ping On 11/25/20, Guohua Zhong <zhongguoh...@huawei.com> wrote: > Permit the user to specify the erase page size as a parameter. > This solves two problems: > > - phram can access images made by mkfs.jffs2. mkfs.jffs2 won't > create images with erase sizes less than 8KiB; many architectures > define PAGE_SIZE as 4KiB. > > - Allows more effective use of small capacity devices. JFFS2 > needs somewhere between 2 and 5 empty pages for garbage collection; > and for an NVRAM part with only 32KiB of space, a smaller erase page > allows much better utilization in applications where garbage collection > is important. > > Signed-off-by: Patrick O'Grady <patr...@baymotion.com> > Reviewed-by: Joern Engel <jo...@logfs.org> > Link: > https://lore.kernel.org/lkml/CAJ7m5OqYv_=JB9NhHsqBsa8YU0DFRoP7C+W10PY22wonAGJK=a...@mail.gmail.com/ > [Guohua Zhong: fix token array index out of bounds and update patch for > kernel master branch] > Signed-off-by: Guohua Zhong <zhongguoh...@huawei.com> > Reported-by: kernel test robot <l...@intel.com> > > ------- > v2: > fix build error which is reported by kernel test robot > > v1: > https://lore.kernel.org/lkml/20201124061053.10812-1-zhongguoh...@huawei.com/ > 1.fix token array index out of bounds > 2.update patch for kernel master branch > --- > drivers/mtd/devices/phram.c | 52 > +++++++++++++++++++++++++++++---------------- > 1 file changed, 34 insertions(+), 18 deletions(-) > > diff --git a/drivers/mtd/devices/phram.c b/drivers/mtd/devices/phram.c > index 087b5e86d1bf..1729b94b2abf 100644 > --- a/drivers/mtd/devices/phram.c > +++ b/drivers/mtd/devices/phram.c > @@ -6,14 +6,14 @@ > * Usage: > * > * one commend line parameter per device, each in the form: > - * phram=<name>,<start>,<len> > + * phram=<name>,<start>,<len>[,<erasesize>] > * <name> may be up to 63 characters. > - * <start> and <len> can be octal, decimal or hexadecimal. If followed > + * <start>, <len>, and <erasesize> can be octal, decimal or hexadecimal. If > followed > * by "ki", "Mi" or "Gi", the numbers will be interpreted as kilo, mega or > - * gigabytes. > + * gigabytes. <erasesize> is optional and defaults to PAGE_SIZE. > * > * Example: > - * phram=swap,64Mi,128Mi phram=test,900Mi,1Mi > + * phram=swap,64Mi,128Mi phram=test,900Mi,1Mi,64Ki > */ > > #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt > @@ -26,6 +26,7 @@ > #include <linux/moduleparam.h> > #include <linux/slab.h> > #include <linux/mtd/mtd.h> > +#include <asm/div64.h> > > struct phram_mtd_list { > struct mtd_info mtd; > @@ -88,7 +89,7 @@ static void unregister_devices(void) > } > } > > -static int register_device(char *name, phys_addr_t start, size_t len) > +static int register_device(char *name, phys_addr_t start, size_t len, > uint32_t erasesize) > { > struct phram_mtd_list *new; > int ret = -ENOMEM; > @@ -115,7 +116,7 @@ static int register_device(char *name, phys_addr_t start, > size_t len) > new->mtd._write = phram_write; > new->mtd.owner = THIS_MODULE; > new->mtd.type = MTD_RAM; > - new->mtd.erasesize = PAGE_SIZE; > + new->mtd.erasesize = erasesize; > new->mtd.writesize = 1; > > ret = -EAGAIN; > @@ -204,22 +205,23 @@ static inline void kill_final_newline(char *str) > static int phram_init_called; > /* > * This shall contain the module parameter if any. It is of the form: > - * - phram=<device>,<address>,<size> for module case > - * - phram.phram=<device>,<address>,<size> for built-in case > - * We leave 64 bytes for the device name, 20 for the address and 20 for the > - * size. > - * Example: phram.phram=rootfs,0xa0000000,512Mi > + * - phram=<device>,<address>,<size>[,<erasesize>] for module case > + * - phram.phram=<device>,<address>,<size>[,<erasesize>] for built-in case > + * We leave 64 bytes for the device name, 20 for the address , 20 for the > + * size and 20 for the erasesize. > + * Example: phram.phram=rootfs,0xa0000000,512Mi,65536 > */ > -static char phram_paramline[64 + 20 + 20]; > +static char phram_paramline[64 + 20 + 20 + 20]; > #endif > > static int phram_setup(const char *val) > { > - char buf[64 + 20 + 20], *str = buf; > - char *token[3]; > + char buf[64 + 20 + 20 + 20], *str = buf; > + char *token[4]; > char *name; > uint64_t start; > uint64_t len; > + uint64_t erasesize = PAGE_SIZE; > int i, ret; > > if (strnlen(val, sizeof(buf)) >= sizeof(buf)) > @@ -228,7 +230,7 @@ static int phram_setup(const char *val) > strcpy(str, val); > kill_final_newline(str); > > - for (i = 0; i < 3; i++) > + for (i = 0; i < 4; i++) > token[i] = strsep(&str, ","); > > if (str) > @@ -253,11 +255,25 @@ static int phram_setup(const char *val) > goto error; > } > > - ret = register_device(name, start, len); > + if (token[3]) { > + ret = parse_num64(&erasesize, token[3]); > + if (ret) { > + parse_err("illegal erasesize\n"); > + goto error; > + } > + } > + > + if (len == 0 || erasesize == 0 || erasesize > len > + || erasesize > UINT_MAX || do_div(len, (uint32_t)erasesize) != 0) { > + parse_err("illegal erasesize or len\n"); > + goto error; > + } > + > + ret = register_device(name, start, len, (uint32_t)erasesize); > if (ret) > goto error; > > - pr_info("%s device: %#llx at %#llx\n", name, len, start); > + pr_info("%s device: %#llx at %#llx for erasesize %#llx\n", name, len, > start, erasesize); > return 0; > > error: > @@ -298,7 +314,7 @@ static int phram_param_call(const char *val, const struct > kernel_param *kp) > } > > module_param_call(phram, phram_param_call, NULL, NULL, 0200); > -MODULE_PARM_DESC(phram, "Memory region to map. > \"phram=<name>,<start>,<length>\""); > +MODULE_PARM_DESC(phram, "Memory region to map. > \"phram=<name>,<start>,<length>[,<erasesize>]\""); > > > static int __init init_phram(void) > -- > 2.12.3
