diff options
| -rw-r--r-- | arch/s390/boot/alternative.c | 135 | ||||
| -rw-r--r-- | arch/s390/boot/boot.h | 1 | ||||
| -rw-r--r-- | arch/s390/boot/ipl_parm.c | 3 | ||||
| -rw-r--r-- | arch/s390/kernel/alternative.c | 55 | ||||
| -rw-r--r-- | arch/s390/kernel/early.c | 1 |
5 files changed, 190 insertions, 5 deletions
diff --git a/arch/s390/boot/alternative.c b/arch/s390/boot/alternative.c index abc08d2c873d..19ea7934b918 100644 --- a/arch/s390/boot/alternative.c +++ b/arch/s390/boot/alternative.c @@ -1,3 +1,138 @@ // SPDX-License-Identifier: GPL-2.0 +#define boot_fmt(fmt) "alt: " fmt +#include "boot.h" + +#define a_debug boot_debug #include "../kernel/alternative.c" + +static void alt_debug_all(int type) +{ + int i; + + switch (type) { + case ALT_TYPE_FACILITY: + for (i = 0; i < ARRAY_SIZE(alt_debug.facilities); i++) + alt_debug.facilities[i] = -1UL; + break; + case ALT_TYPE_FEATURE: + for (i = 0; i < ARRAY_SIZE(alt_debug.mfeatures); i++) + alt_debug.mfeatures[i] = -1UL; + break; + case ALT_TYPE_SPEC: + alt_debug.spec = 1; + break; + } +} + +static void alt_debug_modify(int type, unsigned int nr, bool clear) +{ + switch (type) { + case ALT_TYPE_FACILITY: + if (clear) + __clear_facility(nr, alt_debug.facilities); + else + __set_facility(nr, alt_debug.facilities); + break; + case ALT_TYPE_FEATURE: + if (clear) + __clear_machine_feature(nr, alt_debug.mfeatures); + else + __set_machine_feature(nr, alt_debug.mfeatures); + break; + } +} + +static char *alt_debug_parse(int type, char *str) +{ + unsigned long val, endval; + char *endp; + bool clear; + int i; + + if (*str == ':') { + str++; + } else { + alt_debug_all(type); + return str; + } + clear = false; + if (*str == '!') { + alt_debug_all(type); + clear = true; + str++; + } + while (*str) { + val = simple_strtoull(str, &endp, 0); + if (str == endp) + break; + str = endp; + if (*str == '-') { + str++; + endval = simple_strtoull(str, &endp, 0); + if (str == endp) + break; + str = endp; + while (val <= endval) { + alt_debug_modify(type, val, clear); + val++; + } + } else { + alt_debug_modify(type, val, clear); + } + if (*str != ',') + break; + str++; + } + return str; +} + +/* + * Use debug-alternative command line parameter for debugging: + * "debug-alternative" + * -> print debug message for every single alternative + * + * "debug-alternative=0;2" + * -> print debug message for all alternatives with type 0 and 2 + * + * "debug-alternative=0:0-7" + * -> print debug message for all alternatives with type 0 and with + * facility numbers within the range of 0-7 + * (if type 0 is ALT_TYPE_FACILITY) + * + * "debug-alternative=0:!8;1" + * -> print debug message for all alternatives with type 0, for all + * facility number, except facility 8, and in addition print all + * alternatives with type 1 + */ +void alt_debug_setup(char *str) +{ + unsigned long type; + char *endp; + int i; + + if (!str) { + alt_debug_all(ALT_TYPE_FACILITY); + alt_debug_all(ALT_TYPE_FEATURE); + alt_debug_all(ALT_TYPE_SPEC); + return; + } + while (*str) { + type = simple_strtoull(str, &endp, 0); + if (str == endp) + break; + str = endp; + switch (type) { + case ALT_TYPE_FACILITY: + case ALT_TYPE_FEATURE: + str = alt_debug_parse(type, str); + break; + case ALT_TYPE_SPEC: + alt_debug_all(ALT_TYPE_SPEC); + break; + } + if (*str != ';') + break; + str++; + } +} diff --git a/arch/s390/boot/boot.h b/arch/s390/boot/boot.h index f4af23c142cc..bb6bd9d6d991 100644 --- a/arch/s390/boot/boot.h +++ b/arch/s390/boot/boot.h @@ -64,6 +64,7 @@ void parse_boot_command_line(void); void verify_facilities(void); void print_missing_facilities(void); void sclp_early_setup_buffer(void); +void alt_debug_setup(char *str); void print_pgm_check_info(void); unsigned long randomize_within_range(unsigned long size, unsigned long align, unsigned long min, unsigned long max); diff --git a/arch/s390/boot/ipl_parm.c b/arch/s390/boot/ipl_parm.c index 13316bfa589c..86cfb16dd63d 100644 --- a/arch/s390/boot/ipl_parm.c +++ b/arch/s390/boot/ipl_parm.c @@ -296,6 +296,9 @@ void parse_boot_command_line(void) if (!strcmp(param, "facilities") && val) modify_fac_list(val); + if (!strcmp(param, "debug-alternative")) + alt_debug_setup(val); + if (!strcmp(param, "nokaslr")) __kaslr_enabled = 0; diff --git a/arch/s390/kernel/alternative.c b/arch/s390/kernel/alternative.c index 2f56649bbde8..90c0e6408992 100644 --- a/arch/s390/kernel/alternative.c +++ b/arch/s390/kernel/alternative.c @@ -1,6 +1,11 @@ // SPDX-License-Identifier: GPL-2.0 +#ifndef pr_fmt +#define pr_fmt(fmt) "alt: " fmt +#endif + #include <linux/uaccess.h> +#include <linux/printk.h> #include <asm/nospec-branch.h> #include <asm/abs_lowcore.h> #include <asm/alternative.h> @@ -8,38 +13,78 @@ #include <asm/sections.h> #include <asm/machine.h> +#ifndef a_debug +#define a_debug pr_debug +#endif + +#ifndef __kernel_va +#define __kernel_va(x) (void *)(x) +#endif + unsigned long __bootdata_preserved(machine_features[1]); +struct alt_debug { + unsigned long facilities[MAX_FACILITY_BIT / BITS_PER_LONG]; + unsigned long mfeatures[MAX_MFEATURE_BIT / BITS_PER_LONG]; + int spec; +}; + +static struct alt_debug __bootdata_preserved(alt_debug); + +static void alternative_dump(u8 *old, u8 *new, unsigned int len, unsigned int type, unsigned int data) +{ + char oinsn[33], ninsn[33]; + unsigned long kptr; + unsigned int pos; + + for (pos = 0; pos < len && 2 * pos < sizeof(oinsn) - 3; pos++) + hex_byte_pack(&oinsn[2 * pos], old[pos]); + oinsn[2 * pos] = 0; + for (pos = 0; pos < len && 2 * pos < sizeof(ninsn) - 3; pos++) + hex_byte_pack(&ninsn[2 * pos], new[pos]); + ninsn[2 * pos] = 0; + kptr = (unsigned long)__kernel_va(old); + a_debug("[%d/%3d] %016lx: %s -> %s\n", type, data, kptr, oinsn, ninsn); +} + void __apply_alternatives(struct alt_instr *start, struct alt_instr *end, unsigned int ctx) { - u8 *instr, *replacement; + struct alt_debug *d; struct alt_instr *a; - bool replace; + bool debug, replace; + u8 *old, *new; /* * The scan order should be from start to end. A later scanned * alternative code can overwrite previously scanned alternative code. */ + d = &alt_debug; for (a = start; a < end; a++) { if (!(a->ctx & ctx)) continue; switch (a->type) { case ALT_TYPE_FACILITY: replace = test_facility(a->data); + debug = __test_facility(a->data, d->facilities); break; case ALT_TYPE_FEATURE: replace = test_machine_feature(a->data); + debug = __test_machine_feature(a->data, d->mfeatures); break; case ALT_TYPE_SPEC: replace = nobp_enabled(); + debug = d->spec; break; default: replace = false; + debug = false; } if (!replace) continue; - instr = (u8 *)&a->instr_offset + a->instr_offset; - replacement = (u8 *)&a->repl_offset + a->repl_offset; - s390_kernel_write(instr, replacement, a->instrlen); + old = (u8 *)&a->instr_offset + a->instr_offset; + new = (u8 *)&a->repl_offset + a->repl_offset; + if (debug) + alternative_dump(old, new, a->instrlen, a->type, a->data); + s390_kernel_write(old, new, a->instrlen); } } diff --git a/arch/s390/kernel/early.c b/arch/s390/kernel/early.c index 8d0291c2b68c..b6d3c7a6209d 100644 --- a/arch/s390/kernel/early.c +++ b/arch/s390/kernel/early.c @@ -55,6 +55,7 @@ decompressor_handled_param(nokaslr); decompressor_handled_param(cmma); decompressor_handled_param(relocate_lowcore); decompressor_handled_param(bootdebug); +__decompressor_handled_param(debug_alternative, debug-alternative); #if IS_ENABLED(CONFIG_KVM) decompressor_handled_param(prot_virt); #endif |