From cb70b713a840a6fbdeeb774d1de4be35b0c18418 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Wed, 8 Jan 2020 20:12:34 +0200 Subject: [PATCH] drm/i915/sdvo: Reduce the size of the on stack buffers MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The strings we want to print to the on stack buffers should be no more than 8 * 3 + strlen("(GET_SCALED_HDTV_RESOLUTION_SUPPORT)") + 1 = 61 bytes. So let's shrink the buffers down to 64 bytes. Also switch the BUG_ON()s to WARN_ON()s if I made a mistake in my arithmentic. Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20200108181242.13650-1-ville.syrjala@linux.intel.com Reviewed-by: Jani Nikula --- drivers/gpu/drm/i915/display/intel_sdvo.c | 19 ++++++++----------- 1 file changed, 8 insertions(+), 11 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_sdvo.c b/drivers/gpu/drm/i915/display/intel_sdvo.c index e8819fd21e03..d79d22e1b050 100644 --- a/drivers/gpu/drm/i915/display/intel_sdvo.c +++ b/drivers/gpu/drm/i915/display/intel_sdvo.c @@ -414,12 +414,10 @@ static void intel_sdvo_debug_write(struct intel_sdvo *intel_sdvo, u8 cmd, { const char *cmd_name; int i, pos = 0; -#define BUF_LEN 256 - char buffer[BUF_LEN]; + char buffer[64]; #define BUF_PRINT(args...) \ - pos += snprintf(buffer + pos, max_t(int, BUF_LEN - pos, 0), args) - + pos += snprintf(buffer + pos, max_t(int, sizeof(buffer) - pos, 0), args) for (i = 0; i < args_len; i++) { BUF_PRINT("%02X ", ((u8 *)args)[i]); @@ -433,9 +431,9 @@ static void intel_sdvo_debug_write(struct intel_sdvo *intel_sdvo, u8 cmd, BUF_PRINT("(%s)", cmd_name); else BUF_PRINT("(%02X)", cmd); - BUG_ON(pos >= BUF_LEN - 1); + + WARN_ON(pos >= sizeof(buffer) - 1); #undef BUF_PRINT -#undef BUF_LEN DRM_DEBUG_KMS("%s: W: %02X %s\n", SDVO_NAME(intel_sdvo), cmd, buffer); } @@ -540,8 +538,7 @@ static bool intel_sdvo_read_response(struct intel_sdvo *intel_sdvo, u8 retry = 15; /* 5 quick checks, followed by 10 long checks */ u8 status; int i, pos = 0; -#define BUF_LEN 256 - char buffer[BUF_LEN]; + char buffer[64]; buffer[0] = '\0'; @@ -581,7 +578,7 @@ static bool intel_sdvo_read_response(struct intel_sdvo *intel_sdvo, } #define BUF_PRINT(args...) \ - pos += snprintf(buffer + pos, max_t(int, BUF_LEN - pos, 0), args) + pos += snprintf(buffer + pos, max_t(int, sizeof(buffer) - pos, 0), args) cmd_status = sdvo_cmd_status(status); if (cmd_status) @@ -600,9 +597,9 @@ static bool intel_sdvo_read_response(struct intel_sdvo *intel_sdvo, goto log_fail; BUF_PRINT(" %02X", ((u8 *)response)[i]); } - BUG_ON(pos >= BUF_LEN - 1); + + WARN_ON(pos >= sizeof(buffer) - 1); #undef BUF_PRINT -#undef BUF_LEN DRM_DEBUG_KMS("%s: R: %s\n", SDVO_NAME(intel_sdvo), buffer); return true;