Am Sonntag, den 22.05.2016, 17:39 +0200 schrieb Vegard Nossum: > On 21 May 2016 at 20:18, Thomas Meyer <tho...@m3y3r.de> wrote: > > > > Am 21.05.2016 um 15:51 schrieb Vegard Nossum <vegard.nossum@gmail.c > > om>: > > > > > > I'm having some trouble with using current_thread_info() during > > > UML > > > early boot. Sometimes it works just fine, but often I get > > > segfaults > > > because current_thread_info() is returning an invalid pointer. It > > > looks random: 0x202118, 0x1003e0003, 0xd33b90b3, 0x6db043, etc. > > Mhh. Strange. Do you have a stack trace to call to current thread > > info which ends up with a wrong value. I wonder from were it > > originates. > One such trace would be: > > #2 0x000000006026652c in snprintf (buf=<optimized out>, > size=<optimized out>, fmt=<optimized out>) at lib/vsprintf.c:2181 > #3 0x00000000600046f8 in setup_env_path () at arch/um/os- > Linux/main.c:109 > #4 main (argc=3, argv=0x7ffc3d8c23e8, envp=<optimized out>) at > arch/um/os-Linux/main.c:125 > > I wonder why setup_env_path() ends up calling the kernel's > snprintf(), > I thought that it would be using the glibc snprintf() at this point?
Mhh. Good question! Doing a make ARCH=um V=1 arch/um/os-Linux/main.o results in: gcc -Wp,-MD,arch/um/os-Linux/.main.o.d -Wall -Wundef -Wstrict- prototypes -Wno-trigraphs -fno-strict-aliasing -fno-common -Werror- implicit-function-declaration -Wno-format-security -std=gnu89 -mcmodel=large -fno-builtin -m64 -funit-at-a-time -D__arch_um__ -Dvmap=kernel_vmap -Din6addr_loopback=kernel_in6addr_loopback -Din6addr_any=kernel_in6addr_any -Dstrrchr=kernel_strrchr -D_LARGEFILE64_SOURCE -fno-delete-null-pointer-checks -O2 -- param=allow-store-data-races=0 -fno-reorder-blocks -fno-ipa-cp-clone -fno-partial-inlining -Wframe-larger-than=1024 -fno-stack-protector -Wno-unused-but-set-variable -fno-omit-frame-pointer -fno-optimize- sibling-calls -fno-var-tracking-assignments -g -gdwarf-4 -Wdeclaration- after-statement -Wno-pointer-sign -fno-strict-overflow -fconserve-stack -Werror=implicit-int -Werror=strict-prototypes -Werror=date-time -Werror=incompatible-pointer-types -DCC_HAVE_ASM_GOTO -I./arch/um/include/shared -I./arch/x86/um/shared -I./arch/um/include/shared/skas -D_FILE_OFFSET_BITS=64 -idirafter ./include -idirafter ./include -D__KERNEL__ -D__UM_HOST__ -D_GNU_SOURCE -D_LARGEFILE64_SOURCE -include ./include/linux/kern_levels.h -include user.h -c -o arch/um/os-Linux/main.o arch/um/os-Linux/main.c so it includes user.h and is under os-Linux. So I guess it should actually call the glibc version, I'm not sure why it doesn't. with kind regards thomas > > > Vegard > ------------------------------------------------------------------------------ Mobile security can be enabling, not merely restricting. Employees who bring their own devices (BYOD) to work are irked by the imposition of MDM restrictions. Mobile Device Manager Plus allows you to control only the apps on BYO-devices by containerizing them, leaving personal data untouched! https://ad.doubleclick.net/ddm/clk/304595813;131938128;j _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel
