[PATCH]: 7238806b22 target: fix assert in 'monitor profile' on constant PC

[gerrit]

This is an automated email from Gerrit.

"Antonio Borneo <borneo.anto...@gmail.com>" just uploaded a new patch set to 
Gerrit, which you can find at https://review.openocd.org/c/openocd/+/7400

-- gerrit

commit 7238806b22149f297a5c39e6297393af79428b82
Author: Antonio Borneo <borneo.anto...@gmail.com>
Date:   Wed Dec 14 15:21:43 2022 +0100

    target: fix assert in 'monitor profile' on constant PC
    
    When target is stopped in WFI/WFE or is in an infinite loop, the
    sampled PC will always return the same value.
    Command 'profile' requires that distance between min and max PC
    should be at least 2, which is not the case for constant PC, and
    incorrectly enforces the check through as assert().
    
    Move the code that reads the optional parameters 'start' and 'end'
    and check the gap 'end - start' before running the profile.
    For self-computed min and max, increase max (or decrease min) to
    match the required constraint.
    Drop the assert().
    
    Change-Id: I2be8df8568ce8c889923888c492e4f7ce354b16b
    Signed-off-by: Antonio Borneo <borneo.anto...@gmail.com>

diff --git a/src/target/target.c b/src/target/target.c
index 755a8e283b..e3a6f955ea 100644
--- a/src/target/target.c
+++ b/src/target/target.c
@@ -4253,10 +4253,17 @@ static void write_gmon(uint32_t *samples, uint32_t 
sample_num, const char *filen
                 * Refer to binutils/gprof/hist.c (find_histogram_for_pc) */
                if (max < UINT32_MAX)
                        max++;
+
+               /* gprof requires (max - min) >= 2 */
+               while ((max - min) < 2) {
+                       if (max < UINT32_MAX)
+                               max++;
+                       else
+                               min--;
+               }
        }
 
        uint32_t address_space = max - min;
-       assert(address_space >= 2);
 
        /* FIXME: What is the reasonable number of buckets?
         * The profiling result will be more accurate if there are enough 
buckets. */
@@ -4332,6 +4339,19 @@ COMMAND_HANDLER(handle_profile_command)
 
        COMMAND_PARSE_NUMBER(u32, CMD_ARGV[0], offset);
 
+       uint32_t start_address = 0;
+       uint32_t end_address = 0;
+       bool with_range = false;
+       if (CMD_ARGC == 4) {
+               with_range = true;
+               COMMAND_PARSE_NUMBER(u32, CMD_ARGV[2], start_address);
+               COMMAND_PARSE_NUMBER(u32, CMD_ARGV[3], end_address);
+               if (start_address > end_address || (end_address - 
start_address) < 2) {
+                       command_print(CMD, "Error: end - start < 2");
+                       return ERROR_COMMAND_ARGUMENT_INVALID;
+               }
+       }
+
        uint32_t *samples = malloc(sizeof(uint32_t) * MAX_PROFILE_SAMPLE_NUM);
        if (!samples) {
                LOG_ERROR("No memory to store samples.");
@@ -4384,15 +4404,6 @@ COMMAND_HANDLER(handle_profile_command)
                return retval;
        }
 
-       uint32_t start_address = 0;
-       uint32_t end_address = 0;
-       bool with_range = false;
-       if (CMD_ARGC == 4) {
-               with_range = true;
-               COMMAND_PARSE_NUMBER(u32, CMD_ARGV[2], start_address);
-               COMMAND_PARSE_NUMBER(u32, CMD_ARGV[3], end_address);
-       }
-
        write_gmon(samples, num_of_samples, CMD_ARGV[1],
                   with_range, start_address, end_address, target, duration_ms);
        command_print(CMD, "Wrote %s", CMD_ARGV[1]);

--