linux/arch/microblaze
Jamie Garside c2219eda54 microblaze: Fix syscall error recovery for invalid syscall IDs
This patch fixes two bugs in the Microblaze syscall trap handler when an invalid
syscall ID is used.

First, the range check on line 351 only checks for syscall IDs greater than
__NR_syscalls. A negative syscall ID (either passed to `syscall()` or as returned
by `do_syscall_trace_enter()` on error) will still satisfy this test and cause
the Linux kernel to access an invalid memory location and cause a kernel oops.
This has been fixed by also checking for r12 < 0.

Secondly, the current error recovery at line 378 returns using the wrong register
(r15 instead of r14) and does not restore the previous stack state. This has been
fixed by invoking `ret_from_trap` on error, setting r3 to `-ENOSYS`, similar to
what would happen when calling a valid syscall.

Signed-off-by: Jamie Garside <jamie.garside@york.ac.uk>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
2015-03-04 15:12:27 +01:00
..
boot
configs
include all arches, signal: move restart_block to struct task_struct 2015-02-12 18:54:12 -08:00
kernel microblaze: Fix syscall error recovery for invalid syscall IDs 2015-03-04 15:12:27 +01:00
lib
mm
oprofile
pci
Kconfig
Kconfig.debug
Kconfig.platform
Makefile