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| author | Tony Luck <tony.luck@intel.com> | 2022-10-13 15:10:57 -0700 |
|---|---|---|
| committer | Tony Luck <tony.luck@intel.com> | 2022-10-13 15:10:57 -0700 |
| commit | c8aef396cc8ff29f5c2dcc6dd6dc56ed2d9202ad (patch) | |
| tree | be9f66ff69f85390f96a54c583530ab8d9c60b37 | |
| parent | 9262f4f291dc1511b5d8ba83ffa46e6b7bb944fc (diff) | |
| download | ras-tools-c8aef396cc8ff29f5c2dcc6dd6dc56ed2d9202ad.tar.gz | |
einj_mem-uc: Add new test case for kernel copy-on-write
Someday I'd like to fix this case in the kernel. For now just
create a test case to generate the issue.
Signed-off-by: Tony Luck <tony.luck@intel.com>
| -rw-r--r-- | einj_mem_uc.c | 38 |
1 files changed, 36 insertions, 2 deletions
diff --git a/einj_mem_uc.c b/einj_mem_uc.c index aaba725..17567de 100644 --- a/einj_mem_uc.c +++ b/einj_mem_uc.c @@ -26,6 +26,7 @@ #include <sys/syscall.h> #include <linux/futex.h> #include <pthread.h> +#include <sys/wait.h> #ifndef MAP_HUGETLB #define MAP_HUGETLB 0x40000 @@ -443,9 +444,9 @@ static void *hugetlb_alloc(void) return p + HPS / 4; } -static void *data_alloc(void) +static void *data_alloc_common(int flag) { - char *p = mmap(NULL, pagesize, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_ANON, -1, 0); + char *p = mmap(NULL, pagesize, PROT_READ|PROT_WRITE, flag, -1, 0); int i; if (p == NULL) { @@ -458,6 +459,16 @@ static void *data_alloc(void) return p + pagesize / 4; } +static void *data_alloc(void) +{ + return data_alloc_common(MAP_SHARED|MAP_ANON); +} + +static void *data_alloc_private(void) +{ + return data_alloc_common(MAP_PRIVATE|MAP_ANON); +} + static FILE *pcfile; static void *page_cache_alloc(void) @@ -718,6 +729,25 @@ int trigger_copyout(char *addr) return 0; } +int trigger_copy_on_write(char *addr) +{ + int pid, status; + + switch (pid = fork()) { + case -1: + fprintf(stderr, "%s: fork failed\n", progname); + return -1; + case 0: + /* force kernel to copy this page */ + *addr = '*'; + exit(0); + } + + while (wait(&status) != pid) + ; + return 0; +} + int trigger_patrol(char *addr) { PRINT_TRIGGERING; @@ -898,6 +928,10 @@ struct test { page_cache_alloc, inject_uc, 1, trigger_copyout, F_MCE|F_CMCI|F_SIGBUS|F_FATAL, }, { + "copy-on-write", "Kernel copies user page. Probably fatal", + data_alloc_private, inject_uc, 1, trigger_copy_on_write, F_MCE|F_CMCI|F_SIGBUS|F_FATAL, + }, + { "futex", "Kernel access to futex(2). Probably fatal", data_alloc, inject_uc, 1, trigger_futex, F_MCE|F_CMCI|F_FATAL, }, |