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| author | John Hubbard <jhubbard@nvidia.com> | 2019-10-30 22:21:59 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-12-17 20:39:35 +0100 |
| commit | 6dd08f64d4aec82510820f9359b8e6d37ef61728 (patch) | |
| tree | 4e74b17d223eeb3d359a896bd31e3a0319579126 /drivers/cpufreq | |
| parent | 19c513e62cc6a8b7adb8b9a98c6289bceddbd692 (diff) | |
| download | linux-rt-6dd08f64d4aec82510820f9359b8e6d37ef61728.tar.gz | |
cpufreq: powernv: fix stack bloat and hard limit on number of CPUs
commit db0d32d84031188443e25edbd50a71a6e7ac5d1d upstream.
The following build warning occurred on powerpc 64-bit builds:
drivers/cpufreq/powernv-cpufreq.c: In function 'init_chip_info':
drivers/cpufreq/powernv-cpufreq.c:1070:1: warning: the frame size of
1040 bytes is larger than 1024 bytes [-Wframe-larger-than=]
This is with a cross-compiler based on gcc 8.1.0, which I got from:
https://mirrors.edge.kernel.org/pub/tools/crosstool/files/bin/x86_64/8.1.0/
The warning is due to putting 1024 bytes on the stack:
unsigned int chip[256];
...and it's also undesirable to have a hard limit on the number of
CPUs here.
Fix both problems by dynamically allocating based on num_possible_cpus,
as recommended by Michael Ellerman.
Fixes: 053819e0bf840 ("cpufreq: powernv: Handle throttling due to Pmax capping at chip level")
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: 4.10+ <stable@vger.kernel.org> # 4.10+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/cpufreq')
| -rw-r--r-- | drivers/cpufreq/powernv-cpufreq.c | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c index a28bb8f3f395..33854bf127f9 100644 --- a/drivers/cpufreq/powernv-cpufreq.c +++ b/drivers/cpufreq/powernv-cpufreq.c @@ -1002,9 +1002,14 @@ static struct cpufreq_driver powernv_cpufreq_driver = { static int init_chip_info(void) { - unsigned int chip[256]; + unsigned int *chip; unsigned int cpu, i; unsigned int prev_chip_id = UINT_MAX; + int ret = 0; + + chip = kcalloc(num_possible_cpus(), sizeof(*chip), GFP_KERNEL); + if (!chip) + return -ENOMEM; for_each_possible_cpu(cpu) { unsigned int id = cpu_to_chip_id(cpu); @@ -1016,8 +1021,10 @@ static int init_chip_info(void) } chips = kcalloc(nr_chips, sizeof(struct chip), GFP_KERNEL); - if (!chips) - return -ENOMEM; + if (!chips) { + ret = -ENOMEM; + goto free_and_return; + } for (i = 0; i < nr_chips; i++) { chips[i].id = chip[i]; @@ -1027,7 +1034,9 @@ static int init_chip_info(void) per_cpu(chip_info, cpu) = &chips[i]; } - return 0; +free_and_return: + kfree(chip); + return ret; } static inline void clean_chip_info(void) |