diff options
Diffstat (limited to 'libdwfl/linux-kernel-modules.c')
| -rw-r--r-- | libdwfl/linux-kernel-modules.c | 142 |
1 files changed, 115 insertions, 27 deletions
diff --git a/libdwfl/linux-kernel-modules.c b/libdwfl/linux-kernel-modules.c index 4ea391c0..2aaa25ac 100644 --- a/libdwfl/linux-kernel-modules.c +++ b/libdwfl/linux-kernel-modules.c @@ -63,8 +63,11 @@ #include <fts.h> +#define KERNEL_MODNAME "kernel" + #define MODULEDIRFMT "/lib/modules/%s" +#define KSYMSFILE "/proc/kallsyms" #define MODULELIST "/proc/modules" #define SECADDRDIRFMT "/sys/module/%s/sections/" #define MODULE_SECT_NAME_LEN 32 /* Minimum any linux/module.h has had. */ @@ -116,29 +119,45 @@ kernel_release (void) } static int +find_kernel_elf (Dwfl *dwfl, const char *release, char **fname) +{ + if ((release[0] == '/' + ? asprintf (fname, "%s/vmlinux", release) + : asprintf (fname, "/boot/vmlinux-%s", release)) < 0) + return -1; + + int fd = try_kernel_name (dwfl, fname); + if (fd < 0 && release[0] != '/') + { + free (*fname); + if (asprintf (fname, MODULEDIRFMT "/vmlinux", release) < 0) + return -1; + fd = try_kernel_name (dwfl, fname); + } + + return fd; +} + +static int report_kernel (Dwfl *dwfl, const char *release, int (*predicate) (const char *module, const char *file)) { if (dwfl == NULL) return -1; - char *fname; - if ((release[0] == '/' - ? asprintf (&fname, "%s/vmlinux", release) - : asprintf (&fname, "/boot/vmlinux-%s", release)) < 0) - return -1; - int fd = try_kernel_name (dwfl, &fname); - if (fd < 0 && release[0] != '/') + if (release == NULL) { - free (fname); - if (asprintf (&fname, MODULEDIRFMT "/vmlinux", release) < 0) - return -1; - fd = try_kernel_name (dwfl, &fname); + release = kernel_release (); + if (release == NULL) + return errno; } + char *fname; + int fd = find_kernel_elf (dwfl, release, &fname); + int result = 0; if (fd < 0) - result = ((predicate != NULL && !(*predicate) ("kernel", NULL)) + result = ((predicate != NULL && !(*predicate) (KERNEL_MODNAME, NULL)) ? 0 : errno ?: ENOENT); else { @@ -147,14 +166,15 @@ report_kernel (Dwfl *dwfl, const char *release, if (predicate != NULL) { /* Let the predicate decide whether to use this one. */ - int want = (*predicate) ("kernel", fname); + int want = (*predicate) (KERNEL_MODNAME, fname); if (want < 0) result = errno; report = want > 0; } if (report - && INTUSE(dwfl_report_elf) (dwfl, "kernel", fname, fd, 0) == NULL) + && INTUSE(dwfl_report_elf) (dwfl, KERNEL_MODNAME, + fname, fd, 0) == NULL) { close (fd); result = -1; @@ -177,13 +197,6 @@ dwfl_linux_kernel_report_offline (Dwfl *dwfl, const char *release, int (*predicate) (const char *module, const char *file)) { - if (release == NULL) - { - release = kernel_release (); - if (release == NULL) - return errno; - } - /* First report the kernel. */ int result = report_kernel (dwfl, release, predicate); if (result == 0) @@ -279,15 +292,87 @@ dwfl_linux_kernel_report_offline (Dwfl *dwfl, const char *release, INTDEF (dwfl_linux_kernel_report_offline) -/* Find the ELF file for the running kernel and dwfl_report_elf it. */ +/* Grovel around to guess the bounds of the runtime kernel image. */ +static int +intuit_kernel_bounds (Dwarf_Addr *start, Dwarf_Addr *end) +{ + FILE *f = fopen (KSYMSFILE, "r"); + if (f == NULL) + return errno; + + (void) __fsetlocking (f, FSETLOCKING_BYCALLER); + + char *line = NULL; + size_t linesz = 0; + size_t n = getline (&line, &linesz, f); + Dwarf_Addr first; + char *p = NULL; + int result = 0; + if (n > 0 && (first = strtoull (line, &p, 16)) > 0 && p > line) + { + Dwarf_Addr last = 0; + while ((n = getline (&line, &linesz, f)) > 1 && line[n - 2] != ']') + { + p = NULL; + last = strtoull (line, &p, 16); + if (p == NULL || p == line || last == 0) + { + result = -1; + break; + } + } + if ((n == 0 && feof_unlocked (f)) || (n > 1 && line[n - 2] == ']')) + { + Dwarf_Addr round_kernel = sysconf (_SC_PAGE_SIZE); + first &= -(Dwarf_Addr) round_kernel; + last += round_kernel - 1; + last &= -(Dwarf_Addr) round_kernel; + *start = first; + *end = last; + result = 0; + } + } + free (line); + + if (result == -1) + result = ferror_unlocked (f) ? errno : ENOEXEC; + + fclose (f); + + return result; +} + int dwfl_linux_kernel_report_kernel (Dwfl *dwfl) { - const char *release = kernel_release (); - if (release == NULL) - return errno; + Dwarf_Addr start; + Dwarf_Addr end; + inline int report (void) + { + return INTUSE(dwfl_report_module) (dwfl, KERNEL_MODNAME, + start, end) == NULL ? -1 : 0; + } + + /* This is a bit of a kludge. If we already reported the kernel, + don't bother figuring it out again--it never changes. */ + for (Dwfl_Module *m = dwfl->modulelist; m != NULL; m = m->next) + if (!strcmp (m->name, KERNEL_MODNAME)) + { + start = m->low_addr; + end = m->high_addr; + return report (); + } + + /* Try to figure out the bounds of the kernel image without + looking for any vmlinux file. */ + int result = intuit_kernel_bounds (&start, &end); + if (result == 0) + return report (); + if (result != ENOENT) + return result; - return report_kernel (dwfl, release, NULL); + /* Find the ELF file for the running kernel and dwfl_report_elf it. */ + return report_kernel (dwfl, NULL, NULL); } INTDEF (dwfl_linux_kernel_report_kernel) @@ -306,6 +391,9 @@ dwfl_linux_kernel_find_elf (Dwfl_Module *mod __attribute__ ((unused)), if (release == NULL) return errno; + if (!strcmp (module_name, KERNEL_MODNAME)) + return find_kernel_elf (mod->dwfl, release, file_name); + /* Do "find /lib/modules/`uname -r`/kernel -name MODULE_NAME.ko". */ char *modulesdir[] = { NULL, NULL }; @@ -416,7 +504,7 @@ dwfl_linux_kernel_module_section_address Dwarf_Addr *addr) { char *sysfile; - if (asprintf (&sysfile, SECADDRDIRFMT "%s", modname, secname)) + if (asprintf (&sysfile, SECADDRDIRFMT "%s", modname, secname) < 0) return ENOMEM; FILE *f = fopen (sysfile, "r"); |