After each write operation, confirm that it was successful, otherwise generate a warning.
Signed-off-by: Igor Stoppa <[email protected]> CC: Andy Lutomirski <[email protected]> CC: Nadav Amit <[email protected]> CC: Matthew Wilcox <[email protected]> CC: Peter Zijlstra <[email protected]> CC: Kees Cook <[email protected]> CC: Dave Hansen <[email protected]> CC: Mimi Zohar <[email protected]> CC: Thiago Jung Bauermann <[email protected]> CC: Ahmed Soliman <[email protected]> CC: [email protected] CC: [email protected] CC: [email protected] CC: [email protected] --- mm/Kconfig.debug | 8 ++++++++ mm/prmem.c | 6 ++++++ 2 files changed, 14 insertions(+) diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug index 9a7b8b049d04..b10305cfac3c 100644 --- a/mm/Kconfig.debug +++ b/mm/Kconfig.debug @@ -94,3 +94,11 @@ config DEBUG_RODATA_TEST depends on STRICT_KERNEL_RWX ---help--- This option enables a testcase for the setting rodata read-only. + +config DEBUG_PRMEM + bool "Verify each write rare operation." + depends on PRMEM + default n + help + After any write rare operation, compares the data written with the + value provided by the caller. diff --git a/mm/prmem.c b/mm/prmem.c index e1c1be3a1171..51f6776e2515 100644 --- a/mm/prmem.c +++ b/mm/prmem.c @@ -61,6 +61,9 @@ void *wr_memcpy(void *p, const void *q, __kernel_size_t size) __wr_enable(&wr_state); __wr_memcpy(wr_poking_addr, q, size); __wr_disable(&wr_state); +#ifdef CONFIG_DEBUG_PRMEM + VM_WARN_ONCE(memcmp(p, q, size), "Failed %s()", __func__); +#endif local_irq_enable(); return p; } @@ -92,6 +95,9 @@ void *wr_memset(void *p, int c, __kernel_size_t len) __wr_enable(&wr_state); __wr_memset(wr_poking_addr, c, len); __wr_disable(&wr_state); +#ifdef CONFIG_DEBUG_PRMEM + VM_WARN_ONCE(memtst(p, c, len), "Failed %s()", __func__); +#endif local_irq_enable(); return p; } -- 2.19.1
