[PATCH v5] Add support for NetBSD threads in sparc-nat.c
Simon Marchi
simark@simark.ca
Tue Mar 17 19:09:51 GMT 2020
On 2020-03-17 3:07 p.m., Simon Marchi wrote:
> On 2020-03-17 2:18 p.m., Kamil Rytarowski wrote:
>> NetBSD ptrace(2) accepts thread id (LWP) as the 4th argument for threads.
>>
>> Define gdb_ptrace() a wrapper function for ptrace(2) that properly passes
>> the pid,lwp pair on NetBSD and the result of get_ptrace_pid() for others.
>> ---
>> gdb/sparc-nat.c | 50 ++++++++++++++++++++++---------------------------
>> 1 file changed, 22 insertions(+), 28 deletions(-)
>>
>> diff --git a/gdb/sparc-nat.c b/gdb/sparc-nat.c
>> index dff0f521565..fadcfd34474 100644
>> --- a/gdb/sparc-nat.c
>> +++ b/gdb/sparc-nat.c
>> @@ -78,6 +78,19 @@ typedef struct fp_status fpregset_t;
>> #define PTRACE_SETFPREGS PT_SETFPREGS
>> #endif
>>
>> +static int
>> +gdb_ptrace (PTRACE_TYPE_ARG1 request, ptid_t ptid, PTRACE_TYPE_ARG3 addr)
>> +{
>> +#ifdef __NetBSD__
>> + /* Support for NetBSD threads: unlike other ptrace implementations in this
>> + file, NetBSD requires that we pass both the pid and lwp. */
>> + return ptrace (request, ptid.pid (), addr, ptid.lwp ());
>> +#else
>> + pid_t pid = get_ptrace_pid (ptid);
>> + return ptrace (request, pid, addr, 0);
>> +#endif
>> +}
>> +
>> /* Register set description. */
>> const struct sparc_gregmap *sparc_gregmap;
>> const struct sparc_fpregmap *sparc_fpregmap;
>> @@ -137,22 +150,7 @@ void
>> sparc_fetch_inferior_registers (struct regcache *regcache, int regnum)
>> {
>> struct gdbarch *gdbarch = regcache->arch ();
>> - pid_t pid;
>> -
>> - /* NOTE: cagney/2002-12-03: This code assumes that the currently
>> - selected light weight processes' registers can be written
>> - directly into the selected thread's register cache. This works
>> - fine when given an 1:1 LWP:thread model (such as found on
>> - GNU/Linux) but will, likely, have problems when used on an N:1
>> - (userland threads) or N:M (userland multiple LWP) model. In the
>> - case of the latter two, the LWP's registers do not necessarily
>> - belong to the selected thread (the LWP could be in the middle of
>> - executing the thread switch code).
>> -
>> - These functions should instead be parameterized with an explicit
>> - object (struct regcache, struct thread_info?) into which the LWPs
>> - registers can be written. */
>> - pid = get_ptrace_pid (regcache->ptid ());
>> + ptid_t ptid = regcache->ptid ();
>>
>> if (regnum == SPARC_G0_REGNUM)
>> {
>> @@ -166,7 +164,7 @@ sparc_fetch_inferior_registers (struct regcache *regcache, int regnum)
>> {
>> gregset_t regs;
>>
>> - if (ptrace (PTRACE_GETREGS, pid, (PTRACE_TYPE_ARG3) ®s, 0) == -1)
>> + if (gdb_ptrace (PTRACE_GETREGS, ptid, (PTRACE_TYPE_ARG3) ®s) == -1)
>> perror_with_name (_("Couldn't get registers"));
>>
>> sparc_supply_gregset (sparc_gregmap, regcache, -1, ®s);
>> @@ -178,7 +176,7 @@ sparc_fetch_inferior_registers (struct regcache *regcache, int regnum)
>> {
>> fpregset_t fpregs;
>>
>> - if (ptrace (PTRACE_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
>> + if (gdb_ptrace (PTRACE_GETFPREGS, ptid, (PTRACE_TYPE_ARG3) &fpregs) == -1)
>> perror_with_name (_("Couldn't get floating point status"));
>>
>> sparc_supply_fpregset (sparc_fpregmap, regcache, -1, &fpregs);
>> @@ -189,22 +187,18 @@ void
>> sparc_store_inferior_registers (struct regcache *regcache, int regnum)
>> {
>> struct gdbarch *gdbarch = regcache->arch ();
>> - pid_t pid;
>> -
>> - /* NOTE: cagney/2002-12-02: See comment in fetch_inferior_registers
>> - about threaded assumptions. */
>> - pid = get_ptrace_pid (regcache->ptid ());
>> + ptid_t ptid = regcache->ptid ();
>>
>> if (regnum == -1 || sparc_gregset_supplies_p (gdbarch, regnum))
>> {
>> gregset_t regs;
>>
>> - if (ptrace (PTRACE_GETREGS, pid, (PTRACE_TYPE_ARG3) ®s, 0) == -1)
>> + if (gdb_ptrace (PTRACE_GETREGS, ptid, (PTRACE_TYPE_ARG3) ®s) == -1)
>> perror_with_name (_("Couldn't get registers"));
>>
>> sparc_collect_gregset (sparc_gregmap, regcache, regnum, ®s);
>>
>> - if (ptrace (PTRACE_SETREGS, pid, (PTRACE_TYPE_ARG3) ®s, 0) == -1)
>> + if (gdb_ptrace (PTRACE_SETREGS, ptid, (PTRACE_TYPE_ARG3) ®s) == -1)
>> perror_with_name (_("Couldn't write registers"));
>>
>> /* Deal with the stack regs. */
>> @@ -225,7 +219,7 @@ sparc_store_inferior_registers (struct regcache *regcache, int regnum)
>> {
>> fpregset_t fpregs, saved_fpregs;
>>
>> - if (ptrace (PTRACE_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
>> + if (gdb_ptrace (PTRACE_GETFPREGS, ptid, (PTRACE_TYPE_ARG3) &fpregs) == -1)
>> perror_with_name (_("Couldn't get floating-point registers"));
>>
>> memcpy (&saved_fpregs, &fpregs, sizeof (fpregs));
>> @@ -237,8 +231,8 @@ sparc_store_inferior_registers (struct regcache *regcache, int regnum)
>> to write the registers if nothing changed. */
>> if (memcmp (&saved_fpregs, &fpregs, sizeof (fpregs)) != 0)
>> {
>> - if (ptrace (PTRACE_SETFPREGS, pid,
>> - (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
>> + if (gdb_ptrace (PTRACE_SETFPREGS, ptid,
>> + (PTRACE_TYPE_ARG3) &fpregs) == -1)
>> perror_with_name (_("Couldn't write floating-point registers"));
>> }
>>
>> --
>> 2.25.0
>>
>
> Thanks, this version LGTM.
>
> Simon
Don't forget the ChangeLog entry though.
Simon
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