From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: [PATCH v3 42/51] ubsan: Fix objtool UACCESS warns Date: Thu, 12 Jan 2023 20:43:56 +0100 Message-ID: <20230112195541.906007455@infradead.org> References: <20230112194314.845371875@infradead.org> Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-ID:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:In-Reply-To; bh=tM6S3oZ3zLjQ2zmmTNKitB7HqpfpXnjxYwChM2FqbVs=; b=BJ9XJoRA5PVXo6NmK1y1j4mgxX DGfe1Ta896F3qkk57KxqOit856Whx7pXr9WTIch0khohftRzZ6nkeSuCiqiAyMa3qg2JMRqTwkdcK SZHkiVrlqToqnjdTi1BQtMwas89d1b41aRk7eR9kktg5N/gi7TNwV9TPbfoKKOtW1UuX+e5CZ4VVW USTGfBuu27oryL5tL5ug+EeZMBWzLYDuLZxBl37/OJYoY11N2gX+VEM60a0w4sEUZTi5GdGd5oNiD v4tH8MxJ/EqxydLuQw6fRM3cmCP9pHy61QtCS2aoYs8Sik/mr9QPx70CAPy2SGTADTK3V7C39icf4 nbFCLrEQ==; List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: peterz@infradead.org Cc: richard.henderson@linaro.org, ink@jurassic.park.msu.ru, mattst88@gmail.com, vgupta@kernel.org, linux@armlinux.org.uk, nsekhar@ti.com, brgl@bgdev.pl, ulli.kroll@googlemail.com, linus.walleij@linaro.org, shawnguo@kernel.org, Sascha Hauer , kernel@pengutronix.de, festevam@gmail.com, linux-imx@nxp.com, tony@atomide.com, khilman@kernel.org, krzysztof.kozlowski@linaro.org, alim.akhtar@samsung.com, catalin.marinas@arm.com, will@kernel.org, guoren@kernel.org, bcain@quicinc.com, chenhuacai@kernel.org, kernel@xen0n.name, geert@linux-m68k.org, sammy@sammy.net, monstr@monstr.eu, tsbogend@alpha.franken.de, dinguyen@kernel.org, jonas@southpole.se, stefan.kristiansson@saunalahti.fi, shorne@gmail.com, James.Bottomley@HansenPartnership.com, deller@gmx.de, mpe@ellerman.id.au clang-14 allyesconfig gives: vmlinux.o: warning: objtool: emulator_cmpxchg_emulated+0x705: call to __ubsan_handle_load_invalid_value() with UACCESS enabled vmlinux.o: warning: objtool: paging64_update_accessed_dirty_bits+0x39e: call to __ubsan_handle_load_invalid_value() with UACCESS enabled vmlinux.o: warning: objtool: paging32_update_accessed_dirty_bits+0x390: call to __ubsan_handle_load_invalid_value() with UACCESS enabled vmlinux.o: warning: objtool: ept_update_accessed_dirty_bits+0x43f: call to __ubsan_handle_load_invalid_value() with UACCESS enabled Add the required eflags save/restore and whitelist the thing. Signed-off-by: Peter Zijlstra (Intel) Acked-by: Rafael J. Wysocki Acked-by: Frederic Weisbecker Tested-by: Tony Lindgren Tested-by: Ulf Hansson --- lib/ubsan.c | 5 ++++- tools/objtool/check.c | 1 + 2 files changed, 5 insertions(+), 1 deletion(-) --- a/lib/ubsan.c +++ b/lib/ubsan.c @@ -340,9 +340,10 @@ void __ubsan_handle_load_invalid_value(v { struct invalid_value_data *data = _data; char val_str[VALUE_LENGTH]; + unsigned long ua_flags = user_access_save(); if (suppress_report(&data->location)) - return; + goto out; ubsan_prologue(&data->location, "invalid-load"); @@ -352,6 +353,8 @@ void __ubsan_handle_load_invalid_value(v val_str, data->type->type_name); ubsan_epilogue(); +out: + user_access_restore(ua_flags); } EXPORT_SYMBOL(__ubsan_handle_load_invalid_value); --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -1068,6 +1068,7 @@ static const char *uaccess_safe_builtin[ "__ubsan_handle_type_mismatch", "__ubsan_handle_type_mismatch_v1", "__ubsan_handle_shift_out_of_bounds", + "__ubsan_handle_load_invalid_value", /* misc */ "csum_partial_copy_generic", "copy_mc_fragile",