[Crash-utility] Re: [PATCH v3 2/2] eppic.patch: Add customized functions to eppic

On Thu, Oct 30, 2025 at 9:03 PM lijiang <lijiang(a)redhat.com&gt; wrote: > > On Tue, Oct 28, 2025 at 6:40 AM Tao Liu <ltao(a)redhat.com&gt; wrote: >> >> This patch will add the following functions to eppic: >> >> 1) Allow main() as the entry for any eppic program. Previously only func() >> which companied by func_help() & func_usage() is regarded as the main >> entry of the eppic program. This constraint only makes sense for creating >> a crash-like cmd. If users only want to create a oneshot run program for >> fast testing, then the constraint is misleading. So this patch will add >> main() as entry for eppic programs. >> >> 2) Add new command "eppic" for oneshot run eppic programs. Previously eppic >> expect programs to run as the form of crash-like cmd, and it is not >> convenient for oneshot run programs. With "eppic" command, people can >> use "edit -f" or any other editors to create eppic programs, then run >> it via "eppic myfile.c". >> >> 3) Add a template for any new eppic program files. If "edit -f" a new file, a >> template with an example will be written into the new file. So users can >> refer to it when writting any eppic programs. >> >> Signed-off-by: Tao Liu <ltao(a)redhat.com&gt; >> --- >> extensions/eppic.mk | 9 +- >> extensions/eppic.patch | 210 +++++++++++++++++++++++++++++++++++++++++ >> 2 files changed, 218 insertions(+), 1 deletion(-) >> create mode 100644 extensions/eppic.patch >> >> diff --git a/extensions/eppic.mk b/extensions/eppic.mk >> index 9435793..bf80dd1 100644 >> --- a/extensions/eppic.mk >> +++ b/extensions/eppic.mk > > > Again, please refer to the comment: https://www.mail-archive.com/devel@lists.crash-utility.osci.io/msg01698.html > This looks like: > --- a/extensions/eppic.mk.orig > +++ b/extensions/eppic.mk > ... > And remove the lines: > diff --git a/extensions/eppic.mk b/extensions/eppic.mk > index 9435793..bf80dd1 100644 > > >> >> @@ -53,7 +53,14 @@ all: >> fi; \ >> if [ -f $(APPFILE) ]; \ >> then \ >> - make -f eppic.mk eppic.so; \ >> + if patch --dry-run -N -p0 < eppic.patch >/dev/null ; then \ >> + patch -N -p0 < eppic.patch; \ >> + make -f eppic.mk eppic.so; \ >> + elif patch --dry-run -N -p0 -R < eppic.patch >/dev/null ; then \ >> + make -f eppic.mk eppic.so; \ >> + else \ >> + echo "eppic.so: apply eppic.patch error"; \ >> + fi; \ >> else \ >> echo "eppic.so: failed to pull eppic code from git repo"; \ >> fi; \ >> diff --git a/extensions/eppic.patch b/extensions/eppic.patch >> new file mode 100644 >> index 0000000..ffac6d7 >> --- /dev/null >> +++ b/extensions/eppic.patch >> @@ -0,0 +1,210 @@ >> +--- eppic/applications/crash/eppic.c >> ++++ eppic/applications/crash/eppic.c >> +@@ -20,6 +20,7 @@ >> + #include "defs.h" >> + >> + #include <eppic_api.h> >> ++#include "eppic.h" >> + >> + /* >> + * Global data (global_data.c) >> +@@ -788,6 +789,39 @@ char *sclass_help[]={ >> + NULL >> + }; >> + >> ++char *eppic_help[]={ >> ++ "eppic", >> ++ "Run eppic program(es).", >> ++ "<fileName1.c>[, <fileName2.c>]", >> ++ " Oneshot run eppic program(es) which with a main() entry each.", >> ++ NULL >> ++}; >> ++ >> ++void >> ++eppic_command(void) >> ++{ >> ++ char *buf; >> ++ optind = 1; >> ++ >> ++ if (!args[optind]) { >> ++ cmd_usage(crash_global_cmd(), SYNOPSIS); >> ++ return; >> ++ } >> ++ >> ++ while(args[optind]) { >> ++ buf = eppic_filempath(args[optind]); >> ++ if (!buf) { >> ++ eppic_msg("eppic_filempath error on %s\n", args[optind]); >> ++ return; >> ++ } >> ++ eppic_load(buf); >> ++ if (eppic_findfile(buf, 0)) >> ++ eppic_unload(buf); >> ++ eppic_free(buf); >> ++ optind++; >> ++ } >> ++} >> ++ >> + #define NCMDS 200 >> + static struct command_table_entry command_table[NCMDS] = { >> + >> +@@ -797,6 +831,7 @@ static struct command_table_entry command_table[NCMDS] = { >> + {"sdebug", sdebug_cmd, sdebug_help}, >> + {"sname", sname_cmd, sname_help}, >> + {"sclass", sclass_cmd, sclass_help}, >> ++ {"eppic", eppic_command, eppic_help}, >> + {(char *)0 } >> + }; >> + >> +@@ -885,6 +920,13 @@ char **help=malloc(sizeof *help * 5); >> + } >> + } >> + free(help); >> ++ >> ++ if (load && !strcmp(name, "main")) { >> ++ int optind_save = optind; >> ++ eppic_cmd(name, NULL, 0); >> ++ optind = optind_save; >> ++ } >> ++ >> + return; >> + } >> + >> +--- eppic/libeppic/eppic_api.h >> ++++ eppic/libeppic/eppic_api.h >> +@@ -16,6 +16,9 @@ >> + /* minor and major version number >> + 4.0 switch to new Eppic name and use of fully typed symbols. >> + */ >> ++#ifndef EPPIC_API_H >> ++#define EPPIC_API_H >> ++ >> + #define S_MAJOR 5 >> + #define S_MINOR 0 >> + >> +@@ -298,3 +301,5 @@ void eppic_dbg_named(int class, char *name, int level, char *, ...); >> + >> + /* parsers debug flags */ >> + extern int eppicdebug, eppicppdebug; >> ++ >> ++#endif >> +\ No newline at end of file >> +--- eppic/libeppic/eppic_func.c >> ++++ eppic/libeppic/eppic_func.c >> +@@ -22,6 +22,8 @@ >> + #include <sys/types.h> >> + #include <time.h> >> + #include <sys/stat.h> >> ++#include <fcntl.h> >> ++#include <unistd.h> >> + #include "eppic.h" >> + >> + /* >> +@@ -793,6 +795,42 @@ char *ed=getenv("EDITOR"); >> + if(!system(buf)) eppic_load(fname); >> + } >> + >> ++static const char *example[] = { >> ++"/* ", >> ++" * Example: Print all tasks' PID & command ", >> ++" * ", >> ++" * // Kernel's global variables and data structures can be used directly without", >> ++" * // pre-define it in kernel header. If any are within kernel modules, should", >> ++" * // preload the .ko first via \"mod -S/-s\" cmd in crash before invoke your", >> ++" * // eppic program. ", >> ++" * // ", >> ++" * // Eppic program's syntax is similar to C but with slight differences. ", >> ++" * // Code samples: ", >> ++" * // https://github.com/lucchouina/eppic/tree/master/applications/crash/code";, >> ++" * // Available eppic functions: ", >> ++" * // https://github.com/lucchouina/eppic/blob/master/libeppic/eppic_builtin.c#...;, >> ++" * ", >> ++" * int main(void) ", >> ++" * { ", >> ++" * struct task_struct *p; ", >> ++" * unsigned long offset; ", >> ++" * ", >> ++" * p = (struct task_struct *)&init_task; ", >> ++" * offset = (unsigned long)&(p->tasks) - (unsigned long)p; ", >> ++" * ", >> ++" * do { ", >> ++" * printf(\"PID: %d Command: %s\\n\", (int)(p->pid), getstr((char *)&(p->comm[0])));", >> ++" * p = (struct task_struct *)((unsigned long)(p->tasks.next) - offset);", >> ++" * } while(p != &init_task); ", >> ++" * ", >> ++" * return 0; ", >> ++" * } ", >> ++" * ", >> ++" * crash> eppic program_file.c ", >> ++" */ ", >> ++}; >> ++ >> ++char *eppic_get_func_file(char *); >> + /* >> + This funciton is called to start a vi session on a function >> + (file=0) or a file (file=1); >> +@@ -800,24 +838,31 @@ char *ed=getenv("EDITOR"); >> + void >> + eppic_vi(char *fname, int file) >> + { >> +-int line, freeit=0; >> ++int line=1, freeit=0, fd; >> + char *filename; >> ++char newline = '\n'; >> + >> + if(file) { >> + >> + filename=eppic_filempath(fname); >> + >> + if(!filename) { >> +- >> +- eppic_msg("File not found : %s\n", fname); >> +- return; >> +- >> +- } >> +- >> +- line=1; >> +- freeit=1; >> +- >> +- >> ++ fd = creat(fname, 0644); > > > I would suggest using the open(), it is better than creat(). > Sure, I will fix those when merge: 1) creat -> open 2) file -> file.orig > Other changes are fine, Otherwise: Ack. > > Thanks > Lianbo > >> ++ if (fd < 0) { >> ++ eppic_msg("File not found : %s\n", fname); >> ++ return; >> ++ } else { >> ++ for (int i = 0; i < sizeof(example)/sizeof(char *); i++) { >> ++ write(fd, example[i], strlen(example[i])); >> ++ write(fd, &newline, sizeof(newline)); >> ++ } >> ++ close(fd); >> ++ filename = fname; >> ++ freeit=0; >> ++ } >> ++ } else { >> ++ freeit=1; >> ++ } >> + } else { >> + >> + func *f=eppic_getfbyname(fname, 0); >> +@@ -837,6 +882,10 @@ char *filename; >> + >> + eppic_exevi(filename, line); >> + >> ++ char *fi_name = eppic_get_func_file("main"); >> ++ if (fi_name) >> ++ eppic_deletefile(fi_name); >> ++ >> + if(freeit) eppic_free(filename); >> + >> + } >> +@@ -1184,3 +1233,10 @@ eppic_runcmd(char *fname, var_t*args) >> + return 0; >> + } >> + >> ++char *eppic_get_func_file(char *funcname) >> ++{ >> ++ func *fn = eppic_getfbyname(funcname, 0); >> ++ if (!fn) >> ++ return NULL; >> ++ return fn->file->fname; >> ++} >> -- >> 2.47.0 >>