http://sourceware.org/bugzilla/show_bug.cgi?id=13325
Bug #: 13325
Summary: gprof doesn't work when there are histogram data
before the first symbol
Product: binutils
Version: 2.23 (HEAD)
Status: NEW
Severity: normal
Priority: P2
Component: gprof
AssignedTo: unassig...@sourceware.org
ReportedBy: car...@google.com
Classification: Unclassified
In function hist.c:hist_assign_samples_1, when credit histogram data to symbols
it uses the loop
for (i = 0, j = 1; i < r->num_bins; ++i)
{
...
for (j = j - 1; j < symtab.len; ++j)
{
sym_low_pc = symtab.base[j].hist.scaled_addr;
sym_high_pc = symtab.base[j + 1].hist.scaled_addr;
/* If high end of bin is below entry address,
go for next bin. */
if (bin_high_pc < sym_low_pc)
break;
...
}
}
Usually the last histogram is belong to symtab.base[j-1], and the current
histogram may also belong to symtab.base[j-1], so the loop starts from (j-1).
Suppose we have a histogram data that isn't belong to any known symbol, and its
address is before the first symbol, when it reaches to the inner loop, j=1,
after entering the inner loop, j = 0, then exit the inner loop. When it reaches
the inner loop again, j = 0 - 1 = 4294967295, which is much larger than the
symbol table length, so the following histogram data will never hit any
symbols.
So the inner loop should never modify j if the histogram doesn't hit any
symbol.
--
Configure bugmail: http://sourceware.org/bugzilla/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are on the CC list for the bug.
_______________________________________________
bug-binutils mailing list
bug-binutils@gnu.org
https://lists.gnu.org/mailman/listinfo/bug-binutils
