[PATCH 3/6] Use simple_search_memory in gdbserver
Tom Tromey
tromey@adacore.com
Thu Jul 23 20:12:13 GMT 2020
This replaces gdbserver's memory-searching function with
simple_search_memory.
2020-07-23 Tom Tromey <tromey@adacore.com>
* server.cc (handle_search_memory_1): Remove.
(handle_search_memory): Use simple_search_memory.
* Makefile.in (SFILES): Add target/search.c.
(OBS): Add target/search.o.
---
gdbserver/ChangeLog | 7 +++
gdbserver/Makefile.in | 2 +
gdbserver/server.cc | 112 ++----------------------------------------
3 files changed, 14 insertions(+), 107 deletions(-)
diff --git a/gdbserver/Makefile.in b/gdbserver/Makefile.in
index 9d7687be534..6e5449e3931 100644
--- a/gdbserver/Makefile.in
+++ b/gdbserver/Makefile.in
@@ -220,6 +220,7 @@ SFILES = \
$(srcdir)/../gdb/nat/ppc-linux.c \
$(srcdir)/../gdb/nat/riscv-linux-tdesc.c \
$(srcdir)/../gdb/nat/fork-inferior.c \
+ $(srcdir)/../gdb/target/search.c \
$(srcdir)/../gdb/target/waitstatus.c
DEPFILES = @GDBSERVER_DEPFILES@
@@ -247,6 +248,7 @@ OBS = \
tracepoint.o \
utils.o \
version.o \
+ target/search.o \
target/waitstatus.o \
$(DEPFILES) \
$(LIBOBJS) \
diff --git a/gdbserver/server.cc b/gdbserver/server.cc
index aadcb9b5d30..b050a1d8653 100644
--- a/gdbserver/server.cc
+++ b/gdbserver/server.cc
@@ -1038,89 +1038,6 @@ gdb_write_memory (CORE_ADDR memaddr, const unsigned char *myaddr, int len)
}
}
-/* Subroutine of handle_search_memory to simplify it. */
-
-static int
-handle_search_memory_1 (CORE_ADDR start_addr, CORE_ADDR search_space_len,
- gdb_byte *pattern, unsigned pattern_len,
- gdb_byte *search_buf,
- unsigned chunk_size, unsigned search_buf_size,
- CORE_ADDR *found_addrp)
-{
- /* Prime the search buffer. */
-
- if (gdb_read_memory (start_addr, search_buf, search_buf_size)
- != search_buf_size)
- {
- warning ("Unable to access %ld bytes of target "
- "memory at 0x%lx, halting search.",
- (long) search_buf_size, (long) start_addr);
- return -1;
- }
-
- /* Perform the search.
-
- The loop is kept simple by allocating [N + pattern-length - 1] bytes.
- When we've scanned N bytes we copy the trailing bytes to the start and
- read in another N bytes. */
-
- while (search_space_len >= pattern_len)
- {
- gdb_byte *found_ptr;
- unsigned nr_search_bytes = (search_space_len < search_buf_size
- ? search_space_len
- : search_buf_size);
-
- found_ptr = (gdb_byte *) memmem (search_buf, nr_search_bytes, pattern,
- pattern_len);
-
- if (found_ptr != NULL)
- {
- CORE_ADDR found_addr = start_addr + (found_ptr - search_buf);
- *found_addrp = found_addr;
- return 1;
- }
-
- /* Not found in this chunk, skip to next chunk. */
-
- /* Don't let search_space_len wrap here, it's unsigned. */
- if (search_space_len >= chunk_size)
- search_space_len -= chunk_size;
- else
- search_space_len = 0;
-
- if (search_space_len >= pattern_len)
- {
- unsigned keep_len = search_buf_size - chunk_size;
- CORE_ADDR read_addr = start_addr + chunk_size + keep_len;
- int nr_to_read;
-
- /* Copy the trailing part of the previous iteration to the front
- of the buffer for the next iteration. */
- memcpy (search_buf, search_buf + chunk_size, keep_len);
-
- nr_to_read = (search_space_len - keep_len < chunk_size
- ? search_space_len - keep_len
- : chunk_size);
-
- if (gdb_read_memory (read_addr, search_buf + keep_len,
- nr_to_read) != nr_to_read)
- {
- warning ("Unable to access %ld bytes of target memory "
- "at 0x%lx, halting search.",
- (long) nr_to_read, (long) read_addr);
- return -1;
- }
-
- start_addr += chunk_size;
- }
- }
-
- /* Not found. */
-
- return 0;
-}
-
/* Handle qSearch:memory packets. */
static void
@@ -1130,12 +1047,6 @@ handle_search_memory (char *own_buf, int packet_len)
CORE_ADDR search_space_len;
gdb_byte *pattern;
unsigned int pattern_len;
- /* NOTE: also defined in find.c testcase. */
-#define SEARCH_CHUNK_SIZE 16000
- const unsigned chunk_size = SEARCH_CHUNK_SIZE;
- /* Buffer to hold memory contents for searching. */
- gdb_byte *search_buf;
- unsigned search_buf_size;
int found;
CORE_ADDR found_addr;
int cmd_name_len = sizeof ("qSearch:memory:") - 1;
@@ -1158,25 +1069,13 @@ handle_search_memory (char *own_buf, int packet_len)
return;
}
- search_buf_size = chunk_size + pattern_len - 1;
-
- /* No point in trying to allocate a buffer larger than the search space. */
- if (search_space_len < search_buf_size)
- search_buf_size = search_space_len;
-
- search_buf = (gdb_byte *) malloc (search_buf_size);
- if (search_buf == NULL)
+ auto read_memory = [=] (CORE_ADDR addr, gdb_byte *result, size_t len)
{
- free (pattern);
- error ("Unable to allocate memory to perform the search");
- strcpy (own_buf, "E00");
- return;
- }
+ return gdb_read_memory (addr, result, len) == len;
+ };
- found = handle_search_memory_1 (start_addr, search_space_len,
- pattern, pattern_len,
- search_buf, chunk_size, search_buf_size,
- &found_addr);
+ found = simple_search_memory (read_memory, start_addr, search_space_len,
+ pattern, pattern_len, &found_addr);
if (found > 0)
sprintf (own_buf, "1,%lx", (long) found_addr);
@@ -1185,7 +1084,6 @@ handle_search_memory (char *own_buf, int packet_len)
else
strcpy (own_buf, "E00");
- free (search_buf);
free (pattern);
}
--
2.26.2
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