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Diffstat (limited to 'cpukit/libmisc/stackchk/README')
| -rw-r--r-- | cpukit/libmisc/stackchk/README | 41 |
1 files changed, 0 insertions, 41 deletions
diff --git a/cpukit/libmisc/stackchk/README b/cpukit/libmisc/stackchk/README deleted file mode 100644 index 20e76f07bc..0000000000 --- a/cpukit/libmisc/stackchk/README +++ /dev/null @@ -1,41 +0,0 @@ -# -# $Id$ -# - -This directory contains a stack bounds checker. It provides two -primary features: - - + check for stack overflow at each context switch - + provides an educated guess at each task's stack usage - -The stack overflow check at context switch works by looking for -a 16 byte pattern at the logical end of the stack to be corrupted. -The "guesser" assumes that the entire stack was prefilled with a known -pattern and assumes that the pattern is still in place if the memory -has not been used as a stack. - -Both of these can be fooled by pushing large holes onto the stack -and not writing to them... or (much more unlikely) writing the -magic patterns into memory. - -This code has not been extensively tested. It is provided as a tool -for RTEMS users to catch the most common mistake in multitasking -systems ... too little stack space. Suggestions and comments are appreciated. - -NOTES: - -1. Stack usage information is questionable on CPUs which push - large holes on stack. - -2. The stack checker has a tendency to generate a fault when - trying to print the helpful diagnostic message. If it comes - out, congratulations. If not, then the variable Stack_check_Blown_task - contains a pointer to the TCB of the offending task. This - is usually enough to go on. - -FUTURE: - -1. Determine how/if gcc will generate stack probe calls and support that. - -2. Get accurate stack usage numbers on i960.. it pushes very large - holes on the stack. |