diff options
| author | Richard Weinberger <richard@nod.at> | 2015-10-25 18:54:33 (GMT) |
|---|---|---|
| committer | Richard Weinberger <richard@nod.at> | 2015-11-06 21:49:09 (GMT) |
| commit | 1d80f0cda10118d7505bd0a09a5c1c72f3a5f6c8 (patch) | |
| tree | af1013ab500f852040bfe4ac4f579584e54650ac /arch/um | |
| parent | 44011b897adf4be7a5bd7f2baf2ffec9cd87ec74 (diff) | |
| download | linux-1d80f0cda10118d7505bd0a09a5c1c72f3a5f6c8.tar.xz | |
um: Store syscall number after syscall_trace_enter()
To support changing syscall numbers we have to store
it after syscall_trace_enter().
Signed-off-by: Richard Weinberger <richard@nod.at>
Diffstat (limited to 'arch/um')
| -rw-r--r-- | arch/um/include/shared/os.h | 1 | ||||
| -rw-r--r-- | arch/um/kernel/skas/syscall.c | 13 | ||||
| -rw-r--r-- | arch/um/os-Linux/skas/process.c | 10 |
3 files changed, 11 insertions, 13 deletions
diff --git a/arch/um/include/shared/os.h b/arch/um/include/shared/os.h index ad3fa3a..f3cbaef 100644 --- a/arch/um/include/shared/os.h +++ b/arch/um/include/shared/os.h @@ -274,6 +274,7 @@ extern void initial_thread_cb_skas(void (*proc)(void *), void *arg); extern void halt_skas(void); extern void reboot_skas(void); +extern int get_syscall(struct uml_pt_regs *regs); /* irq.c */ extern int os_waiting_for_events(struct irq_fd *active_fds); diff --git a/arch/um/kernel/skas/syscall.c b/arch/um/kernel/skas/syscall.c index d9ec006..64a8fe5 100644 --- a/arch/um/kernel/skas/syscall.c +++ b/arch/um/kernel/skas/syscall.c @@ -8,6 +8,7 @@ #include <kern_util.h> #include <sysdep/ptrace.h> #include <sysdep/syscalls.h> +#include <os.h> extern int syscall_table_size; #define NR_SYSCALLS (syscall_table_size / sizeof(void *)) @@ -23,16 +24,8 @@ void handle_syscall(struct uml_pt_regs *r) goto out; } - /* - * This should go in the declaration of syscall, but when I do that, - * strace -f -c bash -c 'ls ; ls' breaks, sometimes not tracing - * children at all, sometimes hanging when bash doesn't see the first - * ls exit. - * The assembly looks functionally the same to me. This is - * gcc version 4.0.1 20050727 (Red Hat 4.0.1-5) - * in case it's a compiler bug. - */ - syscall = UPT_SYSCALL_NR(r); + syscall = get_syscall(r); + if ((syscall >= NR_SYSCALLS) || (syscall < 0)) result = -ENOSYS; else result = EXECUTE_SYSCALL(syscall, regs); diff --git a/arch/um/os-Linux/skas/process.c b/arch/um/os-Linux/skas/process.c index 3dddedb..d38f495 100644 --- a/arch/um/os-Linux/skas/process.c +++ b/arch/um/os-Linux/skas/process.c @@ -137,9 +137,6 @@ static void handle_trap(int pid, struct uml_pt_regs *regs, if ((UPT_IP(regs) >= STUB_START) && (UPT_IP(regs) < STUB_END)) fatal_sigsegv(); - /* Mark this as a syscall */ - UPT_SYSCALL_NR(regs) = PT_SYSCALL_NR(regs->gp); - if (!local_using_sysemu) { err = ptrace(PTRACE_POKEUSER, pid, PT_SYSCALL_NR_OFFSET, @@ -174,6 +171,13 @@ static void handle_trap(int pid, struct uml_pt_regs *regs, handle_syscall(regs); } +int get_syscall(struct uml_pt_regs *regs) +{ + UPT_SYSCALL_NR(regs) = PT_SYSCALL_NR(regs->gp); + + return UPT_SYSCALL_NR(regs); +} + extern char __syscall_stub_start[]; static int userspace_tramp(void *stack) |