kernel.git/arch/um/include/os.h, branch linux-2.6.19.y

[PATCH] uml: make execvp safe for our usage

2006-11-25T21:28:34Z

Reimplement execvp for our purposes - after we call fork() it is fundamentally unsafe to use the kernel allocator - current is not valid there. So we simply pass to our modified execvp() a preallocated buffer. This fixes a real bug and works very well in testing (I've seen indirectly warning messages from the forked thread - they went on the pipe connected to its stdout and where read as a number by UML, when calling read_output(). I verified the obtained number corresponded to "BUG:"). The added use of __cant_sleep() is not a new bug since __cant_sleep() is already used in the same function - passing an atomicity parameter would be better but it would require huge change, stating that this function must not be called in atomic context and can sleep is a better idea (will make sure of this gradually). Signed-off-by: Paolo 'Blaisorblade' Giarrusso Acked-by: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] uml: readd forgot prototype

2006-10-11T18:14:20Z

This was forgot in a previous patch so UML does not compile with TT mode enabled. Signed-off-by: Paolo 'Blaisorblade' Giarrusso Cc: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] uml: thread creation tidying

2006-09-27T15:26:16Z

fork on UML has always somewhat subtle. The underlying cause has been the need to initialize a stack for the new process. The only portable way to initialize a new stack is to set it as the alternate signal stack and take a signal. The signal handler does whatever initialization is needed and jumps back to the original stack, where the fork processing is finished. The basic context switching mechanism is a jmp_buf for each process. You switch to a new process by longjmping to its jmp_buf. Now that UML has its own implementation of setjmp and longjmp, and I can poke around inside a jmp_buf without fear that libc will change the structure, a much simpler mechanism is possible. The jmpbuf can simply be initialized by hand. This eliminates - the need to set up and remove the alternate signal stack sending and handling a signal the signal blocking needed around the stack switching, since there is no stack switching setting up the jmp_buf needed to jump back to the original stack after the new one is set up In addition, since jmp_buf is now defined by UML, and not by libc, it can be embedded in the thread struct. This makes it unnecessary to have it exist on the stack, where it used to be. It also simplifies interfaces, since the switch jmp_buf used to be a void * inside the thread struct, and functions which took it as an argument needed to define a jmp_buf variable and assign it from the void *. Signed-off-by: Jeff Dike Cc: Paolo 'Blaisorblade' Giarrusso Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] uml: mark some tt-mode code

2006-09-27T15:26:16Z

Mark a symbol and file as being tt-mode only. This shrinks the binary slightly when tt mode support is compiled out and makes it easier to identity stuff when tt mode is removed. Signed-off-by: Jeff Dike Cc: Paolo 'Blaisorblade' Giarrusso Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] uml: timer cleanups

2006-09-26T15:49:08Z

set_interval returns an error instead of panicing if setitimer fails. Some of its callers now check the return. enable_timer is largely tt-mode-specific, so it is marked as such, and the only skas-mode caller is made to call set-interval instead. user_time_init was a no-value-added wrapper around set_interval, so it is gone. Since set_interval is now called from kernel code, callers no longer pass ITIMER_* to it. Instead, they pass a flag which is converted into ITIMER_REAL or ITIMER_VIRTUAL. Signed-off-by: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] uml: SIGIO cleanups

2006-09-26T15:49:07Z

- Various cleanups in the sigio code. - Removed explicit zero-initializations of a few structures. - Improved some error messages. - An API change - there was an asymmetry between reactivate_fd calling maybe_sigio_broken, which goes through all the machinery of figuring out if a file descriptor supports SIGIO and applying the workaround to it if not, and deactivate_fd, which just turns off the descriptor. This is changed so that only activate_fd calls maybe_sigio_broken, when the descriptor is first seen. reactivate_fd now calls add_sigio_fd, which is symmetric with ignore_sigio_fd. This removes a recursion which makes a critical section look more critical than it really was, obsoleting a big comment to that effect. This requires keeping track of all descriptors which are getting the SIGIO treatment, not just the ones being polled at any given moment, so that reactivate_fd, through add_sigio_fd, doesn't try to tell the SIGIO thread about descriptors it doesn't care about. Signed-off-by: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] uml: header formatting cleanups

2006-07-15T04:53:52Z

Clean up whitespace and return syntax in os.h. Signed-off-by: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] uml: make some symbols static

2006-07-10T20:24:24Z

A few sigio-related things can be made static. Signed-off-by: Jeff Dike Cc: Paolo 'Blaisorblade' Giarrusso Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] uml: remove os_isatty

2006-07-10T20:24:24Z

os_isatty can be made to disappear by moving maybe_sigio_broken from kernel to user code. This also lets write_sigio_workaround become static. Signed-off-by: Jeff Dike Cc: Paolo 'Blaisorblade' Giarrusso Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] uml: signal initialization cleanup

2006-07-10T20:24:23Z

It turns out that init_new_thread_signals is always called with altstack == 1, so we can eliminate the parameter. Signed-off-by: Jeff Dike Cc: Paolo 'Blaisorblade' Giarrusso Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds