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Update block along with the block cache #115

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Update block along with the block cache #115

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fc0b9d3
update block along with block cache
zyd2001 May 18, 2025
e0b029a
use simple fix
zyd2001 May 20, 2025
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17 changes: 15 additions & 2 deletions libipt/src/pt_block_decoder.c
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Original file line number Diff line number Diff line change
Expand Up @@ -45,6 +45,10 @@
static int pt_blk_proceed_trailing_event(struct pt_block_decoder *,
struct pt_block *);

static int pt_blk_proceed_no_event_cached(struct pt_block_decoder *decoder,
struct pt_block *block,
struct pt_block_cache *bcache,
const struct pt_mapped_section *msec);
static int pt_blk_set_trig_anchor(struct pt_block_decoder *decoder)
{
if (!decoder)
Expand Down Expand Up @@ -2431,12 +2435,14 @@ pt_blk_proceed_no_event_fill_cache(struct pt_block_decoder *decoder,
if (status < 0)
return status;


int valid_cache = pt_bce_is_valid(bce);
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Please declare variables at the beginning of the function. We also need to find a better name, because valid_cache refers to an older cache entry that might have been updated when we use the variable. E.g. keep_filling, or just fill.

/* If we don't have a valid cache entry, yet, fill the cache some more.
*
* On our way back, we add a cache entry for this instruction based on
* the cache entry of the succeeding instruction.
*/
if (!pt_bce_is_valid(bce)) {
if (!valid_cache) {
/* If we exceeded the maximum number of allowed steps, we insert
* a trampoline to the next instruction.
*
Expand Down Expand Up @@ -2515,7 +2521,14 @@ pt_blk_proceed_no_event_fill_cache(struct pt_block_decoder *decoder,
* Cache updates are atomic so even if the two versions were not
* identical, we wouldn't care because they are both correct.
*/
return pt_bcache_add(bcache, ioff, bce);
status = pt_bcache_add(bcache, ioff, bce);
if (status < 0)
return status;

if (valid_cache)
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We'd need some comment explaining that we can only proceed with the new cache entry if we have not filled the block.

return pt_blk_proceed_no_event_cached(decoder, block,
bcache, msec);
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Please indent until the opening parenthesis using tabs (tab width 8) as far as possible, then switching to spaces.

Let's also add an empty line between the two returns.

return status;
}

/* Proceed at a potentially truncated instruction.
Expand Down