/init.h) or name the variable: *_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console ---- ".LANCHOR1" is an ELF local symbol, automatically created by gcc's section anchor generation code: https://gcc.gnu.org/onlinedocs/gccint/Anchored-Addresses.html https://gcc.gnu.org/git/?p=gcc.git;a=blob;f=gcc/varasm.c;h=cd9591a45617464946dcf9a126dde277d9de9804;hb=9fb89fa845c1b2e0a18d85ada0b077c84508ab78#l7473 This was verified by compiling the kernel with -fno-section-anchors and observing that the ".LANCHOR1" ELF local symbol disappeared, and modpost no longer warned about the section mismatch. The serial driver code idiom triggering the warning is standard Linux serial driver practice that has a specific whitelist inclusion in modpost.c. I'm neither a modpost nor an ELF expert, but naively, it doesn't seem useful for modpost to report section mismatch warnings caused by ELF local symbols by default. Local symbols have compiler-generated names, and thus bypass modpost's whitelisting algorithm, which relies on the presence of a non-autogenerated symbol name. This increases the likelihood that false positive warnings will be generated (as in the above case). Thus, disable section mismatch reporting on ELF local symbols. The rationale here is similar to that of commit 2e3a10a1551d ("ARM: avoid ARM binutils leaking ELF local symbols") and of similar code already present in modpost.c: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/scripts/mod/modpost.c?h=v4.19-rc4&id=7876320f88802b22d4e2daf7eb027dd14175a0f8#n1256 This third version of the patch implements a suggestion from Masahiro Yamada to restructure the code as an additional pattern matching step inside secref_whitelist(), and further improves the patch description. Signed-off-by: Paul Walmsley Signed-off-by: Paul Walmsley Acked-by: Sam Ravnborg Signed-off-by: Masahiro Yamada Signed-off-by: Sasha Levin

modpost: file2alias: check prototype of handler

2019-04-27T07:34:00Z

commit f880eea68fe593342fa6e09be9bb661f3c297aec upstream. Use specific prototype instead of an opaque pointer so that the compiler can catch function prototype mismatch. Signed-off-by: Masahiro Yamada Reviewed-by: Mathieu Malaterre Signed-off-by: Nathan Chancellor Signed-off-by: Sasha Levin

modpost: file2alias: go back to simple devtable lookup

2019-04-27T07:34:00Z

commit ec91e78d378cc5d4b43805a1227d8e04e5dfa17d upstream. Commit e49ce14150c6 ("modpost: use linker section to generate table.") was not so cool as we had expected first; it ended up with ugly section hacks when commit dd2a3acaecd7 ("mod/file2alias: make modpost compile on darwin again") came in. Given a certain degree of unknowledge about the link stage of host programs, I really want to see simple, stupid table lookup so that this works in the same way regardless of the underlying executable format. Signed-off-by: Masahiro Yamada Acked-by: Mathieu Malaterre [nc: Omit rpmsg, sdw, fslmc, tbsvc, and typec as they don't exist here Add of to avoid backporting two larger patches] Signed-off-by: Nathan Chancellor Signed-off-by: Sasha Levin

modpost: validate symbol names also in find_elf_symbol

2019-02-20T09:13:05Z

[ Upstream commit 5818c683a619c534c113e1f66d24f636defc29bc ] If an ARM mapping symbol shares an address with a valid symbol, find_elf_symbol can currently return the mapping symbol instead, as the symbol is not validated. This can result in confusing warnings: WARNING: vmlinux.o(.text+0x18f4028): Section mismatch in reference from the function set_reset_devices() to the variable .init.text:$x.0 This change adds a call to is_valid_name to find_elf_symbol, similarly to how it's already used in find_elf_symbol2. Signed-off-by: Sami Tolvanen Signed-off-by: Masahiro Yamada Signed-off-by: Sasha Levin

kbuild: Consolidate header generation from ASM offset information

2018-11-27T15:07:57Z

commit ebf003f0cfb3705e60d40dedc3ec949176c741af upstream. Largely redundant code is used in different places to generate C headers from offset information extracted from assembly language output. Consolidate the code in Makefile.lib and use this instead. Signed-off-by: Matthias Kaehlcke Signed-off-by: Masahiro Yamada Signed-off-by: Nathan Chancellor Signed-off-by: Greg Kroah-Hartman

scripts: modpost: check memory allocation results

2018-09-15T07:40:38Z

[ Upstream commit 1f3aa9002dc6a0d59a4b599b4fc8f01cf43ef014 ] Fix missing error check for memory allocation functions in scripts/mod/modpost.c. Fixes kernel bugzilla #200319: https://bugzilla.kernel.org/show_bug.cgi?id=200319 Signed-off-by: Randy Dunlap Cc: Yuexing Wang Signed-off-by: Masahiro Yamada Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

module/retpoline: Warn about missing retpoline in module

2018-02-25T10:03:52Z

(cherry picked from commit caf7501a1b4ec964190f31f9c3f163de252273b8) There's a risk that a kernel which has full retpoline mitigations becomes vulnerable when a module gets loaded that hasn't been compiled with the right compiler or the right option. To enable detection of that mismatch at module load time, add a module info string "retpoline" at build time when the module was compiled with retpoline support. This only covers compiled C source, but assembler source or prebuilt object files are not checked. If a retpoline enabled kernel detects a non retpoline protected module at load time, print a warning and report it in the sysfs vulnerability file. [ tglx: Massaged changelog ] Signed-off-by: Andi Kleen Signed-off-by: Thomas Gleixner Cc: David Woodhouse Cc: gregkh@linuxfoundation.org Cc: torvalds@linux-foundation.org Cc: jeyu@kernel.org Cc: arjan@linux.intel.com Link: https://lkml.kernel.org/r/20180125235028.31211-1-andi@firstfloor.org Signed-off-by: David Woodhouse [jwang: port to 4.4] Signed-off-by: Jack Wang Signed-off-by: Greg Kroah-Hartman

powerpc: Simplify module TOC handling

2018-02-16T19:09:34Z

commit c153693d7eb9eeb28478aa2deaaf0b4e7b5ff5e9 upstream. PowerPC64 uses the symbol .TOC. much as other targets use _GLOBAL_OFFSET_TABLE_. It identifies the value of the GOT pointer (or in powerpc parlance, the TOC pointer). Global offset tables are generally local to an executable or shared library, or in the kernel, module. Thus it does not make sense for a module to resolve a relocation against .TOC. to the kernel's .TOC. value. A module has its own .TOC., and indeed the powerpc64 module relocation processing ignores the kernel value of .TOC. and instead calculates a module-local value. This patch removes code involved in exporting the kernel .TOC., tweaks modpost to ignore an undefined .TOC., and the module loader to twiddle the section symbol so that .TOC. isn't seen as undefined. Note that if the kernel was compiled with -msingle-pic-base then ELFv2 would not have function global entry code setting up r2. In that case the module call stubs would need to be modified to set up r2 using the kernel .TOC. value, requiring some of this code to be reinstated. mpe: Furthermore a change in binutils master (not yet released) causes the current way we handle the TOC to no longer work when building with MODVERSIONS=y and RELOCATABLE=n. The symptom is that modules can not be loaded due to there being no version found for TOC. Signed-off-by: Alan Modra Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman

of: fix autoloading due to broken modalias with no 'compatible'

2016-07-27T16:47:28Z

commit b3c0a4dab7e35a9b6d69c0415641d2280fdefb2b upstream. Because of an improper dereference, a stray 'C' character was output to the modalias when no 'compatible' was specified. This is the case for some old PowerMac drivers which only set the 'name' property. Fix it to let them match again. Reported-by: Mathieu Malaterre Signed-off-by: Wolfram Sang Tested-by: Mathieu Malaterre Cc: Philipp Zabel Cc: Andreas Schwab Fixes: 6543becf26fff6 ("mod/file2alias: make modalias generation safe for cross compiling") Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman

Merge tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

2015-11-09T23:53:39Z

Pull module updates from Rusty Russell: "Nothing exciting, minor tweaks and cleanups" * tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: scripts: [modpost] add new sections to white list modpost: Add flag -E for making section mismatches fatal params: don't ignore the rest of cmdline if parse_one() fails modpost: abort if a module symbol is too long