Messages in this thread Patch in this message | | | From | Andi Kleen <> | Subject | Re: [Bugme-new] [Bug 7891] New: vdso page is no longer mapped for | Date | Mon, 29 Jan 2007 04:10:29 +0100 |
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On Saturday 27 January 2007 23:02, Andrew Morton wrote: > On Sat, 27 Jan 2007 15:01:51 -0500 > > "Parag Warudkar" <parag.warudkar@gmail.com> wrote: > > Here is a patch that does what Andrew Morton suggested (plus some more > > as explained below) . > > Patch inline below and also attached in case there is whitespace > > damage. Compile tested on i386 with make defconfig; make. If anyone > > can test on other arches and provide feedback that'd be great. > > Thanks - I can test elf on powerpc. Does anyone remember how to > create a.out executables?
You need an old toolkit, but the historic section of ftp.funet.fi has a few binaries. I also got a tarball of an old a.out SUSE installation somewhere that I can dig out if there is interest.
> Assuming this works, I'm not surew what to do with it. Jam it into > 2.6.20, I guess. The lateness*largeness product is somewhat high though.
I simpler fix might be to just not require the vDSO for signal handling on a.out.
Here's a untested patch.
-Andi
Don't require the vDSO for handling a.out signals
and in other strange binfmts. vDSO is not necessarily mapped there.
Signed-off-by: Andi Kleen <ak@suse.de>
Index: linux/arch/i386/kernel/signal.c =================================================================== --- linux.orig/arch/i386/kernel/signal.c +++ linux/arch/i386/kernel/signal.c @@ -21,6 +21,7 @@ #include <linux/suspend.h> #include <linux/ptrace.h> #include <linux/elf.h> +#include <linux/binfmts.h> #include <asm/processor.h> #include <asm/ucontext.h> #include <asm/uaccess.h> @@ -349,7 +350,10 @@ static int setup_frame(int sig, struct k goto give_sigsegv; } - restorer = (void *)VDSO_SYM(&__kernel_sigreturn); + if (current->binfmt->hasvdso) + restorer = (void *)VDSO_SYM(&__kernel_sigreturn); + else + restorer = (void *)&frame->retcode; if (ka->sa.sa_flags & SA_RESTORER) restorer = ka->sa.sa_restorer; Index: linux/arch/x86_64/ia32/ia32_signal.c =================================================================== --- linux.orig/arch/x86_64/ia32/ia32_signal.c +++ linux/arch/x86_64/ia32/ia32_signal.c @@ -21,6 +21,7 @@ #include <linux/stddef.h> #include <linux/personality.h> #include <linux/compat.h> +#include <linux/binfmts.h> #include <asm/ucontext.h> #include <asm/uaccess.h> #include <asm/i387.h> @@ -449,7 +450,11 @@ int ia32_setup_frame(int sig, struct k_s /* Return stub is in 32bit vsyscall page */ { - void __user *restorer = VSYSCALL32_SIGRETURN; + void __user *restorer; + if (current->binfmt->hasvdso) + restorer = VSYSCALL32_SIGRETURN; + else + restorer = (void *)&frame->retcode; if (ka->sa.sa_flags & SA_RESTORER) restorer = ka->sa.sa_restorer; err |= __put_user(ptr_to_compat(restorer), &frame->pretcode); Index: linux/fs/binfmt_elf.c =================================================================== --- linux.orig/fs/binfmt_elf.c +++ linux/fs/binfmt_elf.c @@ -76,7 +76,8 @@ static struct linux_binfmt elf_format = .load_binary = load_elf_binary, .load_shlib = load_elf_library, .core_dump = elf_core_dump, - .min_coredump = ELF_EXEC_PAGESIZE + .min_coredump = ELF_EXEC_PAGESIZE, + .hasvdso = 1 }; #define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE) Index: linux/include/linux/binfmts.h =================================================================== --- linux.orig/include/linux/binfmts.h +++ linux/include/linux/binfmts.h @@ -59,6 +59,7 @@ struct linux_binfmt { int (*load_shlib)(struct file *); int (*core_dump)(long signr, struct pt_regs * regs, struct file * file); unsigned long min_coredump; /* minimal dump size */ + int hasvdso; }; extern int register_binfmt(struct linux_binfmt *); - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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