Messages in this thread Patch in this message |  | | | Date | Tue, 29 Aug 2006 03:22:09 +0100 | | From | Ralf Baechle <> | | Subject | Re: [PATCH 3/7] provide kernel_execve on all architectures |
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On Sun, Aug 27, 2006 at 11:47:37PM +0200, Arnd Bergmann wrote:
> This adds the new kernel_execve function on all architectures > that were using _syscall3() to implement execve. > > The implementation uses code from the _syscall3 macros provided > in the unistd.h header file. I don't have cross-compilers for > any of these architectures, so the patch is untested with the > exception of i386. > > Most architectures can probably implement this in a nicer way > in assembly or by combining it with the sys_execve implementation > itself, but this should do it for now. > > Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Two bugs in your MIPS version of kernel_execve(); the inline asm which was copying from _syscall3 macro was still using the #stringify operation. It also didn't get the result return in case of errors right - $a3 = 1 indicates an error in which case $v0 will contain the positive error number.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/kernel/syscall.c b/arch/mips/kernel/syscall.c index 0721314..b73b26c 100644 --- a/arch/mips/kernel/syscall.c +++ b/arch/mips/kernel/syscall.c @@ -399,3 +399,32 @@ asmlinkage void bad_stack(void) { do_exit(SIGSEGV); } + +/* + * Do a system call from kernel instead of calling sys_execve so we + * end up with proper pt_regs. + */ +int kernel_execve(const char *filename, char *const argv[], char *const envp[]) +{ + register unsigned long __a0 asm("$4") = (unsigned long) filename; + register unsigned long __a1 asm("$5") = (unsigned long) argv; + register unsigned long __a2 asm("$6") = (unsigned long) envp; + register unsigned long __a3 asm("$7"); + unsigned long __v0; + + __asm__ volatile (" \n" + " .set noreorder \n" + " li $2, %5 # __NR_execve \n" + " syscall \n" + " move %0, $2 \n" + " .set reorder \n" + : "=&r" (__v0), "=r" (__a3) + : "r" (__a0), "r" (__a1), "r" (__a2), "i" (__NR_execve) + : "$2", "$8", "$9", "$10", "$11", "$12", "$13", "$14", "$15", "$24", + "memory"); + + if (__a3 == 0) + return __v0; + + return -__v0; +} - 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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