* Josh Poimboeuf <jpoimboe@xxxxxxxxxx> wrote: > On Tue, Mar 08, 2016 at 11:37:16AM +0100, Ingo Molnar wrote: > > > > * Josh Poimboeuf <jpoimboe@xxxxxxxxxx> wrote: > > > > > This is v19 of the compile-time stack metadata validation patch set. > > > > > > It's based on tip:core/objtool. > > > > So I've upgraded my main build box to Fedora 23, to: > > > > gcc version 5.3.1 20151207 (Red Hat 5.3.1-2) (GCC) > > GNU assembler version 2.25 (x86_64-redhat-linux) using BFD version version 2.25-15.fc23 > > GNU ld version 2.25-15.fc23 > > > > and I'm now getting a bunch of these warnings: > > > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x2e7: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x2f3: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x2ff: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x30b: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x317: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x323: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x32f: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x33b: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x348: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x355: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x362: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x36f: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x37c: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x389: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x396: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x2e7: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x2f3: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x2ff: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x30b: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x317: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x323: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x32f: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x33b: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x348: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x355: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x362: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x36f: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x37c: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x389: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x396: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x19a: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x1a6: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x1b2: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x1be: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x1ca: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x1d6: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x1e2: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x1ee: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x1ff: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x210: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x221: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x251: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x262: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x273: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x284: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x295: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x2a6: frame pointer state mismatch > > drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x2b7: frame pointer state mismatch > > > > I see nothing particularly weird about rtlwifi_rate_mapping(), except the tons of > > switch statements - maybe GCC does something really clever here? > > > > In any case this needs to be addressed before the merge window. Also, I think we > > should limit the number of objtool warnings to one per function? > > This is a bug in objtool's handling of switch statement jump tables. In > fact, the 0-day bot warned me about this bug yesterday, but I > misinterpreted it: > > https://lkml.kernel.org/r/201603060006.yNZ9xTcs%fengguang.wu@xxxxxxxxx > > I'll fix it up today. I'll also limit the warnings to one per function. > > BTW, I was only able to recreate this particular issue after updating to > today's tip/master. It was triggered by a new config option: > CONFIG_UBSAN_SANITIZE_ALL. ah, makes sense! I also upgraded to the latestest Fedora and misinterpreted the warning. Btw., I like it how in other cases you didn't try to work the warning around in objtool, but improved the C code itself. We can consider this warning as a 'unnecessarily complex switch statement' warning. For example in this case I think we could use something like the patch below, because in reality the various cases are linear ranges. Totally untested. Thanks, Ingo drivers/net/wireless/realtek/rtlwifi/base.c | 196 ++-------------------------- 1 file changed, 12 insertions(+), 184 deletions(-) diff --git a/drivers/net/wireless/realtek/rtlwifi/base.c b/drivers/net/wireless/realtek/rtlwifi/base.c index 0517a4f2d3f2..a8c4e5b5bebd 100644 --- a/drivers/net/wireless/realtek/rtlwifi/base.c +++ b/drivers/net/wireless/realtek/rtlwifi/base.c @@ -890,201 +890,29 @@ int rtlwifi_rate_mapping(struct ieee80211_hw *hw, bool isht, bool isvht, int rate_idx; if (isvht) { - switch (desc_rate) { - case DESC_RATEVHT1SS_MCS0: - rate_idx = 0; - break; - case DESC_RATEVHT1SS_MCS1: - rate_idx = 1; - break; - case DESC_RATEVHT1SS_MCS2: - rate_idx = 2; - break; - case DESC_RATEVHT1SS_MCS3: - rate_idx = 3; - break; - case DESC_RATEVHT1SS_MCS4: - rate_idx = 4; - break; - case DESC_RATEVHT1SS_MCS5: - rate_idx = 5; - break; - case DESC_RATEVHT1SS_MCS6: - rate_idx = 6; - break; - case DESC_RATEVHT1SS_MCS7: - rate_idx = 7; - break; - case DESC_RATEVHT1SS_MCS8: - rate_idx = 8; - break; - case DESC_RATEVHT1SS_MCS9: - rate_idx = 9; - break; - case DESC_RATEVHT2SS_MCS0: - rate_idx = 0; - break; - case DESC_RATEVHT2SS_MCS1: - rate_idx = 1; - break; - case DESC_RATEVHT2SS_MCS2: - rate_idx = 2; - break; - case DESC_RATEVHT2SS_MCS3: - rate_idx = 3; - break; - case DESC_RATEVHT2SS_MCS4: - rate_idx = 4; - break; - case DESC_RATEVHT2SS_MCS5: - rate_idx = 5; - break; - case DESC_RATEVHT2SS_MCS6: - rate_idx = 6; - break; - case DESC_RATEVHT2SS_MCS7: - rate_idx = 7; - break; - case DESC_RATEVHT2SS_MCS8: - rate_idx = 8; - break; - case DESC_RATEVHT2SS_MCS9: - rate_idx = 9; - break; - default: + if (desc_rate >= DESC_RATEVHT1SS_MCS0 && desc_rate <= DESC_RATEVHT2SS_MCS9) + rate_idx = desc_rate-DESC_RATEVHT1SS_MCS0; + else rate_idx = 0; - break; - } return rate_idx; } if (false == isht) { if (IEEE80211_BAND_2GHZ == hw->conf.chandef.chan->band) { - switch (desc_rate) { - case DESC_RATE1M: - rate_idx = 0; - break; - case DESC_RATE2M: - rate_idx = 1; - break; - case DESC_RATE5_5M: - rate_idx = 2; - break; - case DESC_RATE11M: - rate_idx = 3; - break; - case DESC_RATE6M: - rate_idx = 4; - break; - case DESC_RATE9M: - rate_idx = 5; - break; - case DESC_RATE12M: - rate_idx = 6; - break; - case DESC_RATE18M: - rate_idx = 7; - break; - case DESC_RATE24M: - rate_idx = 8; - break; - case DESC_RATE36M: - rate_idx = 9; - break; - case DESC_RATE48M: - rate_idx = 10; - break; - case DESC_RATE54M: - rate_idx = 11; - break; - default: + if (desc_rate <= DESC_RATE54M) + rate_idx = desc_rate; + else rate_idx = 0; - break; - } } else { - switch (desc_rate) { - case DESC_RATE6M: - rate_idx = 0; - break; - case DESC_RATE9M: - rate_idx = 1; - break; - case DESC_RATE12M: - rate_idx = 2; - break; - case DESC_RATE18M: - rate_idx = 3; - break; - case DESC_RATE24M: - rate_idx = 4; - break; - case DESC_RATE36M: - rate_idx = 5; - break; - case DESC_RATE48M: - rate_idx = 6; - break; - case DESC_RATE54M: - rate_idx = 7; - break; - default: + if (desc_rate >= DESC_RATE6M && desc_rate <= DESC_RATE54M) + rate_idx = desc_rate-DESC_RATE6M; + else rate_idx = 0; - break; - } } } else { - switch (desc_rate) { - case DESC_RATEMCS0: - rate_idx = 0; - break; - case DESC_RATEMCS1: - rate_idx = 1; - break; - case DESC_RATEMCS2: - rate_idx = 2; - break; - case DESC_RATEMCS3: - rate_idx = 3; - break; - case DESC_RATEMCS4: - rate_idx = 4; - break; - case DESC_RATEMCS5: - rate_idx = 5; - break; - case DESC_RATEMCS6: - rate_idx = 6; - break; - case DESC_RATEMCS7: - rate_idx = 7; - break; - case DESC_RATEMCS8: - rate_idx = 8; - break; - case DESC_RATEMCS9: - rate_idx = 9; - break; - case DESC_RATEMCS10: - rate_idx = 10; - break; - case DESC_RATEMCS11: - rate_idx = 11; - break; - case DESC_RATEMCS12: - rate_idx = 12; - break; - case DESC_RATEMCS13: - rate_idx = 13; - break; - case DESC_RATEMCS14: - rate_idx = 14; - break; - case DESC_RATEMCS15: - rate_idx = 15; - break; - default: + if (desc_rate >= DESC_RATEMCS0 && desc_rate <= DESC_RATEMCS15) + rate_idx = desc_rate-DESC_RATEMCS0; + else rate_idx = 0; - break; - } } return rate_idx; } -- To unsubscribe from this list: send the line "unsubscribe live-patching" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
