linux/scripts/mod, branch v5.0

x86, modpost: Replace last remnants of RETPOLINE with CONFIG_RETPOLINE

2019-01-09T09:35:56Z

Commit 4cd24de3a098 ("x86/retpoline: Make CONFIG_RETPOLINE depend on compiler support") replaced the RETPOLINE define with CONFIG_RETPOLINE checks. Remove the remaining pieces. [ bp: Massage commit message. ] Fixes: 4cd24de3a098 ("x86/retpoline: Make CONFIG_RETPOLINE depend on compiler support") Signed-off-by: WANG Chao Signed-off-by: Borislav Petkov Reviewed-by: Zhenzhong Duan Reviewed-by: Masahiro Yamada Cc: "H. Peter Anvin" Cc: Andi Kleen Cc: Andrew Morton Cc: Andy Lutomirski Cc: Arnd Bergmann Cc: Daniel Borkmann Cc: David Woodhouse Cc: Geert Uytterhoeven Cc: Jessica Yu Cc: Jiri Kosina Cc: Kees Cook Cc: Konrad Rzeszutek Wilk Cc: Luc Van Oostenryck Cc: Michal Marek Cc: Miguel Ojeda Cc: Peter Zijlstra Cc: Tim Chen Cc: Vasily Gorbik Cc: linux-kbuild@vger.kernel.org Cc: srinivas.eeda@oracle.com Cc: stable Cc: x86-ml Link: https://lkml.kernel.org/r/20181210163725.95977-1-chao.wang@ucloud.cn

kbuild: move modpost out of 'scripts' target

2018-12-01T14:09:34Z

I am eagar to build under the scripts/ directory only with $(HOSTCC), but scripts/mod/ highly depends on the $(CC) and target arch headers. That it why the 'scripts' target must depend on 'asm-generic', 'gcc-plugins', and $(autoksyms_h). Move it to the 'prepare0' stage. I know this is a cheesy workaround, but better than the current situation. Signed-off-by: Masahiro Yamada

modpost: move unresolved symbol checks to check_exports()

2018-12-01T13:21:59Z

This will fit better in check_exports() than add_versions(). Signed-off-by: Masahiro Yamada

modpost: merge module iterations

2018-12-01T13:21:58Z

Probably, this is just a matter of the order of error/warning messages. Merge the two for-loops. Signed-off-by: Masahiro Yamada

modpost: refactor seen flag clearing in add_depends()

2018-12-01T13:21:58Z

You do not need to iterate over all modules for resetting ->seen flag because add_depends() is only interested in modules that export symbols referenced from the given 'mod'. This also avoids shadowing the 'modules' parameter of add_depends(). Signed-off-by: Masahiro Yamada

modpost: file2alias: check prototype of handler

2018-12-01T13:21:58Z

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

modpost: file2alias: go back to simple devtable lookup

2018-12-01T13:21:57Z

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

modpost: skip ELF local symbols during section mismatch check

2018-12-01T13:21:56Z

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

modpost: drop unused command line switches

2018-11-21T14:57:33Z

Drop modpost command line switches that are no longer used by makefile.modpost, upon request from Sam Ravnborg , who wrote: modpost is not supposed to be used outside the kernel build. [...] I checked if there were any options supported by modpost that was not configurable in Makefile.modpost. And I could see that the -M and -K options in getopt() were leftovers. The code that used these option was dropped in: commit a8773769d1a1 ("Kbuild: clear marker out of modpost") Could you add a patch that delete these on top of what you already have. https://lore.kernel.org/lkml/20181020140835.GA3351@ravnborg.org/ Suggested-by: Sam Ravnborg Signed-off-by: Paul Walmsley Signed-off-by: Paul Walmsley Acked-by: Sam Ravnborg Signed-off-by: Masahiro Yamada

modpost: validate symbol names also in find_elf_symbol

2018-11-21T14:57:32Z

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