From 8009206ae2dec541b55edc488103c6c1ccb1416a Mon Sep 17 00:00:00 2001 From: Tom Tromey Date: Fri, 3 Jan 2014 10:55:52 -0700 Subject: [PATCH] Remove some GDBSERVER checks from linux-ptrace This patch removes some GDBSERVER checks from nat/linux-ptrace.c. Currently the code uses a compile-time check to decide whether some flags should be used. This changes the code to instead let users of the module specify an additional set of flags; and then changes gdb's linux-nat.c to call this function. At some later date, when the back ends are fully merged, we will be able to remove this function again. gdb/ 2014-07-24 Tom Tromey Gary Benson * nat/linux-ptrace.c (additional_flags): New global. (linux_test_for_tracesysgood, linux_test_for_tracefork): Use additional_flags; don't check GDBSERVER. (linux_ptrace_set_additional_flags): New function. * nat/linux-ptrace.h (linux_ptrace_set_additional_flags): Declare. * linux-nat.c (_initialize_linux_nat): Call linux_ptrace_set_additional_flags. --- gdb/ChangeLog | 12 +++++++++ gdb/linux-nat.c | 8 ++++++ gdb/nat/linux-ptrace.c | 56 +++++++++++++++++++++++------------------- gdb/nat/linux-ptrace.h | 1 + 4 files changed, 52 insertions(+), 25 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index d6f5148bfd0..e239221c2f1 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,15 @@ +2014-07-24 Tom Tromey + Gary Benson + + * nat/linux-ptrace.c (additional_flags): New global. + (linux_test_for_tracesysgood, linux_test_for_tracefork): Use + additional_flags; don't check GDBSERVER. + (linux_ptrace_set_additional_flags): New function. + * nat/linux-ptrace.h (linux_ptrace_set_additional_flags): + Declare. + * linux-nat.c (_initialize_linux_nat): Call + linux_ptrace_set_additional_flags. + 2014-07-24 Tom Tromey * make-target-delegates (munge_type, write_debugmethod): New diff --git a/gdb/linux-nat.c b/gdb/linux-nat.c index b50a88e3b8f..7db1b3d6e81 100644 --- a/gdb/linux-nat.c +++ b/gdb/linux-nat.c @@ -5033,6 +5033,14 @@ Enables printf debugging output."), sigdelset (&suspend_mask, SIGCHLD); sigemptyset (&blocked_mask); + + /* Do not enable PTRACE_O_TRACEEXIT until GDB is more prepared to + support read-only process state. */ + linux_ptrace_set_additional_flags (PTRACE_O_TRACESYSGOOD + | PTRACE_O_TRACEVFORKDONE + | PTRACE_O_TRACEVFORK + | PTRACE_O_TRACEFORK + | PTRACE_O_TRACEEXEC); } diff --git a/gdb/nat/linux-ptrace.c b/gdb/nat/linux-ptrace.c index 3ad2113d7d6..24b02b930cc 100644 --- a/gdb/nat/linux-ptrace.c +++ b/gdb/nat/linux-ptrace.c @@ -37,6 +37,10 @@ there are no supported features. */ static int current_ptrace_options = -1; +/* Additional flags to test. */ + +static int additional_flags; + /* Find all possible reasons we could fail to attach PID and append these as strings to the already initialized BUFFER. '\0' termination of BUFFER must be done by the caller. */ @@ -359,16 +363,16 @@ linux_check_ptrace_features (void) static void linux_test_for_tracesysgood (int child_pid) { -#ifdef GDBSERVER - /* gdbserver does not support PTRACE_O_TRACESYSGOOD. */ -#else int ret; + if ((additional_flags & PTRACE_O_TRACESYSGOOD) == 0) + return; + ret = ptrace (PTRACE_SETOPTIONS, child_pid, (PTRACE_TYPE_ARG3) 0, (PTRACE_TYPE_ARG4) PTRACE_O_TRACESYSGOOD); + if (ret == 0) current_ptrace_options |= PTRACE_O_TRACESYSGOOD; -#endif } /* Determine if PTRACE_O_TRACEFORK can be used to follow fork @@ -388,16 +392,15 @@ linux_test_for_tracefork (int child_pid) if (ret != 0) return; -#ifdef GDBSERVER - /* gdbserver does not support PTRACE_O_TRACEVFORKDONE yet. */ -#else - /* Check if the target supports PTRACE_O_TRACEVFORKDONE. */ - ret = ptrace (PTRACE_SETOPTIONS, child_pid, (PTRACE_TYPE_ARG3) 0, - (PTRACE_TYPE_ARG4) (PTRACE_O_TRACEFORK - | PTRACE_O_TRACEVFORKDONE)); - if (ret == 0) - current_ptrace_options |= PTRACE_O_TRACEVFORKDONE; -#endif + if ((additional_flags & PTRACE_O_TRACEVFORKDONE) != 0) + { + /* Check if the target supports PTRACE_O_TRACEVFORKDONE. */ + ret = ptrace (PTRACE_SETOPTIONS, child_pid, (PTRACE_TYPE_ARG3) 0, + (PTRACE_TYPE_ARG4) (PTRACE_O_TRACEFORK + | PTRACE_O_TRACEVFORKDONE)); + if (ret == 0) + current_ptrace_options |= PTRACE_O_TRACEVFORKDONE; + } /* Setting PTRACE_O_TRACEFORK did not cause an error, however we don't know for sure that the feature is available; old @@ -433,18 +436,10 @@ linux_test_for_tracefork (int child_pid) /* We got the PID from the grandchild, which means fork tracing is supported. */ -#ifdef GDBSERVER - /* Do not enable all the options for now since gdbserver does not - properly support them. This restriction will be lifted when - gdbserver is augmented to support them. */ current_ptrace_options |= PTRACE_O_TRACECLONE; -#else - current_ptrace_options |= PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORK - | PTRACE_O_TRACECLONE | PTRACE_O_TRACEEXEC; - - /* Do not enable PTRACE_O_TRACEEXIT until GDB is more prepared to - support read-only process state. */ -#endif + current_ptrace_options |= (additional_flags & (PTRACE_O_TRACEFORK + | PTRACE_O_TRACEVFORK + | PTRACE_O_TRACEEXEC)); /* Do some cleanup and kill the grandchild. */ my_waitpid (second_pid, &second_status, 0); @@ -551,3 +546,14 @@ linux_ptrace_init_warnings (void) linux_ptrace_test_ret_to_nx (); } + +/* Set additional ptrace flags to use. Some such flags may be checked + by the implementation above. This function must be called before + any other function in this file; otherwise the flags may not take + effect appropriately. */ + +void +linux_ptrace_set_additional_flags (int flags) +{ + additional_flags = flags; +} diff --git a/gdb/nat/linux-ptrace.h b/gdb/nat/linux-ptrace.h index cffb5ce18de..41b31988839 100644 --- a/gdb/nat/linux-ptrace.h +++ b/gdb/nat/linux-ptrace.h @@ -91,5 +91,6 @@ extern int linux_supports_tracefork (void); extern int linux_supports_traceclone (void); extern int linux_supports_tracevforkdone (void); extern int linux_supports_tracesysgood (void); +extern void linux_ptrace_set_additional_flags (int); #endif /* COMMON_LINUX_PTRACE_H */ -- 2.30.2