diff options
| -rw-r--r-- | gdb/ChangeLog | 8 | ||||
| -rw-r--r-- | gdb/inf-ptrace.c | 142 |
2 files changed, 77 insertions, 73 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 63d7441..2658d917 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,11 @@ +2017-03-14 Andreas Arnez <arnez@linux.vnet.ibm.com> + + PR gdb/21220 + * inf-ptrace.c (inf_ptrace_xfer_partial): In "case + TARGET_OBJECT_MEMORY", extract the logic for ptrace peek/poke... + (inf_ptrace_peek_poke): ...here. New function. Now also loop + over ptrace peek/poke until end of buffer or error. + 2017-03-14 Simon Marchi <simon.marchi@ericsson.com> * parse.c (length_of_subexp): Make static. diff --git a/gdb/inf-ptrace.c b/gdb/inf-ptrace.c index 21578742..32794ec 100644 --- a/gdb/inf-ptrace.c +++ b/gdb/inf-ptrace.c @@ -446,6 +446,72 @@ inf_ptrace_wait (struct target_ops *ops, return pid_to_ptid (pid); } +/* Transfer data via ptrace into process PID's memory from WRITEBUF, or + from process PID's memory into READBUF. Start at target address ADDR + and transfer up to LEN bytes. Exactly one of READBUF and WRITEBUF must + be non-null. Return the number of transferred bytes. */ + +static ULONGEST +inf_ptrace_peek_poke (pid_t pid, gdb_byte *readbuf, + const gdb_byte *writebuf, + ULONGEST addr, ULONGEST len) +{ + ULONGEST n; + unsigned int chunk; + + /* We transfer aligned words. Thus align ADDR down to a word + boundary and determine how many bytes to skip at the + beginning. */ + unsigned int skip = addr & (sizeof (PTRACE_TYPE_RET) - 1); + addr -= skip; + + for (n = 0; + n < len; + n += chunk, addr += sizeof (PTRACE_TYPE_RET), skip = 0) + { + /* Restrict to a chunk that fits in the current word. */ + chunk = std::min (sizeof (PTRACE_TYPE_RET) - skip, len - n); + + /* Use a union for type punning. */ + union + { + PTRACE_TYPE_RET word; + gdb_byte byte[sizeof (PTRACE_TYPE_RET)]; + } buf; + + /* Read the word, also when doing a partial word write. */ + if (readbuf != NULL || chunk < sizeof (PTRACE_TYPE_RET)) + { + errno = 0; + buf.word = ptrace (PT_READ_I, pid, + (PTRACE_TYPE_ARG3)(uintptr_t) addr, 0); + if (errno != 0) + break; + if (readbuf != NULL) + memcpy (readbuf + n, buf.byte + skip, chunk); + } + if (writebuf != NULL) + { + memcpy (buf.byte + skip, writebuf + n, chunk); + errno = 0; + ptrace (PT_WRITE_D, pid, (PTRACE_TYPE_ARG3)(uintptr_t) addr, + buf.word); + if (errno != 0) + { + /* Using the appropriate one (I or D) is necessary for + Gould NP1, at least. */ + errno = 0; + ptrace (PT_WRITE_I, pid, (PTRACE_TYPE_ARG3)(uintptr_t) addr, + buf.word); + if (errno != 0) + break; + } + } + } + + return n; +} + /* Implement the to_xfer_partial target_ops method. */ static enum target_xfer_status @@ -491,79 +557,9 @@ inf_ptrace_xfer_partial (struct target_ops *ops, enum target_object object, return TARGET_XFER_EOF; } #endif - { - union - { - PTRACE_TYPE_RET word; - gdb_byte byte[sizeof (PTRACE_TYPE_RET)]; - } buffer; - ULONGEST rounded_offset; - ULONGEST partial_len; - - /* Round the start offset down to the next long word - boundary. */ - rounded_offset = offset & -(ULONGEST) sizeof (PTRACE_TYPE_RET); - - /* Since ptrace will transfer a single word starting at that - rounded_offset the partial_len needs to be adjusted down to - that (remember this function only does a single transfer). - Should the required length be even less, adjust it down - again. */ - partial_len = (rounded_offset + sizeof (PTRACE_TYPE_RET)) - offset; - if (partial_len > len) - partial_len = len; - - if (writebuf) - { - /* If OFFSET:PARTIAL_LEN is smaller than - ROUNDED_OFFSET:WORDSIZE then a read/modify write will - be needed. Read in the entire word. */ - if (rounded_offset < offset - || (offset + partial_len - < rounded_offset + sizeof (PTRACE_TYPE_RET))) - /* Need part of initial word -- fetch it. */ - buffer.word = ptrace (PT_READ_I, pid, - (PTRACE_TYPE_ARG3)(uintptr_t) - rounded_offset, 0); - - /* Copy data to be written over corresponding part of - buffer. */ - memcpy (buffer.byte + (offset - rounded_offset), - writebuf, partial_len); - - errno = 0; - ptrace (PT_WRITE_D, pid, - (PTRACE_TYPE_ARG3)(uintptr_t)rounded_offset, - buffer.word); - if (errno) - { - /* Using the appropriate one (I or D) is necessary for - Gould NP1, at least. */ - errno = 0; - ptrace (PT_WRITE_I, pid, - (PTRACE_TYPE_ARG3)(uintptr_t)rounded_offset, - buffer.word); - if (errno) - return TARGET_XFER_EOF; - } - } - - if (readbuf) - { - errno = 0; - buffer.word = ptrace (PT_READ_I, pid, - (PTRACE_TYPE_ARG3)(uintptr_t)rounded_offset, - 0); - if (errno) - return TARGET_XFER_EOF; - /* Copy appropriate bytes out of the buffer. */ - memcpy (readbuf, buffer.byte + (offset - rounded_offset), - partial_len); - } - - *xfered_len = partial_len; - return TARGET_XFER_OK; - } + *xfered_len = inf_ptrace_peek_poke (pid, readbuf, writebuf, + offset, len); + return *xfered_len != 0 ? TARGET_XFER_OK : TARGET_XFER_EOF; case TARGET_OBJECT_UNWIND_TABLE: return TARGET_XFER_E_IO; |