Messages in this thread Patch in this message |  | | From | Reinette Chatre <> | Subject | [PATCH 2/2] x86/resctrl: Use appropriate API for strings terminated by newline | Date | Wed, 1 Apr 2020 11:30:48 -0700 |
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The user input to files in the resctrl filesystem are expected to be terminated with a newline. Testing the user input includes a test for the presence of a newline and then replacing the newline with NUL byte followed by comparison using strcmp().
sysfs_streq() exists to test if strings are equal, treating both NUL and newline-then-NUL as equivalent string terminations. Even more, sysfs_match_string() exists to match a given string in an array using sysfs_streq().
Replace existing strcmp() comparisons of strings that are terminated with a newline with more appropriate sysfs_streq() via the sysfs_match_string() API that can perform the match across the different mode strings that are already maintained in an array.
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> --- arch/x86/kernel/cpu/resctrl/rdtgroup.c | 25 +++++++++++++------------ 1 file changed, 13 insertions(+), 12 deletions(-)
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c index fbee891a7d6e..623e33c0a290 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -1412,11 +1412,11 @@ static ssize_t rdtgroup_mode_write(struct kernfs_open_file *of, struct rdtgroup *rdtgrp; enum rdtgrp_mode mode; int ret = 0; + int user_m; /* Valid input requires a trailing newline */ if (nbytes == 0 || buf[nbytes - 1] != '\n') return -EINVAL; - buf[nbytes - 1] = '\0'; rdtgrp = rdtgroup_kn_lock_live(of->kn); if (!rdtgrp) { @@ -1428,11 +1428,15 @@ static ssize_t rdtgroup_mode_write(struct kernfs_open_file *of, mode = rdtgrp->mode; - if ((!strcmp(buf, "shareable") && mode == RDT_MODE_SHAREABLE) || - (!strcmp(buf, "exclusive") && mode == RDT_MODE_EXCLUSIVE) || - (!strcmp(buf, "pseudo-locksetup") && - mode == RDT_MODE_PSEUDO_LOCKSETUP) || - (!strcmp(buf, "pseudo-locked") && mode == RDT_MODE_PSEUDO_LOCKED)) + user_m = sysfs_match_string(rdt_mode_str, buf); + if (user_m < 0) { + rdt_last_cmd_puts("Unknown or unsupported mode\n"); + ret = user_m; + goto out; + } + + /* Do nothing and return success if user asks for current mode */ + if (user_m == mode) goto out; if (mode == RDT_MODE_PSEUDO_LOCKED) { @@ -1441,14 +1445,14 @@ static ssize_t rdtgroup_mode_write(struct kernfs_open_file *of, goto out; } - if (!strcmp(buf, "shareable")) { + if (user_m == RDT_MODE_SHAREABLE) { if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { ret = rdtgroup_locksetup_exit(rdtgrp); if (ret) goto out; } rdtgrp->mode = RDT_MODE_SHAREABLE; - } else if (!strcmp(buf, "exclusive")) { + } else if (user_m == RDT_MODE_EXCLUSIVE) { if (!rdtgroup_mode_test_exclusive(rdtgrp)) { ret = -EINVAL; goto out; @@ -1459,14 +1463,11 @@ static ssize_t rdtgroup_mode_write(struct kernfs_open_file *of, goto out; } rdtgrp->mode = RDT_MODE_EXCLUSIVE; - } else if (!strcmp(buf, "pseudo-locksetup")) { + } else if (user_m == RDT_MODE_PSEUDO_LOCKSETUP) { ret = rdtgroup_locksetup_enter(rdtgrp); if (ret) goto out; rdtgrp->mode = RDT_MODE_PSEUDO_LOCKSETUP; - } else { - rdt_last_cmd_puts("Unknown or unsupported mode\n"); - ret = -EINVAL; } out: -- 2.21.0
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