linux-dev/arch/x86/um/shared, branch master

um: Cleanup syscall_handler_t cast in syscalls_32.h

2022-09-19T19:58:53Z

Like in f4f03f299a56ce4d73c5431e0327b3b6cb55ebb9 "um: Cleanup syscall_handler_t definition/cast, fix warning", remove the cast to to fix the compiler warning. Signed-off-by: Lukas Straub Acked-by: Randy Dunlap # build-tested Signed-off-by: Richard Weinberger

um: include linux/stddef.h for __always_inline

2022-07-17T21:40:09Z

When compiling against musl, their shipped doesn't have __always_inline. So instead explicitly include the kernel uapi header, , which does. This prevents the following build error: In file included from arch/x86/um/shared/sysdep/stub.h:11, from arch/um/kernel/skas/clone.c:14: arch/x86/um/shared/sysdep/stub_64.h:111:23: error: expected ‘;’ before ‘void’ 111 | static __always_inline void *get_stub_page(void) | ^~~~~ | ; make[4]: *** [scripts/Makefile.build:249: arch/um/kernel/skas/clone.o] Error 1 Signed-off-by: Jason A. Donenfeld Signed-off-by: Richard Weinberger

um: Cleanup syscall_handler_t definition/cast, fix warning

2022-03-11T09:48:03Z

The syscall_handler_t type for x86_64 was defined as 'long (*)(void)', but always cast to 'long (*)(long, long, long, long, long, long)' before use. This now triggers a warning (see below). Define syscall_handler_t as the latter instead, and remove the cast. This simplifies the code, and fixes the warning. Warning: In file included from ../arch/um/include/asm/processor-generic.h:13 from ../arch/x86/um/asm/processor.h:41 from ../include/linux/rcupdate.h:30 from ../include/linux/rculist.h:11 from ../include/linux/pid.h:5 from ../include/linux/sched.h:14 from ../include/linux/ptrace.h:6 from ../arch/um/kernel/skas/syscall.c:7: ../arch/um/kernel/skas/syscall.c: In function ‘handle_syscall’: ../arch/x86/um/shared/sysdep/syscalls_64.h:18:11: warning: cast between incompatible function types from ‘long int (*)(void)’ to ‘long int (*)(long int, long int, long int, long int, long int, long int)’ [ -Wcast-function-type] 18 | (((long (*)(long, long, long, long, long, long)) \ | ^ ../arch/x86/um/asm/ptrace.h:36:62: note: in definition of macro ‘PT_REGS_SET_SYSCALL_RETURN’ 36 | #define PT_REGS_SET_SYSCALL_RETURN(r, res) (PT_REGS_AX(r) = (res)) | ^~~ ../arch/um/kernel/skas/syscall.c:46:33: note: in expansion of macro ‘EXECUTE_SYSCALL’ 46 | EXECUTE_SYSCALL(syscall, regs)); | ^~~~~~~~~~~~~~~ Signed-off-by: David Gow Signed-off-by: Richard Weinberger

um: move amd64 variant of mmap(2) to arch/x86/um/syscalls_64.c

2021-12-21T20:30:44Z

Signed-off-by: Al Viro Signed-off-by: Richard Weinberger

um: fix stub location calculation

2021-08-26T20:28:03Z

In commit 9f0b4807a44f ("um: rework userspace stubs to not hard-code stub location") I changed stub_segv_handler() to do a calculation with a pointer to a stack variable to find the data page that we're using for the stack and the rest of the data. This same commit was meant to do it as well for stub_clone_handler(), but the change inadvertently went into commit 84b2789d6115 ("um: separate child and parent errors in clone stub") instead. This was reported to not be compiled correctly by gcc 5, causing the code to crash here. I'm not sure why, perhaps it's UB because the var isn't initialized? In any case, this trick always seemed bad, so just create a new inline function that does the calculation in assembly. Reported-by: subashab@codeaurora.org Fixes: 9f0b4807a44f ("um: rework userspace stubs to not hard-code stub location") Fixes: 84b2789d6115 ("um: separate child and parent errors in clone stub") Signed-off-by: Johannes Berg Signed-off-by: Richard Weinberger

um: Fix tag order in stub_32.h

2021-04-15T21:06:37Z

"static void inline" is the wrong way around, fix that. Reported-by: kernel test robot Fixes: 9f0b4807a44f ("um: rework userspace stubs to not hard-code stub location") Signed-off-by: Johannes Berg Signed-off-by: Richard Weinberger

um: rework userspace stubs to not hard-code stub location

2021-02-12T20:35:02Z

The userspace stacks mostly have a stack (and in the case of the syscall stub we can just set their stack pointer) that points to the location of the stub data page already. Rework the stubs to use the stack pointer to derive the start of the data page, rather than requiring it to be hard-coded. In the clone stub, also integrate the int3 into the stack remap, since we really must not use the stack while we remap it. This prepares for putting the stub at a variable location that's not part of the normal address space of the userspace processes running inside the UML machine. Signed-off-by: Johannes Berg Signed-off-by: Richard Weinberger

um: separate child and parent errors in clone stub

2021-02-12T20:34:33Z

If the two are mixed up, then it looks as though the parent returned an error if the child failed (before) the mmap(), and then the resulting process never gets killed. Fix this by splitting the child and parent errors, reporting and using them appropriately. Signed-off-by: Johannes Berg Signed-off-by: Richard Weinberger

um: Remove update_debugregs()

2018-10-29T21:23:11Z

This function is nowhere used, let's get rid of it. Signed-off-by: Richard Weinberger

um: Drop own definition of PTRACE_SYSEMU/_SINGLESTEP

2018-10-29T21:23:10Z

32bit UML used to define PTRACE_SYSEMU and PTRACE_SYSEMU_SINGLESTEP own its own because many years ago not all libcs had these request codes in their UAPI. These days PTRACE_SYSEMU/_SINGLESTEP is well known and part of glibc and our own define becomes problematic. With change c48831d0eebf ("linux/x86: sync sys/ptrace.h with Linux 4.14 [BZ #22433]") glibc turned PTRACE_SYSEMU/_SINGLESTEP into a enum and UML failed to build. Let's drop our define and rely on the fact that every libc has PTRACE_SYSEMU/_SINGLESTEP. Cc: Cc: Ritesh Raj Sarraf Reported-and-tested-by: Ritesh Raj Sarraf Signed-off-by: Richard Weinberger