From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Ben Hutchings <ben@decadent.org.uk>,
Len Brown <len.brown@intel.com>, Sasha Levin <sashal@kernel.org>
Subject: [PATCH AUTOSEL 4.14 33/36] tools/power x86_energy_perf_policy: Fix "uninitialized variable" warnings at -O2
Date: Wed, 4 Sep 2019 12:01:19 -0400 [thread overview]
Message-ID: <20190904160122.4179-33-sashal@kernel.org> (raw)
In-Reply-To: <20190904160122.4179-1-sashal@kernel.org>
From: Ben Hutchings <ben@decadent.org.uk>
[ Upstream commit adb8049097a9ec4acd09fbd3aa8636199a78df8a ]
x86_energy_perf_policy first uses __get_cpuid() to check the maximum
CPUID level and exits if it is too low. It then assumes that later
calls will succeed (which I think is architecturally guaranteed). It
also assumes that CPUID works at all (which is not guaranteed on
x86_32).
If optimisations are enabled, gcc warns about potentially
uninitialized variables. Fix this by adding an exit-on-error after
every call to __get_cpuid() instead of just checking the maximum
level.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
.../x86_energy_perf_policy.c | 26 +++++++++++--------
1 file changed, 15 insertions(+), 11 deletions(-)
diff --git a/tools/power/x86/x86_energy_perf_policy/x86_energy_perf_policy.c b/tools/power/x86/x86_energy_perf_policy/x86_energy_perf_policy.c
index 65bbe627a425f..bbef8bcf44d6d 100644
--- a/tools/power/x86/x86_energy_perf_policy/x86_energy_perf_policy.c
+++ b/tools/power/x86/x86_energy_perf_policy/x86_energy_perf_policy.c
@@ -1260,6 +1260,15 @@ void probe_dev_msr(void)
if (system("/sbin/modprobe msr > /dev/null 2>&1"))
err(-5, "no /dev/cpu/0/msr, Try \"# modprobe msr\" ");
}
+
+static void get_cpuid_or_exit(unsigned int leaf,
+ unsigned int *eax, unsigned int *ebx,
+ unsigned int *ecx, unsigned int *edx)
+{
+ if (!__get_cpuid(leaf, eax, ebx, ecx, edx))
+ errx(1, "Processor not supported\n");
+}
+
/*
* early_cpuid()
* initialize turbo_is_enabled, has_hwp, has_epb
@@ -1267,15 +1276,10 @@ void probe_dev_msr(void)
*/
void early_cpuid(void)
{
- unsigned int eax, ebx, ecx, edx, max_level;
+ unsigned int eax, ebx, ecx, edx;
unsigned int fms, family, model;
- __get_cpuid(0, &max_level, &ebx, &ecx, &edx);
-
- if (max_level < 6)
- errx(1, "Processor not supported\n");
-
- __get_cpuid(1, &fms, &ebx, &ecx, &edx);
+ get_cpuid_or_exit(1, &fms, &ebx, &ecx, &edx);
family = (fms >> 8) & 0xf;
model = (fms >> 4) & 0xf;
if (family == 6 || family == 0xf)
@@ -1289,7 +1293,7 @@ void early_cpuid(void)
bdx_highest_ratio = msr & 0xFF;
}
- __get_cpuid(0x6, &eax, &ebx, &ecx, &edx);
+ get_cpuid_or_exit(0x6, &eax, &ebx, &ecx, &edx);
turbo_is_enabled = (eax >> 1) & 1;
has_hwp = (eax >> 7) & 1;
has_epb = (ecx >> 3) & 1;
@@ -1307,7 +1311,7 @@ void parse_cpuid(void)
eax = ebx = ecx = edx = 0;
- __get_cpuid(0, &max_level, &ebx, &ecx, &edx);
+ get_cpuid_or_exit(0, &max_level, &ebx, &ecx, &edx);
if (ebx == 0x756e6547 && edx == 0x49656e69 && ecx == 0x6c65746e)
genuine_intel = 1;
@@ -1316,7 +1320,7 @@ void parse_cpuid(void)
fprintf(stderr, "CPUID(0): %.4s%.4s%.4s ",
(char *)&ebx, (char *)&edx, (char *)&ecx);
- __get_cpuid(1, &fms, &ebx, &ecx, &edx);
+ get_cpuid_or_exit(1, &fms, &ebx, &ecx, &edx);
family = (fms >> 8) & 0xf;
model = (fms >> 4) & 0xf;
stepping = fms & 0xf;
@@ -1341,7 +1345,7 @@ void parse_cpuid(void)
errx(1, "CPUID: no MSR");
- __get_cpuid(0x6, &eax, &ebx, &ecx, &edx);
+ get_cpuid_or_exit(0x6, &eax, &ebx, &ecx, &edx);
/* turbo_is_enabled already set */
/* has_hwp already set */
has_hwp_notify = eax & (1 << 8);
--
2.20.1
next prev parent reply other threads:[~2019-09-04 16:06 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-04 16:00 [PATCH AUTOSEL 4.14 01/36] ARM: OMAP2+: Fix missing SYSC_HAS_RESET_STATUS for dra7 epwmss Sasha Levin
2019-09-04 16:00 ` [PATCH AUTOSEL 4.14 02/36] s390/bpf: fix lcgr instruction encoding Sasha Levin
2019-09-04 16:00 ` [PATCH AUTOSEL 4.14 03/36] ARM: OMAP2+: Fix omap4 errata warning on other SoCs Sasha Levin
2019-09-04 16:00 ` [PATCH AUTOSEL 4.14 04/36] ARM: dts: dra74x: Fix iodelay configuration for mmc3 Sasha Levin
2019-09-04 16:00 ` [PATCH AUTOSEL 4.14 05/36] s390/bpf: use 32-bit index for tail calls Sasha Levin
2019-09-04 16:00 ` [PATCH AUTOSEL 4.14 06/36] batman-adv: fix uninit-value in batadv_netlink_get_ifindex() Sasha Levin
2019-09-04 16:00 ` [PATCH AUTOSEL 4.14 07/36] fpga: altera-ps-spi: Fix getting of optional confd gpio Sasha Levin
2019-09-04 16:00 ` [PATCH AUTOSEL 4.14 08/36] netfilter: xt_nfacct: Fix alignment mismatch in xt_nfacct_match_info Sasha Levin
2019-09-04 16:00 ` [PATCH AUTOSEL 4.14 09/36] NFSv4: Fix return values for nfs4_file_open() Sasha Levin
2019-09-04 16:00 ` [PATCH AUTOSEL 4.14 10/36] NFSv4: Fix return value in nfs_finish_open() Sasha Levin
2019-09-04 16:00 ` [PATCH AUTOSEL 4.14 11/36] NFS: Fix initialisation of I/O result struct in nfs_pgio_rpcsetup Sasha Levin
2019-09-04 16:00 ` [PATCH AUTOSEL 4.14 12/36] Kconfig: Fix the reference to the IDT77105 Phy driver in the description of ATM_NICSTAR_USE_IDT77105 Sasha Levin
2019-09-04 16:00 ` [PATCH AUTOSEL 4.14 13/36] qed: Add cleanup in qed_slowpath_start() Sasha Levin
2019-09-04 16:01 ` [PATCH AUTOSEL 4.14 14/36] ARM: 8874/1: mm: only adjust sections of valid mm structures Sasha Levin
2019-09-04 16:01 ` [PATCH AUTOSEL 4.14 15/36] batman-adv: Only read OGM tvlv_len after buffer len check Sasha Levin
2019-09-04 16:01 ` [PATCH AUTOSEL 4.14 16/36] batman-adv: Only read OGM2 " Sasha Levin
2019-09-04 16:01 ` [PATCH AUTOSEL 4.14 17/36] r8152: Set memory to all 0xFFs on failed reg reads Sasha Levin
2019-09-04 16:01 ` [PATCH AUTOSEL 4.14 18/36] x86/apic: Fix arch_dynirq_lower_bound() bug for DT enabled machines Sasha Levin
2019-09-04 16:01 ` [PATCH AUTOSEL 4.14 19/36] netfilter: nf_conntrack_ftp: Fix debug output Sasha Levin
2019-09-04 16:01 ` [PATCH AUTOSEL 4.14 20/36] NFSv2: Fix eof handling Sasha Levin
2019-09-04 16:01 ` [PATCH AUTOSEL 4.14 21/36] NFSv2: Fix write regression Sasha Levin
2019-09-04 16:01 ` [PATCH AUTOSEL 4.14 22/36] kallsyms: Don't let kallsyms_lookup_size_offset() fail on retrieving the first symbol Sasha Levin
2019-09-04 16:01 ` [PATCH AUTOSEL 4.14 23/36] cifs: set domainName when a domain-key is used in multiuser Sasha Levin
2019-09-04 16:01 ` [PATCH AUTOSEL 4.14 24/36] cifs: Use kzfree() to zero out the password Sasha Levin
2019-09-04 16:01 ` [PATCH AUTOSEL 4.14 25/36] x86/build: Add -Wnoaddress-of-packed-member to REALMODE_CFLAGS, to silence GCC9 build warning Sasha Levin
2019-09-04 16:01 ` [PATCH AUTOSEL 4.14 26/36] ARM: 8901/1: add a criteria for pfn_valid of arm Sasha Levin
2019-09-04 16:01 ` [PATCH AUTOSEL 4.14 27/36] sky2: Disable MSI on yet another ASUS boards (P6Xxxx) Sasha Levin
2019-09-04 16:01 ` [PATCH AUTOSEL 4.14 28/36] i2c: designware: Synchronize IRQs when unregistering slave client Sasha Levin
2019-09-04 16:01 ` [PATCH AUTOSEL 4.14 29/36] perf/x86/intel: Restrict period on Nehalem Sasha Levin
2019-09-04 16:01 ` [PATCH AUTOSEL 4.14 30/36] perf/x86/amd/ibs: Fix sample bias for dispatched micro-ops Sasha Levin
2019-09-04 16:01 ` [PATCH AUTOSEL 4.14 31/36] amd-xgbe: Fix error path in xgbe_mod_init() Sasha Levin
2019-09-04 16:01 ` [PATCH AUTOSEL 4.14 32/36] net: stmmac: dwmac-rk: Don't fail if phy regulator is absent Sasha Levin
2019-09-04 16:01 ` Sasha Levin [this message]
2019-09-04 16:01 ` [PATCH AUTOSEL 4.14 34/36] tools/power x86_energy_perf_policy: Fix argument parsing Sasha Levin
2019-09-04 16:01 ` [PATCH AUTOSEL 4.14 35/36] tools/power turbostat: fix buffer overrun Sasha Levin
2019-09-04 16:01 ` [PATCH AUTOSEL 4.14 36/36] net: seeq: Fix the function used to release some memory in an error handling path Sasha Levin
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