From 4a017c0163833fa3b0ebd2419973d30e9bd67e1e Mon Sep 17 00:00:00 2001 From: Florian Rommel Date: Mon, 12 Aug 2024 10:54:59 +0200 Subject: [PATCH] kgdbts: fix hw_access_break_test The test for access watchpoints (hw_access_break_test) was broken (always failed) because the compiler optimized out the write to the static helper variable (hw_break_val2), as it is never read anywhere. This resulted in the target variable (hw_break_val) not being accessed and thus the breakpoint not being triggered. Remove the helper variable (hw_break_val2), and use READ_ONCE to force reading the target variable (hw_break_val). Signed-off-by: Florian Rommel Reviewed-by: Douglas Anderson Link: https://lore.kernel.org/r/20240812085459.291741-1-mail@florommel.de Signed-off-by: Greg Kroah-Hartman --- drivers/misc/kgdbts.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/misc/kgdbts.c b/drivers/misc/kgdbts.c index 88b91ad8e5413..0cf31164b4706 100644 --- a/drivers/misc/kgdbts.c +++ b/drivers/misc/kgdbts.c @@ -95,6 +95,7 @@ #include #include +#include #define v1printk(a...) do { \ if (verbose) \ @@ -126,7 +127,6 @@ static int final_ack; static int force_hwbrks; static int hwbreaks_ok; static int hw_break_val; -static int hw_break_val2; static int cont_instead_of_sstep; static unsigned long cont_thread_id; static unsigned long sstep_thread_id; @@ -284,7 +284,7 @@ static void hw_rem_access_break(char *arg) static void hw_break_val_access(void) { - hw_break_val2 = hw_break_val; + READ_ONCE(hw_break_val); } static void hw_break_val_write(void) -- 2.47.2