On 16/06/25 9:36 pm, Aboorva Devarajan wrote:
From: Donet Tom <donet...@linux.ibm.com> In this patch, we are fixing three issues in the virtual_address_range test. 1. validate_addr() checks if the allocated address is within the range. In the current implementation, if addr is greater than HIGH_ADDR_MARK, the test fails. However, addr will be greater than HIGH_ADDR_MARK if high_addr is set. Therefore, if high_addr is set, we should not check the (addr > HIGH_ADDR_MARK) condition. 2.In main(), the high address is stored in hptr, but for mark_range(), the address passed is ptr, not hptr. Fixed this by changing ptr[i] to hptr[i] in mark_range() function call. 3./proc/self/maps may not always have gaps smaller than MAP_CHUNK_SIZE. The gap between the first high address mapping and the previous mapping is not smaller than MAP_CHUNK_SIZE.
For this, can't we just elide the check when we cross the high boundary? As I see it you are essentially nullifying the purpose of validate_complete_va_space; I had written that function so as to have an alternate way of checking VA exhaustion without relying on mmap correctness in a circular way. Btw @Lorenzo, validate_complete_va_space was written by me as my first patch ever for the Linux kernel : ) from the limited knowledge I have of VMA stuff, I guess the only requirement for VMA alignment is PAGE_SIZE in this test, therefore, the only check required is that the gap between two VMAs should be at least MAP_CHUNK_SIZE? Or can such a gap still exist even when the VA has been exhausted?
$cat /proc/3713/maps 10000000-10010000 r-xp 00000000 fd:00 36140094 10010000-10020000 r--p 00000000 fd:00 36140094 10020000-10030000 rw-p 00010000 fd:00 36140094 4ee80000-4eeb0000 rw-p 00000000 00:00 0 578f0000-57c00000 rw-p 00000000 00:00 0 57c00000-7fff97c00000 r--p 00000000 00:00 0 7fff97c00000-7fff97e20000 r-xp 00000000 fd:00 33558923 7fff97e20000-7fff97e30000 r--p 00220000 fd:00 33558923 7fff97e30000-7fff97e40000 rw-p 00230000 fd:00 33558923 7fff97f40000-7fff98020000 r-xp 00000000 fd:00 33558924 7fff98020000-7fff98030000 r--p 000d0000 fd:00 33558924 7fff98030000-7fff98040000 rw-p 000e0000 fd:00 33558924 7fff98050000-7fff98090000 r--p 00000000 00:00 0 7fff98090000-7fff980a0000 r-xp 00000000 00:00 0 7fff980a0000-7fff980f0000 r-xp 00000000 fd:00 2634 7fff980f0000-7fff98100000 r--p 00040000 fd:00 2634 7fff98100000-7fff98110000 rw-p 00050000 fd:00 2634 7fffcf8a0000-7fffcf9b0000 rw-p 00000000 00:00 0 1000000000000-1000040000000 r--p 00000000 00:00 0 --> High Addr 2000000000000-2000040000000 r--p 00000000 00:00 0 4000000000000-4000040000000 r--p 00000000 00:00 0 8000000000000-8000040000000 r--p 00000000 00:00 0 e800098110000-fffff98110000 r--p 00000000 00:00 0 $ In this patch, the condition that checks for gaps smaller than MAP_CHUNK_SIZE has been removed. Fixes: d1d86ce28d0f ("selftests/mm: virtual_address_range: conform to TAP format output") Fixes: b2a79f62133a ("selftests/mm: virtual_address_range: unmap chunks after validation") Fixes: 010409649885 ("selftests/mm: confirm VA exhaustion without reliance on correctness of mmap()") Signed-off-by: Donet Tom <donet...@linux.ibm.com> Signed-off-by: Aboorva Devarajan <aboor...@linux.ibm.com> --- tools/testing/selftests/mm/virtual_address_range.c | 14 +++----------- 1 file changed, 3 insertions(+), 11 deletions(-) diff --git a/tools/testing/selftests/mm/virtual_address_range.c b/tools/testing/selftests/mm/virtual_address_range.c index b380e102b22f..606e601a8984 100644 --- a/tools/testing/selftests/mm/virtual_address_range.c +++ b/tools/testing/selftests/mm/virtual_address_range.c @@ -80,7 +80,7 @@ static void validate_addr(char *ptr, int high_addr) if (high_addr && addr < HIGH_ADDR_MARK) ksft_exit_fail_msg("Bad address %lx\n", addr);- if (addr > HIGH_ADDR_MARK)+ if (!high_addr && addr > HIGH_ADDR_MARK) ksft_exit_fail_msg("Bad address %lx\n", addr); }@@ -117,7 +117,7 @@ static int validate_lower_address_hint(void) static int validate_complete_va_space(void){ - unsigned long start_addr, end_addr, prev_end_addr; + unsigned long start_addr, end_addr; char line[400]; char prot[6]; FILE *file; @@ -134,7 +134,6 @@ static int validate_complete_va_space(void) if (file == NULL) ksft_exit_fail_msg("cannot open /proc/self/maps\n");- prev_end_addr = 0;while (fgets(line, sizeof(line), file)) { const char *vma_name = NULL; int vma_name_start = 0; @@ -151,12 +150,6 @@ static int validate_complete_va_space(void) if (start_addr & (1UL << 63)) return 0;- /* /proc/self/maps must have gaps less than MAP_CHUNK_SIZE */- if (start_addr - prev_end_addr >= MAP_CHUNK_SIZE) - return 1; - - prev_end_addr = end_addr; - if (prot[0] != 'r') continue;@@ -223,8 +216,7 @@ int main(int argc, char *argv[]) if (hptr[i] == MAP_FAILED)break; - - mark_range(ptr[i], MAP_CHUNK_SIZE); + mark_range(hptr[i], MAP_CHUNK_SIZE); validate_addr(hptr[i], 1); } hchunks = i;
