Show memory map of highlighted process

Action.c

@@ -28,6 +28,7 @@ in the source distribution for its full text.
 #include "ListItem.h"
 #include "Macros.h"
 #include "MainPanel.h"
+#include "MapsScreen.h"
 #include "MemoryMeter.h"
 #include "Object.h"
 #include "OpenFilesScreen.h"
@@ -747,6 +748,7 @@ static const struct {
    { .key = "      i: ", .roInactive = true,  .info = "set IO priority" },
    { .key = "      l: ", .roInactive = true,  .info = "list open files with lsof" },
    { .key = "      x: ", .roInactive = false, .info = "list file locks of process" },
+   { .key = "      r: ", .roInactive = false, .info = "show memory maps of process" },
    { .key = "      s: ", .roInactive = true,  .info = "trace syscalls with strace" },
    { .key = "      w: ", .roInactive = false, .info = "wrap process command in multiple lines" },
 #ifdef SCHEDULER_SUPPORT
@@ -941,6 +943,24 @@ static Htop_Reaction actionShowEnvScreen(State* st) {
    return HTOP_REFRESH | HTOP_REDRAW_BAR;
 }
 
+static Htop_Reaction actionShowMaps(State *st) {
+   if (!Action_readableProcess(st))
+      return HTOP_OK;
+
+   Process *p = (Process *)Panel_getSelected((Panel *)st->mainPanel);
+   if (!p)
+      return HTOP_OK;
+
+   assert(Object_isA((const Object *)p, (const ObjectClass *)&Process_class));
+
+   MapsScreen *es = MapsScreen_new(p);
+   InfoScreen_run((InfoScreen *)es);
+   MapsScreen_delete((Object *)es);
+   clear();
+   CRT_enableDelay();
+   return HTOP_REFRESH | HTOP_REDRAW_BAR;
+}
+
 static Htop_Reaction actionShowCommandScreen(State* st) {
    if (!Action_readableProcess(st))
       return HTOP_OK;
@@ -1007,6 +1027,7 @@ void Action_setBindings(Htop_Action* keys) {
    keys['m'] = actionToggleMergedCommand;
    keys['p'] = actionToggleProgramPath;
    keys['q'] = actionQuit;
+   keys['r'] = actionShowMaps;
    keys['s'] = actionStrace;
    keys['t'] = actionToggleTreeView;
    keys['u'] = actionFilterByUser;

Makefile.am

@@ -62,6 +62,7 @@ myhtopsources = \
 	LoadAverageMeter.c \
 	Machine.c \
 	MainPanel.c \
+	MapsScreen.c \
 	MemoryMeter.c \
 	MemorySwapMeter.c \
 	Meter.c \
@@ -131,6 +132,7 @@ myhtopheaders = \
 	Machine.h \
 	Macros.h \
 	MainPanel.h \
+	MapsScreen.h \
 	MemoryMeter.h \
 	MemorySwapMeter.h \
 	Meter.h \

MapsScreen.c

@@ -0,0 +1,73 @@
+/*
+htop - MapsScreen.c
+(C) 2025 Pierre Wilke
+(C) 2025 htop dev team
+Released under the GNU GPLv2+, see the COPYING file
+in the source distribution for its full text.
+*/
+
+#include "config.h" // IWYU pragma: keep
+
+#include "MapsScreen.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "Macros.h"
+#include "Panel.h"
+#include "Platform.h"
+#include "ProvideCurses.h"
+#include "XUtils.h"
+
+
+MapsScreen* MapsScreen_new(Process* process) {
+   MapsScreen* this = xMalloc(sizeof(MapsScreen));
+   Object_setClass(this, Class(MapsScreen));
+   return (MapsScreen*) InfoScreen_init(&this->super, process, NULL, LINES - 2, " ");
+}
+
+void MapsScreen_delete(Object* this) {
+   free(InfoScreen_done((InfoScreen*)this));
+}
+
+static void MapsScreen_draw(InfoScreen* this) {
+   InfoScreen_drawTitled(this, "Maps of process %d - %s", Process_getPid(this->process), Process_getCommand(this->process));
+}
+
+static void MapsScreen_scan(InfoScreen* this) {
+   Panel* panel = this->display;
+   int idx = MAXIMUM(Panel_getSelectedIndex(panel), 0);
+
+   Panel_prune(panel);
+
+   char* maps = Platform_getProcessMaps(Process_getPid(this->process));
+   if (maps) {
+      char* p = maps;
+      char* pp = maps;
+      while (*p) {
+         if (*p == '\n') {
+            *p = '\0';
+            InfoScreen_addLine(this, pp);
+            pp = p + 1;
+         }
+         p++;
+      }
+      free(maps);
+   } else {
+      InfoScreen_addLine(this, "Could not read process maps.");
+   }
+
+   /* The kernel already lists mappings in ascending start-address order;
+      keep it rather than sorting the lines as text (which would order the
+      addresses lexically). */
+   Panel_setSelected(panel, idx);
+}
+
+const InfoScreenClass MapsScreen_class = {
+   .super = {
+      .extends = Class(Object),
+      .delete = MapsScreen_delete
+   },
+   .scan = MapsScreen_scan,
+   .draw = MapsScreen_draw
+};

MapsScreen.h

@@ -0,0 +1,26 @@
+#ifndef HEADER_MapsScreen
+#define HEADER_MapsScreen
+/*
+htop - MapsScreen.h
+(C) 2025 Pierre Wilke
+(C) 2025 htop dev team
+Released under the GNU GPLv2+, see the COPYING file
+in the source distribution for its full text.
+*/
+
+#include "InfoScreen.h"
+#include "Object.h"
+#include "Process.h"
+
+
+typedef struct MapsScreen_ {
+   InfoScreen super;
+} MapsScreen;
+
+extern const InfoScreenClass MapsScreen_class;
+
+MapsScreen* MapsScreen_new(Process* process);
+
+void MapsScreen_delete(Object* this);
+
+#endif

darwin/Platform.c

@@ -528,6 +528,11 @@ char* Platform_getProcessEnv(pid_t pid) {
    return env;
 }
 
+char* Platform_getProcessMaps(pid_t pid) {
+   (void)pid;
+   return NULL;
+}
+
 FileLocks_ProcessData* Platform_getProcessLocks(pid_t pid) {
    (void)pid;
    return NULL;

darwin/Platform.h

@@ -75,6 +75,8 @@ void Platform_setZfsCompressedArcValues(Meter* this);
 
 char* Platform_getProcessEnv(pid_t pid);
 
+char* Platform_getProcessMaps(pid_t pid);
+
 FileLocks_ProcessData* Platform_getProcessLocks(pid_t pid);
 
 void Platform_getFileDescriptors(double* used, double* max);

dragonflybsd/Platform.c

@@ -267,6 +267,11 @@ char* Platform_getProcessEnv(pid_t pid) {
    return NULL;
 }
 
+char* Platform_getProcessMaps(pid_t pid) {
+   (void)pid;
+   return NULL;
+}
+
 FileLocks_ProcessData* Platform_getProcessLocks(pid_t pid) {
    (void)pid;
    return NULL;

dragonflybsd/Platform.h

@@ -63,6 +63,8 @@ void Platform_setSwapValues(Meter* this);
 
 char* Platform_getProcessEnv(pid_t pid);
 
+char* Platform_getProcessMaps(pid_t pid);
+
 FileLocks_ProcessData* Platform_getProcessLocks(pid_t pid);
 
 void Platform_getFileDescriptors(double* used, double* max);

freebsd/Platform.c

@@ -299,6 +299,11 @@ char* Platform_getProcessEnv(pid_t pid) {
    return env;
 }
 
+char* Platform_getProcessMaps(pid_t pid) {
+   (void)pid;
+   return NULL;
+}
+
 FileLocks_ProcessData* Platform_getProcessLocks(pid_t pid) {
    (void)pid;
    return NULL;

freebsd/Platform.h

@@ -63,6 +63,8 @@ void Platform_setZfsCompressedArcValues(Meter* this);
 
 char* Platform_getProcessEnv(pid_t pid);
 
+char* Platform_getProcessMaps(pid_t pid);
+
 FileLocks_ProcessData* Platform_getProcessLocks(pid_t pid);
 
 void Platform_getFileDescriptors(double* used, double* max);

linux/Platform.c

@@ -568,6 +568,46 @@ char* Platform_getProcessEnv(pid_t pid) {
    return env;
 }
 
+char* Platform_getProcessMaps(pid_t pid) {
+   char procname[128];
+   xSnprintf(procname, sizeof(procname), PROCDIR "/%d/maps", pid);
+   FILE* fp = fopen(procname, "r");
+   if (!fp)
+      return NULL;
+
+   char* maps = NULL;
+
+   size_t capacity = 0;
+   size_t size = 0;
+
+   while (true) {
+      if (size == capacity) {
+         capacity += 4096;
+         maps = xRealloc(maps, capacity);
+      }
+
+      size_t bytes = fread(maps + size, 1, capacity - size, fp);
+      size += bytes;
+      if (bytes == 0)
+         break;
+   }
+
+   bool failed = ferror(fp);
+   fclose(fp);
+
+   if (failed) {
+      free(maps);
+      return NULL;
+   }
+
+   maps = xRealloc(maps, size + 2);
+
+   maps[size] = '\0';
+   maps[size + 1] = '\0';
+
+   return maps;
+}
+
 FileLocks_ProcessData* Platform_getProcessLocks(pid_t pid) {
    FileLocks_ProcessData* pdata = xCalloc(1, sizeof(FileLocks_ProcessData));
    DIR* dirp;

linux/Platform.h

@@ -82,6 +82,8 @@ void Platform_setZfsCompressedArcValues(Meter* this);
 
 char* Platform_getProcessEnv(pid_t pid);
 
+char* Platform_getProcessMaps(pid_t pid);
+
 FileLocks_ProcessData* Platform_getProcessLocks(pid_t pid);
 
 void Platform_getPressureStall(const char* file, bool some, double* ten, double* sixty, double* threehundred);

netbsd/Platform.c

@@ -357,6 +357,11 @@ char* Platform_getProcessEnv(pid_t pid) {
    return env;
 }
 
+char* Platform_getProcessMaps(pid_t pid) {
+   (void)pid;
+   return NULL;
+}
+
 FileLocks_ProcessData* Platform_getProcessLocks(pid_t pid) {
    (void)pid;
    return NULL;

netbsd/Platform.h

@@ -69,6 +69,8 @@ void Platform_setSwapValues(Meter* this);
 
 char* Platform_getProcessEnv(pid_t pid);
 
+char* Platform_getProcessMaps(pid_t pid);
+
 FileLocks_ProcessData* Platform_getProcessLocks(pid_t pid);
 
 void Platform_getFileDescriptors(double* used, double* max);

openbsd/Platform.c

@@ -317,6 +317,11 @@ char* Platform_getProcessEnv(pid_t pid) {
    return env;
 }
 
+char* Platform_getProcessMaps(pid_t pid) {
+   (void)pid;
+   return NULL;
+}
+
 FileLocks_ProcessData* Platform_getProcessLocks(pid_t pid) {
    (void)pid;
    return NULL;

openbsd/Platform.h

@@ -61,6 +61,8 @@ void Platform_setSwapValues(Meter* this);
 
 char* Platform_getProcessEnv(pid_t pid);
 
+char* Platform_getProcessMaps(pid_t pid);
+
 FileLocks_ProcessData* Platform_getProcessLocks(pid_t pid);
 
 void Platform_getFileDescriptors(double* used, double* max);

pcp/Platform.c

@@ -796,6 +796,11 @@ char* Platform_getProcessEnv(pid_t pid) {
    return value.cp;
 }
 
+char* Platform_getProcessMaps(pid_t pid) {
+   (void)pid;
+   return NULL;
+}
+
 FileLocks_ProcessData* Platform_getProcessLocks(pid_t pid) {
    (void)pid;
    return NULL;

pcp/Platform.h

@@ -113,6 +113,8 @@ void Platform_setZfsCompressedArcValues(Meter* this);
 
 char* Platform_getProcessEnv(pid_t pid);
 
+char* Platform_getProcessMaps(pid_t pid);
+
 FileLocks_ProcessData* Platform_getProcessLocks(pid_t pid);
 
 void Platform_getPressureStall(const char* file, bool some, double* ten, double* sixty, double* threehundred);

solaris/Platform.c

@@ -320,6 +320,11 @@ char* Platform_getProcessEnv(pid_t pid) {
    return xRealloc(envBuilder.env, envBuilder.size + 1);
 }
 
+char* Platform_getProcessMaps(pid_t pid) {
+   (void)pid;
+   return NULL;
+}
+
 FileLocks_ProcessData* Platform_getProcessLocks(pid_t pid) {
    (void)pid;
    return NULL;

solaris/Platform.h

@@ -89,6 +89,8 @@ void Platform_setZfsCompressedArcValues(Meter* this);
 
 char* Platform_getProcessEnv(pid_t pid);
 
+char* Platform_getProcessMaps(pid_t pid);
+
 FileLocks_ProcessData* Platform_getProcessLocks(pid_t pid);
 
 void Platform_getFileDescriptors(double* used, double* max);

unsupported/Platform.c

@@ -146,6 +146,11 @@ char* Platform_getProcessEnv(pid_t pid) {
    return NULL;
 }
 
+char* Platform_getProcessMaps(pid_t pid) {
+   (void)pid;
+   return NULL;
+}
+
 FileLocks_ProcessData* Platform_getProcessLocks(pid_t pid) {
    (void)pid;
    return NULL;

unsupported/Platform.h

@@ -58,6 +58,8 @@ void Platform_setSwapValues(Meter* this);
 
 char* Platform_getProcessEnv(pid_t pid);
 
+char* Platform_getProcessMaps(pid_t pid);
+
 FileLocks_ProcessData* Platform_getProcessLocks(pid_t pid);
 
 void Platform_getFileDescriptors(double* used, double* max);